title: [Effects of nitrogen application levels on yield and active composition content of Desmodium styracifolium].
abstract: OBJECTIVE
  To find out the optimal nitrogen application level of Desmodium styracifolium.
  
  
  METHODS
  A field experiment using randomized block design was carried out to study the effects of 5 nitrogen application levels (150, 187.5, 225.0, 262.5 and 300.0 kg x hm(-2)) on yield and active component content of D. styracifolium.
  
  
  RESULTS
  Nitrogen application could increase the yield and contents of polysaccharide, total flavonoides and total saponins of D. styracifolium. However, the enhancing extent of the active component content and the yield were not always significant with the increase of nitrogen level. In which, the yield were not significantly different among the nitrogen application levels of 225.0, 262.5, 300.0 kg x hm(-2) the polysaccharide content was no significantly difference among the nitrogen application levels of 225.0, 262. 5 and 300.0 kg x hm(-2), the total flavonoides content under the nitrogen level of 300.0 kg x hm(-2) was significantly lower than that of 150.0 kg hm(-2) (P < 0.01), and the total saponins content under the nitrogen level of 300.0 kg x hm(-2) was no significant difference compared with that of 262.5 kg x hm(-2).
  
  
  CONCLUSIONS
  The optimal nitrogen application level of D. styracifolium was 225.0-262.5 kg x hm(-2).
authors.affiliation: Research Center of Agricultural Rare Earth, Academy of Hunan Agricultural Sciences, Changsha 410125, China.
authors.forename: Jiamin
authors.initials: J
authors.lastname: Zhou
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yin
authors.forename: Chaojun
authors.initials: C
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Huang
authors.forename: Fuyuan
authors.initials: F
authors.lastname: Peng
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Zhu
mesh_terms: D007887:Fabaceae / Q000737:chemistry* / Q000378:metabolism*; D005308:Fertilizers / Q000032:analysis; D005419:Flavonoids / Q000032:analysis / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D010936:Plant Extracts / Q000032:analysis* / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis / Q000378:metabolism; D012987:Soil / Q000032:analysis
chemical_list: D005308:Fertilizers; D005419:Flavonoids; D010936:Plant Extracts; D011134:Polysaccharides; D012987:Soil; D009584:Nitrogen