Effect of Organic Manure and a Preceding Summer Cover Crop in the Biomass Development and Soil Physico-Chemical Changes in a Succeeding Broccoli.

Soil erosion and environmental problems are the major issues the world faces today. Cover and management techniques, organic farming, and building soil carbon are some of the major solutions recommended. Organic farming has become the fastest growing sector in the field of agriculture worldwide. A short-season summer cover crop, sorghum Sudan grass, was grown for two months and clipped down for raising organic broccoli on Memphis silt loam (Typic, silty, mixed, thermic Hapludalph) in the southwestern part of Mississippi. The research plot was established using randomized complete block design with four dosages of manuring system; control (no manure), low dosage (3,646 kg ha^-1), medium dosage (7,291 kg ha^-1), and high dosage (14,581 kg ha^-1) of composted poultry manure. Cultural practices, including manual weeding and irrigation, were applied uniformly to all treatments. Based on the minimum requirements recommended by the USDA/NRCS for conservation planning, biomass development was recorded covering the parameters plant height, canopy height, canopy width, leaf area index (LAI), and percent canopy cover  for each treatment thrice during the growth period. The dry upper and lower biomass was recorded after the final harvest of edible portion. Crop residue was analyzed for total dry matter, C:N ratios, and macro and micro nutrients. After the final harvest and decomposition of residues, surface soil  was analyzed for macro and micronutrients, carbon buildup, NO₃-N, P, OM, pH, and CEC. While the percent canopy cover, yield, CEC, and carbon buildup were high for high dosage, the total dry biomass and LAI were high for medium dosage. The yield harvested from the control blocks was non-marketable.