英语学术论文写作.docx
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英语学术论文写作.docx
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英语学术论文写作
Typicalfarmlandsoilfertilityascendingmechanismresearchinguangdongprovince
Yankaichen
(Collegeofresourcesandenviroument,SouthChinaAgriculturalUniversity,Guangzhou510642,China)
Abstract:
Naturalqualityisnothigh,cultivatedlandresourcesinourcountryislimited.Althoughwedoalotofworktoimprovesoil,soilstillaccountsformostofthearablelandarea,butnowthemiddlereach2/3.Sincethesecondsoilcensus,organicmattercontentinmostofthefarmlandinChinahasimproved,buttheoveralllevelisnothigh,theaveragecontentislow,onlyaboutEuropeanandAmericandevelopedcountriesgenerally.Withtheimprovementoffarmlandintensiveutilizationdegree,alargenumberoflarge-scaleplantingfarmsprangup,alargenumberofagriculturalchemicalsandthepopularityoflargemachines,andcausealotofnewsoilproblems,suchassoilcompaction,structuredegradation,aggregatestabilitydecreased,soilbiologicaldegradationfunction,reducedwaterraisebufferingcapacityetc,isoneofthemostimportantcontentofsoilorganiccarbonandreducethestabilityoftheaggregate.Generallytakesuphighqualitycultivatedland,cultivatedlandoccupancyandtheincreasingnumberofcultivatedlandisofteninferiorexacerbatetheproblemoffarmlandsoilfertilitydecline.Thisstudybycollectingdifferenttypicalareaofguangdongprovincefarmlandsoilfertilitylevel,throughtheanalysisofcomponents,qualityanddistributionofsoilorganicmattercontent,soilaggregatecharacteristicsanditsinfluencingfactors,explorecanrepresentbasicfarmlandsoilindicatorofsoilfertility,improvethekeybyreveallimitsoilprocessesandfactors,lookingforeffectiveregulationpathway;Throughtheregulationoforganicmattertransformationprocessanditsdrivingfactorsinincreasingsoilorganicmatteraccumulation;Finallyrealizetheascensionoffarmlandsoilfertility,increasingfoodproduction,improvethequalityofthefood.
Keywords:
Typicalfarmland、soilfertility、Ascendingmechanism、Soilquality
1Introduction:
Farmlandsoilorganicmattercontentofthelargeareaappearslowerinourcountry[1],thevariationofsoilphysicalandchemicalproperties,soilfertilitydeclinetrend.Soilaggregateisthebasisoftheformationofsoilstructure,soilis"keepdepots".Researchshowsthat,thehigherthefarmlandfoundationsoil,inthesamevariety,dosageandcontrolmeasuresofwaterproductionandresourceuseefficiencyishigher[2].So,todigupeffectoffoundationsoilfertilitypromoted,promotetheyieldandthecultivatedlandresourceuseefficiency,carryoutthemechanismofpromotingfarmlandsoilfertilityanddirectionalcultivationcountermeasureresearch,toimprovesoilfertilityoflargemiddle-and-low-yieldingfieldstoprovidetheoreticalandtechnicalsupport.Throughrevealinglimitsoilfertilityimprovingkeyprocessandfactors,lookingforeffectiveregulationpathway;Throughtheregulationoforganicmattertransformationprocessanditsdrivingfactorsinincreasingsoilorganicmatteraccumulation;Finallyrealizetheascensionoffarmlandsoilfertility.Toinvestigatethecharacteristicsofsoilstructureandorganicmatter,providethebasisforfarmlandtoraisesoilfertilityandkeep[4].
2.1Thedefinitionoffarmlandsoilfertilitycontributionandsignificance
Soilcontributionreferstonofertilizertreatmentcropyieldoffertilizingcropsyieldpercentage,isanimportantindexofsoilfertility.Ratiothehigherthesoilfertility[4],soilfertilitylevelishigher,thelowerthedependenceonfertilizerstocrops
2.2Farmlandindexofsoilfertility
2.2.1Physicalandchemicalindexoffarmlandsoilfertility
Soilorganicmatterisoneofthemostimportantchemicalindexesoffarmlandsoilfertility.Exceptasasourceofnutrition[5],itcanimprovesoilstructureandwaterholdingcapacityandimprovethebiologicalactivity.Itthroughthetransformationequationtocalculatethesoilbulkdensity,waterholdingcapacity,leachingpotential,ionexchangecapacity(CEC)andsoilproductivity.
OnsoilpH,conductivity,theassessmentofCECandnutrientcontentoffarmlandsoilchemistryisnecessary,becausetheyprovideacanreflectthesoilnutrientsandanimprovedabilitytobufferthechemicalmeasurementindicators[6].PHcanaffectalotoftherelationshipbetweensoilbiologicalpropertiesandchemicalproperties.Ionexchangecapacityistheabilityevaluationofsoilconservationandnutrientsimportantattribute.
Foundationsoilphysicalqualityindexinthequalitydifferencesbetweenthesoiltypeisveryuseful.Soilphysicalpropertiesofsoiltextureisthemostbasic,itcancontrolthemoisture,nutrientsandgasexchange,maintainandabsorption.Soillayerthicknessisaffectedplantsperunitareaofquantitativepropertiesofthenumberofavailableresources.
Soilbulkdensitywiththeorganicmattercontentofthesoiltexture,structure,anddifferentvariationisverybig[7].But,foraspecificsoiltype,densitycanbeusedformonitoringsoilcompactiondegree.Thechangeofsoilbulkdensitybesidesitselfaffectsthemoistureandoxygensupply,mayalsoaffectmanyotherpropertiesandprocess.Thesoilstrengthismeasuredbyconepenetrometercanbeusedasanindexofsoilcompaction.
Moisturepermeability,maintain,availability,drainageandindexesforthecomprehensivemonitoringsoilmoisturebalance[8].Functionisveryimportant.Effectivecapacityaccordingtotherelativestrengthofthesoilwatersupply.Saturatedmoistureconductivityisanindexreflectingsoildrainagespeed,canbeusedtodeterminesoilmoisturebalance[9].
Soilstructureisreferstotheorganicmatterandotherchemicalsedimentsizeandshapeofthebindingtogetherofaggregate.Itcanaffectalmostallthephysical,chemicalandbiologicalpropertiesofsoil.Thestabilityoftheaggregatecanbeusedtodescribewhensoilunderdifferentpressuremaintainabilityoftheproportionofsolidphaseandliquidphase[10].Duetosoilaggregatecanreflectthesoilbiologicalproperties,chemicalpropertiesandtherelationshipbetweenphysicalproperties,sothesoilaggregateisaveryimportantqualityindex.NarrowandCoen_9pointsoutthatthecropandsoilmanagementpracticesonsoilphysicalqualityinfluencesoilaggregatecanbeusedtodescribethesizedistributionandstability[11].
2.2.2Biologicalindicatorsoffarmlandsoilfertility
Duetohaveasimpleandfeasiblemethod,earlyfarmlandsoilfertilityevaluationfocusesonthephysicalandchemicalpropertiesofthesoil.However,soilphysicalandchemicalpropertiesasindicatorsoffarmlandsoilfertilitysometimescannotevaluatetheeffectsofsoilmanagementandlanduse.
Farmlandsoilfertilityevaluationinrecentyears,moreattentionpaidtothebiologicalindicators,biologicalindicatorsincludingsoilonthegrowthofplants,soilanimalsandsoilmicrobes,whichappliedthemostweresoilmicrobialindicators.Soilmicrobialresearchisdividedintothreelevels:
populationlevel,communitylevel,ecologicalsystemlevel,ecologicalsystemlevelresearchisconsideredtobethebestpossiblewaysoffastevaluatingfarmlandsoilfertilitychanges,moststudiessuggestthatsoilmicroorganisms(includingmicrobialbiomass,soilrespiration)isthemostsensitiveindicatoroffarmlandsoilfertilitychanges.Soilanimalistheimportantinstructionsofsoilenvironmentalqualityandhealthqualitycharacteristics,especiallyinvertebratessuchasnematodes,earthwormscansensitivelyreflectthepoisonoussubstancecontentinsoil.Withplantsasthefarmlandsoilfertilityevaluationindex,mainlyonplantgrowth,productionpattern,thestructureoftherootsystem,planttissuecharacteristics,dominantspeciesofherbagespeciesdiversityandweeds,andtheevaluationofsoilfertilityqualityandenvironmentalqualityandhealthquality[12].
KennedvPapendickJandpointsoutthatsoilbiologicalpropertiesandbiologicalchemicalcanbeusedasindicatorstoreflecttheactualchangesinagriculturalecosystemandsoilproductivity.Soilmicrobialpropertiescanpromotealotofthechangeprocessofsoilphysicalandchemicalproperties.Microbialactivitywasalsoinvolvedinthedecomposition[13].Nutrientandenergycirculation,theformationandtransformationoforganicmatterofsoilaggregatecontrolprocess,etc.
Soilmicrobialbiomasswasprovedtobeastableandreliableparameterstodoregionalscaleofquantitativeanalysis,samplinginvegetativegrowthlateorearlyspring.Itcanbeusedaspotentialbalanceoffarmlandsoilfertilityindexindicatinglevelsofsoilorganicmatter,andthetrendofthefuture,canalsobeusedforlong-termmonitoringoffarmlandsoilfertility.Previousstudiesfocusedonthemicroscopicscalesandsoilnutrientcyclingandfarmlandsoilmicrobialactivityofrelatedresearch.However,thespatialdistributionofsoilmicrobialbiomassonlandscapescaleanalysisandstudyoftheveryfew[14].Controlofsoilmicrobialactivityoforganiccarbonconversionprocessandmigrationresearchhelpstoevaluatethefunctionoftheregionalsoilresources.Comprehensivemicrobialindicatorshavebeenchosenforfarmlandproductivitypotentialindex,andunderthebackgroundofsoilphysicalandchemicalpropertiesareanalyzed.
Soilenzymeactivitywasusedtoevaluatethesoilfertilityatfirst,hasrecentlybeenchosenforthepotentialoffarmlandsoilfertilityindex.Theactivityofsoilenzymesplayanimportantroleinnutrientcyclingandhasbeenusedasmicrobialactivityindex.Enzymeactivitycanbecomeagoodfarmlandsoilfertilityindexbecauseitindecompositionandplaysanimportantroleintheprocessofmineralizationandissensitiveto
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