Soil health card development for efficient soil management in Haryana, India

Soil health card (SHC) based management is needed for efficient management of resources and sustainable crop productivity. Soil health index (SHI) could be used as a yardstick for judging the health of the soil. Soil management and assessment framework (SMAF) is widely used to develop soil health indices to assess the impact of different management practices in cropping systems. The three steps used under SMAF are indicator selection, indicator interpretation, and indicator integration into a unified soil quality index. Soil samples were collected from farm fields with diverse management histories. This included application of farm yard manure (FYM), green manure (GM), no manure (NM). The tillage practices used by the farmers were direct seeded rice followed by zero tillage wheat (DSR-ZT), conventional tillage rice followed by zero tillage wheat (CT-ZT), system of rice intensification followed by zero tillage wheat (SRI-ZT) and CT rice followed by CT wheat (CT-CT). The soils were analysed for pH, electrical conductivity (EC), soil organic carbon (SOC), Active carbon (AC), available nitrogen (Av-N), phosphorus (Av-P), potassium (Av-K), iron (Av-Fe), manganese (Av-Mn), zinc (Av-Zn), copper (Av-Cu), bulk density (BD), maximum water holding capacity (MWHC), aggregate stability (AS), microbial biomass carbon (MBC), dehydrogenase activity (DHA), potentially mineralizable nitrogen (PMN). Minimum data set (MDS) decided in conceptual framework (CF) were further reduced by principal component analysis (PCA). The PCA screened SOC, Av-Zn, Av-Mn, Av-K, AS, MBC and PMN as most sensitive soil health indicators. The SHI developed by CF and PCA were significantly correlated with each other suggesting that PCA approach with limited soil parameters could be adequately applied for development of SHI. There were enough variations in the MDS for developing scoring curves that facilitated successful scoring of the data. Native soil texture significantly influenced the SHI; sandy clay loam soil showed highest SHI (0.67) followed by sandy loam (0.57), loamy fine sand (0.44), and fine sand (0.35) soils. Among the manuring management practices, GM showed the highest SHI (0.56) followed by FYM (0.49) and NM (0.47). Among the tillage practices, DSR-ZT showed highest SHI (0.76) followed by CT-ZT (0.59), SRI-ZT (0.55) and CT-CT (0.49). The soil health card developed has vital information on farmers, field location, soil type, and cropping practices. The soil health card also has information on eleven chemical indicators, four physical indicators and three biological indicators and SHI. The SHC has additional advantage over routine soil testing in terms of presenting information on health status of the soil as impacted by different management practices, amelioration recommendations and crop specific fertilizer and manure recommendations.