Soil substrate as a cascade of capillary barriers for conserving water in a desert environment:lessons learned from arid nature

Interaction between soil pedogenesis, subsurface water dynamics, climate, vegetation and human ingenuity in a desert environment has been found to result in a unique ecohydrological system with an essentially three dimensional sedimentation structure in the bed of a recharge dam in Oman. A 3-D array of silt blocks sandwiched by dry sand-filled horizontal and vertical fractures was studied in pot experiments as a model of a natural prototype. Pots are filled with a homogenous sand-silt mixture(control) or artificially structured(smart design, SD) soil substrates. Rhodes grass and ivy(Ipomea, Convolvulaceae) were grown in the pots during the hottest season in Oman. Soil moisture content(SMC) was measured at different depths over a period of 20 days without irrigation. SD preserved the SMC of the root zone for both ivy and grass(SMC of around 25%–30% compared to 10% for control, 3 days after the last irrigation). Even after 20 days, SMC was around 18% in the SD and 7% in the control. This, similar to the case of a natural prototype, is attributed to the higher upward capillary movement of water in control pots and intensive evaporation. The capillary barrier of sand sheaths causes discontinuity in moisture migration from the micro-pores in the silt blocks to sand pores. The blocks serve as capillarity-locked water buffers, which are depleted at a slow rate by transpiration rather than evaporation from the soil surface. This creates a unique ecosystem with a dramatic difference in vegetation between SD-pots and control pots. Consequently, the Noy-Meir edaphic factor, conceptualizing the ecological impact of 1-D vertical heterogeneity of desert soils, should be generalized to incorporate 3-D soil heterogeneity patterns. This agro-engineering control of the soil substrate and soil moisture distribution and dynamics(SMDaD) can be widely used by desert farmers as a cheap technique, with significant savings of irrigation water.     

玉米适期晚收、小麦适当晚播增产技术

玉米适期晚收、小麦适当晚播增产技术（简称“两晚”技术）是一项适用于河南省冬小麦——夏玉米种植区域的节省性增产技术。该技术能使夏玉米充分利用有限光资源提高单产,冬小麦易于形成高质量群体。节约用水用肥、防止旺长冻害,推厂应用意义很大。     

利益相关者对塔里木河下游人工输水工程效益和意义的认知分析

通过问卷调查方法,探讨了塔里木河下游农二师31、34和35团居民对人工输水工程效益的认知、态度以及对节约用水措施实施的支持率,总共300份问卷.结果表明:被调查者中有61.12％了解人工输水工程;88.18％支持该工程继续实施;75％认为人工输水后当地生态环境有了显著好转;84.79％认为节约农业用水是输水工程的重要部分,极力支持;75.68％对于目前的水灌溉系统表示满意.根据被调查者基本信息,使用SPSS软件Logistic二元回归模型进一步分析被调查者基本信息与支持人工输水意愿之间的关系.结果表明:被调查者支持人工输水工程的意愿主要受文化程度、职业和家庭月收入等因素的影响.本研究结果可以为人工输水今后的优化及可持续性提供咨询与建议.     

十个热门项目风光背后暗藏风险

热门项目因卖点突出,总能吸引不少投资者的目光。然而,这些表面风光的项目背后却隐藏着一些风险,投资者稍不留神就会陷入困境。     

园林绿化节水途径探究

园林绿化可以改善城市生态环境,对水资源的消耗量也非常大,我国的可利用水资源较为匮乏,有些城市已经到了严重缺水的地步。在园林绿地规划设计前期,可以从规划设计、改良土壤结构、利用乡土植物资源、采用先进的灌溉技术、利用再生水和雨水等途径,改善园林绿化对水分的需求,达到节约用水的目的。     

滴灌设备的安装与使用

滴灌是一种半自动化的机械灌溉方式,安装好的滴灌设备,使用时只要打开阀门,调至适当的压力,即可把水分送到作物根区自行灌溉。滴灌比地面沟灌节约用水30%～40%,对土壤结构的破坏大大减轻。滴灌的温室地温相对来说要比传统地面灌溉的高,有利于栽培作物早长早发;湿度较低有利于减     

市政园林灌溉系统的设计与施工

市政园林的建设离不开水的灌溉,水赋予了园林生机勃勃的绿意,我国现阶段的很多灌溉设备均为国外进口,灌溉技术起步较晚,设备和技术方面存在诸多问题,发展尚未成熟。本文就市政园林灌溉系统的设计与施工做了重要论述。     

城市用水中节水措施的研究

分析了城市用水中存在的浪费和资源不合理利用的问题，就如何搞好城市节约用水工作提出了若干对策，并对21世纪我国城市节水工作的发展方向进行了展望。     

以水定规模,节水促发展是河西地区可持续发展的关键

一、重新认识河西地区干旱缺水的问题 新中国成立以来,河西地区水利建设基本上经历了两个主要发展阶段.一是六、七十年代,以建水库、打机井、渠系改造、平田整地为主要内容的大规模农田水利基本建设;二是80年代以后,按照"巩固改造,适当发展,加强管理,提高效益"的水利建设方针,开展了以灌区改造挖潜、水库除险加固、田间工程配套、干支渠道衬砌、节水技术推广等为主要内容的水利建设.     

乳头式饮水器的安装及使用

使用槽式饮水器，水易受灰尘、羽毛、饲料等污染，每天还需擦拭水槽，工作量大，且水易漫人饲槽，造成饲料污染变质、铁皮饲槽锈蚀。为了改善饮水卫生，节约用水，现在不少养鸡场开始改用乳头式饮水器。乳头式饮水器在安装和使用中应注意以下问题：