Application Effects of Different Amount of Potassium Fertilizer on Potato in High Altitude and Arid Mountain Area

[Objective] The aim was to provide the scientific basis for reasonable fertilization for potato in arid mountain area.[Method] With Leshu 1 as the material,on the basis of the same amount of nitrogen and phosphorus fertilizer,the effects of different amount of potassium fertilizer(0,60,120,180,240 kg/hm2)on the yield and economic benefit of potato were sutdied.[Result] The yields of potato in treatments with potassium fertilizer application were all higher than that of CK.After potassium fertilizer application,the yield and commodity rate of potato were 21.1%-49.6% and 2.8%-11.8% higher than that of CK.In a certain range,the more the application amount of potassium fertilizer was,the more the yield and commodity rate of potato were.But when the application amount of potassium fertilizer exceeded a certain limit,with the increment of potassium fertilizer rate,the yield of potato showed a decreasing trend.When the application amount of potassium fertilizer was 120 kg/hm2,the yield of potato was the highest(50 544 kg/hm2),and the economic benefit was the best(the income was increased by 7 775.28 yuan/hm2 than that of CK).[Conclusion] The effect equation of potassium fertilizer amount and potato was y=2 193.01+227.82x-12.65x2,according to which the application amount of potassium fertilizer was 135 kg/hm2 when potato yield was the highest in arid mountain area,and its application amount was 130.5 kg/hm2 when the economic benefit of potato was the best.