植物类型与改良方式对重构土壤氮转化速率的影响

目的] 研究不同植物与改良方式对重构土壤氮转化率的影响，为提高矿区重构土壤可利用氮素含量提供理论依据。方法] 以取自内蒙古自治区通辽市扎哈淖尔露天煤矿的采矿剥离物为基质配制重构土壤，分别以鸡粪肥、自制改良剂对其进行改良，并选取4种类型的植物，研究这两个因素对无机氮存在形式、氮净矿化率、净氨化率和净硝化率的影响。结果] 硝态氮是重构土壤中无机态氮存在的主要形式，改良剂、植物及其交互作用对重构土壤氮净矿化率、净氨化率和净硝化率有极显著影响，自制改良剂改良可以显著提高重构土壤中铵态氮、硝态氮和亚硝态氮的含量及净硝化率，紫花苜蓿可以显著提高重构土壤中硝态氮含量及氮净矿化率。90 d时重构土壤的氮净矿化率最高。结论] 播种90 d内，重构土壤中无机态氮存在形式由铵态氮向硝态氮转化，添加自制改良剂能够提高重构土壤中无机态氮含量，对矿区重构土壤的净氨化率、净硝化率及氮净矿化率的提高有促进作用。

Effects of Plants and Improvement Methods on Nitrogen Transformation Rate of Reconstructed Soil

Objective] Effects of different plants and improvement methods on the nitrogen conversion rate of reconstructed soil were studied in order to provide a theoretical basis for improving the available nitrogen content of reconstructed soil at mining areas.Methods] Stripping material from the Zhahanur open pit coal mine in Tongliao City, Inner Mongolia was used as the matrix to prepare reconstructed soil. Chicken manure and self-made amendments were used to improve the soil. Four types of plants were selected to study the effects of these two factors on the existing form of inorganic nitrogen, net mineralization rate, net ammonification rate, and net nitrification rate.Results] Nitrate nitrogen was the main form of inorganic nitrogen in reconstructed soil. The effects of modifiers, plants, and their interactions on the net mineralization rate, net ammonification rate, and net nitrification rate of reconstructed soil nitrogen were very significant. The content and net nitrification rate of ammonium, nitrate, and nitrite nitrogen in reconstructed soil was improved significantly by self-made amendments. Medicago sativa significantly improved nitrate nitrogen content and the net mineralization rate of nitrogen in reconstructed soil. The net mineralization rate of nitrogen in reconstructed soil was the highest at 90 days.Conclusion] Within 90 days after planting, the existing form of inorganic nitrogen in reconstructed soil was transformed from ammonium nitrogen to nitrate nitrogen. Adding self-made amendments improved the content of inorganic nitrogen in reconstructed soil, and increased net ammonification rate, net nitrification rate, and net mineralization rate of nitrogen in reconstructed soil at mining areas.