Effect of Residue Cover and Manure Application Timing on Sediment and Phosphorus Transport.
(4723)
Authors:
J.D. Grande - University of Wisconsin, Madison
K.G. Karthikeyan* - University of Wisconsin, Madison P.S. Miller - University of Wisconsin, Madison
Abstract:
The effect of residue cover achieved by different corn harvesting schemes and manure application timing on sediment and P losses from no-till fields was examined. Treatments included conventional corn grain (G) and silage (SL), and non-conventional, high-cut (24-26 in.) silage (SH). Each treatment received one of 3 manure treatments: no manure, fall or spring application. Simulated rainfall experiments were performed in spring and fall, runoff from 2 x 1.5 m plots collected and a sub-sample analyzed for total sediments, dissolved reactive P (DRP), total P (TP), and particle size distribution. The G and SH treatments
reduced sediment and P losses compared to SL, but their effect varied with season and the level of residue cover. Manure application enhanced infiltration resulting in lower sediment and TP losses, but the beneficial effect diminished as the time interval between manure application and rainfall lengthened. Manure application strongly influenced the DRP concentration but had a limited effect on DRP load.
The converse was true for the impact of residue cover on DRP. While residue cover had a minimal effect on the particle size distribution of transported sediments, spring manure had a dominant effect, especially when combined with G treatment.
Higher residue levels associated with SH can lower sediment and P losses compared to SL, but the benefits are greatest immediately after harvest and diminished with time after harvest.
Speaker Information: KG Karthikeyan, University of Wisconsin, Madison, 460 Henry Mall Biological Systems Engineering Department University of Wisconsin, Madison, WI 53706; Phone: (608)262-9367; E-mail: [email protected]
Session Information: Wednesday, November 3, 2004, 8:25 AM-11:30 AM Presentation Start: 10:45 AM
Keywords: phosphorus; sediment; residue cover; manure application timing
