Effects of Long-Term (7 Years) Adoption of Conservation Agriculture and Nutrient Management Practices on the Soil Properties, System Crop and Water Productivity and Farm Economics of a Maize–Chickpea Rotation&nbsp;
Authors: Pooniya Vijay , Zhiipao R.R. , Biswakarma Niraj , Jat S.L. , Kumar Dinesh , Parihar C.M. , Swarnalakshmi K , Lama Achal , Verma A.K. , Roy Debasish , Das Kajal , Majumdar K. , Satyanarayana T. , Jat R.D. , Ghasal P.C. , Ram Hardev , Jat Rajkumar , Nath Amlan 
Published: December 2020

Abstract
Conservation agriculture (CA)-based practices have been promoted and recouped, as they hold the potential to enhance farm profits besides a consistent improvement in soil properties. The CA-based crop establishment practices (CEP) along with adequate fertilizer inputs in the diversified maize-chickpea rotation (MCR) could be a profitable choice to sustain the crop production of Indo-Gangetic plains in the posterity. Therefore, a seven years' field experiment consisting of three CEP viz., zero till flatbed (ZTFB), permanent beds (PNB), conventional system (CT) along with the three nutrient management practices; nutrient expert assisted: site-specific nutrient management (NE®), recommended fertilization (RDF), and farmers’ fertilizer practice (FFP), was carried out from 2013–2020 in a sandy loam soil of the north-western Indo-Gangetic plains. Seven years’ mean maize grain yield under the ZTFB (4.34 Mg ha-1) and PNB (4.37 Mg ha-1) was significantly (p<0.05) higher than the CT (3.79 Mg ha-1). The NE® and RDF had 25.7% and 22.3% greater maize grain yield than the FFP, respectively. Similarly, ZTFB and PNB had 12.2% and 21.5% greater chickpea seed yield, respectively over the CT. The NE® and RDF gave 12.1% and 8.4% higher chickpea seed yield over the FFP, respectively. The CA-based CEP (ZTFB / PNB) produced 13.9–17.6% (seven years’ mean) higher maize grain equivalent yield (MGEY) compared to the CT, while NE® and RDF had 10.7–20% higher MGEY than the FFP. Furthermore, the PNB and ZTFB gave 28.8% and 24% additional net returns than the CT, while NE® and RDF had 22.8% and 17.4% greater returns, respectively over the FFP. The mean data showed that PNB had 7.5% and 30.8% greater system water productivity (SWP) than the ZTFB and CT, the NE® and RDF had 20% and 14% greater SWP than the FFP, respectively. After harvest of the 7th year maize, the PNB and ZTFB had 2.3–4.1% (0.0-0.20 m soil layers) lower bulk density (ρb) than the CT, however NE® and RDF had 1–1.9% lower ρb compared to the FFP. The CEP had a significant (p<0.05) impact on the soil organic carbon (OC) in 0.0-0.20 m soil layers but it remained unaffected due to the nutrient management beyond 0.10 m soil depth. Microbial biomass carbon (MBC) increased by 8–19% (0.0-0.50 m soil layers) in the ZTFB / PNB over the CT, and by 7.6–11.0% in the NE® / RDF over FFP. The sustainability yield index (SYI) was also greater under the CA-based CEP and with the NE® or RDF compared to the CT practices. Hence, the present study suggests that the CA-based CEP coupled with the NE® or RDF could enhance the yields, farm profits, soil properties of the maize-chickpea rotation, thereby, could sustain the production in long-run.