汾河水库上游水土保持对水库淤积的影响

将汾河水库上游1961-2015年间分为水土保持综合治理前(1961-1987)、一期治汾(1988-1997)、二期治汾(1998-2007)、水土保持综合治理后(2008-2015)四个阶段,分析了水库泥沙淤积量的年际变化情况。结果表明,与1961-1987年相比,1988-1997年间年均淤积量减少58.8%,1998-2008年间年均淤积量减少72.58%,2009-2015年间年均淤积量减少89.29%。水库年淤积量持续减少,水土保持综合治理效果显著。     

抓住“治汾”机遇 加快岚县治理开发

<正> 山西省岚县属汾河水库上游水土流失综合治理区,其中汾河流域面积1131km~2,占全县总面积的74.4％,水土流失面积占岚县汾河流域面积的74.2％,年侵蚀总量596.4万t,占全县侵蚀总量的89.4％。严重的水土流失,落后的自然经济观念,低层次的平面垦殖,形成历史性的生态、经济、社会相互交织的恶性循环。在推行农村大包干形势下,应运而生于80年代初的户包小流域治理,给全县水土保持工作注入了生机和活力。     

因地制宜 引洪淤灌 开发荒滩

<正> 在汾河水库上游水土保持综合治理中,河川区广大干部群众把治滩造地当作拦沙富民的翻身工程来抓,将治坡治沟措施拦蓄不完的泥沙尽可能拦在滩地中,以淤漫荒滩或落淤肥田,把荒滩和滩地作为泥库来用。 滩地是上等基本农田,很容易变成保浇水地。根据1988年提出的《规划纲要》,治汾十年要新建滩地6340m~2。截至1992年底止,五年共建治滩工程119     

对汾河水库上游流域治理的几点建议

汾河水库是山西省最大的水库，担负着向太原市及太原盆地工农业供水的艰巨任务。由于上游水土流失严重，致使水库泥沙淤积量很大。多年来，特别是1988年开展汾河水库上游水土保持综合治理以来，取得了显著成绩，有效减少了入库泥沙。但也存在着治理速度慢、人为新增水土流失严重等问题。今后应采取重视河道治理，大量用洪用沙；加强水土保持，有效拦截泥沙；强化监督管理，防治人为新增水土流失等措施。     

抓住机遇 扎实工作 加快珠江上游地区水土流失防治步伐

搞好水土保持综合治理 ,是实现珠江上游地区经济社会可持续发展的基本要求、推进珠江上游地区全面建设小康社会的现实需要和提高珠江上游地区防洪减灾能力的有效途径。开展珠江上游地区水土保持生态建设 ,要坚持因地制宜 ,综合治理 ,着力解决群众生产生活的实际问题 ,充分依靠生态的自我修复能力 ,创新机制 ,调动社会力量参与水土流失治理。要加强管理 ,搞好前期工作、建设管理、资金使用与管理、工程建后管护、科技推广应用和组织领导 ,力争把珠江上游南北盘江石灰岩区水土保持综合治理试点工程建成精品。     

古交市的水土保持成效与做法

古交市自1995以来，实施了汾河上游水土保持三年试点治理、汾河上游水土保持十年综合治理、黄土高原水土保持世行贷款二期等大型项目，以建设精品流域、精品工程为目标，以专业队治理、工农共建为主要形式，开创了水土保持工作的新局面。     

红砂岩侵蚀区小流域综合治理工程设计研究——以宁都县还安小流域为例

为解决红砂岩特殊地质力学特性下生态环境恶化、水土流失严重等区域问题,对红砂岩侵蚀区小流域综合治理工程规划设计进行了研究。本研究基于第一次全国水利普查江西省水土保持专项普查成果、《江西省水土保持规划(2016—2030年)》与《江西省水土保持区划及防治布局研究》等重要基础成果,以国家水土保持重点建设工程宁都县还安小流域水土流失综合治理工程为典型案例,将红砂岩侵蚀劣地水土保持关键技术与工程设计有机结合,采用"技术集成-应用示范"的方式,因地制宜地对小流域综合治理工程分区进行设计,完成了高效开发型水土流失治理技术集成与示范。具体实践中,牢固树立山水林田湖草是一个生命共同体的理念,统筹山水林田湖草系统治理,通过在红砂岩侵蚀劣地综合治理展示区、坡地水土保持型生态农业示范开发区和生态功能保护区的水土流失综合治理工程设计与实施,对侵蚀坡面进行工程措施和植物措施优化配置,形成了完善的水土保持综合防治体系,使还安小流域治理度达到86%。实践证明,生态恢复和农林经济开发治理相结合的方法能有效遏制小流域内的水土流失,可为红砂岩地区水土保持生态建设及南方红壤低山丘陵区的水土流失综合治理提供有力的科技支撑。     

关岭县小流域综合治理成效与经验

关岭县属于珠江上游典型的喀斯特山区,区域内石漠化程度高,水土流失严重,严重制约着经济社会的快速发展。2003—2013年,关岭县先后实施了"珠治"试点工程、"珠治"重点工程、中央预算内水土保持重点工程等,10年的小流域综合治理,有效地改善了山区的生态环境,水土流失得到有效控制,岩溶地区工程性缺水状况得到明显改善,山区的农业产业结构得到调整,项目区农民每年每户平均可增加经济收入2万元。在治理思路和方法上也取得了突破,为今后的水土流失综合治理工作打下了良好基础,为喀斯特地区人民群众致富奔小康铺了一条新路。     

总结经验 精心谋划 全力开创云南水土保持工作新局面

"十一五"期间,云南水利系统紧紧围绕预防监督、综合治理、生态修复、监测预报四项任务,以促进水土资源的可持续利用和生态环境的可持续维护为根本目标,围绕"七彩云南"保护行动计划,认真实施了"长治"工程、"国债"项目、"珠治"试点工程、生态修复试点工程、大示范区建设、水土保持世界银行贷款项目等综合治理工程,深入贯彻落实开发建设项目水土保持"三同时"制度,水土保持工作取得了显著成绩,积累了很多好经验、好做法。在"十二五"及今后一段时间,要认真总结经验,全面做好预防监督、综合治理、生态修复、监测预报、水源保护和人居环境改善等工作,坚持分区治理、分类指导,综合治理与生态修复相结合,采取小流域综合治理、坡耕地整治、生态修复等措施,扎实推进水土保持重点工程建设,有效防治水土流失,力争每5年减少水土流失面积2百分点以上,全力开创云南水土保持工作新局面。     

以重点项目为依托 广西不断加强水土流失综合治理

<正>2003年以来,广西先后启动实施了珠江上游南北盘江石灰岩地区水土保持综合治理工程、坡耕地水土流失综合治理试点工程、岩溶地区石漠化治理等一批国家水土流失重点防治工程,水土保持重点治理的规模和范     

Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey

Copper (Cu)‐containing fertilizers, fungicides, and bactericides has been used extensively in the greenhouses in the Antalya province in recent decades with the use of such materials tending to increase year by year. The level of DTPA‐extractable Cu was determined in 210 soils (0–20 and 20–40 cm depth) and 105 leaf samples obtained from 105 tomato greenhouses. The DTPA‐extractable Cu contents of the soils taken from the 0–20 depth ranged between 0.76 and 88.03 mg kg^‐1 (mean 7.79 mg kg^‐1). The percentage of soils containing DTPA‐extractable Cu greater than the critical toxicity level (20 mg kg^‐1) was 8.1. The Cu content of tomato leaf samples ranged between 2.4 and 1,490 mg kg^‐1 (mean 166.5 mg kg^‐1). The Cu concentration in leaf samples was very high due to the intensive use of foliar applied Cu‐containing chemicals. As a consequence, 24.8% of the leaf tomato samples analyzed contained over 200 mg Cu kg^‐1, the maximum accepted tolerance level. Therefore, it may be necessary to reduce the use of Cu‐containing pesticides and fertilizers, or at least reduce the amount of Cu‐containing fertilizers being used in those greenhouses where Cu‐containing pesticides have been or are being used.     

Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition

Selenium (Se) is an essential element for humans but is not considered as essential for plants. However, its beneficial role in improving plant growth and stress tolerances is well established. In order to study the role of Se in cadmium (Cd) toxicity in pepper (Capsicum frutescens cv. Suryankhi Cluster), this experiment was carried out in greenhouse conditions. Treatments comprised Cd [0, 0.25, and 0.5 mM cadmium chloride (CdCl₂)] and Se [0, 3, and 7 µM sodium selenite (Na₂SeO₃)] with three replications. The result showed that Cd decreased chlorophyll a, chlorophyll b, and carotenoids, whereas Se supplementation diminished Cd toxicity on photosynthetic pigment. Selenium at 7 µM significantly increased the leaf area in the plants grown at 0.25 mM Cd. The application of Se at 3 µM with 0.25 mM Cd and Se at 3 µM and Se at 7 µM with 0.5 mM Cd increased the activity of catalase (CAT). Selenium at 7 µM decreased the proline content of pepper leaves exposed to Cd at 0.5 mM (30%). Selenium significantly enhanced the antioxidant activity of leaves, which was diminished by Cd toxicity. In general, Se has a beneficial effect on plant growth and is an antioxidant enzyme of pepper cv. Suryankhi Cluster under Cd stress and non-stress conditions.     

红壤区不同肥力水稻土根际硝化作用特征

通过根际培养箱(三室)——速冻切片技术研究了红壤地区高、低两种肥力下水稻苗期根表、根际和土体土壤矿质态氮含量和硝化强度,以及水稻生长、氮素积累的差异。结果表明,肥力水平对水稻根表和根际土壤铵态氮(NH4+-N)含量无显著影响,但高肥力显著提高土体土壤NH4+-N含量,以及根表、根际和土体土壤硝态氮(NO3--N)含量及硝化强度。两种肥力水稻土硝化强度最大值均出现在距根表2 mm处,分别为0.20和0.31μmol kg-1 h-1。土体土壤硝化强度随距根表距离增加而降低,低肥力土壤在距根表10～40mm处时硝化强度接近本底值,而高肥力土壤在距根表20～40 mm处时接近本底值。与不种水稻的CK相比,种植水稻显著提高根际土壤硝化强度。高肥力能显著改善水稻生长,增加植株氮素积累量,尤其显著促进根系生长及通气组织发育。由于红壤稻田肥力水平的差异造成水稻根际硝化强度以及水稻吸收NO3-的差异,导致高肥条件下水稻显示出更强的生长势和氮素吸收利用能力。因此,合理提高红壤稻田肥力水平对改善红壤区水稻根际土壤硝化作用及水稻氮素营养具有重要意义。     

自由基在鸡肾病发生中的作用研究

肾病即急性肾小管坏死.鸡肾病在养鸡生产中极为常见,尤其近年来,鸡肾病的发生日益增多,由于其发生机制不清楚,临床治疗鸡肾病的依据不足,致使治疗效果不佳,为此,提出本研究以探讨鸡肾病的发生机制,为本病防治提供理论依据.     

Occurrence of Sexual Hormones in Sediments of Mangrove in Brazil

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-??-estradiol (E2), and 17-??-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75?±?3.89 ng/g. E2 was also found, with its concentration ranging from 0.90?±?0.03 to 39.77?±?1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO₂ and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.     

Meta-analysis in the Selection of Groups in Varieties of Citrus

Brazil is the largest producer of oranges (Citrus sinensis) in the world. The nutrient management of tree orchards is designed from experiments with a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition and tree demand. Compositional data analysis has been first applied to tissue analysis of agricultural crops using centered log ratios with compositional nutrient diagnosis (CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). We analyzed eleven nutrients: nitrogen (N), sulfur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) in leaf tissue samples across 108 commercial plots (thirty-one grow Valencia, twenty-two Hamlim, twenty Pera, and thirty-five Natal). Nutrients were partitioned between macro- and micronutrients as well as anionic and cationic species. The effect size of varieties over Valencia was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. The nutrient profile of orange varieties could be classified into homogeneous groups to take advantage of fertilizer trials conducted on varieties of the same group. The Aitchison distance and a perturbation vector could be instrumental for diagnostic purposes and nutrient management.     

Effect of iron-quercetin complex on reduction of nitrite in in vitro and in vivo systems

This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions.     

旱地果园水肥管理模式研究进展

分析了旱地果园水肥管理模式的研究进展和存在问题,指出水肥胁迫尤其是水钾已成为旱区果树高产稳产优质化的主要限制因子。在系统探讨旱地果园水分管理、养分管理、综合管理以及果树叶营养综合诊断施肥标准的基础上,提出了旱地果园的高效水肥管理模式。     

Role of aldehyde oxidase in the hepatic in vitro metabolism of 3-methylindole in pigs

The metabolism of 3-hydroxy-3-methylindolenine (HMI), a recently discovered metabolite of 3-methylindole (3MI, skatole) produced by porcine liver microsomes, was investigated in vitro using porcine liver cytosol. HMI was rapidly metabolized to a single product, 3-hydroxy-3-methyloxindole (HMOI), by porcine cytosol. By the use of the selective inhibitors menadione and quinacrine, it was shown that the enzyme responsible for the oxidation of HMI into HMOI was aldehyde oxidase (AO; aldehyde:oxygen oxidoreductase, EC 1.2.3.1). The activity of AO in the conversion of HMI to HMOI was measured in a population of pigs (n = 30) with a wide range of 3MI levels in back fat (0.07-0.30 mg/kg). AO activity was found to be negatively correlated (r = -0.70; P < 0.001) with the level of 3MI in fat. The results of the present study suggest that AO plays an important role in the metabolism of 3MI in the pig and that its catalytic activity is related to an adequate 3MI clearance.     

北京市郊典型农田施肥研究与分析

通过问卷调查形式,对京郊粮田、菜田和果园3种农田施肥现状进行研究.结果表明,菜田和果园化肥施用量较高,氮、磷、钾肥均显著高于粮田.菜田和果园氮肥用量分别为1741.0和1172.8 kg/hm2,分别是粮田氮肥用量的4.5和3.0倍;磷肥用量分别为1375.1和996.4 kg/hm2,分别是粮田磷肥用量的15.5倍和11.2倍;钾肥用量分别为791.3和602.4 kg/hm2,分别是粮田钾肥用量的21.1和16.1倍.另外,3种利用方式的农田氮、磷和钾肥施用比例不同,粮田为75.4%、17.3%和7.3%;果园为42.3%、36.0%和21.7%;而菜田为44.6%、35.2%和20.3%.3种种植类型中均存在氮肥投入过量、钾肥不足的问题.