nitrogen management plan summary report analysis...received - complete yes 1,417 132,945 received -...

Nitrogen Management Plan

Summary Report Analysis

2015 Crop Year

Prepared For

Central Valley Regional Water Quality Control Board

May 1, 2017

SJCDWQC NMP Summary Report Analysis May 1, 2017 1 | P a g e

TABLE OF CONTENTS

Introduction / Background ............................................................................................................................ 1

Avaliable Data ........................................................................................................................................... 2

NMP Summary Report Analysis .................................................................................................................... 5

Conversion Factors and Estimations ......................................................................................................... 5

Data Quality Control ................................................................................................................................. 6

Completeness ....................................................................................................................................... 6

Consistency and quality ........................................................................................................................ 7

Data quality verification and corrections ............................................................................................. 7

Statistical Methods ................................................................................................................................. 10

Results ......................................................................................................................................................... 14

Summary Statistics and Outliers by T-R .................................................................................................. 14

Evaluation of A/Y by Soil Type ................................................................................................................ 15

Evaluation of A/Y by Irrigation Practices ................................................................................................. 20

Nitrogen Management Practices ............................................................................................................ 24

Caveats .................................................................................................................................................... 26

Outreach and Education ............................................................................................................................. 28

Recommendations for Data Analysis .......................................................................................................... 29

LIST OF APPENDICES

Appendix I Summary Statistics by Crop and Township-Range

Appendix II Example of a 2015 Nitrogen Use Evaluation Packet


LIST OF TABLES

Table 1. Summary of members and acreages associated with returned NMP Summary Reports. ............. 2

Table 2. Summary of crops reported in the SJCDWQC, including the acreage and number of members

reporting. ......................................................................................................................................... 4

Table 3. Conversion factor for production units different from pounds. .................................................... 5

Table 4. N Removal Factors from CDFA FREP. ............................................................................................. 6

Table 5. Number of reported MUs and associated acreage excluded from the analysis due to incomplete

data or unverified yields or nitrogen applications. .......................................................................... 9

Table 6. List of specific crop categories with the number of NMP MUs included in the analysis. ............ 10

Table 7. Evaluation of the frequencies of A/Y outliers grouped by mean ksat category for the 12 major

crops in the Coalition region. ......................................................................................................... 20

Table 8. Evaluation of the frequencies of A/Y outliers for the 12 major crops in the Coalition region by

irrigation practices. ........................................................................................................................ 24

Table 9. Evaluation of the effect of PC1, which indicates the implementation of more nitrogen

management practices, on the A/Y of MUs from the 12 mayor crops through the Coalition

region. ............................................................................................................................................ 26

LIST OF FIGURES

Figure 1. Sum of acreage associated with primary crops reported on the NMP Summary Reports

analyzed. .......................................................................................................................................... 3

Figure 2. Box and Whisker plots showing the yield (Y) and nitrogen applied (A) per acre for the most

common crop groups in the region. ................................................................................................ 8

Figure 3. Distribution of mean Ksat values for MUs through the Coalition region ................................... 16

Figure 4. Evaluation of A/Y differences among mayor Ksat soil type categories for the top six specific

crops in the SJCDWQC. .................................................................................................................. 18

Figure 5. Evaluation of A/Y differences among mayor Ksat soil type categories for other mayor crops in

the SJCDWQC. ................................................................................................................................ 19

Figure 6. Evaluation of A/Y differences among MUs with different irrigation practices for the top six

mayor crops in the SJCDWQC. ....................................................................................................... 22

Figure 7. Evaluation of A/Y differences among MUs with different irrigation practices for the next six

mayor crops in the SJCDWQC. ....................................................................................................... 23

Figure 8. Biplot of the PCA for the Nitrogen Management Practices. ....................................................... 25


LIST OF ACRONYMS

A Total available nitrogen applied per acre APN Assessor Parcel Number SJCDWQC San Joaquin County Delta Water Quality Coalition MPEP Management Practices Evaluation Program NMP Nitrogen Management Plan NMP MU or MU Nitrogen Management Plan Management Unit NMP SR Nitrogen Management Plan Summary Report PCA Principle Component Analysis QC Quality Control T-R Township-Range Y Yield per acre

LIST OF TERMS

ArcGIS – Geographic Information Systems mapping software

Central Valley or Valley – California Central Valley

Coalition – San Joaquin County Delta Water Quality Coalition

Coalition/SJCDWQC region – The region within the Central Valley that is monitored by the San Joaquin

County Delta Water Quality Coalition

NMP Management Unit – Reporting unit in the NMP Summary Report

N Removal Factor – Pounds of nitrogen removed per pound of yield

Regional Water Board – Central Valley Regional Water Quality Control Board


INTRODUCTION / BACKGROUND

The Coalition is required to submit a summary of reported nitrogen data as a component of the

Coalition’s Annual Report. The WDR requires that the Coalition submit “At a minimum, the statistical

summary of nitrogen consumption ratios by crop or other equivalent reporting units and the estimated

nitrogen consumed for the different crop types and soil conditions will describe the range, percentiles

(10th, 25th, 50th, 75th, 90th), and any outliers. A Box and Whisker plot or equivalent tabular or graphical

presentation of the data approved by the Executive Officer may be used.” Outliers are defined by the

Regional Water Board as any Management Unit in which the amount of nitrogen applied per unit of

yield (A/Y) falls in the upper 10% of the distribution of Management Units growing the same crop within

a Township-Range.

To facilitate compliance with the requirements above, growers in high vulnerability groundwater areas

are required to prepare and implement a NMP by June 15 of each year (NMP template approved

December 23, 2014). Growers in areas determined to be of high vulnerability to groundwater were

required to submit a NMP Summary Report to the Coalition by May 1, 2016 (NMP Summary Report

template approved December 23, 2015).

On the NMP Summary Report (NMP SR), growers report their nitrogen use by Management Unit. An

NMP Management Unit (NMP MU) is a field, a parcel, or a group of parcels that grow the same crop and

that are managed the same way with respect to nitrogen applications. Each NMP MU can correspond to

a single parcel or include more than one parcel. The NMP SRs include the following information: the

total available nitrogen applied (A) in pounds per acre, the ratio of total available nitrogen applied to

yield (A/Y) per acre. Growers may also provide their yield per acre (Y), though this information is not

required. A/Y is an indicator of the proportion of nitrogen removed from the field at harvest. When

possible, the Coalition converts the yield to the amount of nitrogen removed (R) from the field at

harvest. These calculations are explained in the section Statistical Methods.

This Nitrogen Management Plan Summary Report analysis includes a reporting of A/Y values (and A/R

where nitrogen removed values are known) by Township-Range including a summary of ranges and

percentiles (10th, 25th, 50th, 75th and 90th), and identification of outliers. In addition, the Coalition

describes next steps for performing a more in-depth evaluation of outliers, including verification of

reported information and an evaluation of outlier status by soil type and irrigation practices.

Once the data are analyzed, the Coalition reports back to the member their nitrogen removed estimates

on a per acre basis, and provides summary statistics that place their nitrogen use and nitrogen removal

performance in the context of other growers of the same crop in their region. These efforts are

explained in the Outreach and Education section.


AVALIABLE DATA

The Coalition mailed 2,150 Summary Reports in March 2016 to members in high vulnerability areas, and

by March 2017, received reports from 1,464 members (count includes members that are no longer

required to return a NMP Summary Report). The Coalition received NMP SRs from members through

mail. The Coalition tracked the surveys mailed and received to ensure that all reports returned were

included in the NMP Summary Report database.

This is the first year in which NMP Summary Report submissions are required, and the Coalition is still

receiving surveys from members. NMP Summary Reports received after March 6, 2017 are not included

in this report. The Coalition sent out reminder notices on June 1, 2016 to members that had not

returned NMP SRs; a final email notice was sent on January 11, 2017. Members that did not have an

email on file for the January 11, 2017 final email notice were called personally by Coalition

representatives. The Coalition continues to contact members and to be available for assistance in

completing NMP SRs.

Of the 1,461 returned surveys, 70 were determined to have missing or unlikely data, and were therefore

omitted from the analysis. These were flagged for follow-up with the member; however, the Coalition

was unable to obtain updated information from the members in time to include the information in this

report (Table 1). Members could have surveys that are both complete and incomplete due to multiple

NMP MUs. For example, if a grower reported two MUs, but one MU was reported correctly and the

other was not, this member would be counted as both complete and incomplete in Table 1.

Table 1. Summary of members and acreages associated with returned NMP Summary Reports.

NMP Summary Reports Status Included in

Analysis Count of Members Sum of Acreage

Not Received No 561 33,960

Not Required No 128 8,949

Received - Complete Yes 1,417 132,945

Received - Incomplete1 No 70 4,110

Total Received 1,461 137,055 143 members did not correctly report on 76 MUs, consisting of 89 APNs and 2,062 acres (Table 5). Of the 1,461 received surveys, 27 NMP SRs

had 51 APNs totaling 2,048 acres that were not reported on at all. Both groups were considered incomplete, for a total of 70 members, 140 APNs, and 4,110 acres.

The largest acreage reported is for almonds, followed by grapes, walnuts, tomatoes, and hay (Figure 1).

Table 2 includes a summary of the acreage associated with primary crop groups for returned and

complete NMP Summary Reports. Any available data for nonbearing crops and crops with no yield are

also included. Reasons for no yield include drought, salt damage or pest stress, economic stress, or the

crop is associated with an experimental/research field (e.g. UC Davis).


Figure 1. Sum of acreage associated with primary crops reported on the NMP Summary Reports analyzed. “All Other” crops are listed in Table 2.


Table 2. Summary of crops reported in the SJCDWQC, including the acreage and number of members reporting.

PRIMARY CROP TYPE COUNT OF MEMBERS TOTAL ACREAGE

Almonds 541 37,032

Grapes 371 35,697

Walnuts 306 19,422

Tomatoes 69 8,828

Hay 90 7,256

Cherries 203 7,219

Corn 57 6,237

Oats 26 1,839

Wheat 21 1,361

Pumpkins 7 1,259

Beans 21 989

Safflower 5 690

Melons 9 663

Olives 15 648

Peaches 15 446

Cucumbers 3 370

Silage 5 312

Triticale 4 301

Berries 16 284

Greens 5 237

Onions, dry 4 214

Herbs 5 192

Apricots 3 191

Rice 2 178

Cotton 2 168

Apples 3 143

Pistachios 2 130

Carrots 3 129

Summer Squash 7 117

Barley 1 85

Squash 2 65

Asparagus 2 52

Kiwis 3 43

Potatoes 3 32

Peppers 5 27

Persimmons 4 20

Grains 1 19

Pomegranates 2 13

Peas 3 10

Garlic 4 9

Eggplant 2 5

Pecans 1 3

Jujube 1 3

Plums 1 2

Beets 3 2

Cabbage 1 2

Broccoli 1 1

Celery 1 0.2

Chinese Greens 1 0.2

Leeks 1 0.2

Radishes 1 0.2

Turnips 1 0.2

Totals Acreage Reported 132,945


NMP SUMMARY REPORT ANALYSIS

CONVERSION FACTORS AND ESTIMATIONS

Growers are not required to report their yields in their Summary Report. In cases where yield was not

provided, the Coalition used nitrogen applied and the A/Y ratio values submitted in the NMP SR to

estimate the yield per acre. If the crop yield was reported in a production unit other than pounds, the

Coalition converted the yield to pounds using the conversion values in Table 3.

Table 3. Conversion factor for production units different from pounds.

PRODUCTION UNIT LBS CONVERSION

1/2-bushel carton (28 lbs) 28

1/2-bushel carton (30 lbs) 30

12, 1/2-pint baskets (6 lbs) 6

12, 1-pint (12 lbs) 12

15, 1/2-inch wirebound crate (50-53 lbs)

52

2 Layer Carton (22 lbs) 22

2 layer tray pack (20-25 lbs) 22

2/3 Carton (30 lbs) 30

4/5 Bushel Crate (20 lbs) 20

5-Dozen Bunches (20-25 lbs) 22

Bag (100 lbs) 100

Bag (25 lbs) 25

Bag (50 lbs) 50

Bale (200 lbs) 200

Bale (500 lbs) 500

Bin (1050 lbs) 1050

Bin (800 lbs) 800

Bin (850 lbs) 850

Bin (900 lbs) 900

Box (12 lbs) 12

Bundle (6 lbs) 6

Bushel (25 lbs) 25

Bushel (28-32 lbs) 30

Bushel (30 lbs) 30

Bushel (32 lbs) 32

Bushel (40 lbs) 40

Bushel (48 lbs) 48

Bushel (56 lbs) 56

Bushel (60 lbs) 60

Bushel (70 lbs) 70

Bushel Basket (40 lbs) 40


Carton (100 lbs) 100

Carton (13 lbs) 13

Carton (18 lbs) 18

Carton (20 lbs) 20

Carton (23 lbs) 23

Carton (25 lbs) 25

Carton (30 lbs) 30

Carton (33 lbs) 33

Carton (38 lbs) 38

Carton (40 lbs) 40

Carton (50 lbs) 50

Carton (55 lbs) 55

Carton (60 lbs) 60

Carton (85 lbs) 85

Carton of 30 (11-12 lbs) 12

Carton or Lug (22 lbs) 22

Carton/25 Bunches (8 lbs) 8

Crate (30 lbs) 30

Crate (38 lbs) 38

Crate (40 lbs) 40

Crate (50 lbs) 50

Crate (50-60 lbs) 55

Crate (60 lbs) 60

Cwt (100 lbs) 100

Flat (4-6 lbs) 5

Flat (6 lbs) 6

Flat of 12 pots (10 lbs) 10

Lug Box (112 lbs) 112

Lug Box (12-15 lbs) 14

Lug Box (18 lbs) 18

Lug Box (24 lbs) 24

Lug Box (25-30 lbs) 28



Lug Box (28 lbs) 28

Pounds 1

Sack (25 lbs) 25

Sack (50 lbs) 50

Sack (60 lbs) 60


Sacks (100 lbs) 100

Sacks of 8, 5-pound bags (40 lbs) 40

SX (100 lbs) 100

Tons (2000 lbs) 2000

Units 1

The Coalition used N Removal factors available from the California Department of Food and Agriculture

Fertilizer Research and Education Program (CDFA FREP) fertilizer application guidelines to estimate the

amount of nitrogen removed (R) by the crops at harvest. For those crops for which N Removal Factors

were available, the Coalition calculated R by multiplying the yield (in pounds per acre) by the N Removal

Factor. Available N Removal factors are listed in Table 4.

Table 4. N Removal Factors from CDFA FREP.

CROP N REMOVAL

(POUNDS OF N) PER YIELD UNITS

PERCENT OF SJCD NMP

SUMMARY REPORT ACREAGE1

Almonds 0.068 per pounds of marketable kernels 27.79

Barley, Grain 0.0185 per pounds of grain yield 0.06

Berries 0.0013 per pounds of fruit (based on strawberry) 0.21

Broccoli 0.0055 per pounds of fresh weight 0

Corn, Silage 0.00403 per pounds of yield @ 70% moisture 1.98

Cotton 0.0236 per pounds of lint+seed yield 0.13

Grapes 0.001 per pounds of harvasted clusters 26.96

Pistachios 0.028 per pounds of marketable yield 0.1

Salad Greens 0.0025 per pounds of yield (based on lettuce) 0

Tomatoes 0.00195 per pounds of fruit (based on processing tomatoes) 4.29

Walnuts 0.02 per pounds of nut yield 14.64

Total Percent Acreage 76.16% Nitrogen removal values were obtained from the FREP’s website (https://apps1.cdfa.ca.gov/FertilizerResearch/docs/Guidelines.html). 1

Percent acreage is calculated using complete NMP SR data, not including incomplete and not returned.

DATA QUALITY CONTROL

Completeness

The hardcopy of all received NMP Summary Reports were reviewed for completeness. Any data that

were considered incomplete were flagged for follow-up. A Summary Report was considered incomplete

and required follow-up with the grower if:

1) Not all APNs in high vulnerability areas were reported.

2) Specific crop type was not indicated.

3) Acreage could not be determined through what was provided on the report, or through their

enrolled acreage.

4) NMP MU data could not be associated with a specific APN.

5) Summary Report was missing any of the requisite NMP data, including amount nitrogen applied

per acre, A/Y ratio, or a production unit for the yield.

https://apps1.cdfa.ca.gov/FertilizerResearch/docs/Guidelines.html


Consistency and quality

Complete data were further reviewed for consistency as follows:

1) The Coalition reviewed that all reported APNs were associated with the correct membership ID

and are within the SJCDWQC boundary. Parcels not within the SJCDWQC boundary were

excluded.

2) All APNs or MUs and that were reported as fallow, open, pasture, grass, cover crop, or nursery

were excluded from the analyses. Areas that are not farmed or with cover crops receive no N

applications, and pastures and nurseries have no farming yield in the traditional sense.

3) Duplicated entries based on APN or MU were removed.

4) Management Units that reported yields or nitrogen applications two times larger the 75th

percentile were verified against the hard copies submitted and the member was contacted to

verify the values reported.

5) 30% of NMP Summary Reports were selected at random and reviewed for data entry accuracy.

Data quality verification and corrections

The Coalition reviewed the yield per acre (Y) and the nitrogen applied per acre (A) for all crops to

determine if the reported data appeared reasonable. Among all crops, yields varied by multiple orders

of magnitude, ranging from 0 pounds per acre to more than 100,000 lbs/acre for some tomato NMP

MUs. There were instances of yields higher than 200,000 lbs/acre and nitrogen application rates higher

than 1000 lbs/acre, likely representing errors in the reporting.

The range of A and Y values varied considerably among crops (Figure 2). The median yield of crops

ranges from a few thousand pounds per acre (1-3 tons) for dry crops like almonds or cotton, to about

100,000 pounds (over 50 tons) for tomatoes. The median A for each crop also varied among crop types,

but not as dramatically as yield. Some crops, like grapes, often received very little nitrogen, while

others, like tomatoes or corn, were heavily fertilized, and others, like almonds, had great variability in

the application rates (Figure 2).

The Coalition identified MUs with data quality concerns by comparing reported A and Y values to

thresholds obtained from the distribution of values shown in Figure 2. The Coalition estimates that any

data with an A or Y value that was twice the 75th percentile of all other data for the same crop was most

likely reported incorrectly. The MUs identified as having an unlikely A or Y were flagged for review and

follow-up.


Figure 2. Box and Whisker plots showing the yield (Y) and nitrogen applied (A) per acre for the most common crop groups in the region.

All data that were flagged for follow-up due to incompleteness, inconsistencies, or unlikely yield or

nitrogen applications were addressed as follows: The Coalition first reviewed the original submission to


ensure these values were not the result of data-entry errors. The Coalition then contacted members

with flagged data to correct any reporting errors. By the time this report was prepared, the Coalition

had attempted to contact 102 members with suspect or incomplete data, and had been able to correct

or verify 79 NMP MUs.

After follow-ups, the Coalition was able to use complete NMP SR data from 1,417 members farming

132,945 irrigated acres and 83 specific crop types. The MUs with incomplete data or data with other

quality concerns (that had not been addressed through follow-up by the time this report was prepared)

were excluded from the analysis. The number of NMP MUs and acreage excluded from this analysis are

listed by specific crop in Table 5. In total, 76 NMP MUs were excluded from the analysis due to data

quality issues.

Table 5. Number of reported MUs and associated acreage excluded from the analysis due to incomplete data or unverified yields or nitrogen applications.

SPECIFIC CROP TYPE COUNT OF MUS TOTAL ACRES

HAY 1 45

ALMONDS 18 638

APPLES 5 262

BEETS 1 2

CHERRY 5 123

GRAPES 24 670

CHARD 3 6

GREENS 1 1

KALE 2 6

KALE LACINATO 1 5

LETTUCE 3 4

MUSTARD 1 1

SPINACH 1 4

BASIL 1 2

CILANTRO 1 2

ONIONS 1 5

PEAS 1 1

ZUCCHINI 1 4

TOMATOES 1 5

TRITICALE 1 175

WALNUTS 3 101

Total 76 2,062


STATISTICAL METHODS

The analysis was performed at the level of NMP MUs, which is the level reported by the Coalition

members. After QC, there were 3,085 NMP MUs with complete data. However, A/Y cannot be

calculated for 281 MUs from non-yield (NY) or nonbearing (NB) crops with zero yield. The NY/NB crops

cover 11,387 acres and reported applications of 467,353 lbs of nitrogen (3% of the total nitrogen

applications reported in the Coalition region). These NY/NB MUs and are not reflected in the analysis.

Not including NY/NB, this analysis uses 2,804 MUs with A/Y values.

Many of the crops can be harvested in different ways (e.g. corn grain vs. corn silage; or alfalfa hay vs.

alfalfa haylage). These harvest differences have important implications for the comparisons of yield and

the estimation of N removed at harvest. For example, row crops harvested as hay have lower humidity

content than the same crop harvested as silage or haylage, and crops harvested as grain have a higher N

Removal than the same crop harvested as hay. Lower humidity means that, for example, the yields

reported in NMP SRs for hay harvests (usually around 12 % moisture), would be on average lower than

the yields reported for silage harvests (usually around 70% moisture) even if both harvests remove the

same dry matter and nitrogen content from the field. Similarly, crops harvested as grain need a

different N Removal Factor than crops harvested as hay, and from crops harvested as silage. Other fruit

crops also have yield differences (e.g., fresh market vs. processing tomatoes or peaches). While these

differences are not as marked as the differences seen in field crops, the distinction is important for the

analysis.

To take variability in harvest yields into account, the Coalition classified crops using a specific crop name

that included the harvest type. For example, corn can be categorized into corn, silage; corn, grain; and

corn, sweet; all with different yields and N removal factors. In some surveys, the growers did not

provide the complete information with the crop type in their NMP SR. In those cases, the Coalition

classified the crop as NR, for “Not Reported” (e.g. Corn, NR or Tomatoes, NR). These NR crops may

include a mix of different harvest types, and yields are not useful for some analyses. In future years, the

Coalition will include these NR crops on the follow-up list in the QC checks. A complete list of specific

crop categories, a count of NMP MUs, and a summary of nitrogen applied, yield, and total acreage for

each crop reported by growers in the SJCDWQC is provided in

Table 6. The Coalition continues to improve this list of specific crop categories to best represent the

nitrogen management information required by the Regional Water Board.

Table 6. List of specific crop categories with the number of NMP MUs included in the analysis. Additional information includes the total nitrogen applied, yield, and acreage for each specific crop. Not included are 281 Mus of Non-Yield and Nonbearing crops that are not included in the Summary Statistics.

SPECIFIC CROP NUMBER OF MUS TOTAL N APPLIED

TOTAL YIELD HARVESTED

TOTAL ACREAGE

ALMONDS 811 5,699,373 61,175,409 32,620

APPLES, STANDARD SIZE 4 100 323,432 143

APRICOTS 3 2,348 2,341,404 191

ASPARAGUS 2 4,420 294,667 52

BARLEY, IRRIGATED 1 13,260 442,000 85

BASIL 2 13,525 1,107,503 63

BEANS, BLACK EYED 5 9,290 225,621 111

BEANS, DRY EDIBLE 6 28,444 433,811 260




TOTAL ACREAGE

BEANS, GARBANZO 1 - 221,000 91

BEANS, GREEN 4 480 4,800 10

BEANS, LIMA 6 41,888 1,040,586 442

BEANS, SNAP 1 250 1,497 5

BEETS 3 22 2,203 2

BERRY, BLUEBERRY 4 3,688 424,800 62

BERRY, BOYSENBERRY 1 400 800 8

BERRY, RASPBERRIES 1 171 722 2

BOK CHOY 1 - - 0.2

BROCCOLI 1 43 4,000 1

CABBAGE 1 65 6,000 2

CARROT 3 15,355 516,915 129

CELERY 1 - - 0.2

CHARD, GREEN 2 - 800 1

CHERRY, SWEET 250 457,205 39,383,796 6,511

CORN, NR 21 297,381 74,547,926 1,999

CORN, SILAGE 27 489,207 156,288,178 2,632

CORN, SWEET 15 369,451 31,119,588 1,605

COTTON 3 25,214 200,369 168

CUCUMBERS 3 32,220 6,517,791 370

EGGPLANT 2 222 3,198 5

GARLIC 4 1,183 42,263 9

GRAPES, RAISINS 1 140 348,920 61

GRAPES, TABLE 92 109,962 40,954,794 3,248

GRAPES, WINE 738 1,105,529 475,833,719 30,544

HAY, ALFALFA 90 195,624 84,674,570 6,089

HAY, SMALL GRAIN 17 33,532 4,994,768 641

HAY, TAME, (EXCL ALFALFA & SMALL GRAIN) 9 19,786 1,915,185 264

HAYLAGE, (EXCL ALFALFA) 5 27,176 5,872,005 236

HAYLAGE, ALFALFA 1 1,064 1,064,000 76

HERBS, FRESH CUT 3 27,043 28,263 91

JUJUBE 1 95 23,750 3

KALE 2 43 2,000 1

KIWIFRUIT 3 2,150 580,891 43

LEEKS 1 - - 0.2

MELONS, CANTALOUP 3 13,586 6,965,271 104

MELONS, WATERMELON 6 88,548 50,962,188 559

MUSTARD, GREENS 1 - - 0.1

OATS, BALED 5 2,196 2,418,148 138

OATS, NR 18 91,117 6,655,386 857

OATS, SILAGE 4 108,313 25,371,368 844

OLIVES 16 21,073 6,142,183 552

ONIONS, DRY 4 33,658 6,100,269 214

ONIONS, GREEN 1 35,325 6,280,000 157

PARSLEY 2 15,200 894,118 38

PEACHES, FRESH MARKET 9 20,975 5,515,066 168

PEACHES, PROCESSING 8 29,511 12,843,224 216

PEAS, CHINESE (SUGAR & SNOW) 3 250 2,500 10

PECANS 1 - - 3

PEPPERS, BELL 5 726 21,950 27

PEPPERS, CHILE 1 - - 0.2

PERSIMMONS 4 251 186,173 20

PISTACHIOS 1 2,340 137,647 10




TOTAL ACREAGE

PLUMS 1 - 2,550 2

POMEGRANATES 2 24 5,867 13

POTATOES 1 86 14,405 2

PUMPKINS 7 152,025 50,133,534 1,259

RADISHES 1 - - 0.2

RICE 2 33,355 1,682,292 178

RYE, GRAIN 1 - - 19

SAFFLOWER 5 13,749 1,021,288 396

SPINACH 1 - - 0.1

SQUASH 2 3,815 912,500 65

SQUASH, SUMMER 3 3,172 639,680 89

STRAWBERRIES 10 30,419 7,583,151 188

SWEET POTATOES 2 1,500 12,000 30

TOMATOES, FRESH MARKET 8 86,165 16,536,960 443

TOMATOES, NR 51 630,646 304,197,790 3,070

TOMATOES, PROCESSING 54 1,157,288 540,014,735 5,315

TRITICALE, IRRIGATED 4 43,869 2,150,707 301

TURNIPS 1 - - 0.2

WALNUTS 374 2,713,203 67,505,343 15,929

WATERCRESS 1 16,224 280,692 78

WHEAT, IRRIGATED 25 131,936 7,594,603 1,361

ZUCCHINI 4 4,222 42,820 28

Total 2,804 14,512,113 2,123,790,350 121,558

All analyses and figures were performed using R software for statistical computing1. The Coalition

calculated summary statistics on the NMP SR values by crop. Summary statistics included the minimum,

the maximum, and the 10th, 25th, 50th, 75th, and 90th percentiles of A/Y, A-R, and A/R (if the N Removal

factor was known). Percentiles were calculated using the R function “quantile” per the default method

in R. This is a quantile method for continuous variables, where the quantiles are obtained by linear

interpolation between data points. All data points (NMP MUs) with A/Y values > the 90th percentile

within each group were flagged as outliers.

Summary statistics were also calculated by Township-Range (T-R) to comply with the Order

requirements. Each T-R represents 36 sections (23,040 acres). The NMP data were associated with a T-

R location using ArcGIS by overlapping the TRS layer with the parcel layer. There were 22 MUs

associated with APNs that could not be associated to a T-R. These were labeled as T-R unknown. NMP

MUs associated with more than one T-R, because different parcels or parts of a parcel overlapped with

multiple T-Rs, were assigned to the T-R that included most of the NMP MU area. To calculate Summary

statistics by T-R, the data for each crop type was divided among the different T-Rs where the crop was

planted.

As indicated in the Order, the Coalition used standard Box and Whisker plots to visualize data grouped

by crop and T-R (See Appendix I). In Box and Whisker plots, the “boxes” indicate the 25th, 50th, and 75th

1 R Core Team 2016. R: A language and environment for statistical computing. R Foundation for Statistical

Computing, Vienna, Austria. https://www.R-project.org/

https://www.r-project.org/


percentiles, and “whiskers” the data range. The default boxplot method in R calculates the percentiles

as described above, and the data range as the most extreme data point, which is no more than 1.5 times

the length of the box away from the box. NMP MUS with values larger than the 90th quantile within

each T-R boxplot were highlighted in red to aid in the visualization of outliers.

Outlier A/Y values can be the result of nitrogen applications that are very high, or the result of yield that

was very low, or a combination of the two. The Coalition used standard scatter plots of A vs. Y to

visualize the range of nitrogen applications and Yields for each crop (See Appendix I). In these plots,

each dot is a MU, and outliers (A/Y > 90% for the crop category) are highlighted in red. NMP Summary

Reports do not include information that would explain very low yields (i.e., if a crop was lost or why), or

application rates that are elevated due to irrigation with high nitrate concentration groundwater.

However, these kinds of plots can be used to prioritize Outreach for growers that have outliers due to

high nitrogen applications.


RESULTS

SUMMARY STATISTICS AND OUTLIERS BY T-R

The Order requires the Coalition to report statistical summaries for parcels grouped by township, and

“any outliers for similar soil conditions and similar crops in that township”. In this analysis, the Coalition

provides summary statistics and a list of outliers by similar crops and by T-R (Appendix I). However, all

crops have very small sample sizes in at least some of the T-Rs where they are present. Hence, further

aggregation of the data by soil conditions as suggested by the Order, would have limited the ability of

the Coalition to calculate summary statistics. Instead, to address this requirement of the Order, the

Coalition conducted a separate analysis by soil type and by management practices. This analysis is

presented in the following section.

Even without grouping by soil conditions, the outlier identification by T-R is not reliable. For example, if

only two data points are available, the default method to calculate quantiles assumes that those are the

range (e.g. 0% and 100% percentiles). All other percentiles are then calculated linearly, at the

corresponding steps between those two points (e.g., the median is half way between them, and the 90th

percentile, one ninth of the way between them). Thus, for any T-R with only two MUs for any particular

crop type, the highest value will always be considered an outlier (>90th percentile). This would happen

even if both points have very low A/Y values relative to neighboring T-Rs with more data points.

Similarly, any T-R with only one MU (or two with identical A/Y) will have no summary statistics and no

outliers, even if the MU has a very large A/Y. Hence, the summary statistics are more meaningful when

calculated from the region-wide data grouped by similar crop.

Detailed figures and summary statistics by crop and T-R are provided in Appendix I. For each crop

category (e.g. almonds), the Coalition developed individual box and whisker plots of A/Y by T-R, and

generated tables detailing all summary statistics by T-R. Appendix I also reports summary statistics by

specific crop for the whole Coalition region (independent of T-R). For tree crops, the summary statistics

were calculated by tree age. In lieu of box and whisker plots for the summaries by specific crop,

Appendix I includes scatter plots showing the amount of nitrogen applied vs. the yield in pounds per

acre for each crop within the entire Coalition region. Outliers in both the Box and Whisker plots and

scatter plots are identified as red circles. Tables of summary statistics are also submitted with this

report electronically as an Excel file.

The Regional Water Board requested that the Coalition evaluate and provide an analysis of nitrogen

applied relative to recommended fertilizer application rates. Actual fertilizer recommendations vary

depending on factors such as age of crop, target yield, soil type, and irrigation method. The Coalition

obtained fertilizer rates from the CDFA FREP website (https://www.cdfa.ca.gov/is/ffldrs/frep/) and from

the UC Cooperative Extension cost analysis (http://coststudies.ucdavis.edu/current/). It is important to

note that the data from UC Davis are not recommendations but estimates of the amount of fertilizer

used in a typical operation. The Coalition reviewed all available data from these two sources and, when

possible, selected values from studies conducted in counties within the SJCDWQC. The Coalition plotted

these fertilizer recommendations as part of the scatter plots in Appendix I. A table explaining the source

and applicability of each of the fertilizer recommendations for each crop is provided next to the

corresponding scatter plot. It is also important to note that this is not a comprehensive review of

https://www.cdfa.ca.gov/is/ffldrs/frep/

http://coststudies.ucdavis.edu/current/


recommended application rates and should not be used to draw any conclusions regarding their

accuracy or applicability to specific fields.

EVALUATION OF A/Y BY SOIL TYPE

The goal of this analysis is to determine if soil type groupings can be a useful category to calculate the

summary statistics and identify outliers in a meaningful way. It is possible that farming operations in

sandy soils may have higher A/Y values because of their lower nutrient retention capacity. When soil

nutrient retention is low, farmers may apply larger amounts of fertilizer (increase A) to compensate for

loss due to leaching, or may realize lower yields due to the lower availability of fertilizers (decrease Y),

although these possible scenarios depend largely on management of irrigation water. Both higher A and

lower Y may independently or jointly increase A/Y. To evaluate the possible effect of soil type, the

Coalition tested for differences in A/Y among NMP MUs with different soil types.

The analysis focused on the 12 most common crops in the region, but excluded those NMP MUs where

the specific crop was not detailed (NR crop names). Analyzed NMP MUs covered 88% of the reported

acreage (from NMP MUs included in the analysis).

The Coalition characterized soil types within the SJCDWQC region based on the hydraulic conductivity

(Ksat) of the soils. Ksat is the saturated hydraulic conductivity of the soil, a measure of the potential for

water percolation and leaching of nutrients through the soil. Ksat values are associated with the soil

texture, which determines the rate at which water moves through the soil profile. Lower Ksat values are

characteristic of clay soils, with low porosity, percolation, and low potential for leaching of nutrients to

groundwater. Higher Ksat values are characteristic of sandy soils with high porosity, percolation, and

potential for leaching of nutrients below the root zone and to the groundwater.

Soil data were obtained from the USDA Soil Survey Geographic Database (SSURGO:

http://www.soils.usda.gov/survey/geography/ssurgo/). The “Gridded Soil Survey Geographic

(gSSURGO) Database State-tile Package" product is derived from the Soil Survey Geographic (2.2)

Database dated November 16, 2015. Parcel layer data were developed by the Coalition. Parcel layer

data were overlaid on the SSURGO soil data using the ‘Identify’ processing tool; all soil map units

present in each parcel were identified. Soil information was assigned to each NMP MU by linking the

map unit soil data to each parcel within each NMP MU.

Soil Ksat in each parcel and NMP MU can vary vertically with soil depth, and horizontally among

different soil types. Vertical variation in Ksat was summarized by selecting the minimum value among

all horizons down to a 1 meter depth. The horizon with the minimum Ksat is the one that will limit the

hydraulic conductivity of the soil profile. Summarizing horizontal variation in Ksat within a parcel or

NMP MU was more challenging. Most NMP MUs had two or more soil types associated to them. Some

NMP MUs are comprised of up to 25 different soil types. Soil types within one NMP MUs could have

similar properties or be dramatically different. For example, some NMP MUs had portions of clay and

portions of sandy soils, resulting in Ksat ranges of 92 µm/s within a single NMP MU.

Due to the potential for variability in soil types within each NMP MU, it was necessary to use summary

statistics to obtain a Ksat value representative of each whole NMP MU. For this analysis, the Coalition

calculated the weighted average Ksat in each NMP MU (from here on called mean Ksat). The mean Ksat

is the average of all Ksat values from different soil types inside one NMP MU, weighted by the area of


each soil type. This mean Ksat satisfactorily identifies NMP MUs with consistently large or small Ksat

values. NMP MUs with contrasting soil types produce intermediate mean Ksat that cannot be

differentiated from soil types with intermediate porosity. Figure 3 indicates the frequency of different

mean Ksat values among MUs in the Coalition region.

Figure 3. Distribution of mean Ksat values for MUs through the Coalition region

For the purpose of this analysis, and based on the range of Ksat values in the SJCDWQC region, soils

were classified as “Low” conductivity (Ksat ≤ 10), “Medium” conductivity (Ksat from 10 to 30), and

“High” conductivity (Ksat ≥ 30). Most of the SJCDWQC MUs are characterized by clay and loam soils

(Figure 3).

The Coalition evaluated if A/Y differed among the Ksat categories described above using simple linear

models for each of the major crops (Figure 4 and Figure 5). Linear models test the hypothesis that the

mean A/Y differs among any of the soil type categories. One weakness of linear models is that, in

skewed data such as A/Y, the mean A/Y is mostly influenced by the number and size of the outliers. To

avoid cases were a few values bias the test (by increasing the mean), the Coalition excluded some

extremely large A/Y outliers (larger than two times the 90th quantile of the data for that crop) from the

analysis. Crops were some outliers were eliminated are shown with cut y-axis in Figure 4 and Figure 5.


Overall, there was limited evidence that soil type influenced the mean A/Y in the SJCD region (Figure 4

and Figure 5). Only Olives show a significant difference in average A/Y among soil types (Figure 5).

However, that difference was not consistent with higher A/Y in sandy soils. To confirm the results of the

linear models, the Coalition also evaluated if the frequency of outliers differed among Ksat categories

using Chi-square tests (Table 7).

Chi-squared tests are not affected by the size of the outliers, hence they can use all the data, and are

good compliment to linear models. None of the crops showed a significant difference in the frequency

of outliers among soil types (Table 7).

Notably the significant effect of olives was not seen when looking at the frequency of outliers. In fact,

the contingency table suggests that the effect seen in Figure 5 may be the result of two outlier NMP

MUs combined with the small sample size for the different soil types.

Hence, for the crops that cover nearly 90% of the reported area, the average A/Y and frequency of

outliers is mostly unaffected by the soil type. It is unlikely that differentiating by soil categories could

generally improve the calculation of the summary statistics and identification of outliers through the

Coalition region.

Although more crops could be analyzed similarly, the power of the statistical tests decrease with the

smaller sample size of the other crops. Lower power means a lower likelihood of detecting significant

differences. In fact, some of the crops included in this analysis (e.g., Olives) already have very low

sample size. In addition, when adding more crops to this analysis, the probability of finding a significant

result simply by chance (i.e., not real differences) increases. For instance, when using an α = 0.05 as the

threshold to indicate statistical significance, it is possible to find p-values < 0.05 in 1 in every 20 tests

(5%) purely by chance.

The Coalition recognizes that soil type is important when understanding the potential for nitrogen to

leach past the root zone. The Coalition will continue to work with their members during grower

outreach meeting and the Management Practices Effectiveness Program (MPEP) to better understand

the effectiveness of practices in different soil types.


Figure 4. Evaluation of A/Y differences among mayor Ksat soil type categories for the top six specific crops in the SJCDWQC. Each box represents the distribution of A/Y values within each soil category. The p-value tests the hypothesis that there are no differences in the mean A/Y among soil categories within each crop type. Blue marks indicate the mean of each boxplot as tested in the model. Grey dotted lines show the 10, 50 and 90% quantiles for that crop through the whole Coalition region. Values above the 90% dotted line represent outliers.


Figure 5. Evaluation of A/Y differences among mayor Ksat soil type categories for other mayor crops in the SJCDWQC. Each box represents the distribution of A/Y values within each soil category. The p-value tests the hypothesis that there are no differences in the mean A/Y among soil categories within each crop type. Blue marks indicate the mean of each boxplot as tested in the model. Grey dotted lines show the 10, 50 and 90% quantiles for that crop through the whole Coalition region. Values above the 90% dotted line represent outliers.


Table 7. Evaluation of the frequencies of A/Y outliers grouped by mean ksat category for the 12 major crops in the Coalition region. Outliers were identified grouping by specific crop for the whole Coalition region. Significant p-values are highlighted in bold.

SPECIFIC CROP SOIL TYPE CONTINGENCY TABLE P.VALUE

Non-outlier Outlier

ALMONDS Low 296 27 9% 0.63

Med 198 22 11%

High 148 18 12%

CHERRY, SWEET Low 76 10 13% 0.88

Med 68 9 13%

High 51 5 10%

CORN, SILAGE Low 6 0 0% 1.00

Med 8 1 13%

High 9 1 11%

CORN, SWEET Low 8 1 13% 1.00

Med 2 0 0%

High 3 0 0%

GRAPES, TABLE Low 26 4 15% 0.37

Med 21 1 5%

High 24 5 21%

GRAPES, WINE Low 235 32 14% 0.55

Med 188 19 10%

High 156 16 10%

HAY, ALFALFA Low 24 7 29% 0.06

Med 29 1 3%

High 16 1 6%

HAY, SMALL GRAIN Low 8 1 13% 1.00

Med 3 1 33%

High 2 0 0%

OLIVES Low 8 0 0% 0.10

Med 3 2 67%

High 2 0 0%

TOMATOES, PROCESSING Low 25 1 4% 0.30

Med 8 2 25%

High 11 2 18%

WALNUTS Low 130 16 12% 0.43

Med 104 7 7%

High 68 7 10%

WHEAT, IRRIGATED Low 7 2 29% 0.78

Med 4 1 25%

High 5 0 0% n.a. Not available, p-value cannot be calculated.

EVALUATION OF A/Y BY IRRIGATION PRACTICES

For some crops, recommended nitrogen application rates can be different for flood vs. drip-irrigated

operations. In some cases, recommended application rates can be higher for flood-irrigated operations

to compensate for the different efficiency of the delivery method. Hence, A/Y could be different in

flood vs. pressurized operations. As not all Coalition members are able to switch to more expensive,

pressurized irrigation practices, irrigation type could be a useful grouping to compare A/Y in the region.

The Coalition obtained a list of management practices implemented by members from the Farm

Evaluation (FE) surveys. Coalition members in high vulnerability areas are required to submit Farm


Evaluation surveys annually, which provide information regarding irrigation practices, nitrogen

management practices, active and abandoned wells, pesticide practices and sediment/erosion control

practices. The Coalition determined which irrigation practices were implemented in each NMP MU by

linking the two datasets based on the parcel number. When one parcel included multiple NMP MUs, the

corresponding FE data were identified by the specific crop type. In total, 2,940 NMP MUs were

satisfactorily associated with the respective parcel management practices from the FE surveys. These

NMP MUs covered 127,764 acres (96% of the complete dataset). Of these, 2,687 MUs had non-zero

yields and could be used for the analysis.

The Coalition grouped irrigation practices into two broad categories: flood irrigation (which includes

flood and furrow) and pressurized irrigation (which includes drip, sprinkler, and micro-sprinkler). As

with the soil analysis, the Coalition evaluated the 12 most abundant crops in the region (excluding NR

crops for a total of 2,404 NMP MUs). The Coalition tested whether A/Y and the frequency of outliers

vary depending on the primary irrigation practices.

As with the soil types, the Coalition tested if there were differences in average A/Y among NMP MUs

with different irrigation types. Differences in average A/Y among the different irrigation types were

evaluated using a simple linear model after excluding very large A/Y outliers. The Coalition also

evaluated if the frequency of outliers differed among MUs with different irrigation practices using Chi-

square tests.

Overall, there was limited evidence that average A/Y was significantly different between these two

categories for the 12 evaluated crops (Figure 6 and Figure 7). There were significant differences in

average A/Y among irrigation categories for sweet corn and wine grapes. However, these significant

results showed different trends. The average A/Y of sweet corn was lower in flood irrigated NMP MUs,

while the average A/Y of wine grapes was higher in flood irrigated MUs. Wine and table grapes had

significantly higher frequency of outliers in flood irrigated MUs (Table 8). However, the figures and the

contingency tables (Figure 6, Figure 7, and Table 8) show that the large majority of grape MUs are under

pressurized irrigation. Hence, differentiating MUs by irrigation types is not useful when calculating or

interpreting the summary statistics and identification of outliers.


Figure 6. Evaluation of A/Y differences among MUs with different irrigation practices for the top six mayor crops in the SJCDWQC. Each box represents the distribution of A/Y values within each irrigation category. The p-value tests the hypothesis that there are no differences in the mean A/Y among irrigation categories within each crop type. Blue marks indicate the mean of each boxplot as tested in the model. Grey dotted lines show the 10, 50 and 90% quantiles for that crop through the whole Coalition region. Values above the 90% dotted line represent outliers.


Figure 7. Evaluation of A/Y differences among MUs with different irrigation practices for the next six mayor crops in the SJCDWQC. Each box represents the distribution of A/Y values within each irrigation category. The p-value tests the hypothesis that there are no differences in the mean A/Y among irrigation categories within each crop type. Blue marks indicate the mean of each boxplot as tested in the model. Grey dotted lines show the 10, 50 and 90% quantiles for that crop through the whole Coalition region. Values above the 90% dotted line represent outliers.


Table 8. Evaluation of the frequencies of A/Y outliers for the 12 major crops in the Coalition region by irrigation practices. Outliers were identified by specific crop.

SPECIFIC CROP CONTINGENCY TABLE PROPORTION

OF OUTLIERS P-VALUE

Irrigation Non-outlier Outlier

ALMONDS Pressurized 497 49 10% 0.143

Flood 186 27 15%

CHERRY, SWEET Pressurized 200 25 13% 0.37

Flood 14 0 0%

CORN, SILAGE Pressurized 1 1 100% 0.25

Flood 20 2 10%

CORN, SWEET Pressurized 9 1 11% 1.00

Flood 5 0 0%

GRAPES, TABLE Pressurized 64 4 6% 0.04

Flood 17 5 29%

GRAPES, WINE Pressurized 585 57 10% 0.01

Flood 56 14 25%

HAY, ALFALFA Pressurized 6 1 17% 1.00

Flood 70 6 9%

HAY, SMALL GRAIN Pressurized 0 0 n.a.

Flood 14 2 14%

OLIVES Pressurized 12 2 17% n.a.

Flood 1 0 0%

TOMATOES, PROCESSING Pressurized 28 4 14% 0.65

Flood 15 1 7%

WALNUTS Pressurized 264 30 11% 1.00

Flood 62 7 11%

WHEAT, IRRIGATED Pressurized 10 1 10% 1.00

Flood 10 2 20% n.a. Not available, cannot be calculated

NITROGEN MANAGEMENT PRACTICES

Implementation of some nitrogen management practices can result in reduced nitrogen applications

and hence, an assumed reduction in A/Y. To test this assumption, the Coalition evaluated if nitrogen

management practices reported on the FE surveys affected A/Y.

Nitrogen management practices are normally not implemented in isolation. Growers normally

implement more than one management practice at the same time. Hence, to evaluate the combined

effect of management practices on A/Y the Coalition first conducted a Principal Component Analysis

(PCA). A PCA evaluates which nitrogen management practices are more often implemented together

and joins them into a single variable. For example, instead of conducting three separate analyses for the

effect of testing for the nitrogen content of irrigation water, soil, and tissue, the Coalition can conduct a

single analysis using one single Principal Component (PC) that integrates the three practices.

The PCA is shown in Figure 8. Inspection of the red arrows in Figure 8 gives information about the

variation in the implementation of nitrogen management practices in the Coalition. In Figure 8, the PC1

(horizontal axis) indicates nitrogen management practices that show most variation in implementation,

and that are more likely to be applied together. Because all red arrows in Figure 8 point generally in the


same direction of the PC1 axis, it indicates that all nitrogen management practices covary (or are

implemented together) to lesser or greater extent. Tissue testing, irrigation water testing, and

fertigation represent the larger arrows that are closer to each other along PC1 (horizontal axis). This

means that variation among MUs is explained by all practices, but mostly by these three. PC2 describes

the second largest set of variation, which seems to indicate the use of cover crops or foliar applications.

However, because PC1 seem to cover all practices, the Coalition focused the analysis on this axis. PC1

can be interpreted this way: MUs that implement more management practices have higher values for

PC1; MUs that implement fewer nitrogen practices have lower values of PC1. Or more specifically, NMP

MUs with high values of PC1 probably have grater instances of water or tissue testing; and to a lesser

extent, also fertigation, split fertilization, and soil testing. On the other hand, MUs with low values of

PC1 are more likely to have implemented no nitrogen practices.

Figure 8. Biplot of the PCA for the Nitrogen Management Practices. Black numbers indicate the different MUs. Red arrows show the nitrogen management practices.

Overall, there was little evidence that NMP MUs associated with members implementing more nitrogen

management practices had lower A/Y ratios (Table 9). Although four of the 12 mayor crops analyzed

showed significant changes in A/Y with increasing values of PC1, all those changes suggested increases in

A/Y with increasing PC1.


Table 9. Evaluation of the effect of PC1, which indicates the implementation of more nitrogen management practices, on the A/Y of MUs from the 12 mayor crops through the Coalition region. N indicates the number of MUs that were analyzed for each Crop. The effect gives an indication of how A/Y changes for MUs with more nitrogen management practices. A negative effect indicates lower A/Y when more N practices are implemented. If the standard error is larger than the effect, it means that the effect is effectively zero. The t-value and p-value explicitly test that hypothesis.

CROP N EFFECT OF MORE

N PRACTICES STANDARD ERROR T-VALUE P-VALUE

ALMONDS 686 0.00525 0.00186 2.82 0.00

CHERRY, SWEET 217 -0.00016 0.00072 -0.22 0.83

CORN, SILAGE 21 -0.00018 0.00032 -0.57 0.57

CORN, SWEET 12 0.00819 0.00214 3.83 0.00

GRAPES, TABLE 81 0.00046 0.00025 1.88 0.06

GRAPES, WINE 641 0.00006 0.00006 1.00 0.32

HAY, ALFALFA 81 0.00057 0.00026 2.24 0.03

HAY, SMALL GRAIN 14 0.00257 0.00251 1.02 0.33

OLIVES 13 0.00086 0.00047 1.84 0.09

TOMATOES, PROCESSING 43 0.00017 0.00008 2.11 0.04

WALNUTS 326 0.00194 0.00130 1.50 0.14

WHEAT, IRRIGATED 21 0.00143 0.00517 0.28 0.79

Despite the fact that these results show the opposite to what was predicted, the Coalition believes that

the application of nitrogen management practices should result in a reduction of A/Y over time.

However, at the present time the variability in A/Y among MUs throughout the Coalition is too large to

detect clear trends and is likely leading to the counterintuitive results. Over time, the growers will

become more familiar with the reporting of their nitrogen information, and the Coalition will become

more adept at identifying and addressing data quality issues. It is likely that, as the quality of the data

improves, the variability in A/Y is will decrease, and effects of nitrogen management practices will

become easier to identify.

Meanwhile the main effort of the Coalition to identify management practices assumed most likely to

result in reduced nitrogen leaching to the ground water is through the Management Practice Evaluation

Program (MPEP). Work is performed through the MPEP to evaluate the effectiveness of management

practices on nutrient leaching. Also, additional information is obtained on specific practices

implemented through the Groundwater Quality Management Plan.

CAVEATS

There are several caveats that compromise a meaningful interpretation of the results (and particularly

the correct identification of outliers) including:

1. Although the Coalition has achieved 72% response from members in high vulnerability areas,

less than 100% return of the NMP SRs means that the summary statistics will change when more

data are available. It is not possible to determine how statistics will change, but it will certainly


affect the less common crops. NMP Summary Reports continue to be returned even after the

preparation of this report.

2. Even when all NMP SRs are returned, it is almost certain that many crops will still have only a

few (ten or less) MUs in most T-Rs. The identification of outliers in these cases is not reliable.

3. Some of the reported information clearly is in error. The Coalition has conducted intensive

outreach efforts to fix erroneous values. The Coalition also excluded from the analysis 76 MUs

that had quality concerns and could not be verified with the grower. It is likely that some errors

were not identified and now contribute to the variability and uncertainty of the data. All

summary statistics, box and whisker plots, and outliers, are likely to change as better data

become available through time.

4. The Coalition has made a concerted effort to verify the N Removal factors used in this report.

However, a more comprehensive list of N Removal factors is now available from a report written

by Dr. Daniel Geissler. By the time this report was written, the Coalition had not yet evaluated

and implemented the new N Removal factors.

5. The association of soils characteristics to specific NMP MUs reported by the members is very

inexact. Members can include on a single NMP MU different fields located some distance from

each other provided they are managed the same way. Furthermore, soil types can vary

substantially even within a single field. Thus, soils can vary considerably within MUs, and is

difficult to assign representative soils properties to those MUs.

6. Similarly, the association of irrigation and nitrogen management practices to specific NMP MUs

is also inexact. FE Management Units are recorded by the growers at a much finer scale than

NMP MUs. Hence, similar to soils, a single NMP MU can have an array of irrigation and nitrogen

practices and this results in uncertainty in the association used by the Coalition to conduct those

analyses.


OUTREACH AND EDUCATION

In an effort to educate the members of SJCDWQC on how their nitrogen applications may be

contributing to groundwater quality, The Coalition prepared and mailed Nitrogen Management outreach

materials to each member for whom 2015 data was received and analyzed.

In April of 2017, the Coalition mailed Nitrogen Use Evaluation Packets for 2015 crop year data to 1,425

growers. An example of the packet that these growers received can be found in Appendix II. These

packets include the data reported to the Coalition for 2015, summary statistics by crop type for all

Management Units across the Coalition, nitrogen removal estimates for crops with available R values,

bell curves comparing each grower’s Management Units to others reporting on the same crop across the

Coalition, and identification of outlier status for growers with A/Y values above the 90th percentile.

Members may have Management Units that are considered outliers due to various factors including high

application rates or low yield. High application rates may be due to not accounting for nitrogen in their

irrigation water or over-application of synthetic fertilizer, manure or compost. Low yield may have

occurred for reasons outside of the grower’s control, including pest damage or drought stress. Having

an MU identified as an outlier in these packets will alert growers who reported A/Y values that were

significantly different from their neighbors that they may need to re-evaluate their nitrogen application

practices or be more diligent about providing correct information back to the Coalition.

Ultimately, these evaluations are meant to illustrate nitrogen use efficiency for each grower with the

potential to leach nitrates into groundwater, and to place each of these grower’s practices within the

context of other growers in the Coalition. Additionally, reporting the data the Coalition received back to

each grower provides the opportunity for growers to address any data quality concerns that may not

have been identified in the quality control and follow-up processes outlined above. Growers are

encouraged to contact the Coalition with data change requests, questions, and concerns with their

Nitrogen Use Evaluation, and as such, the packets will aid in more accurate and comprehensive data

over time.


RECOMMENDATIONS FOR DATA ANALYSIS

Because nitrogen use and yields clearly differ among crops, crop type is a good natural grouping for

calculating summary statistics and identifying outliers.

The analysis of A/Y by T-R (Appendix I) shows how, in most T-Rs, there are insufficient data to generate

reliable summary statistics by crop. For instance, in almonds, the most common crop in the region,

nearly one third of the T-Rs had only one or two NMP MUs. It is meaningless to estimate summary

statistics or calculate outliers with a single data point; and T-Rs with only a few data points end up with

an unrealistically high frequency of outliers. In T-Rs with only a few NMP MUs, the highest value will

always be flagged as an outlier if the points are different from each other. Hence, outliers represent

50% of the T-Rs with only two data points, or 33% of three data points. Furthermore, because of the

way 90% quantiles are estimated, all T-Rs had outliers even when all data points had low A/Y values

relative to other T-Rs. In fact, some NMP MUs that could have been associated two T-Rs (because

different parcels or portion of parcels cross T-R boundaries) have been found to be outliers in one T-R

but not in the other for other Coalitions. This was not the case in this analysis because the SJC Coalition

assigned each MU to a single T-R.

For that reason, the Coalition considers that conducting the analysis grouping by T-R, as required by the

Order, results in unreliable summary statistics, and is an unreliable method for identifying management

units that are outliers that require additional outreach, education, and implementation of additional

practices.

The Order additionally requires the Coalition to report statistical summaries for parcels grouped by

similar soil conditions. Using soil types or management practices as subgroupings within T-R

exacerbates the problem with small sample size to a level where statistical analyses are meaningless.

Furthermore, the analysis of A/Y grouped by soil type and irrigation management practices found that

these groupings had very little effect on the A/Y or in the frequency of outliers. The analysis shows that

these factors may only influence A/Y in a few of the crops. Even for those crops, A/Y ranges overlapped

considerably, and the differences among categories (soil type or irrigation method) were quite small.

Hence, subdividing A/Y data by soil type or irrigation method within a T-R will provide no additional

insight into their impact on A/Y and is likely to confuse the issue even further.

The general goal of this NMP SR analysis is to understand nitrogen use in the region, and identify

Coalition members that can be targeted for focused outreach. With this goal in mind, there is little

benefit in using groupings other than crop type to identify outliers for a number of reasons: 1) the

differences in A/Y between soil types or irrigation practices are not large enough to justify separate

analysis; 2) grouping crops by T-R, soil type or management practices will reduce the sample size, and

hence the accuracy of summary statistics, especially for less common crops.

The Coalition recommends grouping only by crop type for calculating summary statistics and identifying

outliers. If over the long term, the quality of the NMP data improves, the Coalition could revisit the idea

of calculating outliers based on soil types or irrigation practices. In the meantime, the most informative

grouping, and the one that yields the better sample size is a simple grouping by specific crop type. This

grouping can be refined by separating those outliers that are due to high nitrogen application rates from

those that are due to low yields. The scatter plots of A vs. Y in Appendix I are a valuable tool for this.

APPENDIX I

NMP SUMMARY STATISTICS

SJCDWQC 2017 NMP Summary Report, Appendix I i | P a g e

TABLE OF CONTENTS

Introduction .................................................................................................................................................. 1

I. Almonds ............................................................................................................................................ 2

II. Cherry, Sweet .................................................................................................................................... 6

III. Corn, Silage ....................................................................................................................................... 8

IV. Corn, Sweet ..................................................................................................................................... 11

V. Grapes, Table .................................................................................................................................. 13

VI. Grapes, Wine ................................................................................................................................... 16

VII. Hay, Alfalfa ...................................................................................................................................... 20

VIII. Hay, Small Grain .............................................................................................................................. 22

IX. Olives ............................................................................................................................................... 24

X. Tomatoes, Processing ..................................................................................................................... 26

XI. Walnuts ........................................................................................................................................... 29

XII. Wheat, Irrigated .............................................................................................................................. 33

XIII. Other Crops ..................................................................................................................................... 35

LIST OF FIGURES

Figure I-1. Box and Whisker plots of A/Y for bearing ALMONDS management units grouped by TR blocks.

......................................................................................................................................................... 2

Figure I-2. Scatter plot of A vs. Y for ALMONDS crops with all TR together. .............................................. 4

Figure II-1. Box and Whisker plots of A/Y for bearing CHERRY, SWEET management units grouped by TR

blocks. .............................................................................................................................................. 6

Figure II-2. Scatter plot of A vs. Y for CHERRY, SWEET crops with all TR together. .................................... 7

Figure III-1. Box and Whisker plots of A/Y for bearing CORN, SILAGE management units grouped by TR

blocks. .............................................................................................................................................. 8

Figure III-2. Scatter plot of A vs. Y for CORN, SILAGE crops with all TR together. .................................... 10

Figure IV-1. Box and Whisker plots of A/Y for bearing CORN, SWEET management units grouped by TR

blocks. ............................................................................................................................................ 11

Figure IV-2. Scatter plot of A vs. Y for CORN, SWEET crops with all TR together. .................................... 12

Figure V-1. Box and Whisker plots of A/Y for bearing GRAPES, TABLE management units grouped by TR

blocks. ............................................................................................................................................ 13

Figure V-2. Scatter plot of A vs. Y for GRAPES, TABLE crops with all TR together. ................................... 15

Figure VI-1. Box and Whisker plots of A/Y for bearing GRAPES, WINE management units grouped by TR

blocks. ............................................................................................................................................ 16

Figure VI-2. Scatter plot of A vs. Y for GRAPES, WINE crops with all TR together. ................................... 18

Figure VII-1. Box and Whisker plots of A/Y for bearing HAY, ALFALFA management units grouped by TR

blocks. ............................................................................................................................................ 20

SJCDWQC 2017 NMP Summary Report, Appendix I ii | P a g e

Figure VII-2. Scatter plot of A vs. Y for HAY, ALFALFA crops with all TR together. ................................... 21

Figure VIII-1. Box and Whisker plots of A/Y for bearing HAY, SMALL GRAIN management units grouped

by TR blocks. .................................................................................................................................. 22

Figure VIII-2. Scatter plot of A vs. Y for HAY, SMALL GRAIN crops with all TR together. .......................... 23

Figure IX-1. Box and Whisker plots of A/Y for bearing OLIVES management units grouped by TR blocks.

....................................................................................................................................................... 24

Figure IX-2. Scatter plot of A vs. Y for OLIVES crops with all TR together. ................................................ 25

Figure X-1. Box and Whisker plots of A/Y for bearing TOMATOES, PROCESSING management units

grouped by TR blocks. .................................................................................................................... 26

Figure X-2. Scatter plot of A vs. Y for TOMATOES, PROCESSING crops with all TR together. ................... 28

Figure XI-1. Box and Whisker plots of A/Y for bearing WALNUTS management units grouped by TR

blocks. ............................................................................................................................................ 29

Figure XI-2. Scatter plot of A vs. Y for WALNUTS crops with all TR together. ........................................... 32

Figure XII-1. Box and Whisker plots of A/Y for bearing WHEAT, IRRIGATED management units grouped

by TR blocks. .................................................................................................................................. 33

Figure XII-2. Scatter plot of A vs. Y for WHEAT, IRRIGATED crops with all TR together. .......................... 34

LIST OF TABLES

Table I-1. Summary statistics for ALMONDS management units grouped by TR blocks. ............................ 2

Table I-2. Summary statistics for ALMONDS management units grouped by specific crop. ....................... 3

Table I-3. List of recommended nitrogen application values for ALMONDS (in lbs/acre). .......................... 5

Table II-1. Summary statistics for CHERRY, SWEET management units grouped by TR blocks. .................. 6

Table II-2Summary statistics for CHERRY, SWEET management units grouped by specific crop. ................ 7

Table II-3. List of recommended nitrogen application values for CHERRY, SWEET (in lbs/acre). ................ 7

Table III-1. Summary statistics for CORN, SILAGE management units grouped by TR blocks. .................... 8

Table III-2. Summary statistics for CORN, SILAGE management units grouped by specific crop. ............... 9

Table III-3. List of recommended nitrogen application values for CORN, SILAGE (in lbs/acre). ................ 10

Table IV-1. Summary statistics for CORN, SWEET management units grouped by TR blocks. .................. 11

Table IV-2. Summary statistics for CORN, SWEET management units grouped by specific crop. ............. 11

Table V-1. Summary statistics for GRAPES, TABLE management units grouped by TR blocks. ................. 13

Table V-2. Summary statistics for GRAPES, TABLE management units grouped by specific crop. ............ 14

Table V-3. List of recommended nitrogen application values for GRAPES, TABLE (in lbs/acre). ............... 15

Table VI-1. Summary statistics for GRAPES, WINE management units grouped by TR blocks. ................. 16

Table VI-2. Summary statistics for GRAPES, WINE management units grouped by specific crop. ............ 17

Table VI-3. List of recommended nitrogen application values for GRAPES, WINE (in lbs/acre). ............... 19

Table VII-1. Summary statistics for HAY, ALFALFA management units grouped by TR blocks. ................. 20

Table VII-2. Summary statistics for HAY, ALFALFA management units grouped by specific crop. ............ 21

Table VII-3. List of recommended nitrogen application values for HAY, ALFALFA (in lbs/acre). ............... 21

Table VIII-1. Summary statistics for HAY, SMALL GRAIN management units grouped by TR blocks. ........ 22

SJCDWQC 2017 NMP Summary Report, Appendix I iii | P a g e

Table VIII-2. Summary statistics for HAY, SMALL GRAIN management units grouped by specific crop. ... 22

Table VIII-3. List of recommended nitrogen application values for HAY, SMALL GRAIN (in lbs/acre). ..... 23

Table IX-1. Summary statistics for OLIVES management units grouped by TR blocks............................... 24

Table IX-2. Summary statistics for OLIVES management units grouped by specific crop. ........................ 24

Table IX-3. List of recommended nitrogen application values for OLIVES (in lbs/acre). ........................... 25

Table X-1. Summary statistics for TOMATOES, PROCESSING management units grouped by TR blocks. . 26

Table X-2. Summary statistics for TOMATOES, PROCESSING management units grouped by specific crop.

....................................................................................................................................................... 27

Table X-3. List of recommended nitrogen application values for TOMATOES, PROCESSING (in lbs/acre).

....................................................................................................................................................... 28

Table XI-1. Summary statistics for WALNUTS management units grouped by TR blocks. ........................ 29

Table XI-2. Summary statistics for WALNUTS management units grouped by specific crop. ................... 31

Table XI-3. List of recommended nitrogen application values for WALNUTS (in lbs/acre). ...................... 32

Table XII-1. Summary statistics for WHEAT, IRRIGATED management units grouped by TR blocks. ........ 33

Table XII-2. Summary statistics for WHEAT, IRRIGATED management units grouped by specific crop. ... 33

Table XII-3. List of recommended nitrogen application values for WHEAT, IRRIGATED (in lbs/acre). ...... 34

Table XIII-1. Summary statistics for crops with limited representation in the SJCDWQC region. ............. 35

SJCDWQC 2017 NMP Summary Report, Appendix I 1 | P a g e

INTRODUCTION

This appendix shows the results of summary statistics calculations for all crops in the region. Each

section (I to XII) contains results for one specific crop. Tree and perennial crops may contain trees of

different age. Several crops had only a few Management Units with complete data in the whole region.

Summary statistics for those crops are listed in Section XIII.

Because this appendix reports summary statistics of A/Y, only management units with complete data are

included. The detailed explanation of data exclusions due to completeness and quality is found in the

NMP Statistical Analysis section in the Annual Report body. Nonbearing and not harvested crops are not

included in the analysis because they do not have a A/Y value.

Each section (I to XII) contains Box and Whisker plots, and summary statistics of A/Y by T-R. Summary

statistics for A/R and A-R are also provided when a Nitrogen Removed Conversion Factor is available.

Box and Whisker plots were not generated for the crops in Section XIII, because there are not sufficient

management units per T-R to produce an informative figure. Each section also contains a scatter plot of

A vs. Y. These plots show when outlier A/Y values result from nitrogen applications that are very high,

from yield that was very low, or from a combination of the two. Nitrogen Management Plan summary

reports do not include information explaining very low yields (i.e., if a crop was lost or why).

Summary statistics include the count of outliers (A/Y > 90% quantile). It is important to note that,

because outliers are defined by the quantiles, the count of outliers is different when the statistics are

calculated by T-R or when they are calculated for the whole region. Because of the very small sample

size of crops in some T-Rs, the identification of outliers for focused outreach is done by crop type.

Scatter plots show lines with some typical nitrogen application rates found in the literature. However,

optimal nitrogen application rates can vary considerably due to factors such as crop stage, soil type, and

irrigation system. Because the goal of this analysis is not to provide a comprehensive review of

recommended application rates or to draw any conclusion regarding their accuracy or applicability to

specific fields, all values are plotted for reference. An associated table in each section provides more

detail regarding the range of values, sources, and specific conditions for the recommended nitrogen

application rates shown in the figure.


I. ALMONDS

Figure I-1. Box and Whisker plots of A/Y for bearing ALMONDS management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table I-1. Summary statistics for ALMONDS management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.

TR N MGMNTUNITS SUM ACRES PARAMETER MIN MAX 10% 25% 50% 75% 90% N OUTLIERS

01N08E 5 402 A/Y 0.068 0.130 0.070 0.073 0.080 0.081 0.111 1

01N09E 1 154 A/Y 0.090 0.090 -- -- -- -- -- --

01S06E 5 213 A/Y 0.015 0.400 0.038 0.072 0.093 0.130 0.292 1

01S07E 108 3242 A/Y 0.000 0.512 0.061 0.082 0.105 0.136 0.174 11

01S08E 98 4350 A/Y 0.000 0.218 0.039 0.071 0.087 0.102 0.122 10

01S09E 64 2499 A/Y 0.000 0.360 0.060 0.071 0.095 0.101 0.141 7

01S10E 9 1120 A/Y 0.000 0.230 0.046 0.078 0.091 0.100 0.126 1

01S11E 1 52 A/Y 0.070 0.070 -- -- -- -- -- --

02N07E 1 27 A/Y 0.140 0.140 -- -- -- -- -- --

02S05E 2 480 A/Y 0.100 0.254 0.115 0.138 0.177 0.216 0.239 1

02S06E 8 855 A/Y 0.046 0.157 0.050 0.054 0.079 0.128 0.138 1

02S07E 150 5782 A/Y 0.003 2.800 0.061 0.080 0.100 0.126 0.161 15

02S08E 183 5623 A/Y 0.000 1.000 0.051 0.079 0.103 0.132 0.174 19

02S09E 126 4477 A/Y 0.000 0.300 0.062 0.070 0.096 0.119 0.163 13

02S10E 11 323 A/Y 0.000 0.262 0.050 0.081 0.107 0.146 0.166 1

03N06E 2 39 A/Y 0.062 0.140 0.070 0.082 0.101 0.121 0.132 1

03S05E 4 409 A/Y 0.067 0.150 0.068 0.071 0.076 0.098 0.129 1

03S06E 19 2043 A/Y 0.024 4.601 0.045 0.072 0.080 0.190 1.196 2

03S07E 5 180 A/Y 0.100 0.115 0.100 0.100 0.100 0.100 0.109 1



04N07E 1 22 A/Y 0.061 0.061 -- -- -- -- -- --

unknown 8 327 A/Y 0.071 0.136 0.087 0.100 0.136 0.136 0.136 0

01N08E 5 402 A/R 1.000 1.918 1.029 1.073 1.177 1.190 1.626 1

01N09E 1 154 A/R 1.321 1.321 -- -- -- -- -- --

01S06E 5 213 A/R 0.224 5.882 0.558 1.059 1.360 1.912 4.294 1

01S07E 108 3242 A/R 0.000 7.537 0.891 1.211 1.527 2.005 2.562 11

01S08E 98 4350 A/R 0.000 3.199 0.529 1.046 1.274 1.496 1.791 10

01S09E 64 2499 A/R 0.000 5.294 0.900 1.066 1.404 1.485 2.075 7

01S10E 9 1120 A/R 0.000 3.382 0.682 1.143 1.338 1.471 1.853 1

01S11E 1 52 A/R 1.029 1.029 -- -- -- -- -- --

02N07E 1 27 A/R 2.056 2.056 -- -- -- -- -- --

02S05E 2 480 A/R 1.471 3.735 1.697 2.037 2.603 3.169 3.509 1

02S06E 8 855 A/R 0.675 2.303 0.741 0.799 1.162 1.887 2.029 1

02S07E 150 5782 A/R 0.043 41.178 0.866 1.177 1.471 1.851 2.370 15

02S08E 183 5623 A/R 0.000 14.706 0.743 1.177 1.522 1.946 2.566 19

02S09E 126 4477 A/R 0.000 4.412 0.907 1.033 1.407 1.756 2.401 13

02S10E 11 323 A/R 0.735 3.857 1.000 1.355 1.656 2.270 2.583 1

03N06E 2 39 A/R 0.919 2.059 1.033 1.204 1.489 1.774 1.945 1

03S05E 4 409 A/R 0.979 2.206 1.005 1.043 1.120 1.434 1.897 1

03S06E 19 2043 A/R 0.359 67.665 0.669 1.059 1.177 2.794 17.588 2

03S07E 5 180 A/R 1.471 1.691 1.471 1.471 1.471 1.471 1.603 1

04N07E 1 22 A/R 0.897 0.897 -- -- -- -- -- --

unknown 8 327 A/R 1.044 2.005 1.274 1.471 2.005 2.005 2.005 0

01N08E 5 402 A-R 0.000 93.800 5.480 13.700 30.100 37.500 71.280 1

01N09E 1 154 A-R 54.000 54.000 -- -- -- -- -- --

01S06E 5 213 A-R -100.200 95.400 -58.360 4.400 23.800 66.400 83.800 1

01S07E 108 3242 A-R -635.500 157.600 -15.140 29.700 63.200 98.100 150.400 1

01S08E 98 4350 A-R -760.400 211.200 -48.000 6.700 41.850 64.000 80.020 10

01S09E 64 2499 A-R -39.800 150.100 -11.860 13.100 38.700 69.600 99.220 7

01S10E 9 1120 A-R -122.400 64.000 -54.240 26.200 50.500 64.000 64.000 0

01S11E 1 52 A-R 3.000 3.000 -- -- -- -- -- --

02N07E 1 27 A-R 74.500 74.500 -- -- -- -- -- --

02S05E 2 480 A-R 36.800 93.000 42.420 50.850 64.900 78.950 87.380 1

02S06E 8 855 A-R -55.300 133.000 -40.740 -15.900 21.150 102.550 126.700 1

02S07E 150 5782 A-R -357.400 164.800 -18.630 30.225 64.000 87.975 109.530 15

02S08E 183 5623 A-R -530.600 248.400 -24.360 23.925 67.200 95.550 127.700 13

02S09E 126 4477 A-R -208.500 197.000 -19.000 2.700 45.300 76.250 109.400 13

02S10E 11 323 A-R -18.400 252.600 4.100 47.050 64.950 108.325 140.100 1

03N06E 2 39 A-R -5.500 85.400 3.590 17.225 39.950 62.675 76.310 1

03S05E 4 409 A-R -4.200 35.700 -0.180 5.850 14.450 23.700 30.900 1

03S06E 19 2043 A-R -196.100 156.200 -18.560 8.250 29.600 65.850 104.400 2

03S07E 5 180 A-R 64.000 70.700 64.000 64.000 64.000 64.000 68.020 1

04N07E 1 22 A-R -21.200 -21.200 -- -- -- -- -- --

unknown 8 327 A-R 7.400 150.400 41.700 70.650 150.400 150.400 150.400 0

Table I-2. Summary statistics for ALMONDS management units grouped by specific crop.

SPECIFICCROP N MGMNTUNITS SUM ACRES PARAMETER MIN MAX 10% 25% 50% 75% 90% N OUTLIERS

ALMONDS /YEAR > 4 477 16960.830 A/Y 0.000 2.900 0.060 0.075 0.098 0 0 48

ALMONDS /YEAR 2 2 26.000 A/Y 0.020 0.400 0.058 0.115 0.210 0 0 1

ALMONDS /YEAR 3 18 612.739 A/Y 0.050 4.601 0.083 0.100 0.153 0 1 2



ALMONDS /YEAR 4 21 528.760 A/Y 0.015 0.355 0.072 0.081 0.103 0 0 2

ALMONDS /YEAR NR 293 14491.810 A/Y 0.000 0.490 0.050 0.080 0.100 0 0 26

ALMONDS /YEAR > 4 477 16960.830 A/R 0.000 42.649 0.875 1.094 1.440 2 2 41

ALMONDS /YEAR 2 2 26.000 A/R 0.294 5.882 0.853 1.691 3.088 4 5 1

ALMONDS /YEAR 3 18 612.739 A/R 0.735 67.665 1.226 1.471 2.250 3 12 2

ALMONDS /YEAR 4 21 528.760 A/R 0.224 5.215 1.059 1.190 1.515 3 4 2

ALMONDS /YEAR NR 293 14491.810 A/R 0.000 7.206 0.750 1.177 1.471 2 2 26

ALMONDS /YEAR > 4 477 16960.830 A-R -760 253 -19 13 53 83 118 48

ALMONDS /YEAR 2 2 26.000 A-R -24 66 -15 -1 21 44 57 1

ALMONDS /YEAR 3 18 612.739 A-R -18 186 10 25 42 68 108 2

ALMONDS /YEAR 4 21 528.760 A-R -100 156 6 18 45 91 114 2

ALMONDS /YEAR NR 293 14491.810 A-R -165 248 -25 26 58 79 126 29

Figure I-2. Scatter plot of A vs. Y for ALMONDS crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.


Table I-3. List of recommended nitrogen application values for ALMONDS (in lbs/acre).

CROP MIN MAX STUDY SPECIFICS

Almonds /Year>4 95 380.00 The fertilization rate of mature trees is dependent on desired yield.

Minimum value yields 1000 lbs/acre; maximum yields 4,000 lbs/acre. Applied by fertigation via low volume irrigation.

Almonds /Year 1 20 35.00 A total annual application of up to 4 ounces/tree (20-35 lbs/acre) to first-

leaf trees may increase growth, while higher rates have no benefits.

Almonds /Year 1 6.25 18.75

Meyer suggested this rates for drip-irrigated trees on non-fertile soils. Values were converted from ounces/tree to lbs/acre assuming 100

trees/acre.


Almonds /Year 3 25 75.00


Almonds /Year 5 100 200.00 Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



II. CHERRY, SWEET

Figure II-1. Box and Whisker plots of A/Y for bearing CHERRY, SWEET management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table II-1. Summary statistics for CHERRY, SWEET management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N07E 9 643 A/Y 0.000 0.089 0.006 0.012 0.012 0.017 0.035 1

01N08E 1 51 A/Y 0.031 0.031 -- -- -- -- -- --

01S07E 6 152 A/Y 0.005 0.056 0.006 0.008 0.013 0.037 0.050 1

01S08E 2 40 A/Y 0.003 1.790 0.182 0.450 0.897 1.343 1.611 1

02N06E 6 260 A/Y 0.006 0.032 0.007 0.010 0.018 0.021 0.027 1

02N07E 136 3456 A/Y 0.000 0.400 0.001 0.003 0.010 0.019 0.028 13

02N08E 5 112 A/Y 0.000 0.010 0.000 0.000 0.002 0.009 0.010 1

02S07E 3 90 A/Y 0.026 0.151 0.037 0.053 0.079 0.115 0.137 1

02S08E 1 4 A/Y 0.011 0.011 -- -- -- -- -- --

03N06E 20 439 A/Y 0.000 0.045 0.000 0.002 0.010 0.016 0.026 2

03N07E 34 613 A/Y 0.000 0.080 0.000 0.000 0.006 0.010 0.022 4

03S05E 1 9 A/Y 0.011 0.011 -- -- -- -- -- --

04N05E 3 96 A/Y 0.000 0.030 0.004 0.010 0.020 0.025 0.028 1

04N06E 18 342 A/Y 0.000 0.048 0.000 0.000 0.011 0.019 0.026 1

04N08E 3 159 A/Y 0.004 0.024 0.004 0.005 0.007 0.015 0.021 1

05N05E 1 35 A/Y 0.009 0.009 -- -- -- -- -- --

unknown 1 10 A/Y 0.002 0.002 -- -- -- -- -- --


Table II-2Summary statistics for CHERRY, SWEET management units grouped by specific crop.


CHERRY, SWEET /YEAR > 4 169 4135.14 A/Y 0 0.114 0 0.003 0.010 0 0 16

CHERRY, SWEET /YEAR 3 1 20.00 A/Y 0 0.000 -- -- -- -- -- --

CHERRY, SWEET /YEAR 4 2 21.78 A/Y 0 0.000 -- -- -- -- -- --

CHERRY, SWEET /YEAR NR 78 2334.51 A/Y 0 1.790 0 0.002 0.009 0 0 8

Figure II-2. Scatter plot of A vs. Y for CHERRY, SWEET crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table II-3. List of recommended nitrogen application values for CHERRY, SWEET (in lbs/acre).


Sweet Cherries /Year < 4 10 30 Values are not recommendations, but rates considered typical of a well-managed orchard. May not be applicable to all operations. Sweet Cherries /Year > 4 35 60

Source: UC Davis - http://coststudies.ucdavis.edu/current/



III. CORN, SILAGE

Figure III-1. Box and Whisker plots of A/Y for bearing CORN, SILAGE management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table III-1. Summary statistics for CORN, SILAGE management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N07E 1 158 A/Y 0.003 0.003 -- -- -- -- -- --

01N08E 3 248 A/Y 0.003 0.004 0.003 0.003 0.004 0.004 0.004 1

01S06E 1 23 A/Y 0.004 0.004 -- -- -- -- -- --

01S08E 2 86 A/Y 0.003 0.003 -- -- -- -- -- --

01S09E 4 215 A/Y 0.002 0.006 0.003 0.004 0.005 0.005 0.006 1

01S10E 1 149 A/Y 0.004 0.004 -- -- -- -- -- --

02N06E 1 220 A/Y 0.003 0.003 -- -- -- -- -- --

02N07E 1 11 A/Y 0.000 0.000 -- -- -- -- -- --

02S05E 2 223 A/Y 0.001 0.003 0.001 0.001 0.002 0.002 0.003 1

02S06E 2 565 A/Y 0.004 0.005 0.004 0.004 0.004 0.004 0.005 1

02S07E 3 153 A/Y 0.003 0.004 0.003 0.003 0.003 0.004 0.004 1

02S09E 2 184 A/Y 0.001 0.003 0.001 0.001 0.002 0.002 0.002 1

03N06E 1 121 A/Y 0.003 0.003 -- -- -- -- -- --

03S06E 1 131 A/Y 0.003 0.003 -- -- -- -- -- --

03S07E 2 144 A/Y 0.003 0.003 0.003 0.003 0.003 0.003 0.003 1

01N07E 1 158 A/R 0.744 0.744 -- -- -- -- -- --

01N08E 3 248 A/R 0.744 1.034 0.776 0.824 0.903 0.968 1.007 1

01S06E 1 23 A/R 1.088 1.088 -- -- -- -- -- --

01S08E 2 86 A/R 0.862 0.862 -- -- -- -- -- --



01S09E 4 215 A/R 0.496 1.489 0.668 0.926 1.180 1.340 1.429 1

01S10E 1 149 A/R 1.063 1.063 -- -- -- -- -- --

02N06E 1 220 A/R 0.810 0.810 -- -- -- -- -- --

02S05E 2 223 A/R 0.198 0.720 0.251 0.329 0.459 0.589 0.667 1

02S06E 2 565 A/R 0.898 1.187 0.927 0.971 1.043 1.115 1.158 1

02S07E 3 153 A/R 0.780 1.030 0.784 0.790 0.800 0.915 0.984 1

02S09E 2 184 A/R 0.279 0.638 0.315 0.369 0.459 0.548 0.602 1

03N06E 1 121 A/R 0.720 0.720 -- -- -- -- -- --

03S06E 1 131 A/R 0.762 0.762 -- -- -- -- -- --

03S07E 2 144 A/R 0.703 0.804 0.713 0.728 0.754 0.779 0.794 1

01N07E 1 158 A-R -69 -69 -- -- -- -- -- --

01N08E 3 248 A-R -62 9 -54 -43 -25 -8 2 1

01S06E 1 23 A-R 16 16 -- -- -- -- -- --

01S08E 2 86 A-R -42 -42 -- -- -- -- -- --

01S09E 4 215 A-R -183 99 -123 -34 27 54 81 1

01S10E 1 149 A-R 14 14 -- -- -- -- -- --

02N06E 1 220 A-R -46 -46 -- -- -- -- -- --

02S05E 2 223 A-R -162 -58 -151 -136 -110 -84 -69 1

02S06E 2 565 A-R -22 39 -16 -7 9 24 33 1

02S07E 3 153 A-R -50 7 -49 -49 -48 -20 -4 1

02S09E 2 184 A-R -163 -102 -157 -148 -132 -117 -108 1

03N06E 1 121 A-R -78 -78 -- -- -- -- -- --

03S06E 1 131 A-R -56 -56 -- -- -- -- -- --

03S07E 2 144 A-R -72 -43 -69 -65 -57 -50 -46 1

Table III-2. Summary statistics for CORN, SILAGE management units grouped by specific crop.


CORN, SILAGE 27 2632.36 A/Y 0.000 0.006 0.002 0.003 0.003 0 0 3

CORN, SILAGE 27 2632.36 A/R 0.198 1.489 0.567 0.726 0.807 1 1 3

CORN, SILAGE 27 2632.36 A-R -182.7 98.5 -131.8 -66.975 -44.3 9 27 3


Figure III-2. Scatter plot of A vs. Y for CORN, SILAGE crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table III-3. List of recommended nitrogen application values for CORN, SILAGE (in lbs/acre).


Corn 180 216

Range of recommended total N application rates (sidedress N plus starter N). Values are for a grain yield of 180 bu/acre (5 tons/acre) or a silage corn yield of 30 tons/acre. They includes

fertilizer N and soil derived N. They represent common recommendations found used in different states. However, these recommendations have not been tested in California.

Corn 225 270 This value correspond to the lowest soil N availability (< 10) and largest desired yield (6.3

tons/acre of grain or 38 tons/acre of silage). Values are from other states and have not been tested in California.

Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



IV. CORN, SWEET

Figure IV-1. Box and Whisker plots of A/Y for bearing CORN, SWEET management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table IV-1. Summary statistics for CORN, SWEET management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N06E 1 37 A/Y 0.018 0.018 -- -- -- -- -- --

01N07E 1 212 A/Y 0.018 0.018 -- -- -- -- -- --

01S06E 1 0 A/Y 0.000 0.000 -- -- -- -- -- --

01S07E 5 615 A/Y 0.018 0.033 0.018 0.018 0.018 0.018 0.027 1

02S06E 2 280 A/Y 0.008 0.010 0.008 0.009 0.009 0.010 0.010 1

02S08E 1 36 A/Y 0.018 0.018 -- -- -- -- -- --

03S06E 3 289 A/Y 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0

03S07E 1 136 A/Y 0.008 0.008 -- -- -- -- -- --

Table IV-2. Summary statistics for CORN, SWEET management units grouped by specific crop.


CORN, SWEET 15 1604.88 A/Y 0 0.033 0.008 0.008 0.018 0 0 1


Figure IV-2. Scatter plot of A vs. Y for CORN, SWEET crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.


V. GRAPES, TABLE

Figure V-1. Box and Whisker plots of A/Y for bearing GRAPES, TABLE management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table V-1. Summary statistics for GRAPES, TABLE management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01S07E 7 137 A/Y 0.000 0.007 0.000 0.000 0.000 0.006 0.007 0

01S08E 2 26 A/Y 0.007 0.010 0.007 0.007 0.008 0.009 0.010 1

01S09E 1 22 A/Y 0.003 0.003 -- -- -- -- -- --

02S06E 1 20 A/Y 0.008 0.008 -- -- -- -- -- --

02S08E 3 62 A/Y 0.002 0.004 0.002 0.002 0.002 0.003 0.004 1

03N05E 2 52 A/Y 0.002 0.002 0.002 0.002 0.002 0.002 0.002 1

03N06E 17 629 A/Y 0.000 0.006 0.000 0.001 0.002 0.003 0.004 2

03N07E 13 150 A/Y 0.000 0.004 0.000 0.002 0.002 0.003 0.003 2

04N05E 10 861 A/Y 0.001 0.004 0.001 0.001 0.001 0.004 0.004 1

04N06E 26 974 A/Y 0.000 0.012 0.001 0.003 0.003 0.005 0.006 3

04N07E 4 111 A/Y 0.001 0.012 0.001 0.002 0.003 0.006 0.010 1

04N08E 1 3 A/Y 0.003 0.003 -- -- -- -- -- --

05N05E 5 200 A/Y 0.001 0.002 0.001 0.001 0.001 0.002 0.002 1

01S07E 7 137 A/R 0.320 6.688 0.353 0.375 0.465 6.083 6.688 0

01S08E 2 26 A/R 6.542 10.000 6.888 7.406 8.271 9.135 9.654 1

01S09E 1 22 A/R 3.460 3.460 -- -- -- -- -- --

02S06E 1 20 A/R 8.300 8.300 -- -- -- -- -- --

02S08E 3 62 A/R 1.900 4.000 1.920 1.950 2.000 3.000 3.600 1



03N05E 2 52 A/R 1.950 2.438 1.999 2.072 2.194 2.316 2.389 1

03N06E 17 629 A/R 0.000 5.555 0.598 1.118 2.140 3.071 4.330 2

03N07E 13 150 A/R 0.783 4.125 1.500 2.125 2.270 2.679 3.250 1

04N05E 10 861 A/R 0.830 4.250 0.983 1.062 1.250 3.806 4.092 1

04N06E 26 974 A/R 0.000 11.957 1.359 2.697 3.125 4.733 6.461 3

04N07E 4 111 A/R 1.150 12.000 1.455 1.912 3.036 5.929 9.572 1

04N08E 1 3 A/R 3.125 3.125 -- -- -- -- -- --

05N05E 5 200 A/R 1.250 1.660 1.250 1.250 1.250 1.600 1.636 1

01S07E 7 137 A-R -11 66 -9 -8 -6 65 66 0

01S08E 2 26 A-R 54 57 54 55 56 56 57 1

01S09E 1 22 A-R 43 43 -- -- -- -- -- --

02S06E 1 20 A-R 88 88 -- -- -- -- -- --

02S08E 3 62 A-R 17 26 17 17 18 22 24 1

03N05E 2 52 A-R 19 23 19 20 21 22 23 1

03N06E 17 629 A-R -12 41 -6 2 12 32 38 2

03N07E 13 150 A-R -3 26 6 12 18 19 25 1

04N05E 10 861 A-R -2 52 0 1 2 38 45 1

04N06E 26 974 A-R -9 50 3 32 32 44 44 3

04N07E 4 111 A-R 1 26 2 4 6 12 20 1

04N08E 1 3 A-R 24 24 -- -- -- -- -- --

05N05E 5 200 A-R 2 4 2 2 2 4 4 1

Table V-2. Summary statistics for GRAPES, TABLE management units grouped by specific crop.


GRAPES, TABLE /YEAR > 4 13 186.83 A/Y 0.000 0.012 0.000 0.002 0.004 0 0 2

GRAPES, TABLE /YEAR NR 79 3061.53 A/Y 0.000 0.012 0.000 0.001 0.002 0 0 8

GRAPES, TABLE /YEAR > 4 13 186.83 A/R 1.833 11.957 2.083 2.716 4.733 9 11 1

GRAPES, TABLE /YEAR NR 79 3061.53 A/R 0.000 12.000 0.616 1.250 2.438 4 5 8

GRAPES, TABLE /YEAR > 4 13 186.83 A-R 10 88 17 23 43 50 54 1

GRAPES, TABLE /YEAR NR 79 3061.53 A-R -12 66 -4 2 18 32 44 5


Figure V-2. Scatter plot of A vs. Y for GRAPES, TABLE crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table V-3. List of recommended nitrogen application values for GRAPES, TABLE (in lbs/acre).


Grapes 20 60 Values for furrow irrigated operations. Lower values recommended for medium vigor vines;

highest for weak vigor, inadequate canopy and sandy soils.

Grapes 0 0 Value for vinyard with vigorous vines and some excess growth. Grapevines have a low N

fertilizer requirement compared to most other crops. On average about 2.9 lbs of N is removed from the vineyard in one ton (2000 lbs) of fresh grapes.

Grapes 10 40 Value for drip irrigated operations. Lower values recommended for medium vigor vines;

highest for weak vigor, inadequate canopy and sandy soils. Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



VI. GRAPES, WINE

Figure VI-1. Box and Whisker plots of A/Y for bearing GRAPES, WINE management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table VI-1. Summary statistics for GRAPES, WINE management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N08E 13 1238 A/Y 0.002 0.004 0.002 0.002 0.002 0.003 0.003 1

01N09E 1 110 A/Y 0.006 0.006 -- -- -- -- -- --

01S07E 6 244 A/Y 0.002 0.003 0.002 0.002 0.002 0.003 0.003 1

01S08E 16 667 A/Y 0.001 0.004 0.001 0.002 0.002 0.003 0.003 1

02N05E 2 436 A/Y 0.002 0.002 -- -- -- -- -- --

02N07E 1 57 A/Y 0.003 0.003 -- -- -- -- -- --

02S07E 4 165 A/Y 0.000 0.006 0.001 0.001 0.002 0.003 0.005 1

02S08E 6 561 A/Y 0.001 10.373 0.001 0.001 0.002 0.005 5.189 1

03N05E 21 1675 A/Y 0.000 0.004 0.002 0.002 0.002 0.004 0.004 2

03N06E 156 6946 A/Y 0.000 69.000 0.000 0.001 0.002 0.004 0.007 16

03N07E 70 1531 A/Y 0.000 29.000 0.000 0.001 0.002 0.003 0.008 7

03N08E 1 6 A/Y 0.001 0.001 -- -- -- -- -- --

03S05E 6 403 A/Y 0.000 0.002 0.000 0.000 0.002 0.002 0.002 1

03S06E 1 228 A/Y 0.004 0.004 -- -- -- -- -- --

03S07E 8 400 A/Y 0.001 0.003 0.001 0.002 0.002 0.002 0.003 1

04N05E 58 3310 A/Y 0.000 0.008 0.001 0.002 0.002 0.003 0.007 6

04N06E 235 8086 A/Y 0.000 0.011 0.000 0.001 0.002 0.003 0.004 24

04N07E 80 2528 A/Y 0.000 0.008 0.000 0.001 0.002 0.002 0.004 8

04N08E 39 1442 A/Y 0.000 0.182 0.001 0.001 0.002 0.003 0.003 4

05N05E 7 331 A/Y 0.000 0.002 0.001 0.001 0.002 0.002 0.002 1



05N06E 1 40 A/Y 0.001 0.001 -- -- -- -- -- --

unknown 6 142 A/Y 0.000 0.003 0.000 0.000 0.002 0.003 0.003 1

01N08E 13 1238 A/R 1.700 3.750 1.840 2.000 2.300 2.700 2.700 1

01N09E 1 110 A/R 5.665 5.665 -- -- -- -- -- --

01S07E 6 244 A/R 1.755 3.114 1.820 1.950 2.296 2.896 3.079 1

01S08E 16 667 A/R 1.100 3.885 1.250 1.637 1.800 3.000 3.000 1

02N05E 2 436 A/R 2.145 2.145 -- -- -- -- -- --

02N07E 1 57 A/R 2.940 2.940 -- -- -- -- -- --

02S07E 4 165 A/R 0.250 5.915 0.586 1.090 1.602 2.855 4.691 1

02S08E 6 561 A/R 1.000 10372.993 1.150 1.455 1.978 5.009 5189.497 1

03N05E 21 1675 A/R 0.000 4.400 1.822 1.900 1.900 3.500 3.800 2

03N06E 156 6946 A/R 0.000 69000.000 0.700 1.490 2.100 4.527 6.720 15

03N07E 70 1531 A/R 0.000 29000.000 0.067 1.445 2.286 3.150 9.513 7

03N08E 1 6 A/R 1.250 1.250 -- -- -- -- -- --

03S05E 6 403 A/R 0.000 2.145 0.000 0.475 1.900 1.900 2.022 1

03S06E 1 228 A/R 4.415 4.415 -- -- -- -- -- --

03S07E 8 400 A/R 0.530 2.815 1.440 1.969 2.265 2.364 2.528 1

04N05E 58 3310 A/R 0.000 8.110 1.118 1.821 2.200 3.330 6.731 6

04N06E 235 8086 A/R 0.000 10.720 0.510 1.015 1.660 2.717 4.116 23

04N07E 80 2528 A/R 0.000 8.260 0.309 0.775 1.900 2.500 3.580 8

04N08E 39 1442 A/R 0.017 182.000 0.814 1.308 1.790 2.565 3.244 4

05N05E 7 331 A/R 0.330 2.340 0.732 1.000 2.030 2.115 2.247 1

05N06E 1 40 A/R 1.335 1.335 -- -- -- -- -- --

unknown 6 142 A/R 0.000 3.370 0.102 0.491 1.746 2.561 3.035 1

01N08E 13 1238 A-R 19 33 20 22 23 24 27 2

01N09E 1 110 A-R 31 31 -- -- -- -- -- --

01S07E 6 244 A-R 16 34 17 18 26 33 33 1

01S08E 16 667 A-R 2 42 5 10 14 23 23 1

02N05E 2 436 A-R 16 16 -- -- -- -- -- --

02N07E 1 57 A-R 33 33 -- -- -- -- -- --

02S07E 4 165 A-R -9 91 -3 6 15 37 69 1

02S08E 6 561 A-R 0 110 3 8 22 79 102 1

03N05E 21 1675 A-R -16 34 12 17 17 25 33 1

03N06E 156 6946 A-R -25 98 -4 7 19 40 69 12

03N07E 70 1531 A-R -17 92 -8 8 18 25 46 7

03N08E 1 6 A-R 1 1 -- -- -- -- -- --

03S05E 6 403 A-R -30 18 -27 -14 17 18 18 0

03S06E 1 228 A-R 74 74 -- -- -- -- -- --

03S07E 8 400 A-R -2 39 19 30 34 35 37 1

04N05E 58 3310 A-R -14 106 2 17 20 34 75 6

04N06E 235 8086 A-R -26 120 -9 0 9 22 48 22

04N07E 80 2528 A-R -19 117 -11 -5 11 20 26 8

04N08E 39 1442 A-R -12 36 -3 4 12 23 26 4

05N05E 7 331 A-R -4 28 -2 0 24 25 27 1

05N06E 1 40 A-R 7 7 -- -- -- -- -- --

unknown 6 142 A-R -21 31 -16 -7 11 19 26 1

Table VI-2. Summary statistics for GRAPES, WINE management units grouped by specific crop.


GRAPES, WINE /YEAR > 4 461 17665.19 A/Y 0.000 0.015 0.000 0.001 0.002 0 0 44



GRAPES, WINE /YEAR 2 1 15.00 A/Y 0.182 0.182 -- -- -- -- -- --

GRAPES, WINE /YEAR 3 7 530.32 A/Y 0.000 0.011 0.001 0.002 0.004 0 0 1

GRAPES, WINE /YEAR 4 3 45.51 A/Y 0.000 0.004 0.001 0.001 0.003 0 0 1

GRAPES, WINE /YEAR NR 266 12287.71 A/Y 0.000 69.000 0.000 0.001 0.002 0 0 27

GRAPES, WINE /YEAR > 4 461 17665.19 A/R 0.000 14.868 0.619 1.214 1.945 3 4 44

GRAPES, WINE /YEAR 2 1 15.00 A/R 182.000 182.000 -- -- -- -- -- --

GRAPES, WINE /YEAR 3 7 530.32 A/R 0.318 10.720 1.087 2.211 4.305 8 11 1

GRAPES, WINE /YEAR 4 3 45.51 A/R 2.734 3.560 2.817 2.941 3.147 3 3 1

GRAPES, WINE /YEAR NR 266 12287.71 A/R 0.000 69000.000 0.397 1.200 2.025 3 6 26

GRAPES, WINE /YEAR > 4 461 17665.19 A-R -30 120 -7 3 15 25 35 45

GRAPES, WINE /YEAR 2 1 15.00 A-R 36 36 -- -- -- -- -- --

GRAPES, WINE /YEAR 3 7 530.32 A-R -2 39 5 13 16 23 30 1

GRAPES, WINE /YEAR 4 3 45.51 A-R 18 70 23 31 44 57 65 1

GRAPES, WINE /YEAR NR 266 12287.71 A-R -25 110 -8 2 17 32 68 26

Figure VI-2. Scatter plot of A vs. Y for GRAPES, WINE crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.


Table VI-3. List of recommended nitrogen application values for GRAPES, WINE (in lbs/acre).


Grapes 20 60 Values for furrow irrigated operations. Lower values recommended for medium vigor vines;

highest for weak vigor, inadequate canopy and sandy soils.

Grapes 0 0 Value for vinyard with vigorous vines and some excess growth. Grapevines have a low N fertilizer requirement compared to most other crops. On average about 2.9 lbs of N is removed from the

vineyard in one ton (2000 lbs) of fresh grapes.

Grapes 10 40 Value for drip irrigated operations. Lower values recommended for medium vigor vines; highest

for weak vigor, inadequate canopy and sandy soils. Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



VII. HAY, ALFALFA

Figure VII-1. Box and Whisker plots of A/Y for bearing HAY, ALFALFA management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table VII-1. Summary statistics for HAY, ALFALFA management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N06E 2 89 A/Y 0.000 0.007 0.001 0.002 0.003 0.005 0.006 1

01N07E 2 139 A/Y 0.000 0.000 -- -- -- -- -- --

01N08E 1 35 A/Y 0.000 0.000 -- -- -- -- -- --

01S06E 3 340 A/Y 0.000 0.006 0.000 0.000 0.001 0.004 0.005 1

01S07E 8 835 A/Y 0.002 0.005 0.002 0.002 0.002 0.002 0.003 1

01S08E 4 225 A/Y 0.000 0.004 0.000 0.000 0.000 0.001 0.003 1

02N06E 7 405 A/Y 0.001 0.001 0.001 0.001 0.001 0.001 0.001 3

02N07E 2 60 A/Y 0.008 0.008 -- -- -- -- -- --

02S04E 4 171 A/Y 0.000 0.008 0.000 0.000 0.003 0.006 0.008 1

02S05E 14 449 A/Y 0.000 0.015 0.000 0.000 0.003 0.003 0.003 1

02S06E 13 1391 A/Y 0.000 0.025 0.000 0.000 0.002 0.003 0.004 2

02S07E 5 142 A/Y 0.001 0.008 0.001 0.002 0.003 0.007 0.007 1

02S09E 1 9 A/Y 0.000 0.000 -- -- -- -- -- --

03N05E 1 70 A/Y 0.031 0.031 -- -- -- -- -- --

03N07E 3 315 A/Y 0.001 0.004 0.001 0.001 0.001 0.002 0.003 1

03S05E 8 569 A/Y 0.000 0.005 0.002 0.003 0.004 0.005 0.005 0

03S06E 11 822 A/Y 0.000 0.003 0.000 0.001 0.002 0.002 0.002 1

03S07E 1 24 A/Y 0.002 0.002 -- -- -- -- -- --


Table VII-2. Summary statistics for HAY, ALFALFA management units grouped by specific crop.


HAY, ALFALFA 90 6088.82 A/Y 0 0.031 0 0.001 0.002 0 0 9

Figure VII-2. Scatter plot of A vs. Y for HAY, ALFALFA crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table VII-3. List of recommended nitrogen application values for HAY, ALFALFA (in lbs/acre).


Hay, Alfalfa 0 0 Alfalfa obtains N from the atmosphere through a symbiotic relationship with bacteria

(Rhizobia) in the root nodules. Therefore, N fertilization of alfalfa is seldom beneficial or profitable.

Hay, Alfalfa (sowing)

20 40 A starter application may be beneficial when residual nitrate concentration is below 3-4

ppm (NO3-N). Larger amounts may inhibit bacterial colonization. Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



VIII. HAY, SMALL GRAIN

Figure VIII-1. Box and Whisker plots of A/Y for bearing HAY, SMALL GRAIN management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table VIII-1. Summary statistics for HAY, SMALL GRAIN management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N07E 1 37 A/Y 0.005 0.005 -- -- -- -- -- --

01S07E 5 191 A/Y 0.009 0.019 0.01 0.011 0.014 0.019 0.019 1

01S09E 4 71 A/Y 0.000 0.012 0.00 0.000 0.000 0.003 0.009 1

02S04E 3 78 A/Y 0.000 0.000 -- -- -- -- -- --

02S05E 1 83 A/Y 0.000 0.000 -- -- -- -- -- --

02S06E 1 55 A/Y 0.000 0.000 -- -- -- -- -- --

03S06E 1 94 A/Y 0.000 0.000 -- -- -- -- -- --

unknown 1 31 A/Y 0.022 0.022 -- -- -- -- -- --

Table VIII-2. Summary statistics for HAY, SMALL GRAIN management units grouped by specific crop.


HAY, SMALL GRAIN 17 640.66 A/Y 0 0.022 0 0 0 0 0 2


Figure VIII-2. Scatter plot of A vs. Y for HAY, SMALL GRAIN crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table VIII-3. List of recommended nitrogen application values for HAY, SMALL GRAIN (in lbs/acre).


Hay, Small Grain 150 Values are not recommendations, but rates considered typical of a well-managed

orchard. May not be applicable to all operations.

Sudan, Silage 60 160 Value depends on residual soil nitrogen. Highest value may be used if the soil is

deficient.

Orchardgrass Hay 200 Total to be divided in three parts during the growing season. Does not include

application at planting.

Sorghum, Silage 140 Value assumes yield of 20 tons/acre (70% moisture). Source: UC Davis - http://coststudies.ucdavis.edu/current/



IX. OLIVES

Figure IX-1. Box and Whisker plots of A/Y for bearing OLIVES management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table IX-1. Summary statistics for OLIVES management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N06E 1 19 A/Y 0.002 0.002 -- -- -- -- -- --

01N08E 1 70 A/Y 0.007 0.007 -- -- -- -- -- --

01S07E 1 11 A/Y 0.002 0.002 -- -- -- -- -- --

02S07E 1 10 A/Y 0.000 0.000 -- -- -- -- -- --

03N05E 3 135 A/Y 0.001 0.003 0.001 0.002 0.003 0.003 0.003 1

03N06E 2 22 A/Y 0.000 0.000 -- -- -- -- -- --

03N07E 1 33 A/Y 0.004 0.004 -- -- -- -- -- --

03S05E 1 1 A/Y 0.001 0.001 -- -- -- -- -- --

03S06E 1 50 A/Y 0.004 0.004 -- -- -- -- -- --

04N06E 2 60 A/Y 0.003 0.005 0.003 0.003 0.004 0.005 0.005 1

05N05E 2 141 A/Y 0.004 0.004 -- -- -- -- -- --

Table IX-2. Summary statistics for OLIVES management units grouped by specific crop.


OLIVES /YEAR > 4 11 424.27 A/Y 0 0.005 0.001 0.002 0.003 0 0 1

OLIVES /YEAR NR 5 127.85 A/Y 0 0.007 0.000 0.000 0.002 0 0 1


Figure IX-2. Scatter plot of A vs. Y for OLIVES crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table IX-3. List of recommended nitrogen application values for OLIVES (in lbs/acre).


Olives 0 144 N applications are dependent on the desired yield: minimum value typically yields 1.2

tons/acre and maximum value yields 5.4 tons/acre. Based on a heavy crop year. Fertilizer applications are based on leaf analysis, optimum levels of N should be between 1.5-2.0%.

Olives /Year 1-2

60 80

High density olive orchard. N applied through drip irrigation system. Olives /Year

>3 80 120

Source: UC Davis - http://coststudies.ucdavis.edu/current/



X. TOMATOES, PROCESSING

Figure X-1. Box and Whisker plots of A/Y for bearing TOMATOES, PROCESSING management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table X-1. Summary statistics for TOMATOES, PROCESSING management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N07E 11 1656 A/Y 0.001 0.003 0.002 0.002 0.002 0.002 0.003 1

01N08E 5 823 A/Y 0.002 0.003 0.002 0.002 0.002 0.003 0.003 1

01S07E 3 250 A/Y 0.001 0.002 0.001 0.002 0.002 0.002 0.002 0

01S08E 1 97 A/Y 0.003 0.003 -- -- -- -- -- --

02N06E 3 98 A/Y 0.002 0.004 0.002 0.002 0.002 0.003 0.003 1

02N07E 1 28 A/Y 0.002 0.002 -- -- -- -- -- --

02S04E 1 110 A/Y 0.002 0.002 -- -- -- -- -- --

02S05E 9 764 A/Y 0.002 0.004 0.002 0.002 0.002 0.003 0.004 1

03N05E 3 471 A/Y 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0

03N06E 1 100 A/Y 0.002 0.002 -- -- -- -- -- --

03N07E 2 166 A/Y 0.001 0.002 0.002 0.002 0.002 0.002 0.002 1

03S05E 8 416 A/Y 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0

03S06E 6 335 A/Y 0.002 0.003 0.002 0.002 0.003 0.003 0.003 1

01N07E 11 1656 A/R 0.485 1.605 0.923 0.951 1.026 1.154 1.462 1

01N08E 5 823 A/R 0.820 1.333 0.903 1.026 1.250 1.324 1.329 1

01S07E 3 250 A/R 0.692 0.942 0.742 0.817 0.942 0.942 0.942 0

01S08E 1 97 A/R 1.462 1.462 -- -- -- -- -- --

02N06E 3 98 A/R 0.897 1.903 0.923 0.962 1.026 1.464 1.727 1



02N07E 1 28 A/R 1.282 1.282 -- -- -- -- -- --

02S04E 1 110 A/R 1.026 1.026 -- -- -- -- -- --

02S05E 9 764 A/R 0.815 1.897 0.819 0.820 1.026 1.620 1.895 1

03N05E 3 471 A/R 0.923 0.974 0.933 0.949 0.974 0.974 0.974 0

03N06E 1 100 A/R 1.026 1.026 -- -- -- -- -- --

03N07E 2 166 A/R 0.746 1.026 0.774 0.816 0.886 0.956 0.998 1

03S05E 8 416 A/R 0.820 1.026 0.820 0.820 0.841 0.949 1.026 0

03S06E 6 335 A/R 1.103 1.513 1.154 1.250 1.397 1.468 1.500 1

01N07E 11 1656 A-R -117 96 -17 -11 5 25 90 1

01N08E 5 823 A-R -36 59 -20 5 48 48 55 1

01S07E 3 250 A-R -90 -13 -75 -52 -13 -13 -13 0

01S08E 1 97 A-R 90 90 -- -- -- -- -- --

02N06E 3 98 A-R -20 140 -15 -8 4 72 113 1

02N07E 1 28 A-R 42 42 -- -- -- -- -- --

02S04E 1 110 A-R 4 4 -- -- -- -- -- --

02S05E 9 764 A-R -40 157 -30 -28 8 112 156 1

03N05E 3 471 A-R -17 -5 -14 -11 -5 -5 -5 2

03N06E 1 100 A-R 4 4 -- -- -- -- -- --

03N07E 2 166 A-R -39 4 -35 -28 -18 -7 0 1

03S05E 8 416 A-R -30 6 -29 -28 -28 -10 4 1

03S06E 6 335 A-R 23 85 33 49 71 80 83 1

Table X-2. Summary statistics for TOMATOES, PROCESSING management units grouped by specific crop.

SPECIFICCROP N MGMNTUNITS SUM ACRES PARAMETER MIN MAX 10% 25% 50% 75% 90% N

OUTLIE

RS

TOMATOES, PROCESSING 54 5314.79 A/Y 0.001 0.004 0.002 0.002 0.002 0 0 6

A/R 0.485 1.903 0.820 0.923 1.026 1 2 6

A-R -117 156 -29 -16 4 47 90 5


Figure X-2. Scatter plot of A vs. Y for TOMATOES, PROCESSING crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table X-3. List of recommended nitrogen application values for TOMATOES, PROCESSING (in lbs/acre).


Tomatoes, Processing

150 175 For drip-irrigated processing tomatoes, a seasonal rate of approximately 175 lbs N/acre is

adequate to maximize fruit yields in most soils.

Tomatoes, Processing

100 150

Value based on studies of response to N fertilization. In the responsive fields, no significant yield increase with sidedress N application rates above 100 lbs/acre was observed. The total available

N in these fields, which included the pre-sidedress nitrate-N in the top 2 feet of the profile and the sidedress N, averaged 170 lbs/acre.

Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



XI. WALNUTS

Figure XI-1. Box and Whisker plots of A/Y for bearing WALNUTS management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table XI-1. Summary statistics for WALNUTS management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N07E 20 1093 A/Y 0.025 0.068 0.029 0.029 0.036 0.049 0.063 2

01N08E 20 2318 A/Y 0.022 0.170 0.030 0.046 0.059 0.064 0.091 2

01N09E 1 69 A/Y 0.049 0.049 -- -- -- -- -- --

01N10E 2 170 A/Y 0.085 0.120 0.089 0.094 0.103 0.111 0.117 1

01S06E 2 42 A/Y 0.025 0.069 0.029 0.036 0.047 0.058 0.064 1

01S07E 16 801 A/Y 0.000 0.106 0.028 0.031 0.039 0.052 0.077 2

01S08E 18 706 A/Y 0.012 0.197 0.017 0.021 0.040 0.061 0.127 2

01S09E 12 384 A/Y 0.000 0.259 0.003 0.032 0.065 0.193 0.202 2

01S10E 3 74 A/Y 0.045 0.110 0.046 0.047 0.048 0.079 0.098 1

01S11E 1 39 A/Y 0.040 0.040 -- -- -- -- -- --

02N06E 11 343 A/Y 0.000 0.600 0.028 0.059 0.074 0.080 0.115 1

02N07E 134 3665 A/Y 0.000 1785.714 0.000 0.026 0.035 0.050 0.066 14

02N08E 9 639 A/Y 0.026 0.059 0.029 0.030 0.040 0.043 0.052 1

02S05E 1 29 A/Y 0.035 0.035 -- -- -- -- -- --

02S07E 12 443 A/Y 0.000 0.120 0.026 0.027 0.032 0.039 0.044 2

02S08E 9 395 A/Y 0.008 0.150 0.014 0.021 0.030 0.044 0.090 1

02S09E 17 648 A/Y 0.000 0.250 0.000 0.026 0.033 0.040 0.052 2

02S10E 28 709 A/Y 0.026 1.264 0.030 0.036 0.041 0.080 0.187 2

03N06E 1 5 A/Y 0.000 0.000 -- -- -- -- -- --

03N07E 12 597 A/Y 0.021 0.058 0.026 0.028 0.030 0.037 0.041 2



03N08E 1 354 A/Y 0.036 0.036 -- -- -- -- -- --

03S05E 10 568 A/Y 0.023 0.048 0.023 0.030 0.038 0.044 0.046 1

03S06E 6 326 A/Y 0.034 0.058 0.038 0.042 0.046 0.052 0.055 1

03S07E 3 48 A/Y 0.040 0.351 0.041 0.044 0.048 0.199 0.290 1

04N05E 1 280 A/Y 0.330 0.330 -- -- -- -- -- --

04N06E 2 20 A/Y 0.025 0.044 0.027 0.030 0.034 0.039 0.042 1

04N07E 5 576 A/Y 0.012 0.060 0.023 0.038 0.041 0.048 0.055 1

04N08E 13 506 A/Y 0.000 0.070 0.021 0.029 0.033 0.036 0.066 2

05N05E 2 48 A/Y 0.041 0.041 0.041 0.041 0.041 0.041 0.041 1

unknown 2 33 A/Y 0.039 0.094 0.044 0.052 0.066 0.080 0.088 1

01N07E 20 1093 A/R 1.250 3.420 1.435 1.450 1.800 2.425 3.127 2

01N08E 20 2318 A/R 1.125 8.500 1.518 2.280 2.940 3.203 4.547 2

01N09E 1 69 A/R 2.470 2.470 -- -- -- -- -- --

01N10E 2 170 A/R 4.250 6.000 4.425 4.688 5.125 5.562 5.825 1

01S06E 2 42 A/R 1.230 3.428 1.450 1.780 2.329 2.878 3.208 1

01S07E 16 801 A/R 0.000 5.300 1.380 1.564 1.946 2.582 3.836 2

01S08E 18 706 A/R 0.600 9.850 0.838 1.033 1.985 3.046 6.375 2

01S09E 12 384 A/R 1.525 12.960 1.588 2.181 4.171 9.886 10.391 1

01S10E 3 74 A/R 2.250 5.500 2.283 2.332 2.415 3.958 4.883 1

01S11E 1 39 A/R 2.000 2.000 -- -- -- -- -- --

02N06E 11 343 A/R 1.375 30.000 2.388 3.463 3.725 4.088 8.175 1

02N07E 134 3665 A/R 0.000 89285.714 0.584 1.350 1.800 2.500 3.335 12

02N08E 9 639 A/R 1.290 2.930 1.458 1.500 2.000 2.143 2.614 1

02S05E 1 29 A/R 1.760 1.760 -- -- -- -- -- --

02S07E 12 443 A/R 0.000 6.000 1.297 1.351 1.586 1.971 2.212 2

02S08E 9 395 A/R 0.400 7.500 0.680 1.050 1.500 2.198 4.500 1

02S09E 17 648 A/R 0.000 12.500 0.000 1.310 1.665 2.000 2.608 2

02S10E 28 709 A/R 1.300 63.199 1.520 1.775 2.050 3.998 9.343 2

03N07E 12 597 A/R 1.050 2.913 1.303 1.411 1.500 1.873 2.067 2

03N08E 1 354 A/R 1.800 1.800 -- -- -- -- -- --

03S05E 10 568 A/R 1.150 2.419 1.150 1.476 1.913 2.201 2.312 1

03S06E 6 326 A/R 1.688 2.900 1.885 2.083 2.292 2.592 2.761 1

03S07E 3 48 A/R 1.990 17.550 2.069 2.188 2.385 9.968 14.517 1

04N05E 1 280 A/R 16.500 16.500 -- -- -- -- -- --

04N06E 2 20 A/R 1.250 2.188 1.344 1.484 1.719 1.953 2.094 1

04N07E 5 576 A/R 0.625 3.000 1.135 1.900 2.039 2.400 2.760 1

04N08E 13 506 A/R 1.000 3.500 1.268 1.436 1.642 1.956 3.393 2

05N05E 2 48 A/R 2.050 2.050 -- -- -- -- -- --

unknown 2 33 A/R 1.935 4.688 2.210 2.623 3.311 3.999 4.412 1

01N07E 20 1093 A-R 20 170 45 47 72 120 148 2

01N08E 20 2318 A-R 15 211 47 86 123 158 202 2

01N09E 1 69 A-R 85 85 -- -- -- -- -- --

01N10E 2 170 A-R 35 44 36 37 40 42 43 1

01S06E 2 42 A-R 34 61 36 40 47 54 58 1

01S07E 16 801 A-R -94 236 22 54 76 108 141 2

01S08E 18 706 A-R -36 315 -17 5 70 179 251 2

01S09E 12 384 A-R 29 183 35 55 87 130 169 1

01S10E 3 74 A-R 65 164 74 87 108 136 153 1

01S11E 1 39 A-R 40 40 -- -- -- -- -- --

02N06E 11 343 A-R 30 153 60 110 131 150 153 1



02N07E 134 3665 A-R -80 294 -12 40 76 110 146 13

02N08E 9 639 A-R 27 190 45 56 80 102 135 1

02S05E 1 29 A-R 37 37 -- -- -- -- -- --

02S07E 12 443 A-R -74 200 37 52 68 106 115 2

02S08E 9 395 A-R -24 130 -17 6 50 87 114 1

02S09E 17 648 A-R -80 167 -30 39 64 84 137 2

02S10E 28 709 A-R 34 217 47 58 79 108 153 3

03N07E 12 597 A-R 4 197 21 29 38 70 136 2

03N08E 1 354 A-R 80 80 -- -- -- -- -- --

03S05E 10 568 A-R 18 123 18 46 69 79 116 1

03S06E 6 326 A-R 25 172 32 39 65 122 153 1

03S07E 3 48 A-R 7 99 15 27 47 73 89 1

04N05E 1 280 A-R 129 129 -- -- -- -- -- --

04N06E 2 20 A-R 30 57 33 37 44 50 54 1

04N07E 5 576 A-R -15 141 22 78 96 107 127 1

04N08E 13 506 A-R 0 80 30 48 70 77 77 1

05N05E 2 48 A-R 69 69 69 69 69 69 69 1

unknown 2 33 A-R 47 236 66 94 141 189 217 1

Table XI-2. Summary statistics for WALNUTS management units grouped by specific crop.


WALNUTS /YEAR > 4 187 8843.75 A/Y 0.000 0.692 0.021 0.031 0.038 0 0 19

WALNUTS /YEAR 2 5 114.60 A/Y 0.000 0.259 0.007 0.017 0.070 0 0 1

WALNUTS /YEAR 3 6 192.97 A/Y 0.015 0.351 0.018 0.044 0.118 0 0 1

WALNUTS /YEAR 4 8 225.17 A/Y 0.037 0.159 0.038 0.043 0.071 0 0 1

WALNUTS /YEAR NR 168 6552.71 A/Y 0.000 1785.714 0.016 0.028 0.037 0 0 17

WALNUTS /YEAR > 4 187 8843.75 A/R 0.000 34.615 1.113 1.550 1.910 2 3 19

WALNUTS /YEAR 2 5 114.60 A/R 0.000 12.960 0.340 0.850 3.500 10 12 1

WALNUTS /YEAR 3 6 192.97 A/R 0.750 17.550 0.875 2.200 5.900 14 17 1

WALNUTS /YEAR 4 8 225.17 A/R 1.850 7.970 1.910 2.149 3.545 5 7 1

WALNUTS /YEAR NR 168 6552.71 A/R 0.000 89285.714 1.150 1.429 1.950 3 5 16

WALNUTS /YEAR > 4 187 8843.75 A-R -80 236 16 50 78 115 159 19

WALNUTS /YEAR 2 5 114.60 A-R -5 70 -4 -3 29 36 56 1

WALNUTS /YEAR 3 6 192.97 A-R -15 200 -7 12 48 153 194 1

WALNUTS /YEAR 4 8 225.17 A-R 35 140 43 53 71 100 121 1

WALNUTS /YEAR NR 168 6552.71 A-R -94 315 13 40 68 114 150 16


Figure XI-2. Scatter plot of A vs. Y for WALNUTS crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table XI-3. List of recommended nitrogen application values for WALNUTS (in lbs/acre).


Walnuts /Year 1 10 20 Nitrogen application rates for young walnut trees. The lower rates refer to fertile

soils and when the N is applied through the drip or microsprinkler irrigation system. On fertile soils, N fertilization can be reduced or even omitted during the first year or

two.

Walnuts /Year 2 25 50




Walnuts /Year > 5 169 Value for fertigation. N application rates dependent on Yield. This value is for 2.5

tons (5000 lbs) of projected yield.

Walnuts /Year > 5 214 Value for split broadcast. N application rates dependent on Yield. This value is for

2.5 tons (5000 lbs) of projected yield. Source: CDFA- https://www.cdfa.ca.gov/is/ffldrs/frep/



XII. WHEAT, IRRIGATED

Figure XII-1. Box and Whisker plots of A/Y for bearing WHEAT, IRRIGATED management units grouped by TR blocks. Numbers at the bottom indicate the number of management units within each TR. The width of the box is proportional to the sample size. Horizontal grey dashed lines represent the 10%, 50% (median), and 90% percentiles for all TRs together. Red dots highlight local outliers (A/Y > 90% percentile within each TR).

Table XII-1. Summary statistics for WHEAT, IRRIGATED management units grouped by TR blocks. TR blocks with only one management unit (Count = 1) have no summary statistics because a range of values is necessary to estimate percentiles. Management units that split across multiple TR blocks are assigned to the TR that contains the largest portion of the Management Unit acreage.


01N06E 2 115 A/Y 0.009 0.019 0.010 0.012 0.014 0.016 0.018 1

01N07E 3 130 A/Y 0.000 0.017 0.003 0.008 0.017 0.017 0.017 0

01N08E 2 192 A/Y 0.021 0.038 0.023 0.025 0.029 0.034 0.036 1

01S06E 6 144 A/Y 0.020 0.050 0.028 0.037 0.037 0.037 0.043 1

01S07E 2 155 A/Y 0.024 0.024 -- -- -- -- -- --

01S08E 4 326 A/Y 0.000 0.037 0.000 0.000 0.000 0.009 0.026 1

02N06E 1 4 A/Y 0.017 0.017 -- -- -- -- -- --

02N07E 2 83 A/Y 0.000 0.000 -- -- -- -- -- --

02S05E 1 80 A/Y 0.013 0.013 -- -- -- -- -- --

03S05E 1 45 A/Y 0.008 0.008 -- -- -- -- -- --

03S06E 1 87 A/Y 0.010 0.010 -- -- -- -- -- --

Table XII-2. Summary statistics for WHEAT, IRRIGATED management units grouped by specific crop.


WHEAT, IRRIGATED 25 1361.07 A/Y 0 0.05 0 0.008 0.017 0 0 3


Figure XII-2. Scatter plot of A vs. Y for WHEAT, IRRIGATED crops with all TR together. Each dot represents one management unit. Red dots represent regional outliers (A/Y > 90% for all TR together). Blue lines represent Recommended N application rates as described in the Table below.

Table XII-3. List of recommended nitrogen application values for WHEAT, IRRIGATED (in lbs/acre).


Wheat 150 200

Recent studies found that 4 to 4.6 tons /acre can be produced with a total N application of 150-200 lbs N/acre in fields where the residual soil nitrate N in the top foot of the profile ranged from 30-80

lbs N/acre at planting. When well water is used for irrigation, the N in the water needs also be taken into account. Wheat does generally not require more than 40-60 lbs N/acre before spring, which

includes residual nitrate-N in the root zone. Source: CDFA - https://www.cdfa.ca.gov/is/ffldrs/frep/



XIII. OTHER CROPS

Table XIII-1. Summary statistics for crops with limited representation in the SJCDWQC region. Crops with only one management unit with complete data (Count = 1) or more than one management units with identical values, have no summary statistics because a range of values is necessary to estimate percentiles.

A/Y

SPECIFICCROP N MGMNT

UNITS SUM

ACRES MIN MAX 10% 25% 50% 75% 90%

N

OUTLIERS

APPLES, STANDARD SIZE /YEAR > 4

4 143 0.000 0.002 0.000 0.000 0.000 0.000 0 1

APRICOTS /YEAR > 4 2 67 0.000 0.000 -- -- -- -- -- --

APRICOTS /YEAR NR 1 124 0.001 0.001 -- -- -- -- -- --

ASPARAGUS /YEAR > 3 2 52 0.000 0.015 0.001 0.004 0.007 0.011 0 1

BARLEY, IRRIGATED 1 85 0.030 0.030 -- -- -- -- -- --

BASIL 2 63 0.008 0.020 0.009 0.011 0.014 0.017 0 1

BEANS, BLACK EYED 5 111 0.018 0.064 0.019 0.020 0.064 0.064 0 0

BEANS, DRY EDIBLE 6 260 0.000 0.091 0.011 0.029 0.051 0.051 0 1

BEANS, GARBANZO 1 91 0.000 0.000 -- -- -- -- -- --

BEANS, GREEN 4 10 0.000 0.167 0.000 0.000 0.030 0.087 0 1

BEANS, LIMA 6 442 0.000 0.073 0.010 0.024 0.040 0.048 0 1

BEANS, SNAP 1 5 0.167 0.167 -- -- -- -- -- --

BEETS 3 2 0.000 0.014 0.000 0.000 0.000 0.007 0 1

BERRY, BLUEBERRY /YEAR > 3 2 16 0.010 0.010 -- -- -- -- -- --

BERRY, BLUEBERRY /YEAR NR 2 46 0.006 0.012 0.007 0.007 0.009 0.010 0 1

BERRY, BOYSENBERRY /YEAR NR

1 8 0.500 0.500 -- -- -- -- -- --

BERRY, RASPBERRIES /YEAR NR

1 2 0.237 0.237 -- -- -- -- -- --

BOK CHOY 1 0 0.000 0.000 -- -- -- -- -- --

BROCCOLI 1 1 0.011 0.011 -- -- -- -- -- --

CABBAGE 1 2 0.011 0.011 -- -- -- -- -- --

CARROT 3 129 0.000 0.030 0.001 0.003 0.007 0.018 0 1

CELERY /YEAR NR 1 0 0.000 0.000 -- -- -- -- -- --

CHARD, GREEN 2 1 0.000 0.000 -- -- -- -- -- --

CORN, NR1 21 1999 0.000 0.025 0.002 0.002 0.003 0.005 0 2

COTTON 3 168 0.120 0.129 0.120 0.120 0.120 0.124 0 1

CUCUMBERS 3 370 0.005 0.050 0.006 0.009 0.013 0.031 0 1

EGGPLANT 2 4 0.011 0.167 0.026 0.050 0.089 0.128 0 1

GARLIC 4 9 0.000 0.420 0.003 0.008 0.016 0.121 0 1

GRAPES, RAISINS /YEAR NR 1 61 0.000 0.000 -- -- -- -- -- --

HAY, TAME, (EXCL ALFALFA & SMALL GRAIN)

9 264 0.000 0.065 0.000 0.000 0.003 0.011 0 1

HAYLAGE, (EXCL ALFALFA) 5 236 0.002 0.006 0.002 0.002 0.004 0.006 0 0

HAYLAGE, ALFALFA 1 76 0.001 0.001 -- -- -- -- -- --

HERBS, FRESH CUT 3 91 0.000 1.095 0.002 0.006 0.012 0.553 1 1

JUJUBE /YEAR NR 1 2 0.004 0.004 -- -- -- -- -- --

KALE 2 1 0.000 0.022 0.002 0.005 0.011 0.016 0 1

KIWIFRUIT /YEAR > 4 1 8 0.006 0.006 -- -- -- -- -- --

1 NR = Crop age Not Reported or Crop type Not Specified. Crop types labeled as NR are not included in the previous sections as they may

contain different harvest types with different range of yields and A/Y.



UNITS SUM

ACRES MIN MAX 10% 25% 50% 75% 90%

N

OUTLIERS

KIWIFRUIT /YEAR NR 2 34 0.000 0.005 0.001 0.001 0.003 0.004 0 1

LEEKS 1 0 0.000 0.000 -- -- -- -- -- --

MELONS, CANTALOUP 3 104 0.002 0.012 0.002 0.002 0.003 0.008 0 1

MELONS, WATERMELON 6 559 0.000 0.050 0.001 0.001 0.002 0.002 0 1

MUSTARD, GREENS 1 0 0.000 0.000 -- -- -- -- -- --

OATS, BALED 5 138 0.000 0.004 0.000 0.000 0.001 0.001 0 1

OATS, NR1 18 857 0.000 0.075 0.000 0.000 0.009 0.015 0 2

OATS, SILAGE 4 844 0.000 0.005 0.001 0.003 0.004 0.005 0 1

ONIONS, DRY 4 214 0.000 0.100 0.001 0.002 0.004 0.029 0 1

ONIONS, GREEN 1 157 0.006 0.006 -- -- -- -- -- --

PARSLEY 2 38 0.000 0.017 0.002 0.004 0.009 0.013 0 1

PEACHES, FRESH MARKET /YEAR > 4

5 66 0.000 0.025 0.000 0.001 0.002 0.010 0 1

PEACHES, FRESH MARKET /YEAR NR

4 102 0.000 0.005 0.001 0.001 0.003 0.005 0 0

PEACHES, PROCESSING /YEAR > 4

8 216 0.001 0.004 0.002 0.002 0.002 0.003 0 1

PEAS, CHINESE (SUGAR & SNOW)

3 10 0.000 0.100 0.000 0.000 0.000 0.050 0 1

PECANS /YEAR NR 1 3 0.000 0.000 -- -- -- -- -- --

PEPPERS, BELL 5 27 0.000 0.200 0.000 0.000 0.017 0.020 0 1

PEPPERS, CHILE 1 0 0.000 0.000 -- -- -- -- -- --

PERSIMMONS /YEAR NR 4 20 0.000 0.007 0.000 0.000 0.000 0.002 0 1

PISTACHIOS /YEAR > 4 1 10 0.074 0.074 -- -- -- -- -- --

PLUMS /YEAR > 4 1 2 0.000 0.000 -- -- -- -- -- --

POMEGRANATES /YEAR > 4 1 1 0.004 0.004 -- -- -- -- -- --

POMEGRANATES /YEAR 3 1 12 0.000 0.000 -- -- -- -- -- --

POTATOES 1 2 0.006 0.006 -- -- -- -- -- --

PUMPKINS 7 1259 0.003 0.003 0.003 0.003 0.003 0.003 0 0

RADISHES 1 0 0.000 0.000 -- -- -- -- -- --

RICE 2 178 0.018 0.024 0.018 0.019 0.021 0.022 0 1

RYE, GRAIN 1 19 0.000 0.000 -- -- -- -- -- --

SAFFLOWER 5 396 0.000 0.030 0.004 0.010 0.010 0.025 0 1

SPINACH 1 0 0.000 0.000 -- -- -- -- -- --

SQUASH 2 65 0.004 0.017 0.005 0.007 0.011 0.014 0 1

SQUASH, SUMMER 3 89 0.000 0.010 0.001 0.002 0.004 0.007 0 1

STRAWBERRIES 10 188 0.000 0.095 0.002 0.005 0.018 0.055 0 1

SWEET POTATOES 2 30 0.000 0.125 0.013 0.031 0.062 0.094 0 1

TOMATOES, FRESH MARKET 8 443 0.000 0.009 0.000 0.001 0.006 0.007 0 1

TOMATOES, NR 1 51 3070 0.001 0.143 0.002 0.002 0.002 0.002 0 5

TRITICALE, IRRIGATED 4 301 0.004 0.025 0.009 0.016 0.020 0.022 0 1

TURNIPS 1 0 0.000 0.000 -- -- -- -- -- --

WATERCRESS /YEAR > 4 1 78 0.058 0.058 -- -- -- -- -- --

ZUCCHINI 4 28 0.000 0.125 0.009 0.022 0.065 0.106 0 1

A/R


UNITS SUM

ACRES MIN MAX 10% 25% 50% 75% 90%

N

OUTLIERS

BARLEY, IRRIGATED 1 85 1.6 1.6 -- -- -- -- -- --

BERRY, BLUEBERRY /YEAR > 3 2 16 7.7 7.7 -- -- -- -- -- --

BERRY, BLUEBERRY /YEAR NR 2 46 4.5 9.2 5.0 5.7 6.9 8.1 9.0 1



UNITS SUM

ACRES MIN MAX 10% 25% 50% 75% 90%

N

OUTLIERS


1 8 384.6 384.6 -- -- -- -- -- --


1 2 182.3 182.3 -- -- -- -- -- --

BROCCOLI 1 1 2.0 2.0 -- -- -- -- -- --

CHARD, GREEN 2 1 0.0 0.0 -- -- -- -- -- --

COTTON 3 168 5.1 5.5 5.1 5.1 5.1 5.3 5.0 1

KALE 2 1 8.6 8.6 -- -- -- -- -- --

PISTACHIOS /YEAR > 4 1 10 0.6 0.6 -- -- -- -- -- --

STRAWBERRIES 10 188 1.6 73.1 2.4 6.4 15.4 48.5 61.0 1

TOMATOES, FRESH MARKET 8 443 1.0 4.4 2.0 3.0 3.3 3.8 4.0 1

TOMATOES, NR 1 51 3070 0.5 73.2 0.8 0.9 1.1 1.3 2.0 5

A-R


UNITS SUM

ACRES MIN MAX 10% 25% 50% 75% 90%

N

OUTLIERS

BARLEY, IRRIGATED 1 85 60 60 -- -- -- -- -- --

BERRY, BLUEBERRY /YEAR > 3 2 16 52 52 -- -- -- -- -- --

BERRY, BLUEBERRY /YEAR NR 2 46 46 54 47 48 50 52 53 1


1 8 50 50 -- -- -- -- -- --


1 2 113 113 -- -- -- -- -- --

BROCCOLI 1 1 21 21 -- -- -- -- -- --

CHARD, GREEN 2 1 -2 -2 -- -- -- -- -- --

COTTON 3 168 121 123 121 121 121 122 122 1

KALE 2 1 38 38 -- -- -- -- -- --

PISTACHIOS /YEAR > 4 1 10 -151 -151 -- -- -- -- -- --

STRAWBERRIES 10 188 19 171 33 55 112 122 170 1

TOMATOES, FRESH MARKET 8 443 -7 175 58 130 152 163 171 1

TOMATOES, NR 1 51 3070 -109 173 -44 -15 17 55 88 3

APPENDIX II

NMP OUTREACH PACKET SAMPLE

SJCDWQC 2017 NMP Summary Report, Appendix II 1 | P a g e

TABLE OF CONTENTS

NMP Outreach Packet Sample ...................................................................................................................... 2


NMP OUTREACH PACKET SAMPLE

nitrogen management plan summary report analysis...received - complete yes 1,417 132,945 received -...

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