【摘要】：通過野外調查結合室內分析,研究了黃土丘陵區(qū)模擬放牧干擾半年和一年后生物結皮土壤全氮、速效氮和微生物生物量氮累積的變化,以期揭示生物結皮土壤氮素對干擾響應的敏感性.結果表明:生物結皮土壤氮素對干擾響應敏感,短期干擾可導致土壤全氮、速效氮和微生物生物量氮含量降低.干擾半年后,生物結皮層全氮和速效氮含量較不干擾分別下降0.17~0.39 g·kg~(-1)、1.78~5.65 mg·kg~(-1);干擾一年后,分別下降0.13~0.40 g·kg~(-1)、11.45~32.68 mg·kg~(-1),生物結皮層微生物生物量氮下降69.99~330.97 mg·kg~(-1),0~2 cm土壤微生物生物量氮增加25.51~352.17 mg·kg~(-1).干擾對生物結皮土壤氮素累積的影響與干擾強度有關,20%和30%干擾強度下生物結皮層氮素累積變化不顯著,40%和50%干擾強度下生物結皮層氮素累積顯著降低.短期干擾降低了生物結皮層氮素累積,但表層5 cm土壤氮素含量變化不顯著.
[Abstract]:Through field investigation and laboratory analysis, the changes of total nitrogen, available nitrogen and microbial biomass nitrogen accumulation in biological crust soil under simulated grazing disturbance for half a year or a year in loess hilly region were studied. In order to reveal the sensitivity of biological crust soil nitrogen to interference response. The results showed that nitrogen in biological crust soil was sensitive to interference, and short-term interference could reduce soil total nitrogen, available nitrogen and microbial biomass nitrogen content. After six months of disturbance, the contents of total nitrogen and available nitrogen in the biological cortex decreased by 0.17g kg~ (-1) and 1.785.65 mg kg~ (-1), respectively. After one year of disturbance, the levels of 0.13g kg~ (-1), 11.45 mg kg~ (-1) and 69.99 mg kg~ (-1) of microbial biomass nitrogen were decreased, respectively, and the microbial biomass nitrogen in the biological cortex decreased by 330.97 mg kg~ (-1), respectively. Soil microbial biomass nitrogen increased by 25.51 ~ 352.17 mg kg~ (-1) at 0 ~ 2 cm. The effect of interference on nitrogen accumulation in biological crust soil was related to the intensity of interference. There was no significant change of nitrogen accumulation in biological crust under 20% and 30% interference intensity, while nitrogen accumulation in biological cortex decreased significantly under 40% and 50% interference intensity. Short-term interference reduced the accumulation of nitrogen in the biological cortex, but the soil nitrogen content did not change significantly in the surface layer for 5 cm.
【作者單位】： 西北農林科技大學資源環(huán)境學院;中國科學院水利部水土保持研究所黃土高原土壤侵蝕與旱地農業(yè)國家重點實驗室;中國科學院大學;
【基金】：國家自然科學基金項目(41571268,41271298)資助~~
【分類號】：S812.2
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本文編號：2349620