Consórcio de guandu e milho cultivados para a produção de forragem em sistema orgânico

Abstract

The objective of this study was to evaluate the productivity and the bromatological composition of forage (in natura and ensilaged) produced from maize’s and pigeon pea’s monocultures and their consortium, as well, in an organic system of production. The experiment was carried out at Fazendinha Agoecológica - Km 47 (Integrated Agroecological Production System - SIPA). The experimental plan adopted was a randomized block design with eight treatments and four replications. The treatments consist of two species of forage plants. Maize’s (Zea Mays, Cv. BRS 4154 - Eldorado) and pigeon pea’s (Cajanus cajan, Cv. BRS Mandarim) monocultures, and maize + pigeon pea consortium, being the pigeon pea planted 60, 45, 30, 15 and 00 days before planting maize, simultaneously with maize and pigeon pea sown in the same groove line.The planting was done in single rows spaced 0,50 m, with resulted in a maize population equivalent to 60,000 plants ha-1 (6 plants per linear meter) and the pigeon pea equivalent to 100,000 plants ha-1 (10 plants per linear meter) whereas in monocultures the populations were equivalent to 120,000 plants and 200,000 ha-1 plants respectively of maize and pigeon pea. In the treatment in which the crops were planted simultaneously in the same planting groove, were used the same planting density of the monocultures. The cutting of forages plants to ensilage was performed at 0,20 m from the soil. The experimental silos used were of PVC with 0,10 m in diameter and 0,50 m in length, with capacity for 2.5 kg of silage (600 kg m-3 ). In addition to the productivity of the species, crude protein (CP), neutral detergent fiber (NDF) and total digestible nutrients (NDT) were evaluated. The total productivity of shoot biomass reached the highest values in the respective maize’s (18.12 t.ms.ha-1 ) and pigeon pea (19.71 t.ms.ha-1 ) monocultures. In the consortium of both species being the sowing done simultaneously the productivity results were the same as reached in the monocultures. In relation of the N total amount accumulated in aerial part of the mixture of both species it was noticed that the highest values were detected when the leguminous was sown at 60 and 45 days before sowing maize. In relation to the CP content in natura forage, the treatment of pigeon pea monoculture and pigeon pea consortia in the diferente sown intervals presented the highest values than the maize’s monoculture and the consortium with simultaneous sown of that species. Regarding silage, the highest CP levels were found in the consortia where the leguminous was planted 60 and 45 days before the maize, being 86% and 105% superior to the silage made with maize’s monoculture, respectively. In the evaluation of the NDF content of forages, the lowest values observed in natura forage were referred to the treatments of pigeon pea monoculture and pigeon peas seeded at 60 and 45 days before maize, which provided the highest NDT values for these treatments. However, when evaluating the NDF and NDT contents of silage, no significant differences were found. In view of the above, the treatment that combined the best values of forage production and quality, both in natura and in the form of silage, was the consortium whose sowing of the leguminous was done at 45 days before maize.