Avaliação da disponibilidade hídrica do solo por meio de índices de vegetação em cultivo de milho sequeiro

Abstract

The integration of remote sensing information with physical-hydraulic data can optimize agricultural production while assisting in the management of finite soil resources. Based on this context, this article aims to estimate Crop Evapotranspiration (ETc) using vegetation indices and examine the correlation between Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDVI) with soil physical-hydraulic attributes to assist in irrigation management on the property. The analyzed crop was rainfed maize in the second crop of 2019, and the Sentinel-2 satellite was used to collect NDWI and NDVI information on four different dates: pre-sowing, 29 days after planting (sowing), 91 days after planting, and 128 days after planting, at Capim Branco farm on the Federal University of Uberlândia. The Allen method (1996) was used to calculate ETc, and soil samples were collected at a depth of 0-0,2 m for analysis of soil physical-hydraulic attributes: sand, clay, electrical conductivity, macro and micro porosity, total porosity, bulk density, field capacity, available water capacity, and permanent wilting point. Pearson correlation coefficient was used to analyze the relationship between NDWI, NDVI, and soil physical-hydraulic attributes. The results showed that vegetation indices had a positive correlation with soil physical-hydraulic resources, with the 91-day after planting date being the most suitable for data collection and use of vegetation indices. ETc proved to be more effective in observing productivity, while NDWI showed a strong correlation with soil microporosity. Therefore, the analysis of vegetation indices can provide useful information for soil water management, assisting producers in decision-making and contributing to increased productivity.