基于分期播种的气候变化对东北地区玉米(Zea mays)生长发育和产量的影响

Effect of climate change on maize(Zea mays) growth and yield based on stage sowing

利用在东北地区中部开展玉米(Zea mays)分期播种试验资料,分析气候变化对玉米出苗速度、生长发育速度、灌浆过程、植株干物质积累和产量的影响,进而分析未来气候变化对东北地区玉米生产的影响及适应性对策。结果表明,气候变化对玉米生长发育和产量的影响十分明显,在水分基本适宜的条件下,东北地区气候变暖导致玉米生长季气温升高、积温增加,使玉米生长发育和灌浆速度加快,生物量增加,从而提高单产。但气候变暖的同时,气候变干会限制热量资源的利用,将缩短玉米灌浆时间,降低灌浆速率,使千粒重下降,从而造成明显减产,而且减产幅度明显大于温度升高的增产幅度。在水分条件基本得到满足的条件下,未来夏半年气候变暖对东北地区玉米生产是有利的,偏晚熟玉米品种比例可以适当扩大,东北玉米带可以向北部和东部扩展,单产和总产都会增加;但如果水分得不到满足,气候的暖干化趋势会使东北地区的中、西部玉米主产区的农业干旱变得更加严重且频繁,造成产量下降和不稳定,给玉米生产带来严重威胁,因而更应加强农业干旱的综合防御工作。

The experiment of sowing by stages can develop different conditions of climate change for maize （Zea mays ） growth in natural fields. Using method of statistic analyses, effect of climate change on maize growth and yield was researched according to 6 years＇ data of the experiment of sowing by stages in the middle of the maize belt of the Northeast China. Here climate change indicated mainly changes of temperature and humidity. The seedling emergence rate, growth rate, filling process, and accumulation of dry matter were indications of the situation of maize growth. Changes of air temperature and humidity can influence obviously vegetative and reproductive growth and production of maize. Under the conditions of normal moisture, if air temperature stage of maize; about 6 days and 4 days will be reduced during rises 1 ~C , there will be 3 days ahead of time in sprouting the period of seedling emergence to tasseling stage and tasseling to mature stage respectively; the seedling emergence rate and growth rate after sprouting stage will increase by 17%. If relatively cumulative temperature increases by 10%, relative dry weight of 100 grains of maize will increase by 13 %. However, filling time will shorten obviously and grain weight will lighten if air humidity is low during filling period. If cumulative temperature of main growing season increases by 100 ℃· d, per unit area yield of maize will increase by about 6.3% ; and if mean temperature rises 1 ℃ during the period of tasseling to mature stage, per hectare yield of maize will increase by about 550 kg; but if aridity index increases 0.1 during the same time, per hectare yield will decrease about 860 kg. When temperature is above 22 ℃during the period of tasseling to mature stage, if aridity index is between 0.75 and 0. 9, maize yield will reach to the maximum, that means that cooperation between higher temperature and larger humidity is favorable to maize filling and mature and yield increase. Under the conditions of suitable moisture, climate warming speeds up maize development and filling and makes biomass increase, so that per unit area yield of maize increases; however, climate drying limits use of heat resources, shortens maize filling time and rate, and decreases weight of 1000 grains of maize in growth season of the Northeast China, so that maize yield decreases. In the future, under the conditions of climate warming and suitable moisture, planting area of late maize should be expanded and the maize belt should extend to the north and the east of the Northeast China, per unit area yield and ultimate production of maize will increase. But trend of climate warming and drying would result in more serious and frequent drought of main planting area of maize in the middle and the west of the Northeast China, which will bring about maize yield decrease and uncertainty and threaten seriously future development of maize production. So, to enhance comprehensive defense of agricultural drought is prerequisite for to suit future climate warming and drying and spread middle-late and late variety of maize.