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作 者 ：王正芳;徐宗敏;

期 刊 ：核农学报 1987年 1卷 04期 页码：73-86

关键词：~(15)N示踪；盖膜施肥；棉花；

摘 要 ：本试验应用~(15)N标记硫铵研究塑料薄膜覆盖下直播棉花的氮素营养特性及其增产效果。试验表明:盖膜棉花吸收的总氮量明显高于不盖膜处理,苗期尤为突出,盖膜棉株的总氮量为不盖膜处理的244—267%。盖膜并施肥不仅增加了棉株对土壤氮和肥料氮的吸收利用,而且,通过营养器官输往生殖器官的肥料氮量与土壤氮量也分别比不盖膜处理高50.5%和157%,初花期追肥,于初花—盛花阶段形成了吸收肥料氮的高峰,在棉株吸自肥料的氮素中有63.3—76.6%是在这一阶段吸收的。盖膜棉花对氮肥的当季利用率为36%,比不盖膜处理高9%。盖膜施肥处理棉花的产量最高,每公顷产籽棉2472公斤。

Abstract:The nitrogen nutrition of directseeding cotton under plastic-film cover and the effect of them on increasing production was studied by using 15N tracer technique.Experiments were conducted on the cotton field of the Institute of Economic Crop in 1984 and four treatments were set up:cover-film with dressing fertilizer N,cover-film without dressing fertilizer N,no cover-film but with dressing fertilizer N,no cover-film and no dressing fertilizer N.The results showed that the nitrogen absorbed by cover-film cotton plant was obviously higher than by no cover-film treatment.especially at seedling stage.The total N content in cotton plant was 244-267% as much as that of no cover-film cotton.It laid a foundation for promoting cotton early-development,early-bearing boll.The treatment of cover-film with dressing fertilizer not only increased the utilization rate of soil and fertilizer nitrogen by cotton,but also promoted the transportation of N from vegetative or-gans to reproductive organ.The transportion rate were 50.5% and 157.0% higher than that by no cover-film treatment.So it provided abundant nitrogen source for reproductive organ growth.At all treatments,in spit of the fact that the nitrogen absorbed by cotton was mostly from soil nitrogen,the base fertilizer and flowering-boll fertilizer adequatly dressed was also needed.It was shown in practice that dressed flowering-boll fertilizer at initial flowering stage could make a high peak of nitrogen absorption from fertilizer nitrogen at initial flowering-profuse flowering stage.In this stage the N derived from fertilizer was 63.3-76.6% of total N derived from fertilizer absorbed by cotton.Under plastic-film cover the utilization rate of nitrogen fertilizer was 36.0% at growth season and it was 9% higher than that without plastic-film cover.Under plastic-film cover with dressing fertilizer,the highest yield of seed cotton was obtained.It was 2472kg/ha.

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