Variabilidade espacial dos atributos físicos e químicos do solo em área sob cultivo de arroz irrigado por inundação em Arari-MA

Abstract

Rice is a product of great importance in several aspects for the State of Maranhão, with emphasis on the social, due to its role in food security, and to the economic, for its potential income generation. Livestock and agriculture are activities that have been part of civilization since ancient times, being fundamental to the survival of man and the maintenance of the world economy. Soil attributes generally present a high degree of spatial variability due to a combination of physical, chemical and biological processes that operate at different scales, and the quantification and interpretation of such spatial variability is a key issue for soil management. The study was carried out in a rural property, located in the municipality of Arari in the Baixada Maranhense. Soil sample collection was carried out in September 2016 in an area measuring 100x100m, in a regular 20x20m mesh and 5x5m thickening, totaling 66 samples, 0-20 cm deep and georeferenced. he study evaluated the spatial variability of soil attributes in a flood irrigated rice cultivation system in an area managed for about 11 years and studied by Farias Filho (2014), using a geostatistical technique, zoning nutrient contents and other attributes relevant to the rhizicultural production and comparing by means of maps of isolines the physical and chemical attributes of the soils. The variables analyzed were pH, MO, P, Ca, Mg, K, H + Al (potential acidity), Al, S, sum of bases (SB), cation exchange capacity (CTC), base saturation and physical analyzes of clay, silt and sand. The results show different values of residues (RSS) and coefficient of determination (R2) closer to 1. S and Ca present a more homogeneous distribution in comparison to Al and S, the latter presenting a very heterogeneous distribution due to management operations and topography, which alters the distribution of attributes.