Impact of long-term integrated nutrient management on soil quality and productivity of cotton (Gossypium spp.) + greengram (Vigna radiata) intercropping system in vertisols under semi-arid agroecosystem

Abstract

Integrated nutrient management has potential to enhance soil quality and sustain agricultural productivity, however, such effects under cotton + greengram intercropping is not well understood in vertisols of Maharashtra, India. Therefore, a field study was conducted during 2016–2017 at the Research field of AICRP for Dryland Agriculture Akola, Maharashtra (India), on an ongoing long-term experiment initiated in 1987–1988 under cotton + greengram (1:1) intercropping system to find out how different nutrient management practices affect the soil quality (SQ) and cotton + greengram productivity. The eight treatments comprised of sole use of organics and chemical fertilizers, integration of organics with chemical fertilizers (INM) to partially substitute nitrogen, and a control treatment. The results after 30th cycle revealed that the partial substitution of N through FYM/gliricidia increased cotton and greengram yield over control. These treatments caused significant improvement in the soil physical and biological properties and also improved the soil fertility status, mainly soil organic carbon (OC) by 53%, available N (AN) by 25%, available P (AP) by 50%, and available K (AK) by 25% over control. The SQ assessment through principal component analysis (PCA) revealed that, in this semi-arid subtropical region, HC, OC, and CO2 evolution can be viewed as important indicators of SQ for cotton + greengram intercropping system. Therefore, we concluded that, INM practice that encourages balanced fertilization must include FYM/gliricidia as part of the nutrient application package in this region to improve soil quality and sustain productivity of cotton + greengram intercropping system.