黑龙江西部浅沟覆膜种植模式在玉米苗期的增温特性

Temperature-Increasing Characteristics of Plastic Film Mulching Planting Mode of the Double-Shallow-Furrow in Broader-Row Ridges in Western Heilongjiang during Maize Seedling

2018年5-6月在黑龙江省玉米主产区的富裕县,通过设置玉米大垄双行浅沟覆膜种植模式(FM)和裸地(CK)对比试验,对两种模式的地下5cm表层土壤温度和地上5cm近地表气温进行24h连续观测,分析比较两种模式下的温度变化及差异,并进一步评价浅沟覆膜种植模式的增温特性和优势。结果表明:浅沟覆膜种植模式相比裸地有显著的增温效应。增温主要在玉米种子萌发、出苗和幼苗生长前期,即破膜放风前,表层地温和近地表气温分别显著提高2.8℃和6.1℃。白天和夜间温度均有升高,增温作用白天大于夜间。在幼苗生长后期,即破膜放风后,表层地温和近地表气温略有下降,但降温主要在白天,夜间增温作用明显,温度日较差平均减小3~4℃。覆膜时段表层地温和近地表气温的日最低温度表现为一致增温,表层地温的最低温度显著升高2.0℃。浅沟覆膜种植模式较裸地积温增加35%,约提早生育期8d。研究结果表明浅沟覆膜种植模式在玉米出苗及幼苗生长期增温效果明显,能够减轻玉米苗期低温、大风等灾害的影响,可以为提高玉米对热量资源的利用率、科学引种和优化种植结构等提供依据。该模式全程机器作业,操作容易,便于大范围推广,在黑龙江省乃至东北地区寒地玉米生产中具有广阔的应用前景。

Temperature changes and their differences were analyzed and compared in a comparative test was conducted between the two planting modes of broader-row ridges with double-shallow-furrow film mulching and bare land in Fuyu County,one of the main maize producing regions of Heilongjiang Province,in May-June 2018,with the soil temperature of 5cm below ground and the near-surface air temperature of 5cm above ground were continuously observed for 24 hours.And the temperature-increasing characteristics and advantages of the shallow-furrow film mulching planting mode were further evaluated.Results show that compared with the bare land,the shallow-furrow film mulching planting mode has a significant warming effect.The temperature increase was mainly at the early stage of maize seed germination,emergence and early stage of seedling growth,that is,before the film mulch was broken and the air was released,and the surface soil temperature and near-surface air temperature significantly increased by 2.8℃and 6.1℃,respectively.The temperature rose both in the daytime and at night,and the warming effect was greater during the day than at night.At the late stage of seedling growth,that is,after the film mulch was broken,the surface soil temperature and near-surface air temperature dropped slightly,but the temperature decrease was mainly in the daytime,while the temperature increase was distinct at night.The diurnal temperature range was reduced by 3-4℃on average.During the filming period,the daily minimum temperature of surface soil temperature and near-surface air temperature showed consistent increase,and the minimum surface soil temperature increased significantly by 2.0℃.The shallow-furrow film mulching planting mode increased the integrated temperature by 35%compared with that of the bare land,and the growth period was reduced by 8 days.Results also show that the shallow-furrow film mulching planting mode has obvious effects on temperature increasing during the emergence and growth of maize seedlings,which can reduce the impact of low temperature and strong winds in the maize seedling period,and can provide the basis for improving the utilization rate of heat resources,scientific introduction and optimizing planting structures.This mode is fully operated by machines,which is easy and favorable for large-scale extension.It has vast potential for further application in maize production in cold regions like Heilongjiang Province and other northeastern regions.