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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
4
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
5
How does container productionfit in the worksheet?
6
# 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
7
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.
8
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 +
+
=
`
9
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”.
`
`
10
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
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
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
13
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
14
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
15
Bed construction
16
Finished beds
17
Runoff water monitoring
18
Substrate
• 80% Fir bark• 20% Sand • 13 lbs/yd 15-9-12 Osmocote Plus • 10 lbs/yd 9-2-0 Apex custom• 6.5 lbs/yd Dolomite
19
Top dress fertilizer
20
Planting
21
Gas sampling
22
Gas sampling
23
End of experiment
24
Harvest
25
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%
26
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
27
Next steps
Examine management methods to reduce N20 emissions• Soil moisture management
• Timing N applications
28
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
29
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
30
Photo: L.Oki
Thank youlroki@ucdavis.edu
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.
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