Nitrogen Recovery and Partitioning with Different Rates and Methods of Sidedressed Manure
- B. R. Ball Coelho *a,
- R. C. Royb and
- A. J. Bruina
Animal manure is an important source of N for crops in areas with intensive livestock production. Variable manure N availability can incite over-application of manure or supplemental fertilizer leading to low N recovery and possible negative environmental and economic impacts. To improve manure N use efficiency, the effects of rate and method of sidedress application of liquid swine (Sus scrofa) manure (LSM) on N recovery by corn (Zea mays L.) were determined. We used in-row injection (INJ) or topdressing (TD) to sidedress LSM from 1999 to 2002 at rates ranging from 0 to 93.5 m3 ha−1, and measured grain N uptake and NO3–N in drainage tile water, stalks, and topsoil postharvest. Apparent recovery of manure total N (LSM-N) ranged from 0 to 57% and was greatest with injection of 37.4 m3 ha−1 (194 kg LSM-N ha−1). Injection rate to achieve 95% of maximum grain yield averaged 216 kg LSM-N ha−1 over 4 yr. Transport of LSM-N to ground- and surface waters was minimized when sidedressed at or below rates for optimal yield. When injected N exceeded crop demand, NO3–N increased to over 10 mg kg−1 in topsoil, 20 mg L−1 in drainage water, and to excessive (3.6 g kg−1) levels in stalks. Due to greater LSM-N recovery, injection (59%) is recommended rather than topdress (41%) for sidedress application of manure.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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