In North China Plain, straw mulching is increasingly applied to the succeeding crops with winter wheat-summer maize double cropping system. However, research results on the effect of maize straw mulching on the yield of winter wheat are inconsistent, and the underlying mechanism of the effect remains unclear. Such information is helpful to guide the field water management for higher yield. In this study, soil moisture, plant growth, photosynthesis and yield of winter wheat field treated with no-till and straw mulching (SM) and non- mulching (N) and three irrigation amounts (high, middle and low irrigation, HI, MI and LI) in four growing seasons in 2013–2016. The results showed that straw mulching improved soil moisture by reducing the days of soil moisture less than 60% field capacity for 2–10 days. Straw mulching increased net photosynthetic rate, stomatal conductance, maximum carboxylation rate (V_cmax), and the maximum rate of photosynthetic electron transport (J_max) of flag leaves, especially at the post-anthesis measurements, during which, the above parameters increased by 20.6%, 21.9%, 28.7% and 25.2%, respectively. Compared with pre-anthesis measurements, the post-anthesis V_cmax and J_max values decreased, but the decrease percentage of the SM treatments (10.8–25.7% for V_cmax and 22.0%−49.6% for J_max) was less than those of N treatments (19.6%−41.4% for V_cmax and 29.3%−61.3% for J_max). V_cmax and J_max were significantly linear correlating to leaf nitrogen content and the relationships between them were not affected by straw mulching. The yield was not affected by straw mulching. However, straw mulching significantly increased the intercept of the linear relationship between yield and canopy potential photosynthetic capacity (the productions of leaf area index and V_cmax, or J_max), indicating that straw mulching may improve the harvest index of winter wheat. The overall net effect of straw mulching was a favorable environment that stimulated plant photosynthesis, which compensated the lower LAI and tiller density, in turn, maintained wheat yield. This study elucidated the physiological basis of straw mulching and no-till effect on yield and provided photosynthetic parameters of winter wheat under such soil management.

在华北平原，冬小麦-夏季玉米双季种植系统越来越多地将秸秆覆盖用于后续作物。然而，关于玉米秸秆覆盖对冬小麦产量影响的研究结果并不一致，其潜在机理尚不清楚。这些信息有助于指导田间水管理提高产量。本研究以免耕和秸秆覆盖（SM）和非覆盖（N）和三种灌溉量（高，中，低灌溉，HI，MI）处理的冬小麦田的土壤水分，植物生长，光合作用和产量和LI）在2013-2016年的四个生长季节中。结果表明，秸秆覆盖可通过减少2-10天的田间持水量低于60％的田间持水量来改善土壤湿度。秸秆覆盖提高了净光合速率，V _cmax）和旗叶的光合电子最大传输速率（J _max），特别是在花后测量期间，上述参数分别增加了20.6％，21.9％，28.7％和25.2％。与花前测量相比，花后V _cmax和J _max值降低，但SM治疗的减少百分比（V _cmax为10.8–25.7％，J _max为22.0％−49.6％）小于N次处理（V _cmax为19.6％−41.4％，J _max为29.3％−61.3％）。V_的Cmax和J _max与叶片氮含量呈显着线性相关，二者之间的关系不受秸秆覆盖的影响。产量不受秸秆覆盖的影响。然而，秸秆覆盖明显增加了产量与冠层潜在光合能力之间线性关系的截距（叶面积指数和V _cmax或J _{max的产生）。}），表明秸秆覆盖可以提高冬小麦的收获指数。秸秆覆盖的总体净效果是促进植物光合作用的有利环境，补偿了较低的LAI和分er密度，从而保持了小麦的单产。这项研究阐明了秸秆覆盖的生理基础和免耕对产量的影响，并提供了在这种土壤管理下冬小麦的光合参数。