Revegetation intervention of drought-prone coal-mined spoils using Caragana korshinskii under variable water and nitrogen-phosphorus resources

Coal-mine spoils are typically drought-prone and deficient in essential nutrients thus creating conditions, which significantly limit plant growth and development. Here, we searched for suitable combinations of key resources water (W) and fertilizers (nitrogen, N and phosphorus, P) to improve physiological and biochemical adaptations of Caragana korshinskii to coal-mined spoils. We observed that under low W and N-P resource availability, C. korshinskii displayed poor growth performance in coal-degraded spoils. Negative growth of C. korshinskii was associated with reduced photosynthetic rate, decreased water status and increased contents of reactive oxygen species (ROS) and malondialdehyde. Overall, we found that optimum growth of C. korshinskii in coal-mined spoils was achieved under W additions corresponding to 68% of field capacity (1.85 mm /d), N and P at 52.0 and 37.0 mg/ kg soil, respectively.