摘要
利用15_N示踪技术,采用不同追施方法研究碳铵、硫铵、尿素在碳酸盐土壤中的转化表明:在种植作物条件下,肥料氮施入土壤后所发生的矿物固定与生物固定具有负相关关系.由于施用方法不同,肥料氮的矿物固定和损失不同,深施氮素矿物固定与损失呈显著负相关(r=—0.8359)。肥料氮在土壤中转化固定有助于减弱氮素的损失。后茬作物对残留氮的利用与生物固定态氮的多少关系不大。但与矿物固定和无机氮总量之和有密切关系。
The transformations of 15N labelled fertilizer N in calcareous soil were studied under greenhouse conditions. The experimental results indicate that the ratio of fixed ammonium is closely related to the methods of fertilizer application to the soil. When fertilizer N applied as deep dressing the fixation of nitrogen by clay minerals and microorganisms may markedly reduce the losses of nitrogen, but the amount of nitrogen fixed by the clay minerals and that by microorganisms showed negative correlation (r=-0.9185**) .The more the amount of fixed nitrogen by clay minerals, the less by microorganisms. No obvious interrelation between the residual utilization of urea, ammonium bicarbonate,ammonium sulfate and the am-mount of nitrogen fixed by organisms can be observed, but the residual utilization of these fertilizers by the succeeding crop has been related to the total amount of mineral nitrogen.
出处
《核农学报》
CAS
CSCD
1990年第4期213-218,共6页
Journal of Nuclear Agricultural Sciences
关键词
施肥方法
氮肥
碳酸盐土壤
转化
Calcareous soil, fixation of nitrogen, residual utilization