通过湖北省5个不同试验点在每公顷施有机肥22.5t～30 t、纯N 180 kg、P2O5 60 kg的前提下,对不同K2O用量0、150、300、450、600 kg/hm2的马铃薯产量和效益的影响进行了探讨。结果表明:施用钾肥均能增产,在K2O的施用量为150 kg/hm2时,商品率最高,产投比最大,经济效益最好;在K2O的施用量为300 kg/hm2时,产量虽然最高,但效益明显下降;在K2O的施用量上升至450 kg/hm2后,不仅产量下降,净收益还出现负增长。建议生产实际中选用150kg/hm2左右的K2O施用量,不宜超过300 kg/hm2。 Through five different experimental sites in Hubei Province, applying organic fertilizer 22.5t-30t, N 180kg and P2O5 60kg per hectare, potatoes with different dosage of K2O 0,150,300,450,600 kg / hm2 The impact of yield and benefit are discussed. The results showed that all the treatments could increase production of potassium fertilizer. When K2O was applied at 150 kg / hm2, the yield was the highest, and the ratio of production to the input was the highest, and the economic benefit was the best. When K2O was applied at 300 kg / hm2, the yield was the highest , But the benefit decreased obviously. After the application of K2O increased to 450 kg / hm2, not only the yield but also the net income also showed a negative growth. Proposed production of practical use of about 150kg / hm2 K2O application rate should not exceed 300 kg / hm2.