ABSTRACT
The search for more sustainable production systems is a necessary challenge. We evaluated different modes of corn and Crotalaria juncea L. intercropping management that enables to optimize the in situ biomass production, without compromising the cereal productive potential. Experiments were carried out at different times: spring/summer (experiment 1) and autumn/winter (experiment 2), in Seropédica - RJ, Brazil. The treatments for experiment 1 were: C. juncea sown seven days before, simultaneously, and 14, and 28 days after corn sowing, respectively for T1, T2, T3, and T4, besides T5-corn monoculture and T6-corn monoculture + nitrogen. The treatments for experiment 2 were: C. juncea sown seven days before, simultaneously, and seven and 14 days after corn sowing, respectively for TA, TB, TC, and TD, in addition to TE-corn in monoculture and TF-corn in monoculture + N. For T1, T2, TA, and TB, C. juncea was mowed approximately 30 days after emergence and its straw was used as nitrogen source for corn; for T3, T4, T6, TC, TD, and TF, castor bean pie was used as nitrogen source. In the spring/summer crop, in T2, the cereal grain production did not differ from monoculture with nitrogen fertilization, with a positive effect on the economic balance. In the autumn/winter crop, the presence of green manure sowed 14 days after corn resulted in benefits to the system. Crotalaria juncea cultivated in the summer presented potential to supply Nitrogen to corn as an alternative for nitrogen fertilization.
Key words:
green manure; polyculture; castor bean pie; nitrogen fertilization; small farming; sustainability