GEOTRAT points: recurso livre de código aberto no software QGIS para mapeamento do desempenho de experimentos agrícolas

Abstract

Agricultural experimentation requires careful selection of the experimental design and model for analyzing treatment data. However, even with rigorous experimental control, the discrepancies between treatments are so subtle that traditional statistical models fail to highlight statistically significant differences that occur in field practice. The incorporation of geotechnologies offers the ability to map agricultural variability, but a gap still exists in the availability of tools designed to map and evaluate the effectiveness of agricultural experiments. To overcome this limitation and promote the wider application of Geographic Information Systems (GIS) in agriculture, the scope of this study focuses on the development of a resource in QGIS software, aimed at evaluating agricultural experiments using a randomized block design with up to five treatments. The resource developed incorporates spatial interpolation techniques using geostatistical kriging, map generation, and statistics. The study used yield samples from six different crops to identify quantitative and spatial differences between two-treatment experiments in terms of yield gain. The results consisted of two surfaces representing the study area treated with each of the treatments (T1 and T2), as well as a surface reflecting the yield gain of the reference treatment in relation to the control treatment, accompanied by relevant descriptive statistics measures on this gain surface. The simulated cartographic representations of the treatments, as well as the maps illustrating the yield gain, revealed both numerical and spatial distinctions between the treatments, with an accuracy of up to 95.40%. The tool, called GEOTrat - Points, offers the flexibility to evaluate agricultural experiments of various designs, encompassing different crops and different quantities of samples, providing both numerical and spatial analysis. This tool is a relevant resource for agricultural experimentation, helping to select appropriate management practices and identify the most effective treatments.