Dissertations and Theses

Summary

Spatial distribution mapping of physical and chemical soil attributes, related to the agricultural productivity, allowed the identification of specific management zones for crops, ensuring greater productivity with lower production costs. The objective of this study was to evaluate the spatial variability of physical and chemical soil attributes related to coffee productivity, identifying and mapping specific culture management areas, using magnetic susceptibility (MS), soil thickness and plant attributes. The study was conducted in Matão, municipality of São Paulo state, at Fazenda Cambuhy Agrícola Ltda, where the soil is classified as dystrophic Ultisol. The area studied, of about 39 hectares, selected by physiographic regional representation, was occupied exclusively by coffee in the last 25 years. The variety studied was Coffea arabica, Catuai Yellow IAC 62 cultivar, 7 years old and planting spacing 3,5 x 0,50 m. To establish the point’s samplings, it was generated a grid with regular intervals of 45 m, totalizing 173 points. In each point, soil samples were collected at 0,0 - 0,20 m and 0,60 - 0,80 m depth to evaluate the physical, chemical and granulometric attributes and magnetic susceptibility (MS). The sampling unit of each point was compounded by nine plants, whose productivity, percentage of grains in the sieves 14, 16 and 17, and coffee type, were evaluated. The plants attributes as content of macro and micronutrients in the leaf, plant height, canopy diameter and reproductive branches length were also evaluated. The area studied was representatively sampled for evaluation of the soil thickness, which allowed the division of the area in two different environments. The statistical and geostatistical analysis showed that most of the attributes studied presented spatial dependence. The analysis of MS, soil fertility, nutritional status of the plant and coffee type was efficient in identifying more favorable environments to the production of coffee with high quality at a low cost. Soil thickness data also allowed the effectively identification of areas with different potential management. The highest production rates were observed at the sites with the highest SM and lowest soil thickness. The conclusion is that the SM and soil thickness can be used as diagnostic attributes to identify areas with different production potentials for the coffee crop.