Double-maize cropping system is an effective option for coping with climate change in the North China Plain. However, the effects of changes in climate on the growth and yield of maize in the two seasons are poorly understood. Forty-six cultivars of maize with different requirements for growing degree days (GDD), categorized as high (H), medium (M) or low (L), and three cultivar combinations for two seasons as LH (using JD27 and DMY1 from category L in the first season; and YD629 and XD22 from category H in the second season), MM (using JX1 and LC3 from category M in the first season; and ZD958 and JX1 from category M in the second season) and HL (using CD30 and QY9 from category H in the first season; and XK10 and DMY3 from category L in the second season) were tested to examine the eco-physiological determinants of maize yield from 2015 to 2017. The correlations between the combinations of cultivars and grain yield were examined. The combination LH produced the highest annual grain yield and total biomass, regardless of the year. It was followed, in decreasing order, by MM and HL. Higher grain yield and biomass in LH were mainly due to the greater grain yield and biomass in the second season, which were influenced mainly by the lengths of the pre- and post-silking periods and the rate of plant growth (PGR). Temperature was the primary factor that influenced dry matter accumulation. In the first season, low temperatures during pre-silking decreased both the duration and PGR in LH, whereas high temperatures during post-silking decreased the PGR in MM and HL, resulting in no significant differences in biomass being observed among the three combinations. In the second season, high temperatures decreased both the PGR and pre- and post-silking duration in MM and HL, and consequently, the biomass of those two combinations were lower than that in LH. Moreover, because of lower GDD and radiation in the first season and higher grain yield in the second season, production efficiency of temperature and radiation (R_a) was the highest in LH. More importantly, differences in temperature and radiation in the two seasons significantly affected the rate and duration of growth in maize, and thereby affecting both dry matter and grain yield. Our study indicated that the combination of LH is the best for optimizing the double-maize system under changing climatic conditions in the North China Plain.

双玉米种植系统是应对华北平原气候变化的有效选择。但是，人们对两个季节中气候变化对玉米生长和产量的影响了解得很少。不同生长发育天数（GDD）需求的46个玉米品种分为高（H），中（M）或低（L）以及三个季节的三个品种组合作为LH（使用JD27和DMY1分类第一个赛季为L；第二个赛季为H类的YD629和XD22）； MM（第一个赛季使用M类的JX1和LC3；第二个赛季M类的ZD958和JX1）；以及HL（使用CD30测试了第一季H类的QY9；第二季L类的XK10和DMY3），以检验2015年至2017年玉米产量的生态生理决定因素。研究了品种组合与籽粒产量之间的相关性。无论哪种年份，LH组合均产生了最高的年度谷物产量和总生物量。MM和HL按照降序排列。LH地区谷物产量和生物量较高的主要原因是第二季谷物产量和生物量较高，这主要受到生长期和后生长期的长短以及植物生长率（PGR）的影响。温度是影响干物质积累的主要因素。在第一个季节中，前生长期的低温降低了LH的持续时间和PGR，而后生长期的高温降低了MM和HL的PGR，导致这三种组合之间的生物量没有显着差异。在第二季 高温降低了MM和HL的PGR以及沉降前和沉降后的持续时间，因此，这两种组合的生物量均低于LH。此外，由于第一季的GDD和辐射较低，第二季的谷物产量较高，因此温度和辐射的生产效率（R _a）在LH中最高。更重要的是，两个季节中温度和辐射的差异显着影响了玉米的生长速度和持续时间，从而影响了干物质和谷物的产量。我们的研究表明，在华北平原气候变化的条件下，LH的组合最适合优化双玉米系统。