%0 Journal Article
%T Effects of Different Irrigation and Nitrogen Supply Levels on Nitrate-N Dynamics in a Recently Reclaimed Sandy Farmland in Heihe River Basin<br>灌溉与施氮对黑河中游新垦沙地农田土壤硝态氮动态的影响
%A WANG Qi
%A LI Feng-rui
%A ZHANG Zhi-hui
%A <br>王琦
%A 李锋瑞
%A 张智慧
%J 环境科学
%D 2008
%I 
%X Improper nitrogen (N) and irrigation management are major causes leading to deterioration in water environmental quality in the middle reaches of Heihe River basin. A controlled experimental study of different irrigation and N supply levels was therefore conducted in the Linze Inland River Basin Research Station, Chinese Academy of Sciences, to determine the influences of N addition and irrigation regime on the dynamics of nitrate-N (NO3--N) distribution in soil profiles over the growing season of spring wheat. The experiment employed a completely randomized block split-plot design, with irrigation treatments 0.6, 0.8, 1.0 of the estimated evapotranspiration (ET), denoting I0.6, I0.8 and I1.0 respectively] and N addition treatments 0, 140, 221, 300 kg.hm-2, denoting N0, N140, N221 and N300 respectively] as the main-plot and split-plot, respectively. Our results show that the rate of N is the key factor in influencing NO3--N content and its leaching. The content of NO3--N in the 0-200 cm soil profiles was found to increase with increased N rates, and in particular this increase was more pronounced when the N rates ranged between 221 kg.hm-2 and 300 kg.hm-2. In addition, NO3--N leaching is relatively less apparent at the N rates in the range of 0-140 kg.hm-2, but this effect became significant when the N rates exceeded 140 kg.hm-2. Our results also show that NO3--N contents were generally higher at the anthesis stage than at the harvest stage within the same soil layer. The observed differences in NO3--N contents between the irrigation treatments of I0.6, I0.8 and I1.0 were insignificant across N rates. This finding suggests that N addition treatments may have greater impacts on NO3--N leaching than irrigation treatments. Although the among-irrigation differences of NO3--N contents within the same soil layer varied with N level, there was a tendency that NO3--N content of I1.0 treatment was significantly lower than that of I0.8, and that of I06 irrigation treatment in the soil layer with significant differences in N contents. This result suggests declined NO3--N leaching with decreased irrigation levels.
%K irrigation
%K nitrogen supply
%K nitrate-nitrogen dynamic
%K recently reclaimed sandy farmland<br>灌溉
%K 施氮
%K 硝态氮动态
%K 新垦沙地农田
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=3FF3ABA7486768130C3FF830376F43B398E0C97F0FF2DD53&cid=A7CA601309F5FED03C078BCE383971DC&jid=64CD0AA99DD39F69401C615B85F123EF&aid=09D3D1E6722AEDB7A83A576FA6964426&yid=67289AFF6305E306&vid=771469D9D58C34FF&iid=DF92D298D3FF1E6E&sid=59C77779BF483289&eid=28A5659E3BD66D6A&journal_id=0250-3301&journal_name=环境科学&referenced_num=2&reference_num=28