The influence of different soil conditioners on the reconstruction of soil nutrients and enzyme activities in open-pit coal mines

To study the effects of three soil conditioners,namely distiller' s grains,corn cobs and sodium humate,on the nutrients and enzyme activities of reconstructed soil in open-pit coal mines,the muck from the Zahanaoer open-pit mine in the eastern part of Inner Mongolia were taken as the research object to analyze the variation characteristics of nutrients and enzyme activities in the reconstructed soil by different conditioners. The response relationship between soil nutrients and soil enzyme activities under different conditioner conditions was established by stepwise regression analysis. The differences in soil nutrients, enzyme activities and their influencing factors under different conditioner conditions were analyzed by one-way analysis of variance. The research results show that distiller's grains can significantly increase the content of available nutrients and enzyme activities in the soil. Among them,the experimental group (Group C) with an addition amount of 12. 0 g/kg of distiller's grains per unit mass of soil is the optimal. The mass fractions of alkali-hydrolyzed nitrogen, available phosphorus and available potassium in the soil increased by 20. 18%,32. 10% and 13. 86% respectively,and the variation range of soil enzyme activities was-16. 9% to 398. 1%. Corn cob is a relatively good mineral muck agent, which has a positive effect on enhancing the activities of four soil enzymes,namely catalase,phosphatase,sucrase and urease,promoting the increase of enzyme activities. Mixing corn cob with distiller's grains can effectively enhance the activity of four soil enzymes. "Distiller's grains 12. 0 g/kg+ corn cob 12. 0 g/kg" is the optimal mass ratio of soil conditioner. The content of alkali hydrolyzable nitrogen is mainly affected by enzyme activity. The enzyme activity of soil after adding distiller' s grains mainly affects the content of alkali hydrolyzable nitrogen. After adding corn cob into distiller' s grains,the enzyme activity mainly affects the content of potassium. After adding sodium humate into distiller's grains,the enzyme activity mainly affects the content of available phosphorus.