气候和人为因素对黄土高原地区小麦生产的影响

为量化气候和人为因素对黄土高原地区小麦产量的影响,找到减少干旱对小麦生产影响的途径,利用气象数据和多种来源的作物数据模拟了1955~2004年冬小麦产量。结果表明,黄土高原地区的降水量和蒸散量在1960~2000年间,以每10年高达20 mm的速度减少,并且自20世纪90年代以来气温上升加剧了土壤水分的亏缺,但黄土高原稳定的春雨降低了气温上升带来的影响。在过去的50年里,人为因素(非气候,技术进步)对小麦总产量的走向起了决定性作用,然而最近10年来,模拟结果显示,气候影响已经上升到了60%,达到每10年每公顷300 kg(总量约500 kg)。现代农业中重型农机具的使用对黄土土壤质量和小麦产量都有不良影响。相反,免耕措施与小麦秸秆覆盖改进土壤水分平衡及其再分配,不仅增加了作物产量,而且降低了减产的风险。

Climate and Human Impacts on Wheat Production in the Loess Plateau,China

This paper is,firstly an attempt to quantify the climate and human impacts,and secondly,an approach to reduce negative impacts of droughts on wheat production.Daily climate data and various sources of crop data have been used to simulate winter wheat yields between 1955 and 2004.The results showed that precipitation has decreased in the Loess Plateau of China by up 20 mm per decade between 1960 and 2000.Moreover,the increase in temperature has accentuated soil moisture deficits since the 1990s.However,stable spring rains in the Loess Plateau were an important factor in reducing the adverse effects of the temperature increases.Over the 50 year period the human impacts(i.e.non-climatic,technical improvements) dominated the total yield trend,while over the last decade the modeled climatic impact has increased to 300 of 500 kg per hectare per decade.The use of heavy field equipment could have adverse effects on erosive prone loess soils both in terms of soil quality and yield output.On the contrary,no-tillage and application of wheat straw mulch has the capacity to increase the crop yield and reducing the risk of a lower yield by improving the soil water balance.