氮钾互作对甘薯氮钾元素吸收、分配和利用的影响及与块根产量的关系

Effect of nitrogen-potassium interaction on absorption and translocation of nitrogen and potassium in sweetpotato and the root yield

选取淀粉型甘薯(Ipomoea batatas)品种‘济徐23’为试验材料,于2013~2014年在山东农业大学农学试验站进行大田试验,采用二因素裂区设计,主区为不同氮肥水平,副区为不同钾肥水平,研究氮钾互作对甘薯氮钾元素吸收、分配和利用的影响及其与块根产量的关系。结果表明,不施用氮肥时的最佳施钾肥量是180 kg·hm^(-2),其氮钾元素利用效率最高、块根产量较高;施氮量为90 kg·hm^(-2)时,施钾肥量至少应该达到360 kg·hm^(-2),其地上部氮钾元素转运率、在块根中分配率和块根产量最高。在适量施氮条件下,获得甘薯高产的关键是促进地上部氮钾元素向块根转运,提高收获期在块根中的分配率。

A field experiment was conducted at agricultural experiment station of Shandong Agricultural Uni- versity, Tai＇an, Shandong Province in 2013-2014. Split plot design with two factors, three nitrogen （N） levels and three potassium （K） levels. Selected material of the ＇Ji Xu 23＇, starch sweetpotato variety, to study N-K in- teraction on absorption, transfer and distribution of N/K in sweetpotato and its relationship with storage root yield. The results show that the best amount of K fertilizer was 180 kg·hm^-2 when without N fertilizer and its N/ K use efficiency was the highest, higher storage root yield. When the amount of N applied was 90 kg·hm^-2, if the shoots of N/K transport rate, roots distribution rate and storage root yield were the highest, the amount of K fertilizer should be at least 360 kg·hm^-2. Under appropriate N application, the key of high yield of sweetpotato could promote the shoot N/K to root transfer, improve the rate of distribution in root at harvest.