|Torbert, Henry - Allen|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/1999
Publication Date: N/A
Citation: Torbert, H.A., Potter, K.N., Gerik, T.J., Richardson, C.W. Surface residue and soil moisture effect on fertilizer loss on a heavy clay soil. Agronomy Abstracts. 1999. p. 292.
Technical Abstract: The objective of this study was to determine the impact of surface residue management and fertilizer application timing on nutrient losses in runoff. Studies were conducted using a rainfall simulator that applied 125 mm h**-1 for 3 h to an Austin (Typic Haplustolls) clay soil. Soil residue treatments were chisel tillage-no added corn (Zea mays L.) residue, chisel tillage with added corn residue, and bermudagrass [Cynodon dactylon (L.)] sod. Rainfall simulation was made following fertilizer (16-20-0) application to relatively dry and relatively wet soil moisture conditions. Runoff samples were collected from a 1-m**2 area and analyzed for NO3, NH4, and PO4. Data indicated that a reduction in nutrient losses in runoff could be achieved by maintaining surface residues and applying N and P fertilizers to relatively dry soils. The largest loss of fertilizer nutrients occurred with the sod treatments, with the losses of PO4 measured under the relatively wet soil condition being approximately 41 percent of the PO4 fertilizer applied. This indicated that careful management of granular fertilizer applications, especially soil water content, should be considered when fertilizing sod.