Effects of Nitrification Inhibitor, Carboxymethyl Pyrazole, Treated Poultry Litter on Growth and Yield of Cotton and Nitrate Leaching.
Reddy S. Sajjala1, Reddy C. Kamireddy1, and Ravu Malik2. (1) Alabama A&M University, Department of Plant and Soil Science, Normal, AL 35762, (2) Albany State University, Department of Natural Sciences, Albany, GA 31705
Fast growing poultry industry in Southeastern states of US is causing heavy accumulation of poultry litter which is leading to its indiscriminate disposal. Application of poultry litter to row crops such as cotton (Gossypium hirsutum L.) may serve as an important means of its safe disposal. An experiment comprising three sources of nitrogen: urea, fresh poultry litter (FPL), and composted poultry litter (CPL) at the rate of 40, 80, and 120 kg N ha-1 with and without the nitrification inhibitor, Carboxymethyl Pyrazole (CMP), treatment were evaluated for growth and yield of cotton and nitrate leaching on a Decatur silt loam soil at Belle Mina, Alabama during 1994 to 1998. Among three sources of nitrogen, FPL produced the highest mean lint yield (1493 kg ha-1) compared to urea (1392 kg ha-1) and CPL (1414 kg ha-1). The increase in cotton lint yields occurred up to a rate of 107 kg N ha-1. Increase in lint yields closely correlated with increase in plant height, main stem nodes, and nodes above white flower at maturity. The nitrification inhibitor, CMP, had no significant effect on cotton growth or lint yield but significantly reduced the NO3- N formation immediately following its application, up to 41 days after planting. Application of FPL in combination with CMP recorded significantly lower nitrates. These results indicate the possibility of using CMP as a means to reduce nitrification thus consequent nitrate leaching.