文献类型：期刊文献

中文题名：氮素营养对西南桦幼苗生长及叶片养分状况的影响

英文题名：Effects of Exponential Nitrogen Loading on Growth and Foliar Nutrient Status of Betula alnoides Seedlings

作者：陈琳[1] 曾杰[1] 徐大平[1] 赵志刚[1] 郭俊杰[1] 林开勤[1] 沙二[1]

机构：[1]中国林业科学研究院热带林业研究所

年份：2010

卷号：46

期号：5

起止页码：35-40

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;Scopus;北大核心:【北大核心2008】；CSCD:【CSCD2011_2012】；

基金："十一五"国家科技支撑专题(2006BAD24B09-02)

语种：中文

中文关键词：西南桦;指数施肥;生长表现;叶片养分含量;氮

外文关键词：Betula alnoides; exponential fertilization; growth performance; leaf nutrient concentration; nitrogen

分类号：S714.8

摘要：设置每株0,50,100,200,300,400,600mg7个氮素处理,开展西南桦幼苗指数施肥试验,探究氮素供应水平对西南桦幼苗生长以及叶片养分状况的影响,旨在揭示西南桦幼苗的氮素需求,确定其适宜施氮量。结果表明:1)西南桦幼苗的地径、苗高、生物量以及叶面积随着氮素供应水平的增加而增大,至氮施用量每株>200mg后其生长表现和生物量趋于稳定,而叶面积则显著递减;2)西南桦幼苗叶片N,P和K含量随施肥量的增加而递增,叶片N和K含量在施氮量每株>200mg、生物量稳定之后仍持续增加,说明由于植株对N和K的奢侈消耗造成植株体内的养分积累,而叶片P含量在施氮量每株>100mg之后即趋于稳定,说明植株对P的需求已满足而保持其含量稳定;3)运用临界浓度法确定出西南桦幼苗叶片N,P,K的临界含量分别为37.8,4.1,24.4g·kg-1,最适含量分别为37.8～59.1,4.1～6.3,24.4～34.7g·kg-1,综合3个最适含量范围,推断出西南桦幼苗的最适施氮范围为每株200～400mg。
Exponential nutrient delivery can bring about a steady state of nutrition in the plant and improve nutrient uptake,and hence accelerate seedling growth. An exponential fertilization trial was conducted with seven N dose levels （applying a total of 0,50,100,200,300,400,600 mg·seedling ^-1in this experiment） of nitrogen to assess the effects of different nitrogen levels on growth and foliar nutrient status of Betula alnoides seedlings. The objective of this study was to reveal the nitrogen demand and determine the optimal nitrogen amount for B. alnoides seedlings. It was indicated that： 1） Ground diameter,height,biomass and leaf area of B. alnoides seedlings increased with the increase of nitrogen supply, up to 200 mg·seedling ^-1 ,after then growth performance and biomass were unchanged and leaf area remarkable decreased. 2） The leaf nitrogen,phosphorus,and potassium concentrations increased in general as the nitrogen addition increased when nitrogen supply was more than 200 mg·seedling ^-1 ,the leaf nitrogen and potassium concentrations continued to increase because of luxury consumption characterized by increased the internal nutrient concentrations without significant changes in total dry mass,while the leaf phosphorus concentration tended to be stable with nitrogen supply above 100 mg ·seedling-1,suggesting that phosphorus was sufficient for plant growth. 3） Critical level approach was used for identifying N,P and K deficiencies by means of foliar analysis in B. alnoides seedlings,and the critical values of N,P,and K were 37. 8,4. 1,and 24. 4 g·kg^ -1 ,while their optimal concentrations ranged from 37. 8 to 59. 1,4. 1 to 6. 3 and 24. 4 to 34. 7 g·kg^ -1 ,respectively. Based on these data,it could be inferred that 200 - 400 mg·seedling ^-1 would be the optimal nitrogen amount for B. alnoides seedlings.