Delineamento de zonas de sites-específicos por meio da relação entre as frações da matéria orgânica do solo, a resistência à penetração e a produtividade do milho

Abstract

Site - specific in agriculture can be defined as a method to manage soil and crop production in a spatial and precise way, which area attractive to delineate productive zones based on the quality of soil and crop yield. The soil organic matter (SOM) is the component that most relates to the physical, chemical or biological quality parameters. The objective of this study was to identify areas with similar limiting factors of production, called sites-specific, for characterizing the spatial variability based on fractions of soil organic matter. To achieve the objective 220 sample points were delimited in a uniform grid 7 x 10 m. At each sample point samples were collected for fractionation of SOM, which was fractionated by two methods: the densimetric and the granulometric. From the densimetric method was obtainedFractions Take the Free and Light weight Intragregado and from the densimetric method he sand, clay and silt fractions. With the digital penetrometer was determined the penetration resistance. In maize crop the productivity components were evaluated. Ordinary kriging was used to interpolate the values, in order to define the spatial pattern of the studied variables through semivariograms, which allowed the elaboration of contour maps. The variables studied were spatially dependent, adjusting to the exponential model for most variables. The experimental grid was adequate for evaluating the spatial dependence of the studied variables. There were significant correlations between the fractions of SOM, soil physical properties and yield components of maize.