Abstract: This paper describes the response of the photosynthetic rate of winter wheat on soil moisture according to the experiment in pot and field during the flowering and filling stage. The results are as follows. 1. Optimal soil moisture for leaf's photosynthetic rate is 70%-80% of field capacity, and the photosynthetic rate is more sensitive to low soil moisture than to high soil moisture. 2. Soil drought strengthens the Photosynthetic Midday Rest, and irrigation can relieve it. 3. The photosynthetic rate increases significantly when watered after soil drought, and watering at the low limit of optimal soil moisture is most effective for the photosynthetic rate.

Key words: Winter wheat Photosynthetic rate Soil moisture, Winter wheat Photosynthetic rate Soil moisture