海岛棉植株测试推荐施肥技术初步研究

通过膜下滴灌条件下海岛棉多水平氮肥试验,分析了海岛棉倒四叶叶柄硝酸盐浓度、生物量、植株全氮和产量的关系,结果表明:海岛棉倒四叶叶柄硝酸盐浓度能够快速、灵敏地反映作物的氮营养状况,可用作海岛棉的氮素营养诊断及氮肥需要量的测算指标.用一元二次模型模拟氮肥与产量之间的关系,得到经济氮量为206 kg/hm2,相应产量为1 182 kg/hm2,棉株花期叶柄硝酸盐浓度与施氮量和产量之间有显著的相关性,以此为依据建立海岛棉植株硝酸盐诊断的氮肥推荐模型,并计算出花期时不同硝酸盐测试值所对应的氮肥追肥用量.

Preliminary Research on Fertilizer Recommendation Techniques for Plant Testing of Sea Island Cotton

Field experiments were conducted to study cotton nitrogen diagnosis and topdressing recommendation under drip irrigation at Fenshou farm,Awati county,Xinjiang.Four fertilization treatments consisting of 0,145,243,340 kg N ha-1 as urea were applied.Nitrate concentration from the 4th expanding leaf petiole were measured by reflectance meter and the biomass,plant total N and the yield were also tested.The results showed that NO3-concentration in the 4th expanding petiole in florescence was significantly correlated with rates of N applied.The reasonable amount of nitrogen needed for getting the economical lint yield of 1 182 kg/hm2 was 206 kg N/hm2;NO3-concentration of cotton in florescence was significantly correlated with cotton lint yield,so based on the good relationship a cotton nitrogen fertilizer recommendation model was established.Then,the rate of nitrogen topdressing in florescence could be recommended according to the recommendation model.