【摘要】 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。更多还原

【Abstract】 Soil net N mineralization and nitrification were determined using the PVC tube closed-top in situ incubation method in different habitats(interdunal lowland,fixed,semi-fixed,semi-moving and moving sand dune) in Horqin sandy land.The results showed that: ①The NO-3-N accounted for larger proportion of mineral N in sandy land.The average NH+4-N concentration was lower from 58.2% to 79.7% than that of NO-3-N across all habitats.②Soil net N mineralization and nitrification rates decreased along the degenerating of plant and soil.Net N mineralization rate was 61.0,43.4,29.1,5.3 mg·m-2·d-1 and 2.7 mg·m-2·d-1 in interdunal lowland,fixed,semi-fixed,semi-moving and moving sand dune,respectively,whereas N nitrification rate was 61.8,46.2,30.1,6.2 mg·m-2·d-1 and 3.4 mg·m-2·d-1.③From interdunal lowland to fixed,semi-fixed,semi-moving and moving sand dune,the total net N mineralization was decreased by 28.8%,52.3%,91.4% and 95.5%,and total net N nitrification by 25.3%,51.3%,90.0% and 94.5%,respectively.④Nitrified N accounted for 100% of mineralized N in all the five habitats.This indicated that the sandy land was prone to losing inorganic N.更多还原