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1 引 言近年来 ,我国城镇保护地蔬菜生产获迅猛发展 ,种植面积逐年扩大 ,品种不断增多 ,有力地缓解了城市居民蔬菜供应 .保护地内因环境的适应 ,蔬菜长势旺 ,但病害传播亦盛[1,2 ,5,8,9] .特别是不少菜农以市场需求及自身习惯 ,常在保护地内多茬、连茬种植单一菜种 ,根腐、枯萎等病猖獗[3 ,4,7] ,蔬菜生产严重受抑 ,产量降低 ,品质下降 .现行的防治方法是大量更新保护地土壤 ,拌施以多种化学药剂 ,但效果不甚明显 ,且耗资、耗力过大 .为此 ,人们着意开拓新的防治法 ,特别是近年来 ,无公害蔬菜市场的大量需求 ,其病害的生态防治受到了广… 相似文献
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无公害蔬菜是指严格按照无公害蔬菜生产安全标准与栽培技术生产的无污染、安全、优质以及营养型蔬菜,且蔬菜中农药残留、重金属及亚硝酸盐等有害物质的含量,控制在国家规定的允许范围内,人们食用后对人体健康没有危害的蔬菜。以下本文对无公害蔬菜种植技术进行阐述与分析,以供参考。 相似文献
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安徽野菜植物资源开发 总被引:4,自引:0,他引:4
沈显生 《中国野生植物资源》1997,16(2):24-25
安徽野菜植物资源开发沈显生(安徽教育学院生物系,合肥230061)随着人们生活水平的不断提高,餐桌上的蔬菜种类必须更加丰富。由于野生蔬菜生长环境优良,基本上没有受到化肥和农药的污染,因而受到人们的青睐。尤其是许多野生蔬菜具有药用价值,其营养更加丰富而... 相似文献
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三种苦竹属竹笋营养成分和矿质元素含量分析 总被引:5,自引:0,他引:5
竹笋脆嫩鲜美,且含有多种营养元素,对人体大有裨益,被称为"森林蔬菜"、"保健食品"等,素有"寒士山珍"之美誉.然而,苦竹属(Pleioblastus Nakai)竹种的竹笋味苦、蔑性较差,其利用价值一直没有引起人们的重视.随着人们对绿色食品认识及需求的不断提高,人们尤其是研究者们开始重新认识苦竹[Pleioblastus amarus (Keng) Keng f.]的利用价值. 相似文献
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皂苷因其在人体中具有重要的生理及药理活性一直是人们研究的热点.番茄是我们日常生活中最常食用的蔬菜,其主要活性物质除了人们熟知的番茄红素外尚含有含量并不低的水溶性番茄皂苷,目前国内有关番茄皂苷的研究报导较少.本文主要对上世纪70年代以来国外研究人员在番茄皂苷研究方面所取得的进展进行综述. 相似文献
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大棚蔬菜种植技术及病虫害防治 总被引:3,自引:0,他引:3
目前在我国,果蔬产业已经成为了我国重要的经济链条,为我国的经济发展做出了很大的贡献。随着国民生活水平的不断提高,人们对蔬菜的需求也越来越大,其要求也越来越高,蔬菜的质量和健康更多的成为了现在人们关注和重视的话题。大棚蔬菜是我国果蔬产业中重要生产途径的一种,大棚蔬菜的种植不但可以提高蔬菜的产量,同时在营养价值方面也具有一定的优势。因此,大棚蔬菜在种植的技术上更应该要及时的更新,及时的创新以及不断的开发出种植的新技术,同时在病虫害的防治方面应该加强防护并采取相应的措施,从而使我国大棚蔬菜更好的、更健康的进入市场。笔者就本文探讨了大棚蔬菜种植的技术,并且进一步的提出了防治病虫害的一些相关措施,旨为相关工作提供借鉴。 相似文献
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Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons. 相似文献
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川东红池坝地区红三叶(Trifoliumpratense)和鸭茅(Dactylisglomerata)人工草地土壤和植物营养元素的含量特征如下:(1)土壤中的元素含量以铁、钾和镁较高,钠、钙、氮、锰和磷较低,硫、锌、硼、铜和钼微少;(2)从元素的富集特征来看,该区土壤中的钙、硫为重度淋溶元素,钾、磷、镁、锌、钠为中度淋溶元素,铁、铜属轻度淋溶元素,锰属富集元素;(3)根据元素的生物吸收系列,红三叶属氮-钙型植物,鸭茅属氮-钾-磷型植物。(4)两种牧草的生物吸收系数,均以钙、硫、磷较高,钠、铁较低,其余7种元素介于二者之间。 相似文献
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日本落叶松人工林针叶中矿质营养元素的季节吸收特点及其相互关系 总被引:3,自引:1,他引:2
本文测定了日本落叶松人工林针叶中N、P、K、Ca、Mg、Cu、Zn、Fe、Mn9种矿质营养元素含量并研究了生长期内元素含量的变化规律。结果表明,在生长期内各元素含量随季节变化可用修正指数曲钱描述;探讨了落叶松针叶中常量元素与某些土壤化学因子之间的关系。土壤有机质仅与土壤全量氮、水解氮表现了显著的线性相关,与落叶松针叶中的氮没有直接的线性相关。土壤中钙镁的含量则表现出明显的对针叶中磷、钾的含量的制约关系。在日本落叶松针叶中的氮、磷、钾3个元素之间,氮、磷的比值与钾的含量有显著的线性负相关,而磷与钾之间则表现为显著的线性正相关关系。 相似文献
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湘西地区木通果实微量元素的测定 总被引:8,自引:1,他引:7
采用马弗炉干法灰化消化样品,火馅原子吸收法连续测定白木通Akebia trifoliata var.australis (Cieli._Kehd、三叶木通A.trifoliata(Thumb.)Koidz、木通A.quinata Decne.果实中微量金属元素,检测出K,Ca,Na,Mg,Fe,Zn,Mn,Cu等8种元素含量。3种植物果实中K,Ca,Mg含量较高(>0.1000mg/g),其中K元素远高于其他元素,Na,Cu含量较低(<0.0100mg/g)。Fe,Zn,Mn的含量处于中等水平。白木通果实中K,Me,Zn,Mn 4种矿质元素高于三叶木通和木通。木通果实中Ca,Fe两种元素稍高于白木通、三叶木通。Na,Cu两种微量元素在3种果实中含量基本相拟。 相似文献
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KENNETH A. BARRICK 《Austral ecology》2003,28(3):252-262
Abstract Trees growing along windy coasts often have canopies that are greatly reduced in size by the sculpting effects of wind and salt spray. Trees with environmentally reduced stature are called elfinwood (windswept shrub‐form or krummholz) and are ecologically important because they represent outposts growing at the limit of tree success. The purpose of this study was to assess if Banksia grandis elfinwood growing at Cape Leeuwin had a different nutrient status than normal low‐form (LF) trees growing nearby, and if nutrient deficiencies, toxicities and/or imbalances were among the limiting factors imposed on elfinwood. The concentrations of N, P, K, Ca, Mg, Na, Cl–, Fe, Mn, Zn, Cu, Mo and B were analysed for mature green foliage, immature foliage, foliage litter, flowers and soil. When the elfinwood and LF trees were compared, the foliar nutrient status was generally similar, except that elfinwood foliage had significantly higher mean concentrations of N, Zn and Cu, while LF trees had higher Fe and Mn contents. Many nutrients were conserved before leaves were shed in both elfinwood and LF trees, including N, P, K, Na, Cl–, Mn and Cu (LF trees also conserved Ca and Mg). However, elfinwood and LF tree‐litter contained significantly higher Fe concentrations than green foliage (elfinwood litter also had higher levels of Mg and B). It is tempting to suggest that the translocation of Fe into leaves before they were shed is a regulation mechanism to prevent Fe toxicity, or imbalance in the Fe : Mn ratio. Proteoid roots strongly acidify the soil to mobilize P, which also chemically reduces Fe+3 to plant‐available Fe+2. The increased supply of Fe+2 in the rhizosphere, caused by the action of proteoid roots, might tend to defeat self‐regulation of Fe uptake. It is possible that excess Fe accumulation in the plant might be regulated, in part, by exporting Fe into the leaves before they are shed. The nutrient status of B. grandis elfinwood is compared with mountain elfinwood of North America. The extreme habitat of coastal elfinwood provides many theoretical pathways for nutrient limitation, but B. grandis elfinwood at Cape Leeuwin does not appear to be nutrient deficient. 相似文献
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毛果苔草湿地植物营养元素分布及其相关性 总被引:15,自引:3,他引:12
研究生物与环境中化学因子之间的相互作用过程 ,主要是指化学物质在生态系统中的运移、转化及归趋与效应。化学物质包括营养物质、污染物质和在生物与环境之间、生物与生物之间起媒介作用的次生代谢物质[1] 。对植物不同组织营养成分的季节性变化研究多集中于叶子 ,但对其他部分的研究则较少[10 ] ,分解过程并不是完全始于凋落物到达地面 ,在凋落前就受到渗滤、裂解和真菌的作用[12 ] ;对枯落物中的有机物质和营养物质浓度的了解可以预测枯落物的分解速率[11] 。目前 ,湿地的研究偏重于资源的开发与利用 ,而对湿地生态系统的生态过程的定位… 相似文献
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A 70-year-old thinned northeastern Fagus-Betula-Acer stand in the Adirondack Mountains of northern New York was fertilized with varying combinations of N, P, K, and lime in the spring of 1976.Betula alleghaniensis Brit.,Acer saccharum Marsh.,Acer rubrum L., andFagus grandifolia Ehrh. foliage was collected in the autumn for 1974 through 1977 and analyzed for foliage areas and weights, and levels of ash, N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, Cu, and Co. Comparisons are made within species and among treatments, expressed as concentrations on a dry weight basis. Elemental composition is examined to determine the differential foliar responses to fertilization.Contribution of State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210.The authors are Graduate Research Assistant, Director of Huntington Forest, Technical Research Assistant, and Professor of Forest Soil Science (now deceased), SUNY, respectively. 相似文献
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川金丝猴体毛微量元素的分析 总被引:1,自引:0,他引:1
应用等离子发射光谱法分析了秦岭产川金丝猴体毛中Na、K、Ca、Mg、Zn、Cd、Co、Cu、Ni、Sr、Li、Fe、Al、Mn、B、P16种微量元素的含量,发现除Zn与Mn有显著的性别差异外,余者无显著的性别差异,一般雄性稍高于雌性。与四川产川金丝猴体毛中的Zn、Ca、Cu、Fe含量比较,两地区样本均有极显著的差异。 相似文献