广元土壤氮钾供应水平与烟草氮钾吸收利用规律试验研究

N,K Supplying Level of Guangyuan Soil and Its Absorption & Utilization Regulation of Tobacco

本文对广元植烟土壤氮钾含量和变化水平,烟株不同时期生物量增长和增长率,烟叶氮钾吸收量和钾氮比进行了研究,结果表明,植烟土壤氮素供应和烤烟对氮素吸收良好,钾素供应和吸收较差,钾素＂回流＂现象和土壤钾素物理固定较为突出,钾含量和钾氮比较低;烤烟移栽后15 d左右土壤氮钾含量偏高,中期不足,后期匮乏,生物量较低,烤烟生物量增长与氮钾供应不协调。应减少前期氮钾供应量,加大移栽后45~75 d的氮钾供应,保持75 d后一定量钾素供应,同时缩短钾素在土壤中的滞留时间,调节植烟根际土壤的pH值,减少钾素的物理固定,增加钾素在土壤中的生物有效性,提高烤烟生物量和烟叶含钾量。初步摸清了川北地区烟草土壤氮钾供肥水平,烟叶的氮钾吸收利用规律,为进一步研制烤烟氮钾缓控专用肥料,集成控氮增钾高效施肥技术提供科学依据。

In this paper,N,K content,the change levels of Guangyuan tobacco soil,the biomass growth rate at different growth stages of tobacco,N,K absorbing quantity and N,K ratio were studied.The result showed that the N supply and absorption of Guangyuan tobacco soil was better,but K amount of tobacco supply,absorption and accumulation was unbalanced,and the significant ＇the backflow＇ phenomenon of potassium was observed.N,K content were very high 15 days after transplanting,but run off in mid stage and was short in last stage,the biomass growth of tobacco and N,K supplying were unbalanced.So,firstly,the N,K supplying content decreased in early period,then the N,K supplying content increased in 45-75 days after transplanting,and their content was adjusted after 75 days,The N,K supplying level of tobacco soil in northern Sichuan area and their absorption and utilization regulation of tobacco were preliminarily confirmed,which provided scientic evidents for further studying on N,K special fertilizer and technical integration of controlling N increasing K in tobacco.