Densidades de plantas aplicadas a unidades de manejo no cultivo de soja

Abstract

Precision agriculture is essential for farmers who want to increase their productivity and reduce costs with agricultural inputs. One way of using precision agriculture is to divide the area used for cultivation into individualized plots with similar productive potentials within the plot and different among plots; these fractions of the total area are called Management Units (MUs). In this context, the objective of the study was to verify the effectiveness of the division of the area in MUs and to define the plant density for the soybean crop that provides greater productive efficiency in each MU in an experimental area with 15.5 ha, located in Céu Azul City, Paraná State, in Brazil. In the experiment, the formation of the MUs occurred following the steps: collection of soil samples to characterize the chemical and physical attributes; selection of attributes with higher correlation with productivity; interpolation and generation of thematic maps with the values of the attributes selected in the sample points; grouping of data and definition of MUs, considering that the entire computational process was performed with the help of the Software for the Definition of Management Units (SDUM). For the formation of MUs, it was used the attributes of altitude and soil penetration resistance 0-0.1m, attributes that have a greater spatial correlation with productivity in the field. The area was divided into 2 MUs, 4 contour lines (CLs) and 16 plots. In the field, 2 plant densities were applied, 214,000 and 257,000 plants ha-1, and each density was applied in 8 different plots, using line spacing of 0.70 m. In order to characterize and quantify differences in MUs and CLs and the efficiency of plant densities in the MUs, the productivity was measured at 37 points in each plot. Regarding productivity, it was found that there was a significant difference at the level of 5% between MUs, being that the MU with greater productive potential, located in the highest part in the area, achieved higher productivity; the application of the two different plant densities in the MUs generated effect, being that the densities of 214,000 and 257,000 plants ha-1 reached, respectively, higher productivity in MU2 and MU1; also, there was a difference in productivity between CLs.