Spatial Variation of Soil Properties and Rice Yield on Recently Cleared Land

Abstract

AbstractCrop yields on cleared forest land of the humid tropics are often highly variable due to spatial heterogeneity of soil properties. This study aimed to characterize spatial variation of soil chemical properties and yield components of upland rice (Oryza sativa) on a 0.1‐ha field of recently cleared land in West Sumatra, Indonesia. Plants were taller, stover and grain yields higher on sites where forest rash had been piled and burned, compared to the surrounding soils and other sites where topsoils had been removed. This pattern was largely caused by lower levels of Al saturation and higher concentrations of exchangeable cations in burned sites compared to other parts of the plot. The range of spatial dependence for soil acidity and exchange characteristics was 3 to 4 m, but increased to 7 m for organic C, total N, and extractable P. Semivariograms of crop components were better structured and had longer ranges (up to 20 m) than the soil chemical properties. Block kriging gave more precise local estimation of grain yield at unsampled locations than terrain unit means because it utiliized the inherent structure of variation determined from quantitative spatial analysis of observed values. Block kriged values of grain yield ranged from 11 to 355 g/m2 with estimation standard deviations ranging from 9 to 24 g/m2, depending on distance of interpolated cells from the 122 sample locations.