Rejuvenation of soil organic carbon through soil amendments: A novel approach to managing heavy metals in soil and plants

Abstract

Soil organic carbon (SOC) imparts better soil structural stability which in turn enhances the soil physical environment. Further, SOC plays a key role in maintaining soil health especially soils under stress. With aim of improving soil resilience under heavy metal stress, this study was formulated to find out the effect of soil amendments on rejuvenating soil organic carbon content under heavy metal stress. The field experiment was conducted in a farmer’s field near SIPCOT industrial area, Cuddalore District, Tamil Nadu, India during June - September 2017. A randomized block design with seven amendments [Farmyard manure (FYM), Press mud (PM), Ethylene diamine tetraacetic acid (EDTA), Lime, Gypsum, Potassium humate (PH), Natural Zeolite (NZ)] and control were replicated thrice for assessing the effects on SOC enrichment in soil and its interventions with heavy metals in soil and plant using sunflower as a test crop. The outcome of the STUDY confirmed that the application of FYM and PM distinctively enriched the soil organic carbon (0.65 and 0.57 g kg-1, respectively) content than the other amendments used from the initial SOC status (0.41 g kg-1). Consequently, the organic amendments halt the heavy metals (lead and cadmium) progress in the soil thus bioavailability is reduced. In contrast, among inorganic amendments application of EDTA induces the mobility of heavy metals in soil (52.3 - 65.7 % over control) so increased the bioavailability and resulting in more uptake by sunflower plants.