Agricultural system under irrigation

Abstract

A field experiment was conducted at the National Rice and Bean Research Center of EMBRAPA, Goiânia, Goiás, Brazil, during four consecutive years under sprinkler irrigation using center pivot. The objective of this study was to evaluate effects of plowing at different depths (15 and 30 cm), fertilizer levels (200 and 400 kg ha^-1) and crop rotation (R1 = rice-bean; R2 = corn-bean and R3 = rice-wheat-corn-bean) on grain yield, and physical and chemical properties of soil. In general, concentrations of AI, Ca+Mg, P, K and MO in soil decreased during the experimentation period with the agricultural system employed. Under treatment of plowing at 30 cm depth, bulk density at 20 and 30 cm depths were lower as compared to initial values. Plowing treatment at 30 cm depth produced higher grain yield of rice in rotation with wheat-corn and bean as compared to rotation with bean. Bean yield was lower after corn than after rice. Plowing depth had no effect on yield of corn, bean and wheat. Higher yields of rice, corn, bean and wheat were obtained at higher fertilizer level. Agricultural system with highest rentability was corn-bean rotation.