REDESIGNING FORAGE GERMPLASM AND PRODUCTION SYSTEMS FOR EFFICIENCY, PROFIT, AND SUSTAINABILITY OF DAIRY FARMS
Location: Dairy Forage and Aquaculture Research
Title: Phosphorus Dynamics in Soil, Runoff, and Sediment from Three Management Systems
Submitted to: Pedosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 2, 2009
Publication Date: March 1, 2010
Citation: Beavers, B.W., Liu, Z., Cox, M.S., Kingery, W.L., Brink, G.E., Gerard, P.D., Mcgregor, K.C. 2010. Phosphorus Dynamics in Soil, Runoff, and Sediment from Three Management Systems. Pedosphere. 20:217-228.
Interpretive Summary: Land application of poultry litter can increase phosphorus level of water runoff and sediment, which contributes to the accumulation of excessive nutrients in water bodies and reduces water quality. We studied phosphorus accumulation and loss in soils receiving poultry litter and managed by different tillage and planting systems. We found that, for a soil having an impermeable subsurface layer, the quantity of dissolved phosphorus in runoff was greater when no tillage was performed prior to planting a grass forage crop. The quantity of phosphorus attached to soil sediment was the same for soils with and without an impermeable layer. The results suggest that, on soils where water movement into the soil is restricted, conventional tillage prior to planting has a beneficial effect on phosphorus loss compared to no tillage. The results also provide producers with the knowledge necessary to reduce phosphorus loss to water bodies when poultry litter is used during establishment of forage crops.
Land application of poultry litter can lead to increased phosphorus (P) level in surface runoff and sediment, which in turn, potentially accelerates the eutrophication in the water bodies. The objective of this research was to study the P dynamics in two poultry litter amended soils using three management systems combining tillage and planting date treatments to identify environment-friendly management practices in southern U.S.A. The management systems in the study were: 1) tillage in the fall prior to litter application followed by a delayed planting of fall forages (CT-DP); 2) tillage followed by immediate planting of the fall forage with subsequent litter application (CT-IP); and 3) no-till with planting prior to litter application (NT-IP). The experimental design was a randomized complete block with soil series as blocks. The results indicated there was significant increase in soil P after 3 years of poultry litter application for both Lexington and Loring soils (p<0.05). Based on P budget analysis, the majority of P from poultry litter application (>90%), was accumulated in both soils. In Loring soil, soluble P mass from management system NT-IP was significantly higher than CT-DP and CT-IP over the entire study period (p<0.01). For both soils, there were no significant differences in sediment P mass between management systems. For Loring soil, CT-DP and CT-IP were environment-friendly management practices to mitigate negative effects due to poultry litter application.