吉林省西部玉米生产水足迹研究

玉米是吉林省西部的主要农作物,通过在吉林省西部开展玉米大田试验,探讨在相同的土壤及农田管理条件下,不同试验年份玉米生产需水及水分来源的变化规律,通过比较分析玉米生产水足迹的动态变化,实现水资源的合理利用,保护生态环境,促进农业的可持续发展。3 a大田试验的研究结果表明,玉米生产水足迹以绿水足迹为主,占80%以上,蓝水足迹不足1%,灰水足迹介于10%～20%之间。而在绿水足迹中,降水较充足的年份,有效降水足迹占70%以上,一般干旱年份有效降水足迹占一半,极端干旱年份有效降水足迹则只占30%,这将对土壤水分平衡带来不利影响。3a中,单位质量玉米蓝水量约0.005～0.006 m3/kg,占单位质量玉米需水量的比例低于1%;单位质量玉米绿水量为0.559～0.839 m3/kg,占单位质量玉米需水量的99%以上;单位质量玉米灰水量为0.099～0.122 m3/kg。通过对玉米生产水足迹的研究,明确了绿水在吉林省西部雨养农业粮食安全中的重要地位。

Production Water Footprint of Maize in the West of Jilin Province

Maize is the main crop in the west of Jilin Province.According to the field experiments in the west of Jilin Province,this paper discusses the water requirement of maize growth and the changes of water source in different years based on the same soil and farm management conditions,namely,comparatively analyzes the dynamic change of maize production water footprint.It is useful for the rational utilization of water resources,the protection of ecological environment and the agricultural sustainable development.The results of the 3 years field experiments(2005,2006 and 2007)indicate that the major portion of maize production water footprint is green water with more than 80%.The blue water footprint is less than 1% and the gray water footprint is between 10%-20%.In the green water footprint,the effective precipitation footprint is more than 70% in the abundant rainfall year.By contrast,in the drought year it accounts for 50%,while in the extreme drought year,it only accounts for 30%.They will bring about an adverse effect on the soil moisture balance.During the 3 years,the blue water per unit weight of maize is about 0.005-0.006 m3/kg,which is lower than 1% of the maize water requirement per unit weight.The green water per unit weight of maize is 0.559-0.839 m3/kg,accounting for more than 99% of maize water requirement per unit weight.The gray water per unit weight of maize is 0.099-0.122 m3/kg.According to the study of water footprint of maize production,it clearly shows that green water occupies an important position in rain-fed agriculture and food security in the west of Jilin Province.