An Assessment of Poultry Litter Based Biochars and Urea in Field-Grown Cotton

Biochar is the product resulting from the low-oxygen combustion of biomass materials such as crop residues and poultry litter. Biochar has been suggested as being a sustainable fertilizer source as well as being beneficial for enhancing soil fertility and soil water retention. Field experiments were conducted at the University of Arkansas Research and Extension Station in Fayetteville, AR in 2011 and 2012. The crop selected was cotton (Gossypium hirsutum L.) which was grown on a Fine-silty, mixed, active, mesic Mollic Paleudalfs Pembroke silt loam soil. The biochar used in the experiment was derived from poultry litter and analyzed for nutrient composition. The biochar was then examined in order to assess its extent of influence on the development of field-grown cotton either used alone or in association with urea. A randomized complete block design, composed of six treatments and three replications was used with biochar rates consisting of a no biochar control (C0), a rate equivalent to 2,000 kg/ha (C1) and a rate equivalent to 4,000 kg/ha (C2). The two rates of urea (46-0-0) were no urea (F0) and a recommended urea rate equivalent to 26.7 kg N/ha (F1) applied twice during the flowering stage. Measurements and data collected during and after harvest included lint weight, number of seeds and number of harvested bolls per plot. Statistical analysis showed that biochar was the only factor of significance with the 2,000 kg/ha rate equivalent being significantly greater than the control and the 4,000 kg/ha rate equivalent for all plant measurements in both years. The factors of urea and the interaction between biochar and urea were determined to be insignificant for both years of the experiment.