Effects of delayed irrigation and different planting patterns on carbon emissions and yield of winter wheat in the North China Plain

We conducted this study considering the global greenhouse effect and world food security to determine a water-saving planting pattern that results in fewer carbon emissions and stable crop yields in the North China Plain (NCP). From 2015 to 2019, we conducted a two-factor winter wheat experiment composed of four treatments, with planting patterns (W, wide-precision planting pattern; and C, conventional planting) as the primary factor and different irrigation timing (I1, 60 mm irrigation at the jointing stage; and I2, 60 mm irrigation 10 days after the jointing stage) as the secondary factor. The treatments were as follows: WI1, WI2, CI1, and CI2. The soil respiration rate, soil carbon emissions, grain yield, and carbon emissions efficiency (CEE) were measured for each treatment. The W treatment resulted in a lower soil respiration rate and reduced soil carbon emissions. The W and I2 treatments resulted in significantly increased grain yields and reduced soil carbon emissions compared to the C and I1 treatments, respectively. The CEE of the WI2 treatment was higher than that of the other treatments. This study demonstrated that the combination of the W planting pattern and delayed irrigation 10 days after the jointing stage was effective in reducing soil carbon emissions while ensuring a stable grain yield in the NCP. The results of this study provide practical evidence for the sustainable development of winter wheat in the NCP. The combination of the W planting pattern and delayed irrigation 10 days after the jointing stage is an agronomic technique worth popularizing.