CHEMICAL PROPERTIES OF SOILS IN TRADITIONAL UPLAND RICE FARMS

Abstract

This study was conducted to assess the soil chemical properties of upland rice farms particularly along different gradients (sloping, steep, and flat) in cultivated and uncultivated sites. Sampling was done in the wet and dry seasons. Results showed that soils in the cultivated sites have relatively lower pH than in uncultivated sites. However, pH values taken during the wet season were relatively higher as compared to soil samples taken from the dry season. Organic matter was generally higher in most uncultivated soils and in soil samples taken during the wet season. Phosphorous was generally abundant in uncultivated soils and in soils collected during the dry season. Potassium levels were observed to vary slightly across seasons and slope gradients. Zinc values were generally higher in cultivated soils and in samples taken during the dry season. Soils from uncultivated areas and in the dry season have generally higher Copper concentrations. Manganese concentration was higher in the dry season than in the wet season. For iron, concentration levels were very much higher in cultivated sites. These results show similar values in the cultivated and uncultivated sites for the concentration of the different macro and micronutrients. This may may be attributed to fallowing and crop rotation that allows replenishment of lost nutrients. The practice of crop rotation from rice to legumes may have enhanced the positive impacts of fallowing particularly in the recycling of nutrients. Although low pH was observed which is characteristic of mountain soils, cultivated sites showed to be more acidic as compared with uncultivated sites. It is therefore relevant that the management practices involved be closely assessed, as these traditional practices may contain important inputs in formulating sustainable measures in maintaining the chemical intergrity of upland soils.