Soil quality indicators under continuous cropping systems in the arid ecosystem of India

Effect of cropping systems (CS) on the soil quality (SQ) and its determinants was assessed for the clay loam soil of Hisar, India. Collected surface soil samples were analyzed for four physical indicators viz. bulk density (BD), saturated hydraulic conductivity (SHC), porosity and mean weight diameter (MWD) seven chemical indicators viz. pH, electrical conductivity (EC), organic carbon (OC), nitrate nitrogen (NO3-N), ammoniacal nitrogen (NH4-N), available phosphorous (AV-P) and available potassium (AV-K) and two biological indicators viz. dehydrogenase activity (DA) and microbial biomass carbon (MBC). Correlation analysis of the 13 soil attributes representing soil physical, chemical, and biological parameters resulted in a significant correlation in twelve (P < 0.01) and nine (P < 0.05) attribute pairs out of the 47 soil attribute pairs. Each SQ indicator was compared with its value under different CS using Duncan Multiple Range Test (DMRT). The results indicated that, the soil properties such as BD, MWD, Av-P, Av-K, and DA were greatly influenced by the components of each CS. The adverse impact of CS on the SQ indicators resulted in deterioration of SQ. Evaluation of SQ using soil quality index (SQI) under CS showed that, SQ was better in T2 (Cotton-wheat-fallow) and T5 (Greengram-mustard+kasni) compared to other. The CS that exhibited negative impacts on SQ should be discouraged for long-term cultivation to maintain good soil health for sustainable agricultural production. Value of SQI was positively and significantly correlated (R2 = 0.50, P < 0.01) with wheat equivalent yield for all the CS. This implies that, the index may have practical utility for quantifying the SQ.   Key words: Cropping system, soil quality, soil quality index, soil physical indicator, soil chemical indicator, and soil biological indicator.