Variability of Maize Yield Over Different Soil Types and Land Suitability Indices In The Humid Tropics, South Sulawesi Indonesia

摘要

An attempt of understanding the influence of land characteristics on crop yields is useful in designing siteudspecific management of land resources. Characteristics of soil and climate in the humid tropics like Indonesiaudvary considerably among agroecological zones. The primary aim of this study is to assess the correlationudbetween land characteristics and maize yields; and to evaluate the variability of land index over different soiludtypes in the humid tropics of South Sulawesi, Indonesia. As many as 30 soil profiles were made at study areaudwithin fourteen different soil types with traditional maize cultivation. A linear regression with Pearsonudcorrelation analysis was undertaken to evaluate maize yields at different soil and climate characteristics. It wasudfound that soil pH, base saturation, and organic carbon have a significant correlation with maize yield with R2udvalue of 0.705, 0.741, and 0.683, respectively. The analysis also shows that correlation between land suitabilityudindex and maize yield reaches an R2 value of 0.807. The scatter points in the diagram depict a good indicationudthat the higher the land index the better maize yield can be produced in the area under consideration. Suitabilityudanalysis indicates that land suitability index (I) value ranges from 11.5 to 55.0, with maize yield from 1.6udton/ha (Typic Dystrudepts) to 5.2 ton/ha (Typic Haplustalfs) and parametric suitability classes are S2 (moderatelyudsuitable), S3 (marginally suitable), N1 (currently not suitable), and N2 (permanently not suitable).