为了改善库布齐沙地的生态环境,实现生态效益和经济效益的有效结合,将暖季型草本能源植物柳枝稷(Panicum virgatum)引种到库布齐沙地.以柳枝稷品种“BL-1”为试验材料,研究了施用硫酸铵和尿素两种氮肥对柳枝稷产量、氮肥利用率及0-40 cm土层土壤硝态氮分布和积累的影响.本研究采用完全随机区组设计,设置0、75、150、225kg· hm-2共4个施氮水平,每个处理3个重复.硫酸铵和尿素分别于苗期、分蘖期和拔节期施入各试验小区,施入量分别为施氮量的1/5、2/5和2/5.在初花期对柳枝稷的产量及土壤硝态氮含量进行测定.结果表明,硫酸铵和尿素的施用均可以显著提高柳枝稷的产量(P＜0.05).柳枝稷的产量、吸氮量、氮肥利用率在施用硫酸铵时随着施氮量的增加逐渐增加;在施用尿素时,随着施氮量的增加出现先升高后降低的趋势,在施氮量为150 kg·hm-2时达到峰值.在0-40 cm土层土壤硝态氮集中分布在10-20 cm,且其积累量随着施氮量的增加而增加.%In order to improve the ecological environment of Kubuqi sandland and realize the effective combination of ecological and economic benefits,the warm-season herbaceous bioenergy plant switchgrass (Panicum virgatum) was introduced to Kubuqi sandland.Switchgrass BL-1 was used as the experimental material to study the effect of ammonium sulfate and urea on the yield and nitrogen-use efficiency of this species,and the distribution and accumulation of soil nitrate nitrogen in the 0-40 cm soil layer.The study used a completely randomized block design.Nitrogen fertilization was carried out with four treatments of nitrogen application rate (0,75,150,and 225 kg · ha-1) and three duplicates for each treatment.Urea and ammonium sulfate were applied directly to the experimental plots at the seedling stage,tillering stage,and jointing stage,with amount equivalent to 1/5,2/5,and 2/5 of nitrogen application rate,respectively.The yield of switchgrass and the content of soil nitrate nitrogen were measured at the early flowering stage.The results showed that the application of both urea and ammonium sulfate could significantly increase the yield of switchgrass (P＜0.05).The yield,nitrogen uptake,and nitrogen-use efficiency of switchgrass fertilize with ammonium sulfate increased the increase in nitrogen application rate,which first increased and then decreased when urea was applied,and the maximum was at the nitrogen application rate of 150 kg · ha-1.The nitrate nitrogen was mainly distributed at 10-20 cm soil layer and the accumulation of nitrate N increased with the increase of nitrogen application rate in the 0-40 cm soil layer.
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