Short-term nickel residual effect in field-grown soybeans: nickel-enriched soil acidity amendments promote plant growth and safe soil nickel levels

Abstract

Nickel-enriched soil acidity amendments (SAA) may be advantageous for neutralizing acidity and providing safe/uniform distribution of Ni in soils. We evaluated the short-term effects of Ni application on field-grown soybean yield, growth, and soil chemical attributes using three sources of SAA, two enriched with Ni (Ni-rich mining by-product and Ni-salt) and a commercial SAA. The tested Ni-enriched sources were effective in providing Ni to the soil at safe levels, neutralizing acidity and increasing base saturation. A one-time Ni application resulted in optimal Ni levels in the first cropping season, enhancing grain yield by up to 658 kg ha−1 and improving nitrogen metabolism in soybean. A low residual effect of Ni was observed in the second year, with soil available Ni and plant Ni concentrations decreasing to sub-optimal levels and yield gains not being observed. In conclusion, the application of Ni-enriched SAA is a sustainable technology for agriculture, optimizing soil management practices. The SAA derived from by-products has benefits to the mining sector, meeting the ‘Ensure Sustainable Consumption and Production Patterns’ (SDG 12). Our findings suggest that this micronutrient may require a year-to-year adjustment via Ni-fertilization and the total Ni concentration in the soil should be monitored over the cropping seasons.