论文： Wen Yeqiang, Shang Songhao, Yang Jian. Optimization of irrigation scheduling for spring wheat with mulching and limited irrigation water in an arid climate . Agricultural Water Management, 2017, 192: 33-44. doi: 10.1016/j.agwat.2017.06.023 . 全文下载（2017.8.30前有效）： https://authors.elsevier.com/a/1VMmw1M27RZA3I 摘要：Combining mulch and irrigation scheduling may lead to an increase of crop yield and water use efficiency (WUE = crop yield/evapotranspiration) with limited irrigation water, especially in arid regions. Based on 2 years’ field experiments with ten irrigation-mulching treatments of spring wheat ( Triticum aestivum L.) in the Shiyang River Basin Experiment Station in Gansu Province of Northwest China, a simulation-based optimization model for deficit irrigation scheduling of plastic mulching spring wheat was used to analyze optimal irrigation scheduling for different deficit irrigation scenarios. Results revealed that mulching may increase maximum grain yield without water stress by 0.4–0.6 t ha −1 in different years and WUE by 0.2–0.3 kg m −3 for different irrigation amounts compared with no mulching. Yield of plastic mulching spring wheat was more sensitive to water stress in the early and development growth stages with an increase of cumulative crop water sensitive index (CCWSI) by 42%, and less sensitive to water stress in the mid and late growth stages with a reduction of CCWSI by 24%. For a relative wet year, when irrigation water is only applied once, it should be at the mid to end of booting growth stage. Two irrigations should be applied at the beginning of booting and heading growth stages. The irrigation date can be extended to the beginning of jointing and grain formation growth stages with more water available for irrigation. For a normal or a dry year, the first irrigation should be applied 5–8 days earlier than the wet year. The highest WUE of 3.6 kg m −3 was achieved with 180 mm of irrigation applied twice for mulching in a wet year. Combining mulch and optimal deficit irrigation scheduling is an effective way to increase crop yield and WUE in arid regions.
研究发现西北干旱区高海拔地区增湿更加明显 姚俊强 气候变化的海拔依赖性是一个尚无定论的命题，核心问题是不同海拔高度的增幅问题。研究表明高海拔地区气候变暖比以前更快，“第三极”青藏高原的气候经历了持续且更显著的变暖，表现出明显的增暖海拔依赖性。高海拔地区快速变暖会加剧山区水循环，水汽和降水变化首当其冲。 西北干旱区山盆结构突出，高海拔地区降水变化对区域水资源有决定性作用。研究发现近 50 年干旱区降水变化趋势与海拔有明显的正相关，相关系数为 0.49 （ p0.001 ），但在不同海拔梯度和不同降水等级存在差异。在 1500m 以上，降水增加趋势最明显，增幅为 13mm/10a ，两者相关为 0.68 （ p0.001 ），但在 1500m 以下相关不大，而 1500m 为山区的分界线。以 500m 为海拔变化梯度，发现 1500-2000m 梯度增湿最明显，为 27mm/10a （相关为 0.66 ， p0.001 ），其次是 500m 以下，为 25 mm/10a （相关为 0.65 ， p0.001 ），但 500-1500m 之间关系不显著，这主要与该区域城市和绿洲分布有关。城市化加剧人为气溶胶排放，在城市热岛效应下增加降水，而绿洲农田灌溉也会通过改变区域水循环增加降水。因此，干旱区有明显的增湿海拔依赖性特征。在季节上，春季和秋季的增湿海拔依赖性明显，而夏季在 90 年代之后明显。 形成机制主要包括：1.山区水汽的增加；2.山区变暖加剧水循环。 增湿海拔依赖性有利有弊，对干旱区来说，总体上利大于弊。有利的方面，高海拔地区降水增多，增加山区固态冰川和积雪的积累，储备干旱区的潜在水资源量。但同时，研究发现山区降水更加极端化，山区降水量增多在很大程度上与降水极值态的变化有关。会引起气象灾害和衍生灾害，加剧山洪、滑坡、泥石流等灾害的频率和强度，对绿洲城市和草场有很大潜在影响。 存在的主要问题是高海拔地区气象观测稀缺 ( 世界上超过 4000m 的站点非常稀少 ) ，且观测规范不统一。积极呼吁加强对全球高山地区气候要素的严格监测。 文章发表在国际期刊 Global and Planetary Change上。 Yao J Q, Yang Q, Mao W Y, Zhao Y, Xu X B.Precipitation trend – Elevation relationship in arid regions of the China, Global and Planetary Change , 2016(143):1-9. doi:10.1016/j.gloplacha.2016.05.007. GPC--2016--Precipitation trend–Elevation relationship in arid regions of the China.pdf
标签: 干旱区
