Effect of temperature and manure placement in a snowpack on nutrient release from dairy manure during snowmelt

Authors: Vadas, Peter; STOCK, MELANIE - University Of Wisconsin; Feyereisen, Gary; ARRIAGA, FRANCISCO - University Of Wisconsin; GOOD, LAURA - University Of Wisconsin; KARTHIKEYAN, K. - University Of Wisconsin

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2018
Publication Date: 7/2/2018
Publication URL: https://handle.nal.usda.gov/10113/6743204
Citation: Vadas, P.A., Stock, M.N., Feyereisen, G.W., Arriaga, F.J., Good, L.W., Karthikeyan, K.G. 2018. Effect of temperature and manure placement in a snowpack on nutrient release from dairy manure during snowmelt. Journal of Environmental Quality. 47:848-855.

Interpretive Summary: Agricultural nutrient management is an issue due to nitrogen and phosphorus loss from fields and water quality degradation. Better information is needed on the risk of nutrient loss in runoff from dairy manure applied in winter. We investigated the effect of temperature on nutrient release from manure during snowmelt, and of manure placement in a snowpack on nutrient release to melting snow. Temperature did not consistently affect manure nitrogen and phosphorus release. During snowmelt, manure phosphorus release was not affected by manure placement in the snowpack, but release may be different for solid and liquid manures. For solid manure, nitrogen released during snowmelt increased with the depth of snow covering it, mostly likely due to less nitrogen volatilization. For liquid manure, there was no effect of manure placement within the snowpack on nitrogen released during snowmelt. These experiments provide valuable data for building computer models that scientists and policy makers can use to estimate nitrogen and phosphorus loss to the environment from manure spread in the winter, with the ultimate goal of providing guidelines for dairy producers.

Technical Abstract: Agricultural nutrient management is an issue due to nitrogen (NH4) and phosphorus (P) losses from fields and water quality degradation. Better information is needed on the risk of nutrient loss in runoff from dairy manure applied in winter. We investigated the effect of temperature on nutrient release from manure to water, and of manure quantity and placement within a snowpack on nutrient release to melting snow. Temperature did not consistently affect manure P and NH4 release during water extraction. Manure P release, but not NH4 release, was significantly influenced by the water-to-manure solids extraction ratio. During snowmelt, manure P release was not affected by manure placement in the snowpack, and the rate of P release decreased as application rate increased. Water extraction data can reliably estimate P release from manure during snowmelt; however, snowmelt water interaction with manure of greater solids content and subsequent P release appears incomplete compared to liquid manures. The rate of manure NH4 released during snowmelt was the same regardless of application rate. For the semi-solid manure, NH4 released during snowmelt increased with the depth of snow covering it, mostly likely due to reduced NH3 volatilization. For the liquid manure, there was no effect of manure placement within the snowpack on NH4 released during snowmelt. Water extraction data can also reliably estimate manure NH4 release during snowmelt as long as NH3 volatilization is accounted for with liquid manures for all placements in a snowpack and semi-solid manures applied on top of snow.