Conservation Tillage, Residue Management, and Crop Rotation Effects on Soil Major and Micro-nutrients in Semi-arid Vertisols of India

Abstract

Due to declining soil quality and increasing climate change, resource conservation technologies are often advocated for the food production system. Conservation agriculture (CA) is one of the technologies that increase soil nutrient status without jeopardizing the soil health and quality. The effects of conservation tillage, residue retention, and cropping systems on soil physical, chemical, and biological properties within the irrigated agricultural system are well established. However, scanty information is available on the combined impact of tillage, residue, and cropping system available on the major and micro-nutrient in the rainfed farming systems. Thus, a field experiment was conducted to measure the short-term effect of CA practices on soil properties and major (N, P, and K) and micro (Fe, Mn, Zn, and Cu)-nutrients in a Vertisol of Central India. The field experiment was laid out in a split-plot design consisting of two tillage systems (TS), conventional tillage (CT) and reduced tillage (RT), as the main plots and six cropping systems (CS) as subplots. A total of 144 soil samples were collected after four crop cycles to assess soil properties and nutrient (major and micro-nutrient) status. Results demonstrated that in the surface soil layer (0–5 cm), the major and micro-nutrient concentrations were higher than subsurface layers, regardless of TS and CS. In the surface soils, soil organic carbon (SOC) varied from 0.58 to 0.60% under CT and from 0.60 to 0.62% under RT. Tillage and cropping systems had a significant effect (p < 0.05) on major available nutrients (N, P, and K) at 0–5-cm depth. The DTPA extractable Fe, Mn, Cu, and Zn concentrations exhibited decreasing trends with increasing depth. At 0–5-cm depth, the DTPA-Fe, Mn, Cu, and Zn under CT varied from 7.56 to 9.58 mg kg−1, 15.04 to 15.91 mg kg−1, 1.37 to 1.80 mg kg−1, and 0.57 to 0.62 mg kg−1 and under RT varied from 8.25 to 11.16 mg kg−1, 15.65 to 17.73 mg kg−1, 1.54 to 1.80 mg kg−1, and 0.59 to 0.67 mg kg−1, respectively. We concluded that RT practices, coupled with crop residue retention, positively affected major and micro-nutrient distribution and availability in this soil. Results highlight the importance of nutrient dynamics under different tillage and cropping systems and thus improve the nutrient recommendation in the semi-arid eco-region of Central India.