Soil quality indexes under different forestry and adjacent native scrubland use and management systems

Abstract

It is difficult to quantify the different soil characteristics that are related to sustainability, and to translate these indicators into soil-quality indexes.  Therefore, this study aimed to establish such indexes for different forestry and adjacent native scrubland use and management systems by the integrated evaluation of physical and chemical properties. To this end, two quality indexes were developed (IQS1 and IQS2), using a database of eucalyptus and native scrubland management systems for latosols in the state of Minas Gerais. In IQS1, natural ecosystems, characterized by minimal anthropic intervention and having the expected equilibrium, were used as reference. IQS2 was generated from an additive model that considers the main soil functions and the quality indicators associated with them by assigning weights to those functions and indicators. IQS1 and IQS2 presented different values ​​for the soils and management systems analyzed. The systems suffered reductions in SQI1 when compared to the native systems, with only the agro-forestry systems having higher soil-quality values, when compared to the reference systems. Using IQS2 the red-yellow latosols  (LVA1 and LVA2) showed higher soil quality than the red latosols (LV1 and LV2), this result being due to the lower limitations of the chemical and physical attributes on the principal soil functions, influenced by the management systems of those soils. Only the agro-forestry systems employing eucalyptus with rice and eucalyptus with soybeans provided improved soil quality when using  the two systems analyzed.