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利用顶盖埋管原位培育法测定了科尔沁沙地不同生境(丘间低地、固定、半固定、半流动和流动沙丘)土壤氮素矿化/硝化速率的月际动态及净矿化/硝化量。结果表明:①沙地土壤无机氮主要以NO3--N的形式存在,各类生境土壤NH4+-N平均含量比NO3--N低58.2%~79.7%;②土壤氮素矿化/硝化速率随植被与土壤条件的恶化呈现递减的趋势,从丘间低地到流动沙丘,净矿化速率分别为61.0、43.4、29.1、5.3 mg.m-2.d-1和2.7mg.m-2.d-1,净硝化速率分别为61.8、46.2、30.1、6.2 mg.m-2.d-1和3.4 mg.m-2.d-1;③从丘间低地到固定、半固定、半流动和流动沙丘,矿化氮总量分别减少28.8%、52.3%、91.4%和95.5%,硝化总量分别减少25.3%、51.3%、90.0%和94.5%;④不同类型生境土壤净硝化氮占净矿化氮的比例都为100%,表明沙地土壤中植物可利用氮素易于淋溶或氨挥发损失。
The in-situ dynamic changes and net mineralization / nitrification of soil nitrogen mineralization / nitrification rate in different habitats (low hills, fixed, semi-fixed, semi-flow and moving dunes) in Horqin sandy land the amount. The results showed that: (1) Inorganic nitrogen in sandy soil mainly existed in the form of NO3 - N, and the average content of NH4 + -N in soil of all kinds of habitats was 58.2% ~ 79.7% lower than that of NO3 - N; ②The rate of soil N mineralization / The degradation of vegetation and soil conditions showed a decreasing trend. The net mineralization rates were 61.0, 43.4, 29.1, 5.3 mg.m-2.d-1 and 2.7 mg.m-2.d -1 and the net nitrification rates were 61.8, 46.2, 30.1, 6.2 mg.m-2.d-1 and 3.4 mg.m-2.d-1, respectively. From the lowland to the fixed, semi-fixed and semi- The total amount of mineralized nitrogen decreased by 28.8%, 52.3%, 91.4% and 95.5% respectively in the mobile dunes and the total nitrification decreased by 25.3%, 51.3%, 90.0% and 94.5% respectively. The proportion of nitrogen is 100%, indicating that plant available nitrogen in sandy soils is easily leached or ammonia volatilizes.