由玉米各生育期所吸收氮素之行動與子實生產之關係

Behaviour of Nitrogen Absorbed at Various Growth Stages Associated with Grain Production in Maize

連深(Lian Shen) ； 張庚鵬(Geng-Peng Chang)

《中華農業研究》 40卷2期 (1991/06) Pp. 123-132

https://doi.org/10.29951/JARC.199106.0002

摘要

應用15N標識氮肥（硝酸銨）以水耕盆栽試驗探討玉米各生育期氮素吸收速率及追蹤所吸收氮素在植株各部之分布、再移動與子實生產之關係。
1．氮素之吸收速率依生育之進展而增，而以吐絲期達到最高。吐絲期以後之吸收速率雖逐漸下降，但仍持續至玉米糊熟期；糊熟期前後之氮素吸收速率仍達吐絲期之五分之一左右。
2．吐絲期以前所吸收氮素主要分布於吸收時生長中之葉片和稈節；吐絲期以後此等氮素之一部份再轉移於穗部。此種吐絲期前一度儲積莖葉而於吐絲後轉移谷中之氮素約佔原吸收量之33%。
3．自吐絲至吐絲後約2週期間所吸收之氮素最有效運積於谷中，達原吸收量58%~67%。
4．糊熟期氦素吸收速率雖減，仍可看到其有效運積谷中。但其分布比率已較吐絲期減低，為原吸收量之46%。
5．以上結果顯示吐絲期前後約3週期間之氮素吸收對谷粒之充實非常重要；該期間之玉米不但吸收能力強，且有效轉移谷中。一般田間試驗結果亦常印證吐絲直前之氮素追肥較其前期所施基、追肥能有效增加子實產量，可謂符合。糊熟期前後所吸收氮素仍可顯著轉移谷中，但其殘留莖稈和根之比率卻較吐絲期所吸收者增加。

關鍵字

玉米 ； 標識氮肥 ； 吸收與分布 ； 子實生產

並列摘要

Rate of uptake, distribution and remobilization in maize (cultivar TNG 351) of the labelled N applied in the form of 15NH4 15NO3 at various growth stages were studied in connection with grain production under water culture condition.
1. The rate of uptake increased as the growth progressed and was at its peak just before silking. The uptake, though slowed down gradually after silking, still kept a moderate rate until dough stage.
2. The nitrogen absorbed by silking accumulated mostly in the leaves and culms that were growing when the nitrogen was absorbed. A part of these nitrogen was retranslocated to the ear after silking the distribution in grain at harvest was 33% of the original amount of uptake.
3. The nitrogen absorbed during the period from silking to blister stage was translocated most efficiently to the grains; up to 58-67% of the original uptake was distributed to the grain.
4. Although nitrogen uptake slowed down during dough stage, a considerable portion of the nitrogen absorbed (46%) still translocated to the grain. The percentage, however, was less as compared to that absorbed during silking, while that which remained in the stem and root increased.
5. All of the above indicates that the nitrogen uptake during silk stage is very efficient for grain production. This is quite coincided with the results of field experiments, which show usually a positive effect of top dressing at this stage.
Although the nitrogen absorbed during dough stage is still translocated to grain considerably, that which remained in stem and root is increased, which may be unfavorable for the dry matter production at this stage. The results of field experiments also show frequently a negative effect of nitrogen top-dressing at this stage.

並列關鍵字

maize ； labelled N ； uptake and distribution ； grain production.