Abstract
This study was carried out to evaluate the physicochemical properties and perform a feasibility analysis of planting material composed of topsoil from river improvement and non-improvement areas. The results showed that the physicochemical properties of topsoil from river improvement areas were on the average sandy loam~loamy sand in soil texture, 5.6~6.8 in pH, 0.01~0.06 dS/m in EC, 0.9~2.1% in OM, 0.02~0.12% in T-N, 8~14 $cmol^+/kg$ in CEC, 0.01~0.08 $cmol^+/kg$ in Ex. $K^+$, 2.55~11.11 $cmol^+/kg$ in Ex. $Ca^{2+}$, 0.34~2.06 $cmol^+/kg$ in Ex. $Mg^{2+}$, and 3~396 mg/kg in Av. $P_2O_5$. And non-improvement areas showed on average sandy clay loam~sand in soil texture, 5.7~6.7 in pH, 0.02~0.08 dS/m in EC, 0.9~4.4% in OM, 0.02~0.23% in T-N, 7~18 $cmol^+/kg$ in CEC, 0.01~0.08 $cmol^+/kg$ in Ex. $K^+$, 3.81~12.67 $cmol^+/kg$ in Ex. $Ca^{2+}$, 0.60~1.95 $cmol^+/kg$ in Ex. $Mg^{2+}$, and 3~171 mg/kg in Av. $P_2O_5$. Meanwhile, the results of an applied valuation of topsoil- based planting were as follows. Ex. $K^+$ levels were low grade in all survey areas. OM was low grade in 12 improvement areas and 11 non-improvement areas. Av. $P_2O_5$ levels were low grade in 10 improvement areas and 10 non-improvement areas. T-N was low grade in six improvement areas and four non-improvement areas. Ex. $Mg^{2+}$ levels were low grade in two improvement areas.
