Enhancing Carbon and Nitrogen Sequestration in Reclaimed Soils through Organic Amendments and Chiseling

Abstract

The choice of reclamation techniques could affect restoration success, ecosystem productivity, and the capacity of reclaimed mine soil (RMS) to sequester soil organic carbon (SOC). A field experiment was conducted at three reclaimed coal mine sites across eastern Ohio to assess the impact of several reclamation techniques on biomass production, soil properties, and temporal changes in SOC and N pools. Amendments and reclamation practices tested were: normal reclamation practice (NRP, control), cow (Bos taurus) manure (10 Mg ha−1), mulching with oat straw (15 Mg ha−1), and chiseling (30‐cm depth). At each site, all treatments were applied in triplicate to experimental plots in accord with a randomized complete block design. After 5 yr of restoration, results showed no effect of mulching on any of the soil properties investigated but significant effects of manuring and chiseling. During that period, SOC sequestration rates ranged between 0.6 and 2.8 Mg C ha−1 yr−1, with the highest rates recorded in the manure‐treated plots. Aboveground biomass production, biomass N content, and soil N and SOC pools were also significantly higher in the manure and chiseling treatments, probably due to greater exploration of the soil volume by plant roots and more efficient uptake of water and available nutrients. Ecosystem C (SOC + biomass C) in these two treatments also exceeded that in the NRP by 25 to 27 Mg C ha−1 Thus, manure application and chiseling are effective reclamation practices for restoring RMS and enhancing C sequestration in these ecosystems.