Effect of potassium application and straw returning on spring maize yield, nutrient absorption and soil potassium balance Potassium balance in farmland in North China plain Potassium balance and management on sloping land in southwest China Effects of long-term potassium application and wheat straw return to cinnamon soil on wheat yields and soil potassium balance in Shanxi Effects of application of potassium fertilizer and straw on crop yields and soil potassium balance in low-yielding fields Effect of different straw return modes on potassium balance
and potassium pool in cinnamon soil