摘要
对1984年建设的渭北旱塬的长期肥料定位试验土壤剖面硝态氮含量进行了分析,结果表明:施肥12a后单施有机肥处理的硝态氮含量在60cm以下土层,与CK、P含量接近,未发现硝态氮淋溶;NPM处理的累积峰在60—140cm,氮磷配施在100—120cm。22a后,除CK和P外,各处理均在40—100cm土层出现累硝态氮积峰,其中N、NP、NPM处理硝态氮分布呈现出双峰曲线(在60cm和200cm处均出现累积峰),表现出向更深土层淋溶的趋势。单施氮肥平均每年累积量高达73.5kg/hm2,虽然NP和NPM年均累积速率比N处理分别减少了57.7%和78.6%,长期超量施用有机肥依然存在生态风险,必将造成氮素的大量损失,但该区的地下水埋藏深厚(50m),对地下水污染风险小。
The nitrate distribution in the soil profile was analyzed based on a long-term fertilization experiment of continuous wheat in the fixed site since 1984. The results showed that NO;--N content was similar to that in the control and the phosphorus treatment after 12 years with organic fertilizer treatment only, and no nitrate leaching was found. The cumulative concentration peak NO3- -N of the NPM treatment was between 60--140 cm, it was at about 100--120 cm in NP treatment. Moreover, for the N, NP, NPM treatments, the double peak of the cumulative NO3-N concentration appeared in both 60 cm and 200 cm depths showing a downward leaching trend. Thus the long-term continuous excessive application of manure still presented the ecology risk. The annual nitrate cumulative content could be as high as 73.5 kg/hm2 in the N treatment, while the content also was 31.1 kg/hm2 in the NP treatment which will cause a large amount of nitrate loss. But it had little effect on the pollution of the underground water due to the deep underground water table.
出处
《水土保持研究》
CSCD
北大核心
2014年第2期43-46,共4页
Research of Soil and Water Conservation
基金
国家科技支撑计划重大项目"农田水土保持关键技术研究与示范"(2011BAD31B01)
宁夏农业综合开发科技推广项目(NTKJ-2013-03-1)
关键词
长期试验
施肥
土壤剖面
硝态氮
累积
淋溶
long-term experiment
fertilization
soil profile
nitrate
accumulation
leaching
