Comparison on potential of sugarcane growing soils in eastern Thailand

Study on comparison on potential of sugarcane growing soils in Eastern Thailand was carried out on representative soils in 10 areas. Pedon analysis in the selected areas, laboratory analyses on their physico-chemical properties, mineralogy, micromorphological characteristics and assessment of their properties related to sugarcane crop requirements were included in the study method. Results of the study revealed that these soil are Quartzipsamments, Endoaqualfs, Hapludalfs and Paleudults in coastal plain. They are very deep soils developed on mainly local alluvium, semi-recent alluvium and wash deposits derived from granite and gneiss. Their micromorphological characteristics indicate subangular to subrounded quartz grains as major fabric component and with clay coatings in subsoils for some areas. Their texture ranges from sand to clay loam and their bulk density ranges from moderately low to moderately high (1.33-1.82 Mg/cubic m). Their saturated hydraulic conductivity ranges from slow to very rapid. Chemical analysis of soils indicates their very strong acid to moderately alkaline condition (pH 3.8-7.9). They have very low to medium organic matter content (1.1-15.6 g/kg). very low total nitrogen (0.01-0.06 g/kg), very low to very high available phosphorus (1-250 mg/kg) and low to very low available potassium (1.5-48.1 mg/kg). The soils have very low to moderately high cations exchange capacity (0.17-16.25 cmol/kg) with the range of their sum of extractable bases of 0.21-17.77 centimoles per kilogram. Extractable acidity in these soils ranges from very low to moderately high (1-8.7 cmol/kg) and their base saturation percentage varies (4-84 percent). Their electrical conductivity range from 0.03-1.89 decisiemen per meter indicating no salt effect in these soils. Fertility assessment results indicate that most of these sugarcane growing soils have low fertility except for some of the areas that the soils have moderate fertility status. Their potential based on suitability assessment indicates that most of them are moderately suited and some of them are very well suited for sugarcane. However, some of them that have sandy texture or very strongly acidic condition are not suited for the purpose. A recommended approach to increase their potential for sugarcane growing includes a more intensive soil-fertilizer management with an emphasis on soil organic matter conservation. To maintain effectiveness in sugarcane growing on these soils continuing effort on soil-fertilizer management is clearly needed to sustain and increase their sugarcane production potential.