Substituting Chemical Fertilizers With Poultry Manure To Reduce Environmental Impact

摘要

According to USDA-NASS, U.S. total broiler production in 2003 was 8.5 billion head. The vast majority of the poultry manure (litter) generated by the poultry industry is land-applied on pastures as a fertilizer usually within short distances of the poultry production. This practice may not be desirable because continued litter application to the same soil for an extended period usually leads to environmentally unacceptable overload of litter nutrients. Some poultry production regions may have already reached that point and are looking for new sites such as row crops or forest land to recycle litter nutrients. One natural alternative would be land under row crops such as cotton (Gossypium hirsutum L.) and pasture productions. We have conducted many studies to determine the proper time, rate, and other management practices related to the use of poultry litter or combination of litter and chemical nitrogen (N) fertilizer to produce maximum forage dry matter and cotton yield. In one study, lint yield increased linearly with increasing rates of litter up to 7 ton/ha with no supplemental N. In a separate study in addition to 1 ton/ha poultry litter, we included 4 inorganic N (urea ammonium nitrate solution) rates (0,34,67, and 101 kg N/ha) as side dress after planting. The largest overall average cotton lint yield of 2750 kg/ha was obtained in 2001 with combination of 1 ton/ha lifter and 34 kg N/ha treatment. However, under more favorable soil moisture conditions, no significant yield differences was observed by increasing the supplemental N rate up to 101 kg N/ha.