Tecnologias adotadas para a melhoria da fertilidade do solo e produção de forragem pela RB867515 em cinco cortes

Abstract

Sugarcane crop has been used as animal feed in several regions of Brazil. In order to increase the sugarcane yield and productive, Brazilian research has recommended several agricultural practices. The present work evaluated the technologies adopted for the production of sugarcane in a dairy farm located in Mercês county, Mata Mineira. The main techniques used for the implantation and conduction of cane fields are described, including the criteria adopted for liming, plastering, chemical fertilization and regrowth. The sugarcane variety used was RB867515, currently the most cultivated in the region and in Brazil, due to its high productive potential. The forage production, the production of industrializable stalks and the production of sugar in five cuts were evaluated: from cane-plant to the fourth regrowth. Based on the soil analysis and research conducted in the region, 5,0t of dolomitic limestone and 1,5t of gypsum per hectare were applied. The planting fertilization consisted of 100kg of phosphorus (229kg of P2O5) using triple superphosphate with source of P. For the planting of sugarcane variety RB867515, eight month old seedlings were used, with excelente vigor and sanity. Thirty days after cane planting, potassic fertilization was carried out in the plant cane, at a dose of 150kg K per hectare. There was no nitrogen fertilization in the cane-plant. At the end of August of the year after planting, the productivity of sugarcane was evaluated. In October of that same year, the first regrowth was fertilized with 150kg of N and 150kg of K. The first, second, third and fourth regrowth were also harvested at the end of August, in the same way as cane-plants, the production of fodder, the accumulation of dry matter, the production of industrializable stalks and sugars were evaluated. In fertilization of the second, third and fourth regrowth 150kg of N and 150kg of K per hectare per year were applied again. The average productivity of the five cuts (cane-plant to the fourth regrowth) was 117t of natural matter per hectare, 35t of dry matter per hectare. The average yield of sugar in the five cuts was 12,94t ha-1. Fourth regrowth productivity was 62% of cane-plant productivity and, for all variables analyzed, the coeficiente of variation was less than 10%, indicating homogeneity. It can be concluded that the criteria adopted for the correction of soil, fertilization of cane-plant and regrowth and management of sugarcane plantations allowed to obtain high productivity in the cane-plant cycle, with small decreases in subsequent cuts.