Semeadura de soja em taxa variável segundo variabilidade da CTC

Abstract

ABSTRACT: The population recommendation of soybean seeds at a Variable rate is a precision agriculture tool that allows producers to optimize seed cost and obtain na increase in productivity per area in relation to sowing at a fixed rate. The objective was to study the effects of soybean population variation in relation to the spatial variability of the soil’s cation Exchange capacity (CTC). The following treatments were used in the experiment (T1 – 5): T1: 293.330 seeds ha -1; T2: 268.886 seeds ha -1; T3: 244.442 seeds ha -1; T4: 219.998 seeds ha -1; T5: 195.554 seeds ha -1. These treatments were based on the spatial variability of (CTC) and Magnesium (Mg) in the area. The results presented by the treatments were compared with those obtained in a control area, which received a fixed sowing population of 244.442 seeds ha -1. It is possible to use the variable rate of soybean seeds using the soil CTC spatial variability map as a reference for population adjustment, Mg was used as a parameter because it was at low levels, and could negatively interfere with the results of the experiment. The result obtained was due to the better population arrangement taking into account the spatial variation of the CTC. The treatment area with variable seed rate showed a 10.3 % increase in productivity compared to the control area sown at a fixed rate.