灌区优化调度的节水作用浅析

以 1个水库灌区为例 ,从节水的 3个作用分析了灌溉水资源在时间和空间上优化调度的 2个模型。优化调度不仅能减少灌区水量损失 ,提高水分生产效率 ,还能在提高灌区水分生产效率方面起明显的作用。这类节水技术对于缓解我国农业供水危机具有重要的现实意义 。

发挥水价杠杆作用,提高节水意识

本文以水价改革为核心,明确了水价与水资源需求之间的关系,分析了现行水价对农业节水的影响,提出具体的水价改革措施,为强化水价节水杠杆作用,提高农民节水意识,促进农业可持续健康发展提供参考。

节水聚水型覆膜栽培

目前我国覆膜技术,多采用起垄弧形覆膜或平覆,因而都存在着阻雨的副作用。若改为“山”字形垄沟凹穴覆膜或“M”字形垄沟覆膜,除仍保留通常覆膜的优点外,又增加了聚水、节水功能。据实验,采用此法,一般单株作物根际受水量是实际降雨量的5～10倍,特别是“山”字形垄沟,连露水和地气也有从膜的内外滴向作物根部。采用此垄形覆膜,可基本满足作物对水分的需求。遇特旱担水浇地也方便省水,若抽水采用垄上沟浇可节水一倍以上。这种垄形既防旱又防涝。

Characteristics and Functions of Cooperative Economic Organizations for Water-saving Irrigation in Agricultural Development in Arid Areas

Agricultural cooperative economic organization for water-saving irrigation in arid areas is a new form of economic organization in production,operation and management during the application process of water-saving irrigation technologies.Currently,there are few researches on this cooperative economic organization.In this study,connotations of cooperative economic organizations for water-saving irrigation are specifically defined,and the characteristics and functions of this cooperative economic organization are analyzed.Based on that,several suggestions are proposed on the continuous development of cooperative economic organizations for water-saving irrigation.

Dwarfing effects of plant growth regulators on narcissi

The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001. The results showed that the regulators could inhibit the growths of height and leaves of narcissi. Of the four regulators, the dwarfing effects of paclobatrazol (PP333) and uniconazole (S3307) on narcissi were better than those of chlorocholine (CCC) and dimethyl amino-sussinamic acid (B9). All of the regulators did not have significant effect on the root length. Moreover, the time of flowering was later for the narcissi treated with regulators than that of the control to a certain extent, and the range delayed was from 2 days to 19 days. The correlation analysis results showed that there was a significant correlation between the time of flowering and the concentrations of regulators. The ornament value of narcissi was obviously improved by using the regulators.

塑料管材阔步进市场

随着化学建材工业的发展,建筑用塑料管材的质量得到进一步提高,此类管材的市场发展潜力日益为人们重视。我国部分大中城市已开始在市政建设和住房内外管线上采用塑料管道代替铸铁管,此举将改变过去铁铸管生产能耗大、成本高、自重大、质量难以保证、施工不便的局面。 经有关部门测试认为,采用塑料管代替铸铁粪便水管道节水作用十分明显,一般可节约用水40％

Effects of Waterlogging in Different Growth Stages on the Photosynthesis,Growth,Yield,and Protein Content of Three Wheat Cultivars in Jianghan Plain

To maintain high wheat grain yield in areas where frequent and periodic waterlogging occurs,the effects of waterlogging on the photosynthesis,growth,yield,and protein content of three wheat cultivars,namely Xiangmai55(X55),Jingmai102(J102),and Zhengmai9023(Z9023),in four different growth stages were investigated.Experiments were conducted in specially designed experimental tanks in the middle and lower reaches of the Yangtze River during the 2012-2013 and 2013-2014 wheat growing seasons in China.Results showed that X55 was the most susceptible to waterlogging,followed by J102 and Z9023.Chlorophyll content reduction and leaf senescence,which resulted in decreased green-to-total leaf number ratio,were induced to the greatest extents by waterlogging in booting and flowering stages,followed by milky stage.Meanwhile,chlorophyll content in flag leaf,plant height were significantly decreased by waterlogging in jointing stage but effectively recovered after waterlogging withdrawal,and recovery ability varied among the cultivars.Plant biomass and grain yield were most significantly decreased by waterlogging in booting and flowering stages,followed by milky and jointing stages.Grain protein content was also considerably affected by waterlogging depending on growth stage and cultivars.The decreased grain yield caused by waterlogging was mostly due to the sharp decline in 1 000-grain mass.Waterlogging led to reduced protein yield in all growth stages in three wheat cultivars.Above all,in this experiment,waterlogging decreased grain yield significantly,and waterlogging at booting stage and flowering stage was most serious.Comparing the three cultivars,X55 was most sensitive to waterlogging.

Cotton Physiological Parameters Affected by Episodic Irrigation Interruption

Improving cotton irrigation management practices in West Texas is important for increasing farmers＇ profits and for sustainability of the Ogallala aquifer. The objective of this work was to evaluate the effects in field controlled episodic drought conditions on cotton gas exchange. Irrigated cotton was subjected to water stress at different timings. Irrigation was interrupted at the squaring stage, early flowering stage, from three weeks at peak bloom, and from peak bloom to the crop termination. These episodic drought treatments were compared with cotton fully irrigated throughout the whole season. From 2010 to 2012, cotton cultivar FM9180 gas exchange was measured throughout the season using a LiCor-6400 portable photosynthesis system. In 2011 and 2012, measurements were also made on DP0935 cultivar. The cotton physiological parameters evaluated included photosynthesis, transpiration and temperature. From the several parameters evaluated, some relationships were presented. Episodic drought periods can affect leaf-level gas exchange and impact yield. Photosynthesis and yield were particularly sensitive to water deficit at early flowering. Despite an increase in leaf water use efficiency under water deficit, overall growth and yield were inhibited in all treatments with a stress component. Understanding the relative sensitivity at different growth stages can help with irrigation decisions when water resources are limited.

Regulatory effects of stage-treatment with established Chinese herbal formulas on inflammatory mediators in pediatric asthma

OBJECTIVE： To explore the regulatory effects of es- tablished Chinese herbal formulas on inflammatory mediators released during asthma attacks, and to elucidate the molecular mechanism of Traditional Chinese Medicine in the treatment of asthma. METHODS： Seventy-five asthmatic children were randomly divided into a Chinese medication group （45 cases） and a Western medication control group （30 cases）. Patients in the Chinese medication group were treated with a series of established Chi- nese herbal formulas, whereas the Western medica- tion control group received a leukotriene receptor antagonist and a bronchial relaxant. Real-time PCR was used to determine the mRNA expression levels of interleukin （IL）-4, cysteinyl leukotriene receptor 1 （CysLTR1）, and interferon （IFN）-γ in peripheralblood mononuclear cells before and after treat- ment. Enzyme-linked immunosorbent assay was used to measure the peripheral blood levels of IL-4, leukotriene （LTE）-4, and INF-γ before and after treat- ment. RESULTS： After treatment, the mRNA expression levels of 11-4 and CysLTR1 were down-regulated （P〈 0.01） and the mRNA expression levels of IFN-γ were up-regulated （P〈0.05） in the Chinese medication and Western medication groups; no significant dif- ference was found between the two groups. In the Chinese medication group, IL-4 blood level was de- creased and it was significantly different from that in the Western medication group （P〈0.05）; there was also a significant increase in IFN-γ blood levels after treatment with Chinese medica- tion （P〈0.05）. There were no significant differenc- es in LTE-4 blood levels between the two groups before and after treatment （P〉0.05）. CONCLUSION： Chinese medication has a regulato- ry effect on leukotriene receptor gene expression and the imbalance of Th1/Th2 immune cells dur- ing asthma attacks in pediatric patients.