施钾量对甘薯产量及钾素吸收利用的影响

摘要

To investigate the effects of potassium ( K) application rates on yields, K absorption and utilization in dif⁃ferent sweet potato genotypes, field tests of K application rates were carried on three different genotypes of edible sweet po⁃tato, Ningshu 192, Zhezi 1 and Xushu 22. The results showed that K fertilization increased tuberous root dry matter of sweet potato by increasing the tuber number, and, to a less degree, the mean tuber weight. Above⁃ground parts got higher K con⁃centration than those in tube, and K concentrations in tube and above⁃ground parts increased with the increase of K fertili⁃zation. The K uptake and utilization varied among genotypes, and Xushu 22, with high use efficiency, got dominant K ac⁃cumulation in tube root, while Zhezi 1 and Ningshu 192 had opposite trends. The K use efficiency ( KIUE) had a significant negative correlation with K concentration in the whole plants at maturity. No significant correlation was found between root dry matter yield and KIUE. It was con⁃cluded that increasing potash application could enhance the sweet potato productivity by improving tuberous root numbers per plant. Tuberous root of sweet potato gave higher response to K supply than above⁃ground part, and the K use efficiency were mainly affected by the K concentration in the tissues of sweet potato.%为探明施钾量对不同主栽甘薯品种产量、产量构成及钾素吸收和利用的影响，以3种甘薯品种为材料，田间设置不同施钾水平试验。结果显示，各甘薯品种产量均随施钾量上升而提高，增施钾肥对甘薯地上部分生物量的影响小于根系，施钾的增产作用主要表现在甘薯数量的增加，单薯质量则次之；甘薯茎、叶钾含量高于薯块，且增施钾显著提高甘薯茎叶和薯块的含钾量。甘薯品种间钾的吸收及利用对施钾的响应不同，相对高效的徐薯22钾素主要积累在根部，宁薯192及浙紫1号则相反。甘薯钾利用效率与植株钾浓度呈显著负相关，而与产量无显著相关性。表明增施钾肥可以提高甘薯产量，其增产作用主要表现在提高单株结薯数；甘薯含钾量对施钾的响应主要体现在根部，甘薯品种间钾利用效率主要受植株钾浓度的影响。