膜下滴施尿素对棉花氮素吸收、分配、利用效率的影响

Effect of nitrogen absorption,distribution and utilization efficiency with urea dripping on mulched-cotton by drip irrigation

在棉花花铃期膜下滴施不同量尿素,结果表明,追氮处理后棉株根、叶片、叶柄和蕾铃的氮含量比不追氮处理要高,但增高多少与追氮量没有明显关系。棉花总吸氮量随着追氮量的增加而增加,但花铃期吸氮量占总吸氮量的比例呈下降趋势。追氮处理对土壤全氮没有明显的影响,但对土壤碱解氮的影响比较大。土壤全氮和碱解氮与棉花各器官氮含量的相关性不显著。随着施氮量增加,追施氮肥的利用率明显下降。

Topdress different amount urea on cotton under film- mulching and drip irrigation during the blooming period, the result showed that content of nitrogen of root, leaf, leaf- stem and reproductive organ of cotton with nitrog entreatment were higher than non - treatment, but the increase had no relation with the amount of nitrogen topdressing. The total absorption of nitrogen increased with the amount of nitrogen topdressing, but the proportion of absorption nitrogen during the blooming period to total nitrogen were downtrend. Topdressing nitrogen treatment had no obvious effect to total nitrogen in soil, but it had a stronger effect to alkalined - nitrogen. There had no significant correlation between content nitrogen of cotton organs and total nitrogen and alkalined-nitmgen in soil.The nitrogen utilization efficiency were downtrend with the amount of topdressing increased.