Precision Litter Application Practices for Cotton Production and Soil Properties.

Interest in using broiler litter as an important and inexpensive source of plant nutrient has been recognized and many farmers have utilized broiler litter in their nutrient management practices. In recent years poultry producers have turned to pelletization of litter to increase the economic feasibility of transporting and handling of poultry litter.  However, information on the properties of pelletized poultry litter (PPL) is limited and research on its effects on cotton and soil chemical, physical and biological properties has not been evaluated. An experiment was conducted at the Plant Science Center of Mississippi State University on a Marietta loam soil in 2010, 2011, 2012 and 2013 to determine the effect of subsurface banding of pelletized litter relative to inorganic fertilizer on cotton growth, yield and soil properties. Experimental design was a randomized complete block with 3 treatments replicated four times. Treatments included pelletized litter at the rate of 6.7 Mg ha^-1 sub-surface banded 15 cm away from plant in both sides of the row, inorganic fertilizer N (UAN-solution) at the rate of 134 kg ha^-1  subsurface injected (56 kg ha^-1 two weeks after planting and 78 kg ha^-1 as siddress) and non-fertilized control. A GPS-guided tractor was used to place pelletized litter in exactly the same place every year.  Pelletized litter application increased cotton lint yield by 4, 5, 6 and 17% in 2010, 2011, 2012 and 2013, respectively as compared to inorganic fertilizer. Cotton mean N uptake was greater by 42% for inorganic fertilizer than pelletized litter resulted in excessive vegetative growth and less lint yields with inorganic fertilizer than pelletized litter. Pelletized litter increased organic C in the soil which would increase biological activities and produce more organic binding or stabilizing agents for soil macro aggregation.  In conclusion, precise sub-surface banding of pelletized litter is more effective in increasing cotton yield and improving soil physical and chemical components than conventional fertilizer.