For reasonable potash application,stable summer maize yield and increasing lodging resistance,a field experiment was conducted in the rotation system of winter wheat and summer maize in the low plain area of Hebei province.Effects of potash application rates on the yield,accumulation and distribution of dry matter and potassium nutrient in different organs,and lodging resistance of stalk in maize were studied.The results showed that increasing potash application rates promoted the transportation and distribution of dry matter and potassium in different organs.Plant dry matter accumulated until maturity.At maturity,dry matter and potassium accumulation in grain to whole plant under different potassium treatments were 51.1%~57.0% and 15.8%~20.7%,respectively.Dry matter and potassium accumulation in grain at maturity were 1.33~1.61 and 0.70~0.97 times of those at grainfilling stage,while in the whole plant it were 0.98~1.15 and 0.75~1.00 times,respectively.These indicated that the process of potassium and dry matter transportation and distribution of maize was not synchronous.Other nutrients application should be regulated reasonably.Potash application increased the tensile strength,flexural strength and puncture strength of stalk,those of K225 were especially larger.The tensile and flexural strength of stalk was the strongest at grainfilling stage.Flexural and puncture strength decreased with the increase of stem section in the same plant,the third section from base had the strongest effect.Therefore,potash application rates of 225 kg·hm-2 not only improved the dry matter and potassium transportation,accumulation and distribution in plant,strengthen the lodging resistance of stalk,but also increased the yield and saved the potassium resources.