Spatial Variability in Soil Fertility and Particle Size and Their Effects on Sugarcane Yield

The object of this study was to evaluate the relationship between the spatial variability in soil particle size and fertility of a Rhodic Nitisol and the yield of sugarcane cultivated in a no-tillage planting system in Mogi Mirim, in the state of Sao Paulo, Brazil. In order to evaluate the sugarcane yield and the soil chemical and physical properties, the area was marked with a 30 x 30 m grid with 203 sampling points. Soil sampling was carried out in January 2011 at depths of 0.0-0.2 and 0.2-0.4 m and soil particle size and fertility were analyzed. Sugarcane yield was evaluated in September 2011. The data was analyzed using geostatistics through the construction of semivariograms and canonical redundancy analysis. Sugarcane yield was mostly related to levels of organic matter, pH, calcium, magnesium, sum of bases and silt, independent of sampling depth. Redundancy analysis showed that existing correlations between yield and soil particle size and fertility did not significantly differ according to depth and proved to be a useful tool in the evaluation and understanding of spatial variability maps.