寒冷地区烤烟氮磷钾的吸收动态

The absorption of N, P, K in flue-cured tobacco in low temperature area in China

本试验采用先进的同位素示踪技术对我省烤烟主栽品种ＮＣ８９生育期间氮、磷、钾的吸收动态以及烟株各器官在不同时期对养分的吸收和分配进行了研究，测定了烤烟不同器官对肥料氮和土壤氮的吸收比例，不同氮肥用量，烟株对肥料氮的吸收量占总吸收量的２０．１％～４３．４％，氮肥水平越高，从肥料中吸收氮量越多；烤烟对ＮＨ４ＮＯ３利用率为４０．５％，以叶利用率最高。ＮＨ４ＮＯ３在土壤中平均残留量为１２．９％，施氮越多，残留越高；氮肥损失率较大，平均为４６．６％。烤烟对肥料磷的吸收占总吸磷量的３９．６％，栽后６０ｄ前烟株以吸收肥料磷为主，以后对土壤磷的依存率增加，肥料磷的分配以叶片最多，叶＞茎＞根，磷肥利用率较低，仅为 １２．４％。烤烟对钾的吸收是前期较少，栽后 ４５～６０ｄ时为吸钾高峰期，此后吸钾量迅速降低。

The advanced isotopic trace technique was used to determine the N, P, K absorption during the growing period of variety NC89 in Helongjiang Province. The absorption and distribution of nutrition in different tobacco organs was also studied in different growing period and the ratio of N, P absorbed from soil and fertilizer was assayed in different tobacco organs. Result shows that the ratio of N and P absorbed from fertilizer is 20. 132. 4% and 39. 6% respectively. The utilization ratio of N-NH4NO3 and P is 40. 5% and 39. 6% The ratio of residue N-NH4NO3 in soil is 12. 9%, indicating a loss of 46. 6% P in tobacco was mainly absorbed from fertilizer in the first two months after transplanting and from soil thereafter. The peak period of tobacco absorbing K is between the 45th day to the 60th day after transplanting.