Cowpea, Corn, and Soybean Yield Using Fertilizer Based on the Bone Meal in the Eastern Amazon

The objective of this study was to evaluate the efficiency of granulated formulations, made using calcined bone meal as a phosphorus source, on cowpea, soybean, and corn in the Amapa State, Eastern Brazilian Amazon. In the greenhouse, the treatments consisted of two soils with different clay contents (231 and 376 g kg-1), three granulated NPK formulations (08-20-10, 02-20-10, and 01-20-00 prepared with bovine bone meal, monoammonium phosphate, ammonium sulfate, urea, and potassium chloride and phosphorite), and three crop successions (cowpea/corn/soybean, soybean/cowpea/corn, and corn/soybean/ cowpea). In the field, treatments consisted of four levels of NPK 08-20-10 for corn and NPK 02-20-10 for soybean, in a Cerrado, and NPK 02-20-10 for cowpea, in both Cerrado and upland forest environments. NPK formulations fertilizer promotes greater soybean, cowpea, and corn shoot dry weight in the sandy loam compared to sandy clay soil. NPK promotes greater cowpea grain yield in the Cerrado than in the upland forest environment. The grain yield of the cowpea cultivar BRS Tumucumaque and corn BRS 206 responds linearly to the increase in fertilization with NPK formulations. The increasing levels of NPK formulation made with calcined bone meal do not affect soybean BRS Tracaja grain yield in the Cerrado environment.