农学专业英语

v1.0可编写可改正Unit1basicpartsofaplantatherootsystem,whichisbelowtheground,andtheshootsystemabove.一植株最基本构成部分是地下根系统和地上茎系统takesin,orabsorbs,waterandmineralfromthesoilthroughtheroothairs,whicharesinglecellsnearthetipofeachroot根毛是凑近根顶端的单细胞，它能够从土壤中汲取水分和矿物质addition,plantssuchascloverandLucerne,knownas‘legumes’havespecialbacteriawhichliveontheroots.此外，一些豆科作物，如三叶草和苜蓿，有特别的寄生在根部的细菌importantfunctionistoenablewaterandmineraltopassupfromtherootstotheleavesandflowers.另一种重要的功能是使水和矿物质从根运输到叶片和花上mainjobistomakefoodfortheplantbytheprocessknownasphotosynthesis.它们的主要任务是光合作用为作物供给营养fromthesoilandcarbondioxidefromtheairareconvertedintosugarsandothercarbohydrates.来自土壤中的水和来自傲气中的二氧化碳被转变为糖和碳水化合物stamensproducethemalesexcells,orspermatic,whicharecarriedinthepollengrains雄蕊产生雄性细胞或是性孢子，它们被花粉粒携带.fruit,theripenedovaryoftheflower,enclosestheseedsandprotectsthemwhiletheyaredeveloping，果实，花中成熟的子房，包围着种子，当它们发育时候并保护它们seeditselfconsistsofanembryoandfoodstore种子是由胚和.胚乳构成的embryoisthepartwhichwilldevelopintoantherplantandthefoodstoreisnecessarytoprovidenourishmentfortheyoungplantwhileitisgrowing.胚是能发育成此外作物的器官，胚乳是为发育中的幼体供给必需的营养Unit2remaindormant,orinarestingstate,iftheyarekeptcoolanddry.种子在低平和干燥条件下，处于休眠状态theamountofmoistureandthetemperaturelevelareright,theseedsgerminateandstartgrowing.当温度和湿度适合时，种子抽芽并开始生长isbecausewetsoilsremaincoldforalongerperiodoftimethandrier,well-drainedsoils.这是因为湿的土壤比干燥的排水好的土壤更能保持更长时间的低温seedsrequireverylittleoxygeninordertostayalive,butwhentheystarttogerminatetheyrequiremore.种子在休眠状态时为保持活力需要较少o2，但当它们抽芽时需要许多的o2theearlystagesofdevelopmenttheseedlingdependsentirelyonthefoodstoreintheseedbutassoonasthefirstleavesareproduced,itisabletomanufacturefoodforitself.发育初期，幼苗完整依赖种子中的胚乳，可是一旦第一片子叶产生，它就能为自己生产食品theprocessofpollinationthepolleniscarriedbywindorinsectsfromthestamenstothestigmaofthecarpel.流传花粉过程中，花粉被风或是昆虫从雄蕊流传，到雌蕊柱头上germinatesonthestigmaandgrowsdownthestyleintotheovary,wherefertilizationtakesplace.它在柱头上产生并在子房中发育，进行受精Unit3111v1.0可编写可改正materialoriginatesfromdeadplantsandanimalsandmaterialotherthanthisarederivedfromrocksofvariouskinds.有机质起源于死的动植物，而矿物质是与之不一样的不经分解，根源于不一样种类的岩石rocksarebrokendownintosmallparticlesbymechanicaldisintegrationandchemicaldecomposition.这些岩石经过物理和化学分解成小颗粒aridregionsweatheringismostlybyphysicalmeans.在干旱地域，风化主要因为物理因素inhumidregionschemicalprocessesofweatheringareequallyimportant可是在润湿的地域，风蚀的化学过程是同等重要的.,theinsolublemineralresiduesinthesoilshavelessresemblancetotheoriginalrocks.所以，土壤中难以溶解的剩余矿物质与原始的岩石无什么近似处ofthemcontainvariousproportionsofsand,siltandclayandthesevaryingproportionsmakeupasoil’stexturalclass.土壤主要包含沙子，粉砂，黏土。。它们不一样的比率构成了土壤不一样的质地等级principleclassesinorderofincreasingfinenessofmaterialaresand,loamysand,loamy,siltloamy,siltyclayloam,clayloam,siltandclay.依据矿物质纯度次序摆列挨次为沙土，壤砂土，壤土粉砂土，粘壤土，粉砂和黏土istosay,smallersizedparticlescanreactorcombinewithwater,nutrientsandhumusmoresassilythanlargersizedparticles.就是说，小颗粒与水，营养和腐殖质比大颗粒更简单联合fromdecomposedorganicmatterisvitaltoasoilasitmakesaheavysoillighter.根源于腐化有机物质的腐殖质，对土壤至关重要，因为它使土壤变的更松散Unit42.Theeasewithwhichwatersanpassthroughasoildependsontheproportionsinitofcoarseandfineparticlessuchassandandclay.水分浸透土壤的简单度依赖土壤粗细比率，比如砂土和黏土10.Anotheradvantageisthatawell-drainedsoilwillhaveenoughairforaerobicbacteriatobreakdownhumusandsoprovidefoodfortheplant.另一个长处是排水很好的土壤会有足够的空气，为好氧的细菌去分解腐殖质，而后为作物供给营养12.Ditchescanbecutatcertainintervalsbetweenthecrops.在作物之间水渠被切割成特定的间隔16.Porousdrainagetilesmaybelaidinoronthelandandthesewillhelpdrawoffthesurpluswater.多孔排水管平放入地下或地面下，这样会有助于放掉剩余水分17.Thedistancebetweenthedrainswilldependsontheleveloftheland,thepermeabilityofthesoil,andtheamountofrainfall.排水间的距离取决于土地的平展程度，土壤浸透性和雨量的多少22.Weshoulddistinguishbetweenthecollectionofwateranditsapplication我们应鉴别水的会合和它的利用之间加以差别.23.Therearetwomainsourcesofirrigationwater:surfacewaterandgroundwater.有两种主要的浇灌水资源：地表水和地下水31.Bythiswemeantheamountofwaterwhichisneededtobringthesoiltofullcapacity.意思是需要的水的量是能使土壤达到充分的的数目32.Italsodependsonthetypeofcrop,thestageofgrowthofthecropandtheamountwhichitwilluseatthatparticulartime.它也取决于作物的种类，作物生育时期和它在特别时期的使用量222v1.0可编写可改正34.Mostplantsrequirelargerquantitiesofwaterduringthelaterstagesthanintheearlierstages.大多半作物在后期比先期需要更大批的水Unit58.Finally,itmakesupfortheplantnutrientswhichhavebeenremovedbycropsorlostbyleachingandsoilerosion.最后，它填补了作物汲取，淋溶土壤侵害所流失的营养14.So,theymaybegroupedasnitrogenousfertilizers,phosphaticfertilizers,potassicfertilizersandsoon.所以，它们被分为氮肥，磷肥，钾肥等15.Themostcommonlyusedfertilizerwhichcontainsnitrogenisammoniumsulphate,whichismadefromammoniaandsulphuricacid,andwhichcontains21%nitrogen使用最广泛的肥料是含氮的，主要有硫酸铵等，它由氨和硫酸组成，此中含氮量百分二十一.16.Thiselementencouragesrapidvegetativegrowthandgivesplantsahealthygreencolour.这个因素促使作物快速生长并给作物一个健康的绿色19.Phosphorousstimulatestheformationofaplant'sroot,andpromotesfruitandseedproduction.磷刺激根系形成，促使结果和种子产量21.finally,whereverhighcropyieldsareexpected,potashisusedtogetherwithnitrogenandphosphorous.最终，不论在哪高产量都是被希望的，经过k与n,p混淆使用23.Thishelpplanttowithstandmechanicaldamagesuchasbrokenbranchesandtorn有助于作物抵挡机械损害，例如残枝败叶27.Itisusuallysuppliedintheformofmuriateofpotash(potassiumchloride),whichcontains50to60%potassiumoxide(K2O)andsulphateofpotash(potassiumsulphate).它老是以k的化合物形式被使用，包含百分五十到60的k2o和k2so432.Ifasoilisveryacid,withapHvalueoflessthan,limecanbeaddedtocorrectthisacidity.假如土壤极酸性，ph小于5，石灰能够改良土壤的酸性35.Nitrogen,phosphorousandpotassiumaremoreeasilyavailableinawell-limedsoilthaninanacidsoil.氮磷钾在用石灰办理的土壤中比在酸性的土壤中更简单被利用Unit61Incropproductionthecontrolofweeds,diseasesandpestsisessentialtoobtainhighyields.杂草和虫害的控制关于获取高产量是有必需的5Weedsreducecropyieldsonaccountofthefactthattheycompetewithcropsforwater.杂草使作物产量降低的原由是它与作物竞争水分，营养，光照7Mostweedsareaggressiveandinvasive,theygrowquicklyandspreadfar,andsoaredifficulttogetridof.大多半杂草是有竞争性和损害性的，它们生长快速，流传的远，所以很难挣脱8Onerecommendedwayoferadicatingmanypersistentweedsisfirsttoploughuptherootsandundergroundpartsoftheplant.一种值得介绍的消除多年生杂草的方法是第一根系和作物地下部分11Weedsmayalsobekilledbymeansofchemicalswhichhavethecollectivenameofherbicides.杂草也能够被称为除草剂的化学药剂杀死333v1.0可编写可改正17Theymustbeusedextremelycarefullyforthesimplereasonthattheywilleradicateallplantsonc