【摘要】 作者于1981—1984年间应用¹⁵N对粮棉两熟制土壤上氮素动态进行了研究,认为湖北省两熟棉田氮肥用量太大必须加以控制;应改撒施或表层浅施为耕层深施,以提高氮肥利用率和减少环境污染;轮作换茬,增加豆科作物的比重,既可减少氮肥用量,又是防止农田生态系统氮污染的重要措施。更多还原

【Abstract】 A study on nitrogen dynamics in soil under grain-cotton double cropping system has been carried out by using isotope 20N from 1981 to 1984. The results showed that too much nitrogen fertilizer has been used for cotton fields in Hubei province. The amount of nitrogen fertilizers applied in the cotton fields in Hubei province was excessive and it should be controlled. Broadcasting or shallow dressing, methods should be changed to deep layer dressind in order to increase the utilization ratio of N fertilizers and to reduce pollution to the environment. Increasing the proportion of legume crops in the rotation systems could decrease the amount of N fertilizers required and at the same time, could serve as an important method of preventing nitrogen pollution within the field ecosystem.更多还原