Behavior of Sodium Chlorate in Different Soil Types in Forest Land

Abstract

The herbicidal activity and persistence of sodium chlorate (NaClO₃, 50%) was investigated in following types of forest soils; B_C, B_D, B_E and B1_C soils, in relation to the distribution of Kumai sasa (Sasa Paniculata) rhizome in the soils.
1. The herbicidal activity of sodium chlorate appears remarkably in B_C soils but it is not so remarkable in both type of B_E and B1_C soils.
2. The persistence of sodium chlorate was about 60 days in B_C soil, but that in both B_E and B1_C soils was not so long (about 14-21 days).
3. Kumai sasa rhizome is shallowly distributed in the surface of weakly dried brown forest soils (0-10cm depth) but it is distributed deeply reaching 30cm depth in rather wet soils like B_E and B1_C soils. The herbicidal activity of sodium chlorate on Kumai sasa with deeply distributed rhizome is less than that on it with shallowly distributed rhizome.