Soil quality, resistance and resilience in traditional agricultural and agroforestry ecosystems in Brazil's semiarid region

Abstract

Agroforestry represents an alternative to traditional agricultural systems in semiarid regions, since it effectively provides soil coverage and improves the amount and quality of soil organic matter. The sustainability of agricultural systems can be assessed by evaluating soil quality, resistance and resilience. Therefore, this work evaluated soil quality, resistance and resilience under traditional cropping and agroforestry systems. The study took place at an experimental station in Brazil’s semiarid northeast region. Studied land use systems include agrosilvopastoral, silvopastoral and traditional cropping, as well as areas under traditional fallow for six and nine years and unaltered ecosystem. Small trenches were dug randomly to collect soil from three depth increments. Soil Quality (SQ) was assessed using chemical, physical and biological indicators. Based on these indicators, resistance, resilience and soil quality indices were calculated. The index quality of the soil was generated using soil water retention, nutrient supply and biological activity promotion functions. Comparisons of index means indicate that agroforests maintained SQ, while traditional fallow systems resulted in improved SQ up to levels similar to the unaltered ecosystem. Traditional cropping lead to a reduction in SQ, resistance and resilience. Agroforestry systems are sustainable. Fallow can improve soil quality, soil resistance and resilience. Key words: Agrosilvopastoral, silvopastoral, slash-and-burn agriculture, agricultural sustainability, soil management, conservation.