Polímero, palhiço e sistema de plantio em cana-de-açúcar

Abstract

The Brazilian production of sugar cane in the harvest that begins in 2010 is estimated at 664.34 million tonnes grown on 20.0 million acres. This volume exceeds 9.9% in the last harvest, or 59.82 million tons additional. The South-Central region accounts for 90% of the crop in Brazil and Sao Paulo state is expected to 384.6 million tonnes in an area of 10.9 million acres. The cultivars can produce unwanted features, such as problems in the regrowth, lower productivity, lower sugar content, the occurrence of pith, among others, these problems can usually be associated with climatic factors. Most of the areas planted with sugar cane in western São Paulo state are subject to moisture stress. In order to study the reduction or elimination of problems arising from water stress, was investigated the interaction of soil conditioner (hydrogel polymer) with the addition of straw in two tillage systems. The experiment was located on the campus II of UNOESTE , whose soil was characterized as Acrisol Distroferric typical A moderate, medium-textured clay. The climate is classified as Aw, and the summer rainy season and dry season in winter. The variety RB 86 7515 was planted on December 2007 and harvested in June 2009 (18 months), sprouting of this cultivar was used in the study, statistical scheme was split-plot (2x4), two planting systems used in 2007 when the installation process of culture (windrow and grooves), were four doses of hydrogel polymer, (0, 10.79, 21.58 and 32.38 kg of polymer per acres) plots with the dose of polymer, were divided into four treatments with straw in ratoon sugarcane (no leaves, dry leaves, the dose of 2.02 t acres-1, green leaves, at a dose of 6.75 t acres-1, mixture of green leaves and more leaves at a dose of 8.77 t acres-1). To check the moisture in the soil for different treatments, we performed the analysis directly in the soil in each plot using TDR instrument with rods of 0.20 m. To measure the temperature of the soil in each plot, we used analog thermometer deep, with stems to 0.20 m, making the measurement in lines and in between lines. The biometric analysis were: height of tillers, average stem diameter, number of tillers per meter, number of leaves positive, negative, dry leaves and number of leaves. Were performed using analysis of solids and made the determination of technological parameters (Fiber, Pol. Brix, RS, and TRS). Were analyzed for total biomass yield, stalk yield and productivity of trash. All data were subjected to analysis of variance (ANOVA, p <0.05) and the comparison test of means Scott-Knott (p <0.05). The planting in windrow promoted greater tillering, reaching optimal values, also caused higher temperatures in the soil, both on line and in between lines, provided smaller values of TRS compared with traditional cropping system in the groove and did not cause differences in productivity values. The use of polymer showed higher vegetative growth, higher productivity, higher values of RS especially when using mixed coverage. The use of polymer did not alter the levels of soil moisture and decreased temperature in the line as the leading, resulted in higher leaf production due to use of polymer. The use of cover, mainly leaves mixed in a greater biometric growth, especially in the planting furrow, equaled the TRS between Windrow and groove, which was always smaller than in windrow, promoted greater soil moisture in both windrow and in the groove, between the lines this occurred only to groove. The fiber content was higher in bare soil using polymer. The use of cover resulted in lower temperatures both windrow and in the groove.