Adubação boratada na cultura do arroz em solos de cerrado de baixa fertilidade

Abstract

The production cost of new areas in the cerrado presents high values due to larger amount of farming operations when compared to conventional crops. The cerrado soils have low natural fertility and require large quantities of limestone for its correction significantly increasing the cost of production. The objective this study was to evaluate whether the Boro when applied in the cultivation of upland rice with low technological level, increases the productivity rice. The field work was conducted in the municipality of Nova Xavantina - MT in 2009/10 in two areas (first and second year of production). We used six treatments of boron in the source of boric acid (17 % of B), with doses of 0, 0.5, 1.0, 1.5, 2.0, and 2.5 kg B per ha. The plots were 10 m long and 3.4 m wide with 20-sowing rows, with spaced at 0.17 m. The fertilization of 160 kg of 08-28-16 fertilizer was formulated according to the results of soil analysis and used the cultivar BRS Sertaneja in amount of 115 kg of seeds per ha. Among the variables analyzed the productivity in the area of the first year was influenced by boron fertilization, whre the treatment that used a dose of 2.5 kg B hit productivity of 2.677 kg/ha-1. The cost analysis positive for both areas, where in the area of the first year, the cost benefit of boron fertilization was R$169,44 (with a dose of 1 kg B/ha). As for the second year the area of greatest cost benefit was obtained with a dose of 2.5 kg B, which resulted in na increase in productivity of 11.80 bags (60 kg) and therefore a cost benefit of R$333.83 per hectare. The use of boron into new areas of cerrado compensated the low technological level that was used in the formation of the crops, providing positive results in the cost benefit of the crop without significant increases inproduction costs.