寒地稻田施氮状况与氮素调控对水稻投入和产出的影响

文章通过对黑龙江省1～3积温带240个农户的施肥情况调查,以及对试验区水稻氮素收支状况分析,研究了黑龙江省稻田土壤氮循环规律。结果表明,寒地稻田化肥投入氮量平均为150 kg.hm-2,占投入总量的72.4%,而且90%以上作基蘖肥施用,近60%的稻田氮素用量过高,稻田氮有17.2%的盈余,氮肥利用率较低。针对寒地水稻施氮问题,提出进行实地氮肥管理的策略,经过3年9个点次田间对比试验,证明该技术能降低氮肥用量30%以上,水稻产量增加10%以上,每公顷增收1 450元。

Nitrogen application situation and effects of nitrogen management on cost and output of paddy field in cold area of northeast China

A fertilization investigation with 240 farmers and nitrogen output and input were conducted to find out problems of nutrient management and regularity of nitrogen balance from 2004 to 2005 in Heilongjiang Province.Results showed that average N rate was 150 kg·hm-2 in rice production.There was 17.2% surplus between N input and output in Heilongjiang Province.Basal and tiller N accounted for above 90% of total N.This was also an indication of unreasonable use of N fertilizers,and irrational application timing was the other hand.This resulted in lower N use efficiency.Site-specific nitrogen management(SSNM) was used to solve nitrogen fertilization problems,and 9 field experiments with two fertilization methods,SSNM and Farmer′s fertilization practice(FFP),were conducted to study the effects of SSNM on rice yield,output and input from 2004 to 2006.Results showed that SSNM decreased N rate by above 30%,increased yield and profit by above 10% and 1 450 Yuan·hm-2,correspondingly.