不同施氮水平对紫云英腐解与土壤供氮特性的影响  

Effects of nitrogen levels on decomposition of Chinese milk vetch and soil nitrogen supply characters

作　　者：马艳芹 杨文亭[2] 黄国勤[2] MA Yan-qin;YANG Wen-ting;HUANG Guo-qin(Jiangxi College of Foreign Studies,Nanchang 330099,China;Research Center on Ecological Science,Jiangxi Agricultural University,Nanchang 330045,China)

机构地区：[1]江西外语外贸职业学院,南昌330099 [2]江西农业大学生态科学研究中心,南昌330045

出　　处：《南方农业学报》2018年第9期1745-1752,共8页Journal of Southern Agriculture

基　　金：国家重点研发计划项目(2016YFD0300208);国家自然科学基金项目(41661070)

摘　　要：【目的】探讨不同施氮水平下紫云英腐解特征及对土壤供氮特性的影响,为南方稻田冬季绿肥资源的合理利用和农田养分科学管理提供理论依据。【方法】采用盆栽法将紫云英装入尼龙网袋内后置于水稻盆中,设不同的施氮水平(A:不施氮;B:减氮40%,1.8 g/盆;C:常规施氮,3.0 g/盆),分别于装盆后第3、6、10、20、30、40、50、60、70、80和90 d取样测定紫云英全氮含量,并于网袋取走后收集土样测定土壤全氮、碱解氮、铵态氮和硝态氮含量。【结果】不同施氮水平下紫云英的腐解速率表现出前期快、后期慢的特征,其中前10 d为快速腐解期,10～50 d为缓慢腐解期,50～90 d为稳定腐解期,经过90 d腐解,3个处理的紫云英腐解率均在60.0%以上;紫云英腐解前30 d,水稻群体吸氮量整体较低,3个处理间无显著差异(P>0.05,下同),40 d后水稻群体吸氮量开始迅速增加,第90 d时3个处理的水稻群体吸氮量均达最大值;施氮对紫云英还田后的土壤氮素含量有一定影响,尤其是对碱解氮、铵态氮和硝态氮影响明显,但对全氮影响不明显。相关性分析结果表明,紫云英腐解第3 d时,土壤全氮与施氮量间呈极显著相关(P<0.01,下同),土壤碱解氮、铵态氮和硝态氮与施氮量间呈显著相关(P<0.05),前30 d中,施氮量与紫云英养分释放量、植株群体吸氮量间相关性不显著,到第40 d时,紫云英施氮量、水稻群体吸氮量则与土壤全氮和碱解氮间呈极显著相关。【结论】不同施氮水平下紫云英腐解和氮素释放量均呈现出前期快后期慢的特征,适当的氮肥施用量可刺激紫云英腐解和氮素释放,增加土壤中碱解氮、全氮和矿质态氮含量,提高土壤氮库活性成分和土壤供氮能力,以常规施氮基础上减施40%氮效果较好。【Objective】Decomposition characteristics of Chinese milk vetch(Astragalus sinicus L.)and its effects on nitrogen supply in soil were studied to provide reference for reasonable use of winter green manure and field nutrient management in paddy fields in the southern China.【Method】Pot culture was used in the experiment,the Chinese milk vetch was placed in nylon net bags and placed in a rice bowl under three different nitrogen treatments(A:no nitrogen application;B:reduced 40%nitrogen application,1.8 g/pot;C:conventional nitrogen application,3.0 g/pot).Total nitrogen content of Chinese milk vetch was determined 3,6,10,20,30,40,50,60,70,80 and 90 d after potting respectively.Soil total nitrogen,alkali-hydrolyzable nitrogen,ammonium nitrogen and nitrate nitrogen were collected from soil samples after the net bag was taken away.【Result】The decomposition rate of Chinese milk vetch at different nitrogen application rates was fast at early stage and slow at late stage.The first 10 d was fast decomposition period,10-50 d was slow decomposition period and 50-90 d were stable decomposition period,after 90 d decomposition,the decomposition rates of Chinese milk vetch reached over 60.0%under three treatments.In the first 30 d of the decomposition,the nitrogen uptake of rice was low,and there was no significant difference among the three treatments(P>0.05,the same below),nitrogen uptake of rice began to increase rapidly after 40 d of decomposition,and reached the maximum on day 90 under three treatments.Nitrogen application had certain effect on soil nitrogen content after Chinese milk vetch returned to the field,especially on alkali-hydrolyzable nitrogen,ammonium nitrogen and nitrate nitrogen,but not on total nitrogen.Correlation analysis showed that soil total nitrogen was extremely significantly correlated with nitrogen application rate(P<0.01,the same below)on day 3 of the Chinese milk vetch decomposition,and soil alkaline nitrogen,ammonium nitrogen and nitrate nitrogen were significantly correlated with nitroge

关 键 词：施氮 紫云英 腐解 土壤氮素 

分 类 号：S158.3[农业科学—土壤学]