播期调整对华北北部冬小麦、夏玉米产量和品质的影响

Effects of Sowing Date Adjustment on Yield and Quality of Winter Wheat and Summer Maize in Northern Area of North China

【目的】基于田间分期播种试验,研究华北北部冬小麦、夏玉米播期调整,其生长发育、光合生理特性、籽粒灌浆和产量形成及品质对气候变暖的不同响应,为华北平原农业生产采取措施应对气候变化提供科学依据。【方法】采用分期播种方法,于2017—2023年在华北北部的河北固城农业气象国家野外科学观测研究站开展冬小麦和夏玉米的大田分期(早播10 d、正常播期、晚播10 d、晚播20 d)播种试验,获取冬小麦和夏玉米的生育进程、地上干物质累积和分配、叶片光合特性、籽粒灌浆速率以及产量农艺性状和籽粒营养成分等资料。【结果】冬小麦全生育期随播期推迟而缩短,主要原因在于冬前幼苗期缩短;夏玉米全生育期与播期呈抛物线关系,播期每推迟10 d,幼苗期缩短1.3 d,花粒期和籽粒形成-灌浆期分别延长1.5和1.6 d。冬小麦、夏玉米籽粒灌浆过程对播期调整的响应完全不同,冬小麦籽粒灌浆特征在播期间反应并不敏感,夏玉米籽粒灌浆速率在播期间差异较小,但籽粒形成期、灌浆结束日期和峰值日期因播期推迟顺次延后,且灌浆持续日数因播期每推迟10 d,灌浆持续日数缩短4 d。北方麦区在秋暖和冬暖背景下,冬小麦播种期界限延宽,播期对产量的影响明显减弱,播期推迟配套增加播种量,产量不减且会小幅增产;夏玉米产量随播期推迟明显递减,理论产量播期每推迟10 d递减率1381.50 kg·hm^(-2),但冬小麦和夏玉米晚播20 d产量都凸显跳跃变小。播期每推迟10 d,冬小麦籽粒分配率递增1.67%,夏玉米则递减1.57%,冬小麦收获指数提高0.017,而夏玉米降低0.016。冬小麦和夏玉米叶片光合速率(Pn)对播期的响应亦不同,冬小麦播期间的Pn较为相近,而夏玉米播期每推迟10 d Pn递减率1.21μmol·m^(-2)·s-1。播期调整对华北北部冬小麦、夏玉米籽粒品质不会产生明显影响。【结论】气候变暖背景下我国北方冬小麦延迟播种,延宽适宜播种期是适应气候变暖的积极有效措施,华北平原夏玉米适期早播可避免高温热害影响,有助于稳产增产。

【Objective】Based on the field staging experiments,this study revealed the different responses of winter wheat and summer maize sowing date adjustments in growth and development,photosynthetic physiological characteristics,grain filling,yield formation and quality to climate warming in northern area of North China,providing scientific basis for agricultural production measures to cope with climate change in North China Plain.【Method】Different sowing date experiments of winter wheat and summer maize have been conducted at Hebei Gucheng Agricultural Meteorology National Observation and Research Station in northern area of North China from 2017 to 2023,which were set up in four sowing dates,including 10 d early sowing,10 d late sowing,20 d late sowing,and control.The growth process,above-ground dry matter accumulation and distribution,photosynthetic characteristics of leaves,grain filling rate,yield agronomic traits,and grain nutrients of winter wheat and summer maize were observed.【Result】The whole growth period of winter wheat was shortened with the delay of sowing date,mainly because of the shortening of seedling stage before winter.There was a parabolic relationship between the whole growth period and sowing date of summer maize.The seedling stage was shortened by 1.3 d,and the flowering stage and grain formation-filling stage were extended by 1.5 d and 1.6 d for every 10 d delay of sowing date.The grain filling characteristics of winter wheat and summer maize were not sensitive to sowing date adjustments,and the grain filling rate of summer maize was little different during different sowing dates,but the grain formation period,the filling end date and the peak date were successively delayed due to the delay of sowing date,and the duration of filling days was shortened by 4.0 d for every 10 d delay of sowing date.Under the background of warm autumn and winter in northern wheat region,the sowing duration of winter wheat was extended,while its influence on the yield was obviously weakened.The delay of sowing date with the increase of sowing seed amount would result in yield increase slightly.The yield of summer maize decreased significantly with the delay of sowing date,and the decline rate of theoretical yield was 1381.50 kg·hm^(-2) for every 10 d delay of sowing date,but the yield of winter wheat and summer maize showed a jumping decease for 20 d late sowing.The grain distribution rate increased by 1.67%for winter wheat,decreased by 1.57%for summer maize with every 10 d delay of sowing date.As a result,the harvest index increased by 0.017 for winter wheat,and decreased by 0.016 for summer maize with every 10 d delay of sowing date.The leaf photosynthetic rates(Pn)of winter wheat and summer maize were also different in response to sowing date,they were similar for winter wheat during different sowing dates,while decreased by 1.21μmol·m^(-2)·s-1 for summer maize for every 10 d delay after sowing date.Sowing date adjustments had no significant effects on grain quality of winter wheat and summer maize in northern area of North China.【Conclusion】Extending suitable sowing date range and sowing date delay of winter wheat in North China Plain were positive and effective measures to adapt to climate warming.The early sowing of summer maize in North China Plain might avoid the negative effects of high temperature and heat damage,and would promote the increase of yield.