Bioresource management for improvement of soil chemical and biochemical quality in arid environment | Manejo de los biorecursos para el mejoramiento de la calidad química y biológica de los suelos en ambientes áridos

Abstract

Fauna-induced litter decomposition and associated changes in soil organic carbon (SOC), total soil nitrogen (TSN), soil ammonium nitrogen (SAN), soil nitrate nitrogen (SNN) and soil available phosphorous (SAP), soil respiration (SR) and soil dehydrogenase activity (SDA) were studied in Tecomella undulata (T) tree based silvipature system integrated with Cenchrus ciliaris (CC) and Lesiurus sindicus (LS) grasses in dry region of India. The litter bag experiment was performed using tree and grass litters. The faunal association was maximum in T+LS litter. Whereas the litter decomposition was maximum in T + CC litter. Thus decomposition was influenced by litter mixtures and associated soil fauna. Faunal population and litter decomposition were highest inside the canopy of tree at 5 cm depth defining preferred faunal niche. SOC, TSN, SNN, SR and SDA were significantly (P < 0.05) higher in the mixture of tree and grass litters than tree litter alone at all decomposition periods. TSN, SAN, SNN, SAP, SR and SDA were significantly (P < 0.05) higher under the canopy zone. The higher nutrient enrichment and biochemical activities in the mixture of litters under the tree canopy at 5 cm depth may be due to the mixing and decomposition of greater volume of litters by soil biota. However, SOC was significantly (P < 0.05) higher at surface and minimum at 5 cm depth. It may be due to the loss of carbon as CO2 by higher microbial population at 5 cm. A positive and significant correlation and interaction among litter-associated soil fauna, litter decomposition, soil chemical and biochemical properties clearly demonstrate the importance of soil fauna in organic resource management in dry areas. Key words: Dry region, soil fauna, litter decomposition, soil nutrients, silvipasture system. RESUMEN Se estudiaron la descomposición inducida por la fauna de la hojarasca y los cambios asociados en el carbono orgánico del suelo (COS), nitrógeno total del suelo (NTS), nitrógeno amónico del suelo (NAS), nitrógeno en forma de nitrato del suelo (NNS), fósforo disponible del suelo (FDS), respiración del suelo (RS) y la actividad de la deshidrogenasa del suelo (ADS) en árboldes de Tecomella undulate (T) basado en un sistema silvipasture integrado con las gramíneas Cenchurus cilliaris (CC) y Lesiurus sindicus (LS) en la región seca de la India. El experimento en bolsas con hojarasca se realizó usando hojarascas de arboles y gramíneas. La asociación faunística fue máxima en T + LS, mientras la descomposición de la hojarasca fue máxima en T + CC. Así, la descomposición estuvo influenciada por la calidad de la hojarasca y asociada con la fauna del suelo. La población de la fauna y la descomposición de la hojarasca fueron mayors dentro del dosel del árbol a 5 cm de profundidad definiendo el nicho preferido de la fauna. COS, NTS, NNS, RS y ADS fueron significativamente (