Amelioration of fluoride toxicity by vitamins and calcium on reproductive organs of female rat

Normal female rats of Wistar strain (Rattus norvegicus) weighing between 150–200 g were treated with fluoride (Fl) contaminated drinking water (FW, 5.8 ppm), vitamin C (6 mg) and vitamin C (6 mg) + D (6 mg once a week) + calcium (6 mg) for 30 days. Fl water treatment to rats produced reduction in weights of ovaries, uterus, vagina, kidneys, and adrenal glands, circulating levels of estrogen, number of litters, fertility rate, and altered tissue and serum biochemistry compared to control rats. However, cholesterol concentrations of ovaries and adrenals increased significantly. The above altered parameters were restored partially/completely after exogenous feeding with vitamin C and vitamins (C + D) and calcium. The data suggest that Fl-induced adverse effects on reproductive and other organs in female rats, whereas vitamin C, vitamin D and calcium treatment ameliorated Fl toxicity. Therefore, vitamins (C and D) and calcium play an important role in prophylactic treatment of fluorosis.     

广东土壤及其农业利用改良区域

综合论述广东土壤的形成、分类和利用改良分区;阐述了黄壤、红壤、赤红壤、砖红壤和水稻土等主要土类的性质及利用现状;分析了各个地带、各个地区的自然条件、土壤组合以及土壤利用改良的特点。针对这些特点,提出了广东今后土壤资源利用的具体措施。     

平原湖区潜育化水稻土改良与利用的研究

对平原湖区农业持续发展急需研究解决的一个重要问题——潜育化水稻土改良与利用,进行全面系统研究总结。阐明了在特定环境条件下,潜育化水稻土分布、成因、类型、特性及障碍因素,并着重对采用耐潜(渍)高产优质水稻品种(组合)、开沟治渍、水稻垄作、优化施肥、水旱轮作等改良利用技术及其组装配套的综合改良利用技术体系的试验研究作了深入系统的阐述。对改良利用的经济、生态和社会效益进行了综合评价。     

磷石膏对盐碱土的改良研究

介绍了磷石膏对盐碱土的改良机理,结合对天津经济技术开发区的盐碱地改良试验介绍了磷石膏的施用方法,并分析了其改良的效果（包括土壤的化学性质,物理性质等）,得出了磷石膏能有效的对盐碱土壤进行改良,操作方便,并能提高土壤肥力的结论。     

Analysis of monitoring data on the Russian desman (<Emphasis Type="Italic">Desmana moschata</Emphasis>) in the Oka state biosphere reserve in relation to the problem of species’ population decline

Data on the effect of environmental factors on the Russian desman population of the Oka Reserve (Ryazan oblast) have been analyzed over the period from 1938 to 2004. Against the background of global climate warming, the number of desmans has decreased by a factor of 2.75 as a consequence of hydrotechnical amelioration in the early 1960s. Prior to amelioration, relatively dry, low-water, and cool years were more favorable for these animals; after amelioration, their demand for more abundant moistening has increased.     

Formation Process and Amelioration of the Loess Plateau in China

Abstract

Based on the formation process of the Loess Plateau, the characteristics comparison between loess and ancient soil and the located materials of spore- pollen, ancient stone artifact, history, geography and soil erosion, the analysis reveals that the present state serious soil erosion in Loess Plateau, instead of being a natural geologic course, is a consequence of destruction of vegetation, irrational land utilization and the direct destruction of soil permeability and anti-erosion ability, esp. anti-scourability. The water and soil conservation measures, with the twenty-eight-word amelioration principle as the core, are the basis for exploiting and improving water and soil resources of the Loess Plateau so as to harness the Huanghe (the Yellow River).     

三峡工程对长江中游地下水动态和土壤潜育的影响

通过对长江中游四湖地区地下水动态观测数据分析得出，长江对沿岸平原地下水影响程度随距离增大而逐渐减弱。用遥感技术和实地调查，确定了潜育化、沼泽化土壤在四湖和沿庭湖地区分布以及潜在威胁面积。并依此分析了三峡工程对土壤潜育化沼泽化的影响。在大量调查和田间试验的基础上，提出了适用于当地的潜育化沼泽化土壤改良利用途径。     

湖泊基质客土改良的环境效应:对芦苇生长及光合荧光特性的影响

湖泊底质对根着水生植物生长发育有重要的影响,通过滨岸底质植生性改良、重建水生植被被认为是污染湖泊生态修复的重要手段.本研究模拟5种客土厚度对芦苇生长和叶绿素荧光参数的影响,结果表明,覆盖5 cm处理芦苇总生物量、株高、叶长和叶宽显著大于覆盖18 cm处理(P0.01),实验第120 d,地下/地上部生物量和细根/地下部生物量显著大于其他处理(P0.05).表明覆盖18 cm显著抑制芦苇生长,但对照组富营养底质可能对芦苇生长造成轻微胁迫,随覆盖厚度增大,显著降低芦苇的地下部/地上部生物量比值,芦苇优先生长地下部,特别是细根的生物量,以便从底质中吸收更多养分供植物生长.不同处理芦苇F_v/F_m、Yield、q P和q N变化差异不显著(P0.05),覆盖厚度越大,芦苇光合结构PSⅡ更易受到损坏,主要是通过较高的热耗散、降低叶片光合面积与叶片捕光色素含量来维持光合结构PSⅡ保持正常.就客土改良对芦苇生长与叶绿素荧光参数总体影响而言,覆盖2 cm和5 cm能有效改善基质Eh和营养条件,促进植物生长,其中覆盖2 cm处理能有效地提高芦苇光合利用效率(α)、相对电子传递速率(ETRmax)和半饱和光强(E_k),覆盖18 cm使得芦苇对冬季的低光抑制有更强的适应能力.     

基于GIS的盐渍土改良区耕地土壤适宜性评价

论文以山东禹城市为例, 进行了盐渍土改良区耕地土壤适宜性评价研究。采用灰色关联分析法与Delphi法结合筛选参评因素,用层次分析法(AHP) 确定其权重,建立了土壤适宜性综合评价模型。通过比较空间插值方法后,采用反距离加权(IDW)空间插值技术,获取了研究区土壤适宜性等级空间分布图。结果显示,禹城市耕地土壤适宜性总体状况良好,Ⅰ、Ⅱ等级面积占27.24%;Ⅲ、Ⅳ等级面积占45.48%,Ⅴ、Ⅵ等级面积占27.28%。耕地土壤适宜性等级分布受到地形地貌的影响,由地势较高的河滩高地向地势较低的洼地过渡,土壤适宜性变差;土壤适宜性等级分布同时受引黄灌溉的影响,在引黄干渠的低洼处,土壤适宜性差。该研究探索了盐渍土改良区耕地土壤适宜性的评价技术方法,对盐渍土改良区耕地资源的持续利用和土壤改良有积极意义。     

Changes in Soil Properties After Establishment of Artemisia halodendron and Caragana microphylla on Shifting Sand Dunes in Semiarid Horqin Sandy Land, Northern China

In the semiarid Horqin sandy land of northern China, establishment of artificial sand-fixing shrubs on desertified sandy lands is an effective measure to control desertification and improve the regional environment. Caragana microphylla Lam. and Artemisia halodendron Turcz. ex Bess. are two of the dominant native shrub species, which are adapted well to windy and sandy environments, and thus, are widely used in revegetation programs to control desertification in Horqin region. To assess the effects of artificially planting these two shrub species on restoration of desertified sandy land, soil properties and plant colonization were measured 6 years after planting shrubs on shifting sand dunes. Soil samples were taken from two depths (0–5 cm and 5–20 cm) under the shrub canopy, in the mid-row location (alley) between shrub belts, and from nonvegetated shifting sand dune (as a control). Soil fine fractions, soil water holding capacity, soil organic C and total N have significantly increased, and pH and bulk density have declined at the 0–5-cm topsoil in both C. microphylla and A. halodendron. At the 5–20 cm subsurface soil, changes in soil properties are not significant, with exception of bulk density and organic C concentration under the canopy of A. halodendron and total N concentration under the canopy of C. microphylla. Soil amelioration processes are initiated under the shrub canopies, as higher C and N concentrations were found under the canopies compared with alleys. At the same time, the establishment of shrubs facilitates the colonization and development of herbaceous species. A. halodendron proved to have better effects in fixing the sand surface, improving soil properties, and restoring plant species in comparison to C. microphylla.