Field experiments were conducted to study the effects of different amount of biochar application(0,10,20,40,80 t/hm2) on potassium content,stalk morphological characteristics,stalk quality and yield of maize.The results showed that soil applying biochar increased potassium content in each internode of maize stalk,and biochar application resulted in dwarfing of the 3rd~5th internodes at the lower part of maize stalk,increased stalk diameter,enhanced stalk elasticity and rind puncture force,increased dry matter accumulation,and strengthened stalks.With the increase of the amount of biochar application,the effects on potassium content,stalk characters and yield of maize all showed the trend of first increased and then decreased.Biochar applied at 40 t/hm2 was the optimal application rate,leading to a yield of 13 261 kg/hm2,which was 25.99% higher than that of the control.When biochar application was at 80 t/hm2,its improving effects on potassium content,stalk morphological characteristics,stalk quality and yield of maize slightly declined.