Sensoriamento remoto para identificação das causas da variabilidade no índice de massa da soja

Abstract

Remote sensing is the use of sensors to capture electromagnetic energy reflected by objects. The quantification and qualification of the reflected energy can help the diagnosis of plant development and the presence of anomalies. The presence of nematodes has been observed in several areas of Rio Grande do Sul state. The most frequent species are the Meloidogyne sp. (root-knot nematode) and Heterodera glycines (cyst nematode). All species can reduce productivity. In order to establish control programs, is essential to know the spatial distribution of nematodes species. The present study aims to evaluate the remote sensing tools to help in the detection of variability in soybeans and diagnosis of possible causes. Spectroradiometer, active sensor and satellite image were used to diagnose areas with different mass indexes. It was analyzed the presence of nematodes, soil fertility, soil compaction, land declivity and number of plants, in order to understand the causes of indices variation. The active sensor showed good performance in the detection of mass indexes. No correlation between index mass, soil fertility and soil compaction. When mass index grouped into classes, it was related to the presence of nematodes. The land declivity and the number of plants are correlated with mass indexes.