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氮输入是影响土壤氧化吸收大气甲烷(CH_4)的重要因子之一。通过对琼北5种旱地土壤进行室内培养实验,评价不同类型土壤对低浓度CH_4的吸收能力及其对硝态氮和不同浓度铵态氮的响应。结果表明:火山灰土、富铁土、雏形土、铁铝土和淋溶土的CH_4氧化速率分别为67.01,50.05,47.00,72.82和57.10 ng/(kg·h)。按100(mg/kg)N添加的硝态氮仅对铁铝土CH_4氧化有显著的抑制效果,而按此浓度添加的铵态氮能显著降低5种土壤的CH_4氧化速率。铵态氮对5种土壤CH_4氧化的抑制率与铵态氮添加量均呈极显著的线性正相关。每单位(mg/kg)铵态氮添加量对铁铝土CH_4氧化的抑制率最低,仅为其他4种土壤的53%~60%,这很可能跟铁铝土的高C/N和低N/P有关。因此,对这些土壤进行科学管理时,应根据土壤类型选用适宜的N肥类型,同时,还应提高土壤有机质含量,增施P肥,充分发挥土壤对大气CH_4的氧化潜力。
Nitrogen input is one of the important factors affecting soil oxidation and absorption of atmospheric methane (CH_4). Through laboratory experiments on five kinds of dryland soil in the north of Qiongbei, the response of different types of soil to low concentration of CH_4 and their responses to nitrate nitrogen and different concentrations of ammonium nitrogen were evaluated. The results showed that CH 4 oxidation rates of volcanic ash, iron-rich soil, embryonic soil, ferric-aluminous soil and leached soil were 67.01, 50.05, 47.00, 72.82 and 57.10 ng / (kg · h), respectively. The nitrate nitrogen added at 100 mg / kg N had a significant inhibitory effect on the oxidation of CH 4 in ferro-aluminous soil. The addition of ammonium nitrogen at this concentration significantly reduced the CH 4 oxidation rate of the five soils. There was a significant linear positive correlation between ammonium nitrogen inhibition rate of CH 4 oxidation and ammonium nitrogen addition. The ammonium nitrogen addition per unit (mg / kg) had the lowest inhibition on the oxidation of CH 4 in ferriferous soil, which was only 53% -60% of the other four soils, which was probably related to the high C / N and the low N / P related. Therefore, the scientific management of these soils should be based on the type of soil selected appropriate N fertilizer type, at the same time, should also increase soil organic matter content, increase P fertilizer, give full play to the potential of soil oxidation of CH4 on the atmosphere.