不同土壤大气湿度组合下玉米生长及水分光合特性反应

Response of Maize Growth and Water Photosynthesis Characteristic to Different Combination of Air Humidity with Soil Moisture

通过对不同土壤大气湿度组合下玉米生长、水分及光合特性的研究，认为土壤水分亏缺对玉米的影响要超过大气干旱。玉米的水分状况及生理活性主要决定于土壤的水分条件。短期干旱使气干土干、气湿土干处理净光合速率下降的主要原因是非气孔限制，而气干土湿处理前期光合速率下降主要是由于气孔限制，后期则为非气孔限制。

Through the research of growth, water and photosynthesis characteristic of maize under different combination of air humidity with soil moisture, the results showed the harm of soil water deficit exceeded that of air drought, water status and physiological activities were mainly decided by soil moisture. Short term drought made photosynthetic rate decrease. For soil dry treatments, the main reason was nonstomatal limitation, but for air dry soil wet treatment, stomatal limitation at first but nonstomatal limitation later. Dry matter continued to increase during the period of short term drought.