Characterization of soil physical properties under different land Use Systems.

Abstract

Soil physical properties have enormous influence on water and nutrient dynamics. Characterization of soils for different properties will help to plan suitable land uses and implement appropriate control measures in order to achieve maximum land utilization and growth and yield of crops. With this objective, attempts were made to characterize the soils of Gunegal Research Farm (GRF), CRIDA, Hyderabad spread over an area of 80 ha and divided into 67 blocks representing six different land uses viz. mono cropping, intercropping, agro forestry, forestry, horticulture and medicinal crops. Composite surface soil samples were collected from 0–15 cm depth and were analyzed for soil physical properties that influence water, nutrient retention and availability to trees and crops such as particle size analysis (PSA) and few basic soil physical constants such as bulk density (BD), total porosity (TP), maximum water holding capacity (MWHC) and available water content (AWC). The data on distribution of various soil properties in the whole farm was presented using Geographic Information System. Majority of soils in the whole farm had a medium coarse (sandy clay loam) texture. The bulk density of soils under different land use classes varied between 1.3 and 1.7 Mg m−3 and was better correlated with the organic carbon content of soils. The water retention by the soil at −33 KPa in the entire farm varied from 8 to 38% (w/w) and was significantly correlated with the fine soil fractions under most of the land uses Studied. The water retention at −1500 KPa varied between 1.4 to 7.5% depending on the soil texture and soil fertility conditions. The maximum water holding capacity of soils was in the favorable range of 17 to 34% and found to have well correlated with the soil clay contents. Regression studies were conducted to explain the variations in soil BD, maximum WHC and AWC for the entire farm soils and it was found that clay and organic carbon contents significantly explained the variations in the above key soil properties. Based on the relationships existed among various soil properties, it was found that regular additions of organic and inorganic inputs is required in monocropping and horticulture systems in order to maintain a desirable levels of soil organic carbon and favorable soil physical properties.