Zero-tillage in Mung Bean-Wheat Cropping System: Impact on Soil Properties and Crop Productivity

Background: Inclusion of legume crops in efficient cropping system is important to maintain soil bio-physical property for sustainable production systems. Conservation agriculture (CA) practices have been demonstrated to be successful in cereal based systems. But the information on zero-tillage as CA practice in legume based systems is lacking, which may further help in conservation of soil resources on sustainable basis. Hence study on impact of zero-tillage on soil biological and physico-chemical properties was undertaken at CCS Haryana Agricultural University, Regional Research Station, Bawal (Rewari), India during 2019-20 and 2020-21. Methods: The soil of experimental site was loamy sand in texture and low in organic carbon, N and P, while medium in K. The treatments included nine tillage combinations for crop establishment under mung bean [Vigna radiata (L.) Wilczek]-wheat (Triticum aestivum L.) cropping system (MWCS) viz., Zero-tillage mung bean (ZTM) fb zero-tillage wheat (ZTW), ZTM fb reduced tillage wheat (RTW), ZTM fb conventional tillage wheat (CTW), reduced tillage mung bean (RTM) fb ZTW, RTM fb RTW, RTM fb CTW, Conventional tillage mung bean (CTM) fb ZTW, CTM fb RTW, CTM fb CTW. The experiment was laid out in randomized block design with three replications. Result: After two years, there was no change in soil texture and EC of the soil due to different crop establishment methods, while the bulk density of upper soil layer (0-15 cm) decreased marginally under system-based ZT method. The Infiltration rate increased with decrease in the frequency of tillage in both the crops. Organic carbon in upper layer increased while pH decreased marginally under ZTM-ZTW as compared to CTM-CTW. Available N and P showed increasing trend with decrease in number of tillage operations after two years of MWCS. Tillage practices had no significant effect on available K. The grain yield of wheat was not influenced by tillage during 2019-20, but in 2020-21 it was significantly higher under ZT wheat sown after ZTM (5025 kg ha-1) than RTW (4622-4722 kg ha-1) and CTW (4593-4641 kg ha-1), irrespective of tillage practices in mung bean. The seed, stover and biological yields of mung bean were similar under all crop establishment methods in MWCS. This indicated sustainability of zero-tillage methods of establishment in MWCS.