摘要
在我国东北一季作农田地区 ,秋季作物收获时土壤中累积的无机氮并不多 ,但经过秋末一段温度、湿度都适宜矿化作用又无作物生长利用的时期以后 ,封冻前旱地土壤中累积的无机氮可以达到一个较高的水平 ,单施化肥的旱地农田 1m土体中累积的无机氮为 99 9kg·hm-2 ,化肥和有机肥配施的农田为14 5 4kg·hm-2 ;水田土壤中累积的无机氮较低 ,这是由于水田土壤长期淹水 ,通透性不及旱田 ,尽管落水后透气性有所改善 ,但不充分的含氧条件有利于反硝化作用 ,矿化的无机氮最终以N2 O形式损失掉 .
The study showed that in northeast China,the farmlands with a mono-harvesting agricultural system had a low accumulation of soil inorganic nitrogen after harvest.In late autumn,there was an interval of about 20～30 days when the temperature and humidity were appropriate to soil N mineralization,but the mineralized nitrogen could not be used by crops in this non-growing season.The accumulation of inorganic nitrogen in upland soil reached a high level before freezing.Its inorganic nitrogen content in 1m depth soil was 99.9 kg·hm -2 in the treatment of commercial fertilizers(N 150 kg·hm -2;P 16.4 kg·hm -2;K 62.3 kg·hm -2)and 145.4 kg·hm -2 in the treatment of commercial fertilizers plus manure(pig manure by a reutilization of 80% product).While in rice field,its inorganic nitrogen content was relatively low before freezing.The reason might be that the soil permeability was not as good as that in upland for its long-term water-logging,and its insufficient aeration would be favorable to denitrification which induces the inorganic nitrogen loss via N 2O emission.
出处
《应用生态学报》
CAS
CSCD
2004年第10期1887-1890,共4页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目 ( 3 0 10 0 0 2 2 )
中国科学院陆地生态过程重点实验室基金资助项目
关键词
无机氮积累
一季作农田
非生长季
Accumulation of inorganic nitrogen, Mono-harvesting farmland, Non-growing season.
