春季干旱对旱地冬小麦生产的影响及施肥和灌溉的应对效果——以2003年和2009年山西垣曲县冬小麦生产的调查和试验观察为例

Impact of Spring Drought on Winter Wheat Yield and the Mitigation by Fertilization and Irrigation: An Example of Survey and Field Experiments in 2003 and 2009 in Yuanqu County, Shanxi Province, China

旱灾多发是气候变化中农业生产面临的日益严重的挑战。而干旱半干旱区农业对旱灾表现出明显的脆弱性。本文收集了2009年和2003年山西省垣曲县农业生产调查资料和山西省农业科学院在该县的肥料试验示范地小麦生产试验资料，统计分析了2009年干旱下小麦产量与正常气候年（2003年）对比的变化，表明气候变化下小麦生长期干旱导致大田小麦减产超过30％，并田块间产量变率由正常气候年的10％左右提高到22％-42％。在雨养旱地，施肥技术试验示范地减产幅度在6％以下；干旱年水浇地的增产效果达到48％-64％，而施肥技术的增产效果达到30％-44％。而水浇地优化施肥示范地产量甚至比正常气候年产量提高36％～77％。肥水协调技术大幅度减缓了干旱下产量损失，同时大大降低了田块间产量变率，达到有效抵御干旱对小麦产量的影响。因此，发展优化施肥及肥水协调技术在应对气候变化的影响中具有显著的减缓潜力，而水资源的有效供应可能成为北方气候变化下干旱对旱地作物生产的主要挑战。

The increasing drought hazard is one of the increasingly severe challenges of China＇s crop production under impact of climate change. Agriculture in arid and semi-arid regions has been considered very susceptible to climate change, especially to the increasing drought impacts. In this paper, data was collected of winter wheat yield both from farm survey and field experiments in a normal climate year of 2003 and a drought year of 2009, respectively. As in the studied region, drought frequency has been increased and winter wheat yield had been much impacted by spring drought during wheat active growing. Wheat yield was seen decreased by over 30% and the plot yield variability increased from 10% to 22%-42% in the drought year of 2009 compared to of 2003. Nevertheless, in unirrigated raided fields, yield reduction was seen at 6% under well fertilization treatments, while irrigation only and better fertilization only brought an yield increase by 48% -64% and 30%-44% respectively compared to unirrigated respectively in the drought year. However, better fertilization in irrigated fields resuited in high yield, even higher by 36%-77% than the mean yield in the normal year. In addition, field variability of wheat yields was also reduced under irrigation and better fertilization. Therefore, drought impacts had been effectively mitigated using better designed fertilization and proper irrigation performed for the production of dry land wheat. It is suggested that available nutrient amendment and irrigation will have much potential for mitigating drought impacts on rainfed agriculture.