The Utilization of Soil Testing Data for Soil Fertility Interpretation, Amelioration and Fertilizer Recommendation

Abstract

Seventy seven samples of acid sulphate soils in Nakon Nayok Province were collected following the detailed reconnaissance soil map of the Department of Land Development. The main objective is to evaluate the common constrains from major chemical properties and characteristics related to agricultural utilization especially for rice. These include Al concentration, depth to jarositic horizon, pH, OM, available P, extractable K, Al, active Fe, and Mn. Chemical properties and characteristics were classified into three classes according to their degree of limitation to plant growth : very severe, moderately severe and none severe. Distribution of each class was delineated on map by using isoline technique. All maps had been compiled by using the overlaying technique. The published map has been presented at scale of 1:200,000. Each mapping unit represents a combination of various degree of constraints related to agricultural use. According to the study, 23 mapping units had been identified. The map could be used as a guide to manage the acid sulfate soils in Nakon Nayok province in which most of the poor soils occupied.