水分

This paper has made systematic research about characteristics of soil water dynamic changes, water deficit of the root-zone of pear-jujube tree with regulated deficit irrigation, physiological control in the process of the water use and the stomal response mechanism of pear-jujube tree under the water deficit environment, and the effects of different deficit irrigation levels at different growth stages vegetative growth and repproductive growth of pear-jujube trees, and also its regulation mechanism.

针对西北半干旱区果业生产面临水资源紧缺的现实，论文以该区特色经济果树梨枣树为研究对象，在西北农林科技大学旱区农业水土工程教育部重点实验室、陕西省大荔县城关镇梨枣园分别开展了温室与大田试验，对调亏灌溉的梨枣树根区土壤水分动态变化特征、水分亏缺与复水环境下梨枣树用水过程、生理调控与气孔响应机理、不同生育期不同水平亏水处理对营养生长与生殖生长的影响及其调控机制等进行了较系统的研究，分析了各生育期不同亏水处理对梨枣耗水规律、产量、品质、作物系数、水分利用效率及经济效益的影响，取得了以下成果：⑴通过亏水处理与复。。。

The compensation effect of water stress only was observed in the percentage distribution values in fine roots of RAWS plants, which kept significantly higher than that of CK during rewatereing. However, there apparently was an after-effect of water stress, as revealed by the delayed recovery of almost all of the three parameters in RAWS plants.

水分胁迫解除期间，细根获得同化物百分比仍保持在显著高于对照水平，表明水分胁迫对细根具有一定的补偿效应；尽管茎尖、粗根、韧皮部、木质部获得的同化物绝对量、相对量及分配系数均在复水后5天内完全恢复，但它们起始恢复的时间大多与复水并不同步，而是表现出一定程度的滞后，表明水分胁迫对这些器官同化物分配过程具有后效作用。

Under the condition of sufficient water supply, ETa can be calculated with ETp; While, under the condition of the soil wilting point was smaller than 0.37, ETa equals to 0; when under the condition of insufficient water supply, the equation could be expressed as ETa = Sw×ETp.

在土壤水分供应充足的情况下，农田实际蒸散量与潜在蒸散量相等；当土壤含水量低于萎焉点(0.37)时，则实际蒸散量近似为零；在水分胁迫的条件下，即当土壤水分供应系数在(0.37，1)之间时，则ETa=S_w×ETp。

By using the basic principle of soil hydrodynamics,this paper designs the indoor experiment of soil water infiltration under surge furrow irrigation ,and in the light of the influence of the different water-supplying times,circulating ratios and periods on the soil water infiltration process,determines some parameters related to the soil water movement.

应用土壤水动力学的基本原理，设计了波涌沟灌条件下水分入渗的室内试验，针对不同供水时间、循环率及周期对土壤水分入渗过程的影响，测定土壤水分运动有关参数。

The author also analyzed the difference of soil moisture between furrow and ridge, inside and outside of film, wide and narrow furrow under water control condition, put forward the index of soil moisture for postponed irrigation of maize, expounded the influence of water control in later stage on products and soil moisture of monoculture Maize.

在控水条件下，分析了垄背与垄沟、膜内与膜外、宽沟与窄沟的土壤水分差异，提出了玉米推迟灌头水的土壤水分指标，并阐述了后期控水对单种玉米产量及土壤水分的影响。

It proves that tree top leaves suffer from water stress and hydraulic limitation becomes greater with tree height.Water stress influence tree height growth in several aspects:firstly is the influence of exterior water condition,and community average tree height is positive with exterior water condition.Secondly, hydraulic limitation influences individual tree structure and function.Xeromorphic structure,Lower water potential and turgor pressure limit cell division and expansion,which restrict gas exchange and carbon assimilation capability.However,respiration consumption increases with the spread of tree crown.Shortage of nutrient limits carbon investigation on new leave growth and may ultimately limit tree growth.Thus,the main limitation of tree height is water.

水分对树高生长的限制首先是外在的水分状况，群落的总体高度随外界水分状况的变差而变矮；再就是水力限制对单株树木的结构和功能的影响，水势降低、膨压减小使细胞的分裂和扩展受限，旱生型结构加剧水力对气体交换能力的限制、使光合碳同化能力受到限制、而呼吸消耗却随着树木个体的增大而增大，制造营养物质不足、使得营养亏缺、造成投入新枝叶的营养受限，最终限制了树高继续增长。

The roots of spring-sown maize and summer-sown maize could touch with each other in relay-planting system, which made the roots competed for water and nutrition. Thus, more of the water and nitrogen in those soil layers were used, which led to the decrease of water and nitrogen in those soil layers.

玉米根系数量和TTC还原总量在剖面分布上均发生交叉，春、夏玉米间存在养分与水分的竞争，使根系所达到的区域土壤养分和水分利用量增加，从而使相应土层土壤全氮含量和水分含量下降。

Soil water characteristic curve was measured with a sand column for both drying and wetting processes, and the data were used to fit the van Genuchten model. The fitted curve is in good agreement with the actual measurements, residual water content and other factors used in the van Genuchten model were obtained. For the sand studied,. The results from this study may provide reference for research of water and solute movement in unsaturated soil.

利用Van Genuchten模型对用砂性漏斗测量中砂的吸湿过程和脱湿过程土壤水分特征曲线进行拟合，结果表明实测曲线和拟合曲线吻合很好，并得出Van Genuchten模型中的残余含水量、特性参数α和n，模拟计算表明，中砂有α=1.69α的关系，为研究水分和污染物在非饱和土壤中运移问题提供土壤水分运动键参数。

Study on the ecological effect of rice rhizosphere microbes under three water regimes and two nitrogen application levels was conducted in 2005 in pot experiment.

研究了3种水分模式（干旱交替型，浅水层连续灌溉型和控水模式）及分次施氮条件下，施氮对水稻根际土壤微生物生态效应的影响，结果表明：水稻根际土壤微生物生态效应，不仅仅受到水分条件和施氮的影响，还受到水分条件和施氮的交叉影响。

VA mycorrhizae could enhance plant dry weight and improve plant P concentration, as well as increase the resistance to drought and water utilization efficiency under water stress and normal water supply at the same P application level.

在水分胁迫和正常供水条件下，施磷量相同，接种菌根组的地上和根系生物量干重显著高於不接种组，干物质累积增加，减轻水分胁迫对植株生长的抑制程度，改善了植株体内磷素养分状况，提高了白三叶对土壤磷的有效利用及水分利用率。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了