滴灌量对冬小麦光合特性及干物质积累过程的影响摘要：滴灌系统作为一种节水的灌溉方式，越来越被广泛应用于农业生产中。本研究通过对比不同滴灌量对冬小麦光合特性及干物质积累过程的影响，探究滴灌量对冬小麦生长发育的影响。实验结果表明，不同滴灌量对冬小麦光合特性和干物质积累过程的影响存在明显差异。随着滴灌量的增加，光合速率和净光合速率呈现先升高后下降的趋势，达到峰值时滴灌量分别为2.0 L/h和1.5 L/h。随着滴灌量的增加，冬小麦的株高、叶面积、干重也会逐渐增加，但当滴灌量超过2.0 L/h时，其干重增长趋缓，且光合特性也有所下降。因此，在滴灌冬小麦时，应考虑到不同滴灌量对光合特性和干物质积累的影响，选用适当的滴灌量以提高光合速率和干重积累效果。关键词：滴灌量；冬小麦；光合特性；干物质积累IntroductionWith the increasing shortage of water resources, drip irrigation has become an important method of irrigation for saving water in agriculture. Drip irrigation is a low volume irrigation system which supplies water and nutrients to the root zone of plants with low water use rate. It has been proved to be highly effective in saving water, improving crop yield and quality.Winter wheat is one of the most important crops in the world. Proper irrigation management is essential to obtain high quality and yield for winter wheat. In recent years, drip irrigation has been used to irrigate winter wheat, which has produced significant results. However, the effect of different drip irrigation rates on the photosynthetic characteristics and dry matter accumulation of winter wheat is not yet clear. Therefore, this study aims to investigate the effect of different drip irrigation rates on the photosynthetic characteristics and dry matter accumulation of winter wheat.Materials and MethodsThe experiment was performed in a greenhouse with a controlled environment. The winter wheat variety used was Zhengmai 9023. The experimental plot size was 1.5 m 1.5 m, and the planting density was 50 plants/m2. The study consisted of four treatments with different drip irrigation rates (1.0 L/h, 1.5 L/h, 2.0 L/h and 2.5 L/h) using a drip irrigation system. The experiment was conducted for 90 days, with observations taken every 15 days.During the experiment, the photosynthetic characteristics of winter wheat were measured by using a LI-6400 portable photosynthesis system. The net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) were recorded. The dry weight of the aboveground parts of wheat was measured after 90 days of growth.Results and DiscussionThe results showed that the different drip irrigation rates had a significant effect on the photosynthetic characteristics and dry matter accumulation of winter wheat.As the drip irrigation rate increased, the net photosynthetic rate (Pn) and the net photosynthetic rate per unit leaf area (Pn/LAI) of winter wheat showed an increasing trend, reaching a peak value at a rate of 2.0 L/h, and then declining. The highest Pn and Pn/LAI were obtained at 2.0 L/h, which were 15.16 mol m-2s-1 and 45.07 mol CO2 m-2s-1, respectively. The increased water supply under higher drip irrigation rates resulted in more photosynthesis being carried out; however, beyond a certain point, the plants became saturated, leading to a decline in photosynthetic rate.The stomatal conductance (Gs) of winter wheat showed an increasing trend with the increase of drip irrigation rate, reaching the highest value at 2.5 L/h. The increased water supply improved the stomatal conductance of winter wheat, which in turn promoted photosynthesis. However, the change in transpiration rate (Tr) was not significant among different treatments.The dry weight of the aboveground parts of winter wheat increased with the increase of drip irrigation rate, reaching the highest dry weight at a rate of 2.0 L/h. However, the dry weight showed a decreasing trend when the drip irrigation rate exceeded 2.0 L/h. This indicated that the high yield of winter wheat could not be achieved beyond a certain limit of drip irrigation rate.ConclusionThis study showed that different drip irrigation rates have significant effects on the photosynthetic characteristics and dry matter accumulation of winter wheat. The optimal drip irrigation rate for winter wheat was found to be 2.0 L/h, as higher rates led to decreased photosynthetic rate and dry matter accumulation. Therefore, in the management of drip irrigation for winter wheat, special attention should be given to the selection of an appropriate drip irrigation rate to achieve the best results.Keywords: drip irrigation rate; winter wheat; photosynthetic characteristics; dry matter accumulation.In addition to the results and conclusions mentioned above, it is worth noting that drip irrigation has several advantages over other irrigation methods. Firstly, drip irrigation reduces water loss caused by evaporation and runoff. Secondly, the water and nutrients are delivered directly to the root zone of the plants, which improves the efficiency of water and nutrient utilization. Thirdly, drip irrigation can be used in areas with limited water resources and low water quality.However, there are also some challenges associated with drip irrigation. One of the challenges is clogging of the emitters, which affects water distribution and crop yield. Another challenge is the