摘要
在北京地区生态条件下,渍水稻田土壤的固氮活性在水稻孕穗至抽穗期出现一个高峰。植稻土壤的固氮活性明显高于未植稻土壤。表施氮肥(50kg 硫酸铵/亩)降低了稻田水层和土表氧化层的固氮活性,但提高了耕层下层(2～15cm)土壤的固氮活性。施稻草(200kg/亩处理),对稻田各层次土壤的固氮活性均有促进作用。粗略估计水稻田土壤(水)不同层次的固氮能力,表明耕层还原土层是北京地区稻田土壤-水系统的最重要因氮部位。
Nitrogen fixing activity in paddy soil in the suburbs of Beijing was measured by ecetylene reduction method.Nitrogen fixing activity in paddy soil with rice was higher than in submerged soil when rice was not planted, and the peak of nitrogen fixing activity was presented from booting to earing stage of rice growth.Nitrogen fixing activity was reduced in water layer and aerobic layer but increased in anaerobic layer when ammonium sulphate was applied (300kg/ha) .Nitrogen fixing activity was stimulated by straw appling in all layer of paddy soil.The capacity of nitrogen fixation in anaerobic layer was the highest in flooded soils in suburbs of Beijing.
基金
国家自然科学基金
