Can we maintain turf to customers’ satisfaction with less water?

Science-based, holistic, site-specific water conservation practices can reduce water use on turfgrass sites without adversely affecting turfgrass performance. However, when water use is decreased below a certain threshold, performance declines. Water conservation measures that reduce turfgrass performance essentially decrease its economic, environmental, recreational, and aesthetic values, which can in turn adversely impact many ‘stakeholders’, including the local economy and those affected by increased wind erosion, water erosion, or fire hazard. On larger turfgrass sites, considerable costs are associated with some water conservation strategies, especially when the quality of an alternative irrigation water source is poor or redesign of the landscape and/or irrigation system is involved.     

An integrated modelling toolbox for water resources assessment and management in highland catchments: Model description

Water and land resource competition and environmental degradation pose difficult questions for resource managers. In particular, the ensuing trade-offs between economic, environmental, and social factors and their spatiotemporal variability must be considered when implementing management policies. This paper describes an integrated modelling toolbox that has been developed for highland catchments – specifically the Mae Chaem catchment in Northern Thailand. This toolbox contains models of crop growth, erosion and rainfall-runoff, as well as household decision and socioeconomic impact models. The approach described advances and complements previous approaches by: considering more complex interactions between land-use decisions and the hydrological cycle; modelling household decisions based on uncertain expectations; and assessing impacts of changes not only on flows and household income, but also on subsistence production and erosion. An example of the types of trade-offs and scenarios that can be assessed using the integrated modelling toolbox is also presented. This demonstrates that for the scenarios presented, the magnitude and direction of impacts simulated by the model is not dependent on climate. Further testing of the model is demonstrated in a companion paper. Overall, the plausibility of the model is shown.     

A tool for community-based assessment of the implications of development on water security in hillside watersheds

Development and population growth in Latin American countries with steep slope farming are likely to further increase pressures on water and land resources. A methodology was developed for assessing water availability and use under different development pathways at a watershed scale to determine whether water security is a potential problem, and if so, under what conditions it is likely to occur. This methodology makes use of a GIS-based spatial water budget model for simulating stream water availability, water use and stream flow control on a daily basis at a watershed scale. Here, we analysed water availability under three plausible development scenarios for the 3246 ha Cabuyal River watershed in southwest Colombia in the year 2025: Corporate Farming (CF), Ecological Watershed (EW), and Business as Usual (BU). Simulated average river flows at the watershed outlet were, respectively, 874, 796 and 925 l s⁻¹ for the CF, EW and BU scenarios. The contribution of base flow to river flow (base flow index) was on average, 80.8, 85.6 and 77.9%, respectively, for the three scenarios. The watershed had the potential to meet the anticipated increase in water use under each explorative scenario. However, dams were necessary to store irrigation water in the CF scenario, otherwise over 60% of the available water would have been used during the dry season. Such a high figure raises concerns about effects on aquatic and riparian ecology, concentrations of potential contaminants, water reserves for especially low rainfall years, and the watershed resilience to meet temporarily higher water needs during the day. Analyses indicated that current water-use conflicts in the watershed can be resolved if irrigation water supply is separated from drinking water supply. This study helped reduce some of the complexity associated with the interdependencies between land and water resources, the impact of using them, and spatial linkages within the watershed. Results of this study can be used for teaching local stakeholders about basic landscape responses and helping multi-institutional alliances to become proactive and to guide development to the benefit of local communities.     

节水灌溉实时决策系统

为寻求利用有限水资源取得最高作物产量或最大效益的灌溉方案,应根据不同供给水源的时空分布,作物品种与生长期和农田水分状况进行综合分析,系统分析方法的线性或非线性规划方法可望得到最优结果。     

河北二季作区马铃薯节水灌溉研究初报

为研究河北二季作区马铃薯整个生育期不同灌水量对其生长发育的影响,以该地主栽品种为材料,根据不同生育期需水规律,设定5个不同水量梯度的滴灌处理和1个常规沟灌处理(CK);调查分析了不同处理间物候期、重要农艺性状、病害发生情况和产量等相关指标。结果表明,处理3(采用滴灌模式,水量为110 m3)与常规沟灌相比,马铃薯生长势、总产量和商品薯产量无显著差异,生育期提前,病害较轻,商品薯率提高7.2%,节水35.41%,综合表现优于其他处理,为试验地区最佳灌水量。     

滇东地质高背景区土壤镉的伴矿景天修复及其对后茬水稻的影响

云南是我国典型的重金属元素地球化学高背景区,超积累植物能否有效修复镉（Cd）地质高背景土壤,从而实现农产品安全生产,尚鲜见报道。以云南石林、富源和罗平等三地的典型Cd地质高背景农田土壤为对象,开展温室盆栽试验,探究Cd、锌（Zn）超积累植物伴矿景天对土壤Cd的吸取修复效果,及对后茬水稻生长和Cd吸收的作用。结果表明,种植三季伴矿景天使三地土壤全量Cd分别下降24.8%、30.9%和58.8%;伴矿景天在富源玄武岩风化物母质发育的土壤上长势最好,与富源土壤肥力相对最高有关;伴矿景天在罗平石灰岩风化物发育的土壤上重金属吸取修复效果最佳,与罗平土壤呈中性、酸化作用更为明显有关,这些差异由土壤母质、养分与重金属有效性等综合影响所致。经伴矿景天吸取修复三季后,全生育期淹水种稻,其糙米和秸秆Cd浓度均大幅降低,可实现糙米Cd安全生产。未经植物吸取修复,旱作处理下水稻糙米Cd存在超标风险。植物吸取修复后种植水稻,再结合水分管理措施,可进一步降低稻米中Cd浓度,实现稻米安全生产,为Cd地质高背景区土壤的农作物安全生产提供理论依据和技术支撑。     

北京地区春大棚小型西瓜基质栽培优质高效栽培技术

介绍了北京地区春大棚小型西瓜基质栽培优质高效栽培技术,包括品种选择、整枝方式、定植密度、种植模式、水肥管理、病虫害防治等方面.     

施用畜禽有机肥对辽河三角洲养蟹稻田水土环境的影响

经3 a的试验研究,探讨了施用畜禽有机肥对辽河三角洲养蟹稻田水土环境的影响.结果显示,畜禽有机肥可极显著地增加养蟹稻田耕层土壤的速效氮、磷、钾的供应量,显著增加有机质含量,最终显著增加水稻产量,增产的幅度可达10.6％～14.8％.畜禽有机肥可降低耕层土壤氧化还原电位(Eh),增大田面水体中BOD5、COD的含量,所以...     

水分高效利用型谷子新品种"冀谷19"选育研究

冀谷19是采用杂交方法从"矮88×青丰谷"中选育而成,表现优质、高产和水分利用效率高.2002年和2003年国家夏谷新品种区域试验,平均单产5 296.5 kg/hm2,较对照豫谷5号增产14.4%.2004年通过全国谷子品种鉴定委员会鉴定.2004年推广面积58 000 hm2,最高单产达8 430 kg/hm2,成为河北省旱地无公害优质小米开发的骨干品种.     

Physiological and anatomical changes in two rapeseed (Brassica napus L.) genotypes under drought stress conditions

Understanding the mechanisms of drought resistance in crop species is crucial for the selection and breeding of tolerant rapeseed (Brassica napus L.) varieties. The present study aimed to assess the physiological and anatomical responses of two rapeseed genotypes, P287 (drought-tolerant) and T88 (drought-sensitive) under three intensities of drought stress. All physiological and anatomical parameters related to drought acclimation were significantly altered in both genotypes under stress conditions. At the fourth-leaf stage, the relative water content, chlorophyll content, protein content, malondialdehyde content, and the activities of peroxidase and catalase in P287 were significantly higher than those in T88, particularly under severe drought conditions. After rehydration, all physiological indexes recovered rapidly, especially in P287. In addition, under drought stress, compared with T88, P287 had thicker palisade tissue, thinner spongy tissue, higher ratio of chloroplast length to chloroplast width, higher stomatal density and stomatal closure rate. Overall, the interaction between physiological and anatomical features improved the drought tolerance of P287 under drought stress conditions.