不同钾肥用量对冬种马铃薯产量、品质和钾肥利用率的影响

Effects of Potassium Application Rate on Yield,Quality and Potassium Efficiency of Winter Potato

通过田间试验研究钾肥用量对珠三角地区冬种马铃薯生长、产量、钾素利用率和品质的影响。结果表明,施用钾肥能够一定程度提高马铃薯叶绿素含量和叶面积,起到较好的壮苗效果;在K2O 300 kg/hm2时产量和经济效益最高。与对照相比,马铃薯块茎粗蛋白和可溶性糖含量在K2O 225 kg/hm2以上用量时显著提高,淀粉含量在K2O 300 kg/hm2以上用量时显著提高,而施钾一定程度降低了维生素C含量。随钾肥用量的增加,钾素农学利用率和生理利用率显著下降,钾素吸收利用率呈先升高后下降的趋势,在K2O 225 kg/hm2时达最大值。建议珠三角地区冬种马铃薯钾（K2O）用量以225-300 kg/hm2为宜。

A field experiment was carried out to investigate the effects of potassium application rate（K2O 0,150, 225, 300, 375, 450 kg/hm2） on growth, yield, potassium use efficiency and quality of winter potato in PearlRiver Delta area. The results showed that chlorophyll content, leaf area, and stem diameter of potassiumtreatment were better than those of control, the yield and economic effectiveness of K2O 300 kg/hm2treatmentwas the highest. The content of crude protein and soluble sugar of potato tuber enhanced with potassiumfertilizer application rate increased and significantly enhanced above K2O 225 kg/hm2compare to control, whilethe same effect was observed on starch content and significantly enhanced above K2O 300 kg/hm2. However,the content of vitamin C was decreased when potassium applied. Agronomic K2O use efficiency andphysiological K2O use efficiency were decreased with potassium application rate increased. Apparent K2Orecovery efficiency was improved then reduced with potassium application rate increased and peaked at K2O225 kg/hm2. It is suggested that K2O 225-300 kg/hm2application on winter potato in Pearl River Delta area was advisable.