品种和播期对华北春玉米产量及水分利用效率的影响

Effects of sowing date and cultivar on grain yield and water use efficiency of spring maize in the North China Plain

华北平原冬小麦夏玉米一年两作种植制度主要受水资源的约束,发展休耕轮作是实现该区域农业可持续发展的途径之一。春玉米高效生产是提升休耕轮作产能的关键因素,如何利用品种特性进行播期调整以适应区域生产特点提高产量是该区春玉米生产中面临的主要问题。为此,于2016年5—9月在中国科学院南皮生态农业试验站以5个玉米品种(‘华农887’、‘胡新338’、‘郑单958’、‘华农866’和‘联创1号’)为材料,比较分析了3个播期(5月1日、5月15日和5月30日)下春玉米生育时期、产量及产量要素、耗水和水分利用效率的变化情况,并结合气象因子分析探讨了春玉米产量及其构成要素与环境因子的关系。结果表明:随着播期推迟,不同春玉米品种的生育期总天数均呈显著减少趋势(P<0.05),生育期总天数的减少主要是播种到抽雄天数减少所致。不同春玉米品种的生育期总天数也存在较大差异,在各播期处理下均相差5~7 d。在产量方面,5月1日和5月15日播种的5个玉米品种间平均产量没有显著差异,5月30日播种的平均产量显著高于前2个播期,其产量提升主要是百粒重增加所致。随着播期的推迟,春玉米的耗水量变化不大,水分利用效率呈增加趋势,这主要与降水的分布有关。通过气象因子分析,不同播期下百粒重与抽雄前后的积温和降水呈显著相关(P<0.05)。综合产量、耗水和水分利用效率分析,在该区域推荐5月30日左右为春玉米的适宜播种日期,‘华农866’和‘华农887’是适宜该区生产的潜力品种。

The double winter wheat and summer maize rotation cropping system in the North China Plain（NCP） is mainly limited by water shortage. To solve this problem, a land fallow policy has been introduced in NCP, especially in the groundwater-over-exploited region. A three cropping system in two years which includes winter wheat, summer maize and spring maize was introduced in place of the double cropping system in a year. Meanwhile, grain yield of spring maize is mainly limited by environmental（e.g.,precipitation and temperature）, biological（e.g., released cultivar） factors. Improving spring maize yield and water use efficiencyusing optimal sowing date that is adapted to maize cultivar characteristics is critical in solving this problem. A field experiment was conducted in Nanpi Eco-agricultural Station of Chinese Academy of Science in 2016, consisting of 5 maize cultivars（HN887,HX338, ZD958, HN866 and LC1） and 3 sowing dates（May 1, May 15 and May 30） treatments. The phenological stages were observed, and soil water content in the 2 m soil profile, grain yield and yield components were measured and weather factors recorded for the period of study. The results showed that the days from sowing to maturity of the 5 cultivars all significantly reduced with sowing date delay, which mainly reduced the days from sowing to tasselling stage（P 0.05）. For different cultivars, the days from sowing to maturity were significantly different and the differences were similar（5-7 d distance） for all three sowing date treatments. There was no significant difference between averaged grain yield for 5 cultivars for May 1 and May 15 sowing date treatments. May 30 sowing date had the highest grain yield, which was mainly caused by the higher 100-grain weight（3.3 g higher than others）. For water consumption, there was no significant difference among 3 sowing dates because there was no irrigation during the growth stage for all treatments and precipitation was 405.2–416.0 mm. There was also no significant difference in water consumption among different maize cultivars. The trend in water use efficiency（WUE） was also similar to that in grain yield, which increased with sowing date delay. There were significant differences in WUE among different sowing dates and maize cultivars.Meanwhile, the correlation was significant between 100-grain weight and precipitation before and after tasselling and then between 100-grain weight and accumulated temperature before and after tasselling. The comprehensive analysis of the grain yield, water uptake and water use efficiency showed that the optimal sowing date was May 30, with ‘HN866＇ and ‘HN887＇ as the cultivars with the best performance in the study area.