高钾肥力土壤增施钾肥对马铃薯的生物效应

为了优化马铃薯生产过程中肥料养分管理和高效利用，于2011年在甘肃省定西市选择高钾肥力土壤布置大田试验，在等氮磷用量基础上，研究了施钾水平（0，120，240，360，480 K₂O kg·hm^-2）对马铃薯产量和品质及经济效益的影响。结果表明，马铃薯商品率、产量和产值随施钾水平的提高而呈先增高后下降的趋势，商品率、产量以K120和K240较高，但纯收入以K120最高；马铃薯块茎淀粉、总糖、还原糖、Vc、蛋白质和干物质含量随施钾水平的提高而呈先增高后下降的趋势，淀粉和总糖含量以K240最高，而还原糖、Vc、蛋白质和干物质含量以K120最高，说明在高钾肥力土壤上适量增施钾肥可以提高马铃薯的产量和改善其品质。本试验条件下，马铃薯最高产量施钾量与经济最佳施钾量分别为162.06 kg·hm^-2和126.44 kg·hm^-2。

Biological effects of potassium fertilizer application on potato in high potash soil

In order to optimize nutrient management and to raise use efficiency of fertilizer in the process of potato production, a field experiment was conducted in high potash soil in Dingxi, Gansu Province in 2011. Based on equivalent dosage of nitrogen and phosphorus, the influences of potassium rates (K0, K120, K240, K360 and K480 representing 0, 120, 240, 360 and 480 kg K₂O·hm^-2, respectively) on yield, quality and economic benefit of potato were studied. The results showed that the commodity ratio, yield and output value increased at first and then decreased with the increasing of potassium rate. Under the potassium rates of K120 and K240, the commodity ratio and yield were relatively high, and the net income was the highest under K120. The contents of starch, total sugar, reducing sugar, Vc, protein and dry matter increased at first and then dropped with the increasing of potassium rate. The contents of starch and total sugar were the highest under K240, while the contents of reducing sugar, Vc, protein and dry matter were the highest under K120. It was indicated that the proper application of potassium fertilizer could increase the yield and improve t he quality of potato in high potash soil. Under the experimental condition, the optimal potassium rates for the highest yield and largest economic benefit were 162.06 kg K₂O·hm^-2 and 126.44 kg K₂O·hm^-2, respectively.