SOIL CHARACTERISTICS IN SOME HUMAN IMPACTED AREAS AT KAMBURUPITIYA FOLLOWING THE NILWALA PROJECT

Abstract

The study involved characterization of physical, chemical, and biologicalproperties of a severely disturbed soil in Kamburupitiya, which has beenpreviously maintained under agroforestry.

The bulk density, true density, and porosity of the soil were l.163 gcrrr', 2.14gcrrr' and 45.6% respectively, with a water holding capacity of 28.5%. The percent organic matter and N in the soil were 0.451 and 0.0088, respectively,whereas the corresponding values in an undisturbed neighboring site, were 1,214and and 0.095. The cation exchange capacity of the degraded soil was 4.71 m.e.per 100g. of soil and had a H value of 4.2. The corresponding figures for thereference site were 7.4 and 5.43, respectively. Biological activity of the soil asmeasured by soil respirometry, amounted to 0.716 mg COilOOOg of soil/hr andl.355 mg CO2/lOOOg. of soil/hr in disturbed and undisturbed soil, respectively.No macro fauna was evident in the soil. Even after 12 years of disturbance, soilregeneration was extremely slow, thus agronomic interventions prove important toaccelerate the soil restoration process