Distribuição da palhada de trigo e seu efeito sobre a microvariabilidade da cultura da soja

Abstract

Precision and digital agriculture is rapidly gaining space in Brazil. The advent of technologies coming from the fourth technological revolution in which we live is paving the way for better crop management. This has made it possible to identify microvariability in the same field, helping the farmer to be more accurate in the interventions, helping him to get closer to the productive potential of the crop and the production environment. Vegetal coverage in the field plays a crucial role in order to obtain a good yield for the subsequent crop, in addition to being crucial for soil preservation. There are many benefits brought by good coverage, the main ones are: preservation of soil temperature and humidity, control of weeds, erosion control, maintenance and increase of organic matter, preservation of soil biology, nitrogen supply and reduced compaction from soil. The harvester is the main way to spread the straw on the soil, as it performs this task simultaneously with the harvest. However, when this distribution varies due to some external variables, an inadequate straw distribution may happen, which can cause microvariability in productivity, which cannot be identified by conventional measurement methods. The present work had as target to study the distribution of wheat straw and its effect on the microvariability of the soybean crop, under field condition. The study was carried out in the city of Eugênio de Castro-RS, where samples of wheat straw were collected in the center of the harvester's guidance lines, and between the lines, in order to verify the variability of the deposition of the vegetation cover. Subsequently samples of soybean yields were collected, as well as yield components, at the same points where straw was collected. Descriptive statistics were used to analyze all variables, and for the variables productivity and dry straw, analyzes of variance, linear regression correlations were performed. The results showed that seven of the nine yield components analyzed had higher averages at the center of the harvest line than between the lines. Soybean productivity was about 12% higher at the center of the harvest line, equivalent to 6 bags of soybeans per hectares. Analysis of variance showed that treatment A (central harvest lines) generate higher averages than treatment B (between the lines). Correlation analyzes indicated a moderate relationship between soybean yield and wheat straw quantity.