Integrated plant nutrient supply modules for enhancing crop growth, productivity and nutrient balance in maize - chickpea cropping sequence

A long-term field study was conducted to evaluate integrated plant nutrient supply (IPNS) system in maizechickpea cropping sequence. In this study, twelve IPNS modules of Soil Test Crop Response (STCR) based fertilizers, recommended dose of fertilizers (RDF), farmyard manure (FYM), poultry manure (PM), urban compost (UC), maize residue (MR) and Gliricidia loppings (GL) were investigated. Results indicated that plant height, dry biomass, yield parameters (cob length and girth, grains/cob and 1000-grains weight) and yields (grain and stover) of maize significantly (p=0.05) improved with IPNS module (75% NPK +5 t FYM) and increased 31.8 and 23.8% grain yield over the RDF and 100% NPK of STCR, respectively. In chickpea, the higher plant height, dry biomass, pods/ plant and yields (grain and straw) were obtained with the residual fertility of FYM @ 25 t/ha every year and followed by IPNS module (75%NPK +5 t FYM). However, residual fertility of PM and UC based IPNS modules also considerably improved the crop growth and yields of chickpea. Substantially higher system productivity was also noticed with 75% NPK +5 t FYM and followed 75% NPK +1 t PM based IPNS modules which was 1.86 and 0.99 t/ ha higher than RDF. A positive nutrient balance was recorded with addition of higher level FYM only (25 t/ha) Whereas, a negative nutrient balance was noticed for N and K in all plots excluding higher level of organic manures. However, there has been substantial build-up of N, P and K in plots receiving 25 t FYM every year. The additional supply of nutrients (organic + inorganic) is crucial for positive nutrients balance. Thus, STCR based fertilizers (75% NPK) along 25% nutrients through organic manures (FYM and PM) sustained the crop yield while the addition of FYM (25 t/ha) is essential for a positive balance of nutrients in the soil.