电子文档交易市场
安卓APP | ios版本
电子文档交易市场
安卓APP | ios版本

留学生Essay写作—植物生长的环境因素

13页
  • 卖家[上传人]:BayD****论文写...
  • 文档编号:78411450
  • 上传时间:2019-02-13
  • 文档格式:DOCX
  • 文档大小:25.92KB
  • / 13 举报 版权申诉 马上下载
  • 文本预览
  • 下载提示
  • 常见问题
    • 1、http:/ 留学生论文专业定制代写网站留学生Essay写作植物生长的环境因素AbstractDifferent environmental conditions contribute to the limitations of plant growth.Salts are common and a natural constituent of all soils.Normally,salts are present in low amounts in top soil and plant growth is not affected.However,accumulation of salts,through natural means or mans activities,can cause plant growth problems and result in poor growth or death of plants.Considering that Bermuda is such a small island,farmerscrops are constantly being

      2、 exposed to salt spray.Therefore,there must be a saline threshold for the various crops.Bermuda is famous for The Bermuda Yellow Onion,therefore I felt it was appropriate to investigate The Salinity Tolerance of the Bermuda Yellow Onion.The objective of this study is to find out if the Bermuda Yellow Onion has a saline threshold,and if so what is this saline limit.To examine this question,I have constructed several small experiments,including the Saline Affect on Biomass,Germination Rate,Onion G

      3、rowth,and the Water Content in Soil after Plant Growth.Throughout this investigation,I found that salinity effects both germination and overall growth of the Bermuda Yellow Onion,decreasing the yield percentage produced.The appearance of all plants grown in saline solutions are recognized as an effect of salt stress;poor germination and establishment,reduced plant vigour and stunted growth,smaller than normal leaves,slightly yellowing leaves,and a burnt appearance on tips of leaves.All experimen

      4、ts carried out show that salinity has an affect on the osmotic ability of both seed and plant,which has an effect on other plant functions such as photosynthesis and transpiration.Without the plant able to function effectively nor efficiently,the plant will produce fewer yields or eventually die,depending on the salinity strength.This discovery suggests that there is a definite saline threshold for the Bermuda Yellow Onion.IntroductionOriginally,Bermuda grew and exported tobacco,but during the 1

      5、870s and 1880s Bermudians approached the production of crops with a more serious attitude,and agriculture became a thriving export business.Every onion was hand picked,wrapped and packed for the market in New York.Every member of the family was involved in preparing the garden produce for export for the steamers that sailed twice a month from Hamilton.Bermuda did not only export onions to the New York market but also other garden produce such as arrowroot,celery,tomatoes,and potatoes.Because Ber

      6、mudas onions were so delicious they were widely sought and enjoyed not only in the U.S.but all over,so production increased to meet the growing demand.Bermuda was often referred to as The Onion Patch and Bermudians were obviously nicknamed Onions because of this.The export of Bermuda onions came to an abrupt end when U.S.tariff walls were raised against such imports.Bermuda is quite a small island,only 21 square miles,and the crops are often exposed to salt spray from the surrounding ocean,which

      7、 affects the soil that will in the long run affect plant growth.Soil is a multicomponent system,which means that soil is made up of solid,liquid and gaseous components.This system consists of inorganic and organic solid components,soil solutions and as well as a gaseous phase.These three states are in a constant flux,maintaining a state of equilibrium.This is maintained by a chain reaction,one phase will manipulate the following phases until the equilibrium state is achieved.One way of achieving

      8、 equilibrium is cation exchange;this involves cations interchanging between the solid phase and the liquid phase.This exchange reaction occurs from the negative charge of soil colloids.Soil contains a mixture of different types of clays;soil salinity causes particles to bind together into aggregates,this process is called flocculation.Flocculation is good for soil aeration,root penetration,and root growth.Increasing soil salinity may have a positive effect on soil aggregation and stabilization,b

      9、ut high salinity also has a negative effect on plants.High sodium concentration in soil,gives an opposite affect than soil salinity.Sodium causes soil dispersion and the clay platelets and aggregate swelling.When too many sodium ions come between the clay particles,the bonded clay particles are disrupted.This separation of clay particles causes them to swell and soil dispersion occurs.Soil dispersion causes clay particles to clog soil pores;this reduces the permeability of the soil.When soil is wetted and dispersion occurs repeatedly,it then becomes solidified to a cement-like soil with little or no structure.The reason why other salts such as calcium and magnesium do not have the same affect as sodium is because they are smaller so they can collect closer to the clay particles.As shown in figure 1.Soil dispersion also has an affect on infiltration and hydraulic conductivity of the soil.A Lack o

      《留学生Essay写作—植物生长的环境因素》由会员BayD****论文写...分享,可在线阅读,更多相关《留学生Essay写作—植物生长的环境因素》请在金锄头文库上搜索。

      点击阅读更多内容
    最新标签
    发车时刻表 长途客运 入党志愿书填写模板精品 庆祝建党101周年多体裁诗歌朗诵素材汇编10篇唯一微庆祝 智能家居系统本科论文 心得感悟 雁楠中学 20230513224122 2022 公安主题党日 部编版四年级第三单元综合性学习课件 机关事务中心2022年全面依法治区工作总结及来年工作安排 入党积极分子自我推荐 世界水日ppt 关于构建更高水平的全民健身公共服务体系的意见 空气单元分析 哈里德课件 2022年乡村振兴驻村工作计划 空气教材分析 五年级下册科学教材分析 退役军人事务局季度工作总结 集装箱房合同 2021年财务报表 2022年继续教育公需课 2022年公需课 2022年日历每月一张 名词性从句在写作中的应用 局域网技术与局域网组建 施工网格 薪资体系 运维实施方案 硫酸安全技术 柔韧训练 既有居住建筑节能改造技术规程 建筑工地疫情防控 大型工程技术风险 磷酸二氢钾 2022年小学三年级语文下册教学总结例文 少儿美术-小花 2022年环保倡议书模板六篇 2022年监理辞职报告精选 2022年畅想未来记叙文精品 企业信息化建设与管理课程实验指导书范本 草房子读后感-第1篇 小数乘整数教学PPT课件人教版五年级数学上册 2022年教师个人工作计划范本-工作计划 国学小名士经典诵读电视大赛观后感诵读经典传承美德 医疗质量管理制度 2 2022年小学体育教师学期工作总结 2022年家长会心得体会集合15篇
    关于金锄头网 - 版权申诉 - 免责声明 - 诚邀英才 - 联系我们
    手机版 | 川公网安备 51140202000112号 | 经营许可证(蜀ICP备13022795号)
    ©2008-2016 by Sichuan Goldhoe Inc. All Rights Reserved.