Submitted to: Journal of Environmental Quality
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/21/2010
Publication Date: 9/1/2010
Citation: Verbree, D., Duiker, S., Kleinman, P.J. 2010. Runoff losses of sediment and phosphorus from no-till and cultivated soils receiving dairy manure. Journal of Environmental Quality. 39(5):1762-1770. Interpretive Summary: No-till is credited with improving water quality by lowering erosion, but questions remain as to no-till’s effects on phosphorus from soils receiving livestock manure. This study compared phosphorus losses in runoff from different Pennsylvania soils receiving dairy manure. While no-till clearly lowered phosphorus runoff from well drained soils, losses were exacerbated in soils with poor drainage. Soil hydrology must be considered in targeting tillage management, especially in systems where manure is used.
Technical Abstract: Managing manure in no-till systems is a water quality concern because surface application of manure can enrich runoff with dissolved phosphorus (P) while incorporation by tillage increases erosion potential and particulate P loss. This study compared runoff from well-drained and somewhat-poorly-drained soils under corn (Zea mays, L.) production that had been in no-till for more than 10 yrs. Dairy cattle (Bos Taurus L.) manure was either broadcast into a fall planted cover crop prior to no-till corn planting, or incorporated by chisel/disk tillage in absence of a cover crop. Rainfall simulations (6 cm hr-1) were performed after planting, at mid-season, and after harvest in 2007 and 2008. In both years and on both soils, no-till yielded significantly less sediment than did chisel/disking. Relative effects of tillage on runoff and P loss differed with soil. On the well-drained soil, runoff depths from no-till were much lower than with chisel/disking, producing significantly lower total P loads (22-50% less). On the somewhat-poorly-drained soil, there was little to no reduction in runoff depth with no-till, and total P loads were significantly greater than with chisel/disking (40-47% greater). Particulate P losses outweighed dissolved P losses as the major concern on the well-drained soil while dissolved P from surface applied manure was more important on the somewhat-poorly-drained soil. This study confirms the benefit of no-till to erosion and total P runoff control on well-drained soils, but highlights trade-offs in no-till management on somewhat-poorly-drained soils where the absence of manure incorporation can exacerbate total P losses.