Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/3/2007
Publication Date: 11/3/2007
Citation: Cambardella, C.A., Moorman, T.B., Singer, J.W. 2007. Coupling Cover Crops and Manure Injection: Soil Inorganic N Changes [CD-ROM]. In: ASA-CSSA-SSSA Annual Meeting Abstracts, Nov. 3-6, 2007, New Orleans, LA.
Technical Abstract: Integration of a rye/oat cover crop with liquid swine manure application may enhance retention of manure nitrogen (N) in corn-soybean cropping systems. The objective of this study was to evaluate changes in soil inorganic N following injection of liquid swine manure to plots seeded with a rye/oat cover crop. Manure was injected in the fall, 6-8 weeks after a 70% rye/30% oat mixture was drop-seeded into soybean. For two consecutive years, we measured surface soil (0-20 cm) NO3-N and NH4-N in the manure injection band and in the non-injected rows every week for up to six weeks after manure application and in the following spring before and up to six weeks after killing the cover crop prior to corn planting. Soil profile (to 120 cm in 20 cm increments) inorganic N was also quantified before manure application and before the cover crop was killed. Temporal patterns of surface soil NO3-N and NH4-N were different in fall 2005 and fall 2006. Surface soil NO3-N was significantly lower in soil under rye/oat cover crop at 21 d (2005) and 42 d (2006) after manure application, although absolute amounts of NO3-N differed 10-fold. Deep core data indicates the rye/oat cover crop reduces deeper soil NO3-N in the manure band to a depth of approximately 100 cm. Results show that integration of rye/oat cover crop with swine manure reduces soil NO3-N after manure injection which can lower the potential for N leaching after liquid swine manure application.