Vegetation, soil survey and analysis at Okinawa Japan

Abstract

Soil, vegetation survey and analysis were carried out at Yona. Results from soil physical analysis showed that percolation, total porosity, fresh soil water content, moisture content of air-dry soils and roots decreased with depth from soil surface. However, bulk density, specific gravity and clay content of the soils increased with depth. Two soil textures were identified, light clay and heavy clay. Results from chemical analysis showed that cation exchange capacity, calcium, magnesium, potassium , sodium, available phosphorus, carbon and nitrogen were highest in horizon A. However, carbon to nitrogen ratio increased with depth from the soil surface. PH in water was one unit lower than pH in potassium chloride. Results from soil survey showed two soil types: dry yellow soils, granular and nutty structure type (YB) and weakly dried yellow soils (YC). Vegetation survey showed high species diversity in the shrub and less than one metre height (herb) and a low tree volume in the survey site.