Crop choice and irrigation technology decisions: what are the future regional

hydrological impacts?

Michael Brady and Jon YoderBioearth Integration Seminar

Research Questions/Ideas

• How do previous decisions constrain changes in crop and irrigation technologies?

• What is the impact of changes in cropping patterns on consumptive use via irrigation technology?

• What is the impact of increased water scarcity on crop choice?

• Forecast 10, 20, or 30 years ahead the effect of changes in food market conditions (e.g. prices, trade) on water scarcity in the Yakima Basin.

Prob[Crop|Irrig]

Center Pivot

Alfalfa

Potatoes

Drip

Orchard

Vineyard

Prob[Irrig|Crop]

Alfalfa

Center Pivot

Wheel Line

OrchardDrip

Sprinkler

Direction of effect goes both ways

• More rapid crop change may increase consumptive use because it allows producers to change their irrigation delivery system (technology). – Relative Crop PricesCrop Change Irrigation

ChangeIncrease Consumptive Use

• Increased water scarcity increases the return from investing in more efficient irrigation systems and less water intensive crops.– Less WaterIncrease Consumptive UseIrrigation

ChangeCrop Change (perhaps)

Previous Research• A lot of work done in California, but also in the Great Plains (fewer crop choices).

• Aggregate data:– Higher water cost increases the likelihood of adopting more efficient irrigation technology (Caswell and

Zilberman, 1985).– Land quality influences technology choice to a greater extent than water cost (Negri and Brooks, 1990).

• Field-level, single cross-section:– Assuming technology choice is conditional on crop choice, Green and Sunding (1997) find that the relative

influence of land quality and water cost varies by perennial crop type.

• Field-level, panel data set:– Moreno and Sunding (2005) estimate a model that allows them to drop the sequential assumption. Results

point towards financial drivers for increased water use efficiency as the dominant factor. – Kandouri et al. (2006) introduce uncertainty over water availability in drought years into decision making.

Studying farmers in Crete, find that risk management is important factor influencing irrigation technology choice.

• **I have not found an example of an empirical economic analysis linked with an engineering model to forecast basin-wide hydrological impacts of increased consumptive use driven by economic factors (relative profitability of each crop and return on investment in more efficient irrigation system).

Construction of field-level panel data set for the Yakima Basin from 2007 to 2011 using the WSDA data

Cowlitz

Palouse

Lewis

Lower Crab

Lower Yakima

Soleduc

KettleNooksack

Pe

nd O

reill

e

Upper Crab-Wilson

Esquatzel CouleeUpper Chehalis

Queets-Quinault

Puyallup-White

San Juan

Lower Spokane

Elwha-Dungeness

Lower Snake

Grand Coulee

Stillaguamish

Alkali-Squilchuck

Middle Lake Roosevelt

Little Spokane

Hangman

Wind-White Salmon

Quilcene-Snow

Cedar-Sammamish

Duwamish-Green

Lower Skagit / Samish

Grays/Elochoman

Deschutes

Skokomish-Dosewallips

Upper Lake Roosevelt

Salmon-Washougal

Lower Lake Roosevelt

Nespelem

Middle Spokane

Kennedy-Goldsborough

Fields sampled by year

2011 2010

20092008

2007

Irrigated LCC (1=most fertile)

1

2

3

4

5

6

7

NRCS Irrigated Land Classifications

Year t+1 Field Boundary (red)

Year t Field Boundary (black)

Year t+1 Field Centroid (red)

Panel is created by spatially joining points in year t+1 with polygons in year t because field boundaries change over time.

Total Acres % by crop group Center pivot Drip Rill Sprinkler Wheel lineCereal Grain 49,899 20% 25% 0% 59% 1% 14%Hay/Silage 41,396 16% 33% 0% 7% 11% 49%Herb 33,584 13% 0% 61% 29% 1% 9%Orchard 73,808 29% 0% 7% 2% 92% 0%Vegetable 12,830 5% 27% 9% 52% 3% 10%Vineyard 40,668 16% 0% 37% 29% 35% 0%% by technology 12% 16% 24% 35% 13%

Total Acres % by crop group Center pivot Drip Rill Sprinkler Wheel lineCereal Grain 66,501 23% 36% 2% 47% 2% 13%Hay/Silage 40,564 14% 37% 0% 5% 12% 45%Herb 37,920 13% 2% 74% 16% 0% 9%Orchard 67,332 23% 0% 7% 1% 92% 0%Vegetable 11,372 4% 26% 22% 40% 3% 9%Vineyard 38,598 13% 0% 45% 16% 39% 0%% by technology 16% 20% 19% 32% 12%

Irrigation acreage share by crop group and irrigation technology for 2007

Irrigation acreage share by crop group and irrigation technology for 2011

• For perennials, increase in vineyards and decrease in orchards.• Much greater share of cereal grains irrigated by center pivot and less using rill. • Orchard irrigation stayed the sum, BUT orchard acreage shrank.• Greater share of vineyards irrigated by drip versus sprinkler because new

ground was planted in vineyards.

Irrigation technology

Crop Group Same Different Total

Same 9,435 699 10,134

71% 5%

Different 2,461 669 3,130

19% 5%

Total 11,896 1,368 13,264

Crop group and irrigation technology adoption by observation (field, not area).

• 13,264 observations is the number of fields that were resampled from 2008 to 2011 where 2007 is the first year with data.

• Almost 30% changed either crop or technology.

• As expected, change in cropping more common than irrigation.

• 10% change in irrigation which could be significant over time.

Irrigation technology transitions

  Transitioned into          

Transitioned out of Center pivot Drip Rill Sprinkler Wheel Line Total

Center pivot 842 4 16 7 10 879

Drip 8 1,878 58 74 12 2,030

Rill 68 231 2,518 191 95 3,103

Sprinkler 13 196 100 5,455 71 5,835

Wheel Line 37 57 67 53 1,203 1,417

Total 968 2,366 2,759 5,780 1,391 13,264

Net change 89 336 -344 -55 -26

Net change in crop group and irrigation technology combinations (positive changes in red).

Center pivot Drip Rill Sprinkler Wheel line

Cereal Grain 106 24 21 6 16

Hay/Silage 16 0 -48 -30 -83

Herb 5 203 -80 -1 12

Orchard 0 13 2 -227 -2

Vegetable -26 31 -79 9 -8

Vineyard 1 64 -153 29 2

Cereal Grain Hay/Silage Herb Hops Mint Non-Crop Orchard Unknown Vegetable Vineyard0

1,000

2,000

3,000

4,000

5,000

6,000

Annual Change in Crop Group/Irrigation Technology

diff/diff diff/same

same/diff same/same

Original Crop Group

Obs

erva

tions

Cereal

Grain

Hay/Si

lage

Herb HopsMint

Non-Crop

Orchard

Unknown

Vegeta

ble

Vineyard

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Annual % Change in Crop Group and Irrigation Technology

diff/diff

diff/same

same/diff

same/same

Original Crop Group

Moving forward...

• Finish empirical economic analysis of historical data (possibly one paper). – Estimate influence of crop prices, growing conditions,

and other factors on choice.

• Forecast basin-wide hydrological impacts of future changes in cropping and irrigation technology (integrated economics-CropSyst/VIC). – Forecast future crop/irrigation pattern as a function of

future prices and water scarcity.