Root zone temperature regulates potassium absorption and photosynthesis in maize (Zea mays)

Affected by climate warming, the impact of crop root zone warming (RZW) on maize seedling growth and nutrient uptake deserve attention. The characteristics of K uptake in maize under root zone warming and the combined impacts of potassium deficiency and RZW are still unclear. The present study aimed to investigate the effects of RZW on potassium absorption and photosynthesis of maize seedlings under the difference in potassium. The results showed that RZW and low potassium treatment significantly affected root shoot development and photosynthetic physiological characteristics of maize seedlings. Moreover, the interaction of RZW and potassium content had striking influence on maize seedlings. Under the normal potassium with root zone medium temperature treatment, the development of maize was the most vigorous. Under the dual stress of high root zone temperature and low potassium, the root absorption area, total potassium content and root activity were significantly reduced, which then influenced the light energy use efficiency and dry matter accumulation. Securing the supply of potassium fertilizer under high root zone temperature stress is useful to alleviate the impact of high temperature stress.