Long-term sustaining crop productivity and soil health in maize–chickpea system through integrated nutrient management practices in Vertisols of central India.

Highlights • Balanced use of nutrients through STCR based fertilizers with organic manures recorded increasing trend of yield. • Sole use of chemicals or organics could not sustain the yield and system productivity of maize- chickpea system. • Long-term integrated use of organic and inorganic sources of nutrients enhanced the system productivity and soil health. Abstract Long-term sustainability concerns are growing in agriculture owing to over and under application of fertilizers and poor management of available resources which are resulting into soil health deterioration and declining crop productivity. Balanced and integrated use of organic and inorganic fertilizers is the most logical concept for managing and sustaining long term soil health and crop productivity. Hence, a long-term field experiment was conducted from 2012 to 2017 to develop integrated nutrient management (INM) practices for sustaining crop productivity and maintaining soil health under maize (Zea mays L.) chickpea (Cicer arietinum L.) cropping system in Vertisols of central India. Twelve treatments that comprised of various combinations of general recommended dose (GRD) of NPK, farmyard manure (FYM), poultry manure (poultry manure), urban compost (UC), maize residue (MR), glyricidia loppings (GL) and soil test crop response (STCR) based NPK with target yield 5.0 and 1.50 Mg ha1 in maize and chickpea, respectively were tested. The experiment was conducted following a Randomized Complete Block Design (RCBD) set up with three replications and Simple Random Sampling (SRS) technique of sampling. The results indicated that the grain yield and system yield were observed to be significantly higher with 75% NPK of STCR + FYM at 5 Mg ha1 treatment and recorded an increase of 20.9% and 13.08% in mean grain yield of maize and chickpea, respectively over GRD. The combined analysis results illustrated significant (P < 0.0001) year x nutrient management interaction effect on grain yield with N input (R2 = 0.80) and N uptake (R2 = 0.91). Stepwise multiple regression model also showed that the N input and N uptake significantly (P < 0.05) influenced the system yield under different INM practices. However, apparent nutrient balance was negative for N and K in all treatments except higher level of FYM treatment (FYM at 20 Mg ha1) while P balance was positive under balanced and complete nutrition through organic and inorganic treatments over the years. A significant increase was observed in the various soil health indicators (physical, chemical and biological) under balanced and integrated use of organic and inorganic fertilizers. FYM, poultry manure and urban compost improved the physical properties of soil like mean weight diameter (MWD), water stable aggregates (WSA), bulk density and porosity. The application of higher level of FYM (20 Mg ha1) significantly increased the soil organic carbon (SOC) (6.30 g kg1), SOC stock (11.8 Mg ha1), carbon sequestration rate (213.1 kg ha1 year1), KMnO 4 -N (121.7 mg kg–1), Olsen-P (23.8 mg kg–1) and NH 4 OAc-K (273.5 mg kg–1) concentration in surface soil as compared to GRD and control treatments. The soil enzymes, dehydrogenase (DHA), alkaline phosphates (Alk-P) and fluorescein diacetate (FDA) were enhanced significantly with the application of FYM at 20 Mg ha1 and STCR based 75% NPK + FYM at 5 Mg ha1. The STCR based 75% NPK along with FYM at 5 Mg ha1 treatment recorded highest sustainable yield index (SYI) 0.84 and 0.92 with maximum guaranteed yield of 6.19 and 1.99 Mg ha1 in maize and chickpea, respectively. The results indicate that the chickpea yield was more sustainable as compared to the maize. [ABSTRACT FROM AUTHOR]