Soil quality assessment using soil organic carbon, total nitrogen and microbial properties in hilly agro-ecosystem

Abstract

Assessment of soil quality is an invaluable tool in determining the sustainability and environmental impact of agricultural ecosystems. The study was conducted to assess the quality of soils under traditional cultivation practices, i.e. shifting cultivation, agriculture practice, forestry plantations of Pinus kesiya, Alnus nepalensis, Parkia roxburghii, Michelia oblonga and Gmelina arborea) and modified agro-forestry system of agri-horti-silvi-pastoral system using soil organic carbon (SOC), soil total nitrogen (STN) and soil microbial biomass C (SMBC) and N (SMBN) at ICAR Complex for NEH Region, Umiam, Meghalaya, India. The shifting cultivated areas had the lowest SMBC value of 192 mg kg−1 while soil under M. oblonga plantation had significantly (P < 0.05) highest value of 478 mg kg−1. The proportion of SMBC to total soil organic carbon (SOC) was in the range of 0.9 to 1.9% across all the systems. The forestry plantation soils had higher SMBC and SMBN as a percentage of SOC and STN respectively than the cultivated arable land soils. The study suggests that the forestry followed by agri-horti-silvi-pastoral system seems to be of better option for sustainable crop production with maintenance of soil quality/health under tropical agro-ecosystems of North-east India.