Distribuição espacial da condutividade elétrica do solo e sua interferência na definição de zonas de manejo.

Abstract

Brazilian and global agriculture has shown a significant increase in productivity in recent years. The use of precision agriculture has brought several technological advances that have allowed for increasingly higher production and more efficient investment. Soil fertility variability has received special attention from producers and researchers due to the direct effects it has on productivity. Among soil attributes, special importance has been given to reading soil electrical conductivity (EC). This study aimed to evaluate the spatial variability of soil electrical conductivity and its influence on the definition of management zones. The study was conducted at the Capim Branco Experimental Farm, in the city of Uberlândia, in a 25 hectares area cultivated with grains under dry land. A grid of 50 georeferenced points was generated for sampling soil attributes. The samples were located in the field using a GNSS navigation device. Data on altitude, texture, organic matter, cation exchange capacity (CEC) and electrical conductivity (EC) were collected, all at a depth of 0 - 0.2 m. The results were analyzed using descriptive statistics, Pearson correlation, and geostatistics, the latter using the Smart Map plug-in in the QGIS environment. The results showed that electrical conductivity changed over a five-year period and was related to CTC, indicating a good relationship between these attributes. In addition, from 2017 to 2022 there was a change in the management zones at the study site, from three in 2017 to two in 2022. This change is related to the subsoiling activity and the variation in soil attributes resulting from this. It was concluded that there is variation in the definition of management zones when driven by changes in soil structure. In addition, electrical conductivity directly interferes with the definition of management zones and serves as an indicator of changes in soil chemistry.