Soil macroarthropod community and soil biological quality index in a green manure farming system of the Brazilian semi-arid

Abstract

Soil macroarthropods are organisms considered as key factors to sustain soil quality and sustainability due to their services to soil ecosystem. The community structure and seasonal variation of soil macroarthropods in 5-year cultivation of green manure plant species in the Brazilian semi-arid, Areia, Paraiba, Brazil were investigated between June and December 2018. Soil samples and macroarthropod specimens were collected using soil cores and Provid-type traps, respectively, during rainy and dry seasons. We characterized both soil chemical properties and macroarthropod community under ten green manure plant species: Brachiaria decumbens Stapf. cv. Basilisk, Canavalia ensiformis (L.) DC, Crotalaria juncea L., Crotalaria ochroleuca G. Don, Crotalaria spectabilis Roth, Lablab purpureus (L.) Sweet, Mucuna pruriens (L.) DC., Neonotonia wightii (Wight & Arn.) J.A. Lackey, Pennisetum glaucum L., and Stilozobium aterrimum Piper & Tracy. The highest values of richness, diversity and dominance in the macroarthropod community during the rainy season were found on the plots where C. spectabilis and M. pruriens were cultivated, whereas during the dry season the highest values were found in the plots where C. ochroleuca, C. spectabilis, and S. aterrimum were cultivated. In the plots where B. decumbens and P. glaucum where cultivated, we found lower values of richness, diversity, and dominance in the macroarthropod community compared to the leguminous plant species during rainy and dry seasons. Our findings suggest that: 1) green manure practice and seasonality changed soil macroarthropod community, trophic structure, and ecological processes in semi-arid conditions; and 2) abundance of predators, ecosystem engineers, decomposers and herbivores was promoted by plant species from Fabaceae family. The results highlight the importance to consider plant species from Fabaceae family as habitat and food resources for soil fauna community.