Distribuição espacial de variáveis do clima e do solo: um estudo geoestatístico

Abstract

The aims of this work were: 1) to generate information through variability análisis and establishment of the structure of spatial dependence and linear correlation of some soil attributes, in order to assist in the planning of agricultural activities in six cities in the province of El Oro, Ecuador, 2) to evaluate if the application of amendments improves PR in the short term and describes the spatial variability of PR in the surface horizon of a soil under no-tillage, in the province of Entre Rios, Argentina, and 3) to analyze the spatial distribution of average, máximum and minimum temperatures in the region of Galicia, Spain. The need for soil studies in the province of El Oro, Ecuador, made it possible to carry out this study and generate information through the analysis of variability and establishment of the structure of spatial dependence and linear correlation of some soil attributes, in order to assist in the planning of agricultural activities in the province. In all of them, initial descriptive analysis, geostatistics and simple linear correlation matrix were performed based on a mesh with 368 sample points. The longest range was indicated by magnesium (41.500 m) and the shortest by copper (7.740 m). The Mg pair versus sum of bases was the highest linear correlation among all analyzed attributes. The pH stood out as an intermediary and influencer of other soil attributes. The quest for understanding the influence of organic and inorganic fertilizers on penetration resistance (PR) in the province of Entre Rios, Argentina, generated important data. The four treatments tested, which consisted of Surface applications with: poultry litter (PL) as organic amendment, gypsum (G) as inorganic amendment, a combination of both (PL+G), reapplication of PL over half of plots PL+G and PL, and control (T), were evaluated using descriptive analysis, spatial variability and spatial dependence between sample units. The highest PR was found in the T treatment (1.96 MPa) and the lowest in the PL+G+PL (0.21 MPa). The reapplication over PL+G caused effects in all PR ranges, with the surface represented by the range 1.2 – 1.8 MPa decreased from 54.17 to 6.65%. When analyzing the spatial distribution of the average temperature in the Galicia region, data on average air temperature measured on a monthly scale during the years 2013, 2014, 2015 and 2016, provided by the networks of 167 meteorological stations from AEMET and METEOGALICIA. The geographic coordinates allow the calculation of the experimental semivariogram and interpolations using kriging with external drift L. The semivariograms revealed that the spherical model was adjusted to the monthly average temperature data series with full frequency. The average and minimum average temperature for the month of June 2014 showed the greatest range (4464735.39 meters. The validations for the months of March/2013, January/2014 and February/2014 showed the best fit (R = 0.98) for the variable of average temperature. Regarding the minimum average temperature variable, the months of January/2014 and February/2014 also showed the best adjustment (R = 0.98). Finally, the month of January/2014 showed the best adjustment among all for the maximum average temperature variable (R = 0.99). Using the geostatistical technique, it was possible to analyze the spatial variability of soil and climate variables.