Plant Growth, Uptake and Partitioning of Nitrogen in Alfalfa Seedlings as Affected by the Form of 15N-Labelled Combined Nitrogen

Japanese Journal of Crop Science

Daisuke HIROSE¹  Hyoe TSUGAWA¹  Kin-ichi NISHIKAWA¹  Jiro TATSUMI¹ 

关键词: Alfalfa;    アルファルファ;    Ammonium-N;    アンモニア態N;    Nitrate-N;    N施肥;    Nitrogen fertilizer;    N回収率;    Nitrogen uptake and partitioning;    Nの吸収と分配;    Recovery of 15N;    硝酸態N;    Root growth;    根の生長;   

DOI  :  10.1626/jcs.63.26

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

We investigated the growth, uptake and partitioning of nitrogen (N) in alfalfa seedlings grown in the pot soil where 15N-labelled combined N was applied as nitrate-N or ammonium-N by means of basal dressing or topdressing. Dry weight, N content, and 15N recovery, in the plant were greater when N was applied as ammonium-N than nitrate- N in both basal dressing and topdressing. Elongation of the roots was more strongly promoted by ammonium-N than nitrate-N, and this was associated with increased uptake of 15N from labelled fertilizer topdressed in ammonium form. Absorbed 15N was more preferentially allocated to the roots than the stem in the plant when ammonium-N was topdressed, while a reverse trend was found in the plant to which nitrate-N was topdressed. These results indicate that ammonium-N is more effective source of N for the growth of alfalfa seedlings as compared with nitrate-N.

【 授权许可】

Unknown