Nitrogen Management Plans€¦ · Gas sampling 22. N2 makes of 72% of atmosphere so is difficult to measure.\爀匀漀 一㈀伀 椀猀 洀攀愀猀甀爀攀搀⸀ 吀栀椀猀 椀猀
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Nitrogen Management Plans In Nursery Production Bruno J.L. Pitton and Lorence R. Oki Department of Plant Sciences University of California, Davis Cultivate ‘19 Columbus, OH July 14, 2019
Nitrogen Management Plans In Nursery ProductionBruno J.L. Pitton and Lorence R. Oki
Department of Plant SciencesUniversity of California, Davis
Cultivate ‘19Columbus, OHJuly 14, 2019
Why Nitrogen Management Plans?• Ground water contamination in
the Central Valley of California• ‘Blue Baby’ syndrome
• Max level = 45 ppm NO3-
• 54% of NO3- from synthetic
fertilizers • 34% of applied N ends up in
harvested products• In ornamentals, 28% of applied N
is taken up by plants• Problem likely to continue for
decades• Harter and Lund recommend a tax
on nitrogen fertilizer
97% from Cropland
Harter, T. & Lund, J. 2012 Addressing Nitrate in California’s Drinking Water: Executive Summary
Nitrate sources to groundwater in the Tulare Lake Basin and Salinas
Valley study areas
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Presenter
Presentation Notes
Depends on total applied, better efficiency with lower use rates
Nitrogen management plans• California has 9
regional water boards• Plans are required from
all growers within Central Valley Regional Water Quality Control Board watersheds
• Certification required in high-vulnerability groundwater areas
• Determined by Groundwater Quality Assessment Reports
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How does container productionfit in the worksheet?
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Presenter
Presentation Notes
Use subtraction to determine how potential N that can leach into groundwater,
# of production units grown or sold
How much N removed with product?
Total production units grown or sold
N fertilizer not applied as lbs/ac
Based on UCCE, CDFA, Consultants, etc.
Container plants
Plant type (herb,woody, annual) & container size
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Presenter
Presentation Notes
# of production units grown = if they don’t sell, do you count them as yield? Each container should have it’s own N management plan
N in container media
Liquid feed, CRF, top dress
Organic fertilizers
Sum of above
Foliar N
Box 24 + 25
Sum of all N applied
Well, surface, recycled, etc.
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Presenter
Presentation Notes
Credits aren’t really credits in nursery production, more like application
122144
266
267.1
1.1
0
0
1.1
267.1267.1
12.5
Cont. ornamentalsEachVarious
+
=
+
=
Difficult to Determine
Type of crop is container ornamentals. When product is sold, soil goes with plants. Due to various container sizes, difficult to determine “yield/acre”.
500 +
+
=
`
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Presenter
Presentation Notes
Use subtraction to determine how potential N that can leach into groundwater. N recommended from ANR publication.
122144
266
267.1
1.1
0
0
1.1
267.1267.1
12.5
Cont. ornamentalsEachVarious
Difficult to Determine
Type of crop is container ornamentals. When product is sold, soil goes with plants. Due to various container sizes, difficult to determine “yield/acre”.
`
`
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Presenter
Presentation Notes
I went in search of red box info, including how much N is in the plants. Use subtraction to determine how potential N that can leach into groundwater,
Cabrera 2003• N balance of plant and container
• N applied, leached, in plant, and in soilless media
• Evaluated two woody species from Aug to May including overwintering in Mid Atlantic
Ilex opaca1 gal cont
69,92960 ppm
1
69,929162100 62 unutilized
Lagerstroemia1 gal cont
69,92960 ppm
1
69,929230167 63 unutilized
38% unaccounted 27% unaccounted11
Presenter
Presentation Notes
Overwintering is common in northeastern US, very different from California, May affect N utilization and retention in container. Calculated total N applied for a single 1 gal., then extrapolated to per acre. Used Raul’s % N in uptake and remaining in substrate from article to calculate “N removed” I chose the N rate that was applicable based on Richard’s experiments to determine liquid feed conc for ornamentals.
Narvaez et al. 2012 & 2013• N balance of plant and container
• N applied, leached, in plant, and in soilless media
• Evaluated one woody (May to Dec) and one herbaceous species (May to July)
Viburnum tinus
1.25 gal cont69,93057.4 ppm
1
69,930493330 163 unutilized
Osteospurmum1 gal cont
87,412120 ppm
1
87,4121,4261,127 299 unutilized
33% unaccounted 21% unaccounted12
Presenter
Presentation Notes
Can tight per 1 acre Extrapolated amount of N applied by researcher to plant (Total N applied) and remaining in substrate and plant at end of experiment (N removed)
Where does unutilized N go?
• Some N loss through leaching• How much is lost through
denitrification (N2 or N2O gas)?• Container substrate• Soil below growing bed
• How much N leaves nursery at sale?
• N utilized by plant• N left in container substrate NO3
-
N2N2O
N2ON2
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Research Objectives
• Develop system nitrogen balance for container plant production
• Document N amounts• Applied• Leached • Utilized by plant• In substrate• Emitted as N2 or N2O gas
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N mass balance experiment
• Installed two bed styles at cooperator nursery & collected runoff• Unlined (typical) bed, gravel over soil, 40 × 15• Poly-lined
• Plant up Lagerstroemia indica ‘Dynamite’, #5• Determine total N in plants and media at start of experiment• Applied N in CRF and top dress
• Monitor runoff water (volume and N conc)• Collect gas samples to estimate N in gas emissions
(as N2 and N20)• Determine N in plant and substrate at harvest
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Bed construction
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Presenter
Presentation Notes
40’ x 15’ beds Weed barrier fabric – polyethylene sheeting – fabric �Bender board at perimeter to retain water within bed
Finished beds
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Presentation Notes
8 beds total �4 lined, 4 unlined Irrigation boxes hold pumps and flow meters. Pumps move water from sumps through meter to drainage canal
Runoff water monitoring
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Presentation Notes
Buried drum as a sump to collect runoff water. Float switch turns on pump to move water through flow meter. Flow meter is connected to data logger to record water volumes. Water from sumps goes through poly tubing that allows collection of water samples every week. N concentration determined and with flow volumes, the total amount of N in the runoff.
Substrate is 80% fir bark and 20% sand�Added fertilizers are Osmocote Plus, a custom blended sulfur-coated urea, and dolomite Photo shows fertilizers being added to the substrate prior to canning
Top dress fertilizer
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Presentation Notes
Top dress is added 3 days after canning. Photo was taken approximately a week after top dressing was applied.
Planting
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Presentation Notes
Shift from 1 gallon to 5’s Hand planted about 300 to allow for gas sampling apparatus. Plants had to be located off-center in the can. Total of about 1300 plants in the experiment. Most plants were planted using the grower’s planting line conveyor belt system. Hand-planted containers marked with tape and mixed with belt planted ones so that the test plants were randomly placed in the beds among the non-test plants.
Gas sampling
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Presenter
Presentation Notes
N2 makes of 72% of atmosphere so is difficult to measure. So N2O is measured. This is done by capturing gas samples. An “anchor” made of a 4” section of 4” PVC is pounded into the soil. N2O is converted to N2 by an enzyme in the soil. Acetylene inhibits this conversion. Water saturated with acetylene is added to the soil within the anchor (left pane). Wait 2.5 – 3 hours. Measure T in bed and collect gas samples. In containers, measure T and VWC. Chamber installed shows insulation to reduce T fluctuations and vent to eliminate pressure changes as gas sample is removed from chamber.
Gas sampling
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Presenter
Presentation Notes
In order to document dinitrogen emissions, we need to measure nitrous oxide. Acetylene injected into substrate in container. Left photo shows device used to make actetylene and distribute it to two perorated stainless steel tubes inserted into the container substrate. The red balloon contains water and calcium carbide which, when mixed together, produces acetylene gas. The balloon swells, the valve is opened to allow gas to fill pore space in the substrate. Aiming for a concentration of 1-10 %. Wait 2.5 to 3 hours, take T and VWC measurements. Collect 20 mL gas sample using syringe. Sample is transferred to storage vial. A number of samples are collected to be able to determine gas flux which is the mass of nitrogen per area per day.
End of experiment
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Presentation Notes
Collected samples weekly over a period of 13 weeks. When plants were ready for sale, the experiment ended.
Harvest
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Presentation Notes
Root ball at harvest. Detmn N amount in soil. Break up root ball and soil collect sample for analysis. Stems and leaves collected dried and ground. Samples sent to lab for analyses.
What we found
Use analytical results to estimate N amounts:
• In plant• Remaining in substrate• In runoff water• Leached into bed soils• Lost from denitrification
• N2O-N ~1.5%
~5%~55%~6%<4%~30%
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Presenter
Presentation Notes
From the results of the analyses we can estimate for each bed, the total amount of N: Applied Taken up by the plant Remaining in the substrate at harvest The total of the amount in the plant and substrate is the total amount harvested Lost from denitrification as N2 and N2O Lost in runoff water And leached into the soils beneath the beds from the difference between the amount of N in the runoff from unlined vs. lined beds. This is the amount that could potentially enter groundwater.
What we found
Greenhouse gas emissions• Methane: negligible• CO2-C: ~470 mg m-2 h-1
• N2O-N: 3.6 mg m-2 h-1
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Presenter
Presentation Notes
From the results of the analyses we can estimate for each bed, the total amount of N: Applied Taken up by the plant Remaining in the substrate at harvest The total of the amount in the plant and substrate is the total amount harvested Lost from denitrification as N2 and N2O Lost in runoff water And leached into the soils beneath the beds from the difference between the amount of N in the runoff from unlined vs. lined beds. This is the amount that could potentially enter groundwater.
Next steps
Examine management methods to reduce N20 emissions• Soil moisture management
• Timing N applications
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Presenter
Presentation Notes
From the results of the analyses we can estimate for each bed, the total amount of N: Applied Taken up by the plant Remaining in the substrate at harvest The total of the amount in the plant and substrate is the total amount harvested Lost from denitrification as N2 and N2O Lost in runoff water And leached into the soils beneath the beds from the difference between the amount of N in the runoff from unlined vs. lined beds. This is the amount that could potentially enter groundwater.
What can we do with this information?• Identify environmentally harmful discharges
and develop mitigation strategies• Inform growers about BMPs to improve NUE • Inform Water Boards in development of next
generation nursery specific NMPs
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Presenter
Presentation Notes
Identify where potentially environmentally harmful losses may be occurring�Develop mitigation strategies to reduce those losses Inform growers of management practices that can minimize N losses, improve N use efficiency, and potentially reduce fertilizer inputs Inform water boards in the development of more accurate tracking of the fate of applied N in fertilizers. Currently there is a draft of a plan proposed by the East San Joaquin Water Quality Coalition Control Board that is open for public comment. Go to UCNFA.UCANR.EDU for the link.
Acknowledgements
• Jared Sisneroz• Xia Zhu-Barker• Pauline Fadakaran• Galen Wolf• Richard Evans• Will Horwath• Perry Laboratory• Funding provided by HRI,
CANGC, CDFA-SCBGP, CDFA-FREP
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Presenter
Presentation Notes
Jared was helpful in setting up the experiment and collecting samples and data Xia provided advice on gas sample collection and GC operation and conducting analyses Pauline undergraduate student who did all of the plant grinding Galen assisted with the electrical equipment set up RE and WH are faculty advisors of Bruno�Perry Labs conducting the substrate, plant and water analyses Funding to support his project has been provided by the Horticultural Research Institute, California Association of Nurseries and Garden Centers, the CDFA Specialty Crops Block Grant Program and the CDFA Fertilizer Research and Education Program
Cabrera, R.I. (2003) Nitrogen balance for two container-grown woody ornamental plants. Scientia Horticulturae 97(3-4), 297-308. https://doi.org/10.1016/S0304-4238(02)00151-6
Cregg, B., Rios, C., Hart, J. and Briggs, D. (2004) Fate of nitrates in field nursery production systems. atmosphere 10, 50.
Dumroese, R.K. and Wenny, D.L. (1991) Developing a nitrogen-balance sheet for a container nursery. Proceedings, Intermountain Forest Nursery Association / 211, 34-38.
Evans, R.Y. and L.L. Dodge. 2007. Determination of nursery crops yields, nutrient content, and water use for improvement of water and fertilizer use efficiency. Final Report. Ca;lifornia Department of Food and Agriculture Fertilizer Research and Education Program. https://www.cdfa.ca.gov/is/ffldrs/frep/pdfs/completedprojects/02-0651Evans2007.pdf
He, F.F., Chen, Q., Jiang, R.F., Chen, X.P. and Zhang, F.S. (2007) Yield and nitrogen balance of greenhouse tomato (Lycopersicum esculentum Mill.) with conventional and site-specific nitrogen management in northern China. Nutrient Cycling in Agroecosystems 77(1), 1-14.
Lea-Cox, J.D., Ross, D.S. and Teffeau, K.M. (2001) A water and nutrient management planning process for container nursery and greenhouse production systems in Maryland. Journal of Environmental Horticulture 19(4), 230-236. https://hrijournal.org/doi/abs/10.24266/0738-2898-19.4.230
Min, J., Zhao, X., Shi, W.M., Xing, G.X. and Zhu, Z.L. (2011) Nitrogen Balance and Loss in a Greenhouse Vegetable System in Southeastern China. Pedosphere 21(4), 464-472.
Narvaez, L., Caceres, R. and Marfa, O. (2012) Effects of climate and fertilization strategy on nitrogen balance in an outdoor potted crop of Viburnum tinus L. Spanish Journal of Agricultural Research 10(2), 471-481. DOI: 10.5424/sjar/2012102-238-11
Narvaez, L., Caceres, R. and Marfa, O. (2013) Effect of different fertilization strategies on nitrogen balance in an outdoor potted crop of Osteospermum ecklonis (DC.) Norl. 'Purple Red' under Mediterranean climate conditions. Spanish Journal of Agricultural Research 11(3), 833-841. DOI: 10.5424/sjar/2013113-3764
Stewart, J.A., Lund, L.J. and Branson, R.L. (1981) Nitrogen balances for container-grown privet. Journal of the American Society for Horticultural Science 106(5), 565-569.
