Soil Quality Assessment in Diversified Long-Term Experimentation Under Different Agriculturally Based Cropping Systems

The purpose of present study was to assess soil quality under different agricultural-based cropping systems which otherwise has been depleted by the long-term practice of rice–wheat (R-W) system. Presently, there is a need to diversify the predominant rice–wheat cropping system with more remunerative leguminous crops to improve soil quality and crop productivity. With this consideration, the present investigation was carried out at Research Farm Area, PAU, Ludhiana to assess the soil quality as affected by long-term practice (since 2016) of six different cropping systems, viz., rice–wheat, maize–wheat, cotton–wheat, mung bean–raya, mung bean–wheat, and soybean–wheat. From the cropping systems, the soil samples were analyzed for soil organic carbon (SOC), macro, micro, and secondary nutrients using standard methodologies. Soil quality index under different cropping systems was computed using soil organic carbon (SOC), macro, micro, and secondary nutrients. Then, the soil quality index was correlated with system productivity to evaluate the effect of soil quality on the productivity of different cropping systems. The outcomes of results revealed that there was significant variation in surface (SOC, Olsen P, micronutrients (DTPA-Zn, Fe, Mn, and Cu)) and available B using azomethine under different cropping systems. The long-term practice of different cropping systems led to changes in soil quality index (SQI) where soybean–wheat system led to the maximum SQI values (0.82) which resulted in higher system productivity followed by cotton–wheat system (0.81). Traditionally cultivated rice–wheat system resulted in the minimum SQI values (0.77) due to significant losses in SOC and nutrients, thereby decreasing its productivity. Among various soil parameters, the best four indicators (SOC, EC, available P, and K) were selected to interpret SQI values under different cropping systems. Soybean–wheat system resulted in maintaining higher SQI and crop productivity, thereby indicating the promising long-term effects of inclusion of leguminous crops in the main cropping systems. SOC resulted in an explanation of the maximum variability of the data set, suggesting it to be the most pragmatic and key important indicator to assess soil quality. Hence, diversification of R-W system with leguminous crops in the main cropping systems like soybean and mung bean is the prime need of sustainability of agricultural systems to promote soil quality and retain the productive capacity of soil in the long run.