不同钾肥处理对秋甘薯性状产量的影响

Effect of Potassium Fertilizing on Yield of Fall Sweet-potato

以西成薯007为试验材料,研究了钾肥施用量与秋甘薯性状及产量之间的关系,结果表明,施钾有利于提高秋甘薯植株的同化能力,在一定程度上抑制茎叶徒长,增加干物质积累。施钾肥能增强地上部同化产物向地下块根运输的能力,从而降低T/R值,提高经济产量。块根干率和茎粗是由甘薯品种特性决定的,施钾与否对其影响不大。低钾能提高秋甘薯的大中薯率,增加秋甘薯的最长茎长和基部分枝数。而施钾后其干物率较不施肥下降。只施氮和磷的叶绿素含量高于施钾处理,同时均显著高于不施肥。秋甘薯在低钾水平土壤下以薯干和淀粉为目标产品的最佳施肥量在253.05～262.46kg.hm-2,而以粮饲型生物产量和鲜薯产量为目标产品的最佳施肥量在316.05～321.59kg.hm-2。虽然使用钾肥能有效提高其生物产量和块根产量,但其对薯干的贡献在低钾和高钾水平没有显著差异。

Relationship between applying K fertilizer and the yield of sweet potato was studied with variety ot Xicheng Potato 007. The results showed that： K fertilizer improved the assimilative capacity of the sweet potato, and increased the dry matter accumulation while the plants partly inhibited in excessive growth of the stems and leaves. K fertilizer enhanced the plant capability in transporting assimilate to underground tuber, by which reducing the value of T/R and increasing economic production. Root dry rate and stem diameter were related with the species characteristics of sweet potato instead of K fertilizer amount. Reducing K fertilizer amount increased the portion in large- and medium-sized sweet potato, the length of the longest stem and the number of base branches. Comparing to control, the dry matter content was decreased by applying K fertilizer. The chlorophyll content of plants was higher in those treated with N and P fertilizer than with K fertilizer and without fertilization. For a low K level soil, the optimal amount of K fertilizer was 253.05--262.46 kg ~ hm--z for producing high yield of dried sweet potato and starch, and was 316.05-- 321.59 kg ~ hm 2 for producing high yield of fresh potato tuber yield. There was no difference observed between low K and high K levels on dry matter production, although K fertilizer improved fresh yield effectively.