甘肃陇中半干旱区旱作马铃薯水肥效应研究

Effect of Application of Potassium and Different Stage of Water Supplement on Potato Yield in Semi-arid Area

采用裂区试验设计,以施钾水平为主处理,补水时期为副处理,研究了补充供水和钾素处理对马铃薯产量的影响。结果表明:补水和施钾有效改善了土壤水肥条件,使马铃薯植株健壮、茎杆坚实、叶片较厚,增强光合作用能力,从而促使马铃薯块茎增产优质。在陇中半干旱区,旱作马铃薯最佳补水时期是苗期(补水量为90m3/hm2)。氯化钾施用量为150kg/hm2,马铃薯鲜薯产量最高为36324.97kg/hm2,经济最佳投入量为127.48 kg/hm2,对应的马铃薯鲜薯产量为35178.71kg/hm2。在马铃薯生育前期土壤严重缺水,降水较少的情况下,苗期补水可改善土壤水分从而增加钾肥的生物有效性,增加钾肥的扩散,有利于马铃薯根系对钾营养的吸收,钾肥的利用效率较高,最高值为37.92kg/kg,而过量施用钾肥其利用率下降。

The experiment of split-plot design with main treatments potassium application and sub treatments different stage of water supplement was conducted to study the effect of the treatments on potato yield in semi-arid area. The results showed that the soil water and soil fertility were improved dramatically when applying potassium fertilizer and water supplement in seedling stage, it can improve plant growth, increase the photosythetic rate and the yield, seedling stage was considered as the optimal water supplement period to potato in arid and semi-arid in north china （supplementary water amount is 90m^3/hm^2）. The highest yield and economic yield reached 36324.97kg/hm^2, 35178.71 kg/hm^2 respectively when the potassium application rate at 150kg/hm^2, 127.48 kg/hm^2 respectively. Under the condition of less soil water and rainfall in seedling stage, water supplement can improve soil moisture, increase potassium biological availability, which would benefit the absorption of potassium and improve the efficiency of potassium. The highest efficiency of potassium was 37.92kg/kg, but the efficiency of potassium increased with the increase of potassium rate when the potassium was less than 150kg/hm^2, they were decreased by higher potassium application.