Evaluation of soil quality and degradation in the agroecosystems according integrated index of chemical, biochemical and biological features

Abstract

Overall evaluation of the soil quality and degradation towards sustainability is quite complicated and still not solved problem because of the complexity of ecosystems and the soil itself as a complex ecosystem. Various methods of calculations of the integrated soil quality index will be overlooked and data of soil quality and degradation index in some Lithuanian agroecosystems will be presented. Investigations were carried out in the Luvisols at the conventional, organic, and extensive agroecosystems under different crop rotation. Soil agrochemical, biochemical and microbiological properties were determined in order to investigate relationships and to develop the integrated index of the soil quality and degradation. Standardized chemical, physico-chemical and microbiological methods were used to determine soil quality indexes. Statistical methods such as correlation and regression were used for the data analysis. Soil agrochemical, biochemical and microbiological properties varied greatly in the soils. For the highly correlated indexes such as organic matter, C/N ratio, mineral nitrogen, pH, electrical conductivity, enzymes activity and Rhysobium Galegae regression analysis was performed and integrated index was developed. In general, soil quality index in the conventional and organic farming systems was higher and degradation lower than in the extensive agroecosystem while process of the renaturalization was observed in the last. Fabaceae crops increased soil quality while Poaceae decreased. Under the proper crop rotation system soil quality remained constant.