Effect of Different Approaches of Nutrient Application on Soil Quality Index Under Maize-Wheat Cropping System in Mollisol Region of Uttarakhand

A field experiment was conducted at GBPUA&T, Pantnagar, to study the effect of different approaches of nutrient application on soil fertility and soil quality under maize-wheat cropping system. Nine treatment combinations were compared namely, Recommended Doses of Fertilizers (RDF), Soil Test Crop Response (STCR), and various combinations of organic and inorganic fertilizers. This paper aims to develop Soil Quality Index (SQI) based on Minimum Data Set (MDS) using Principal Component Analysis (PCA). Different indicators were employed to formulate the SQI, derived from surface soil layer measurements (0–15 cm). Each MDS indicator was then converted into a dimensionless score using linear scoring function and then integrated into SQI. Results showed that the key soil quality indicators identified as MDS using PCA under maize-wheat cropping system were Water Holding Capacity, organic carbon, available N and dehydrogenase activity. These soil quality indicators were found to be best for monitoring soil health status. After rabi wheat 2019–2020, SQI varied from 1.22 to 2.21 across the treatments whereas, after rabi wheat 2020–2021, SQI varied from 1.13 to 2.23 across the treatments. Among different approaches of nutrient application, STCR-based use of fertilizers along with FYM (T4) helped in maintaining better soil physical, chemical and biological properties and ultimately sustaining soil quality, which was followed by the treatment receiving 75% STCR dose of N (inorganic mode) + full P and K (T5). Integration of organics with inorganic fertilizers maintained soil quality, environmental health and reduced greater dependency on chemical fertilizers.