摘要
Solution culture experiments were conducted to study N uptake kinetics snd the relatively uptake ofammonium- and nitrate-N by rice (Oryza sativa ) at different growth stages. The relative uptake or the ratios(NH:N/NO-N) of ammonium-N to nitrate-N absorbed by rice varied with its growth stages. At different stages, riceplant had different preference to either ammonium-N or nitrate-N when both NH and NO were present equally inthe nutrient solution. From transplanting to initial tillering, the absorbed ratio was 1. 15 on average, and the absorbed ammonium-N accounted for 53. 48% of the total uptake nitrogen during the same period. During the tilleringperiod, the absorbed ratio was 2. 55 on average, and the absorbed ammonium-N accounted for 71. 8% of the total atthis stage. This phenomenum that rice preferred ammonium-N to nitrate-N during the vegetative growth periodcould be explained by kinetic parameters(Vma. and K.) of absorption. During the reproductive period from elongation to maturity, the absorbed ratios tended more or less towards l, and either of the nitrogen forms could be takenup efficiently by the crop. For the whole growth duration, the absorbed ratios ranged from 0. 98 to 2. 62 with 1. 28on average, the accumulated ammonium-N absorbed being 56. 1 % of the total nitrogen.
Solution culture experiments were conducted to study N uptake kinetics snd the relatively uptake ofammonium- and nitrate-N by rice (Oryza sativa ) at different growth stages. The relative uptake or the ratios(NH:N/NO-N) of ammonium-N to nitrate-N absorbed by rice varied with its growth stages. At different stages, riceplant had different preference to either ammonium-N or nitrate-N when both NH and NO were present equally inthe nutrient solution. From transplanting to initial tillering, the absorbed ratio was 1. 15 on average, and the absorbed ammonium-N accounted for 53. 48% of the total uptake nitrogen during the same period. During the tilleringperiod, the absorbed ratio was 2. 55 on average, and the absorbed ammonium-N accounted for 71. 8% of the total atthis stage. This phenomenum that rice preferred ammonium-N to nitrate-N during the vegetative growth periodcould be explained by kinetic parameters(Vma. and K.) of absorption. During the reproductive period from elongation to maturity, the absorbed ratios tended more or less towards l, and either of the nitrogen forms could be takenup efficiently by the crop. For the whole growth duration, the absorbed ratios ranged from 0. 98 to 2. 62 with 1. 28on average, the accumulated ammonium-N absorbed being 56. 1 % of the total nitrogen.
出处
《中国水稻科学》
CAS
CSCD
北大核心
1998年第4期249-252,共4页
Chinese Journal of Rice Science
关键词
溶液培养
吸氮量
铵态氮
硝态氮
水稻
ammonium nitrogens kinetic parameter
nitrogen uptake
nitrate nitrogen
solution culture
