Biomonitoring and GIS-based Spatial Modelling for Soil Ecosystem Health in Rural Home Garden Agroecosystems in Chengamanad, Kerala, India

This study addresses the microarthropod-based estimation of biological soil quality in rural home gardens using the QBS-ar index. Soil microarthropods, soil properties, soil nutrients, and trace elements were systematically estimated from soil samples collected from 25 home gardens during summer and North East monsoon seasons over five years. The relationships among QBS-ar, microarthropod abundance, soil properties, and soil nutrients were assessed. The microarthropods reported from the study area included Protura, Collembola, Coleoptera, Hymenoptera, Diplopoda, Araneae, Acari, Diptera, and Hemiptera. The Qualitative Biological Soil - arthropods (QBS-ar) index values indicated that the home gardens ranked medium to good in soil quality, with index values ranging from 2 to 4 throughout the study period. Discriminant analysis of soil nutrients with soil properties and microarthropod abundance showed that the 2018 dataset was distinctly separated from the other years. A notable finding was the absence of trace elements above permissible limits. Hazard estimation through Geographic Information System (GIS), integrating soil properties and QBS-ar, indicated that the home gardens functioned as healthy ecosystems. This study is among the first to utilize combined QBS-ar scores, soil properties, soil nutrients, and trace elements for long term soil quality estimation in rural home garden agroecosystems. The study provides a simple, scalable methodological approach for soil ecosystem monitoring and management.