简介：Agreenhousepotexperimentwasconductedwithhybridrice(OryzaSativaL.)inordertostudyNStatusandutilizationintherhizosphereofrice,Theexperimentwascomposedofthreetreatments:withoutN,15NH4-Nand15NO3-N.Plantrootswereseparatedfromthesoilbyanyloncloth,and1mmincrementsofsoil,movinglaterallyawayfromtheroots,weretakenandanalyzedforvariousNfroms.ThelabelledNintheplantsrangedfrom67\51%to69.24%ofthetotalamountofNabsorbedbythericeseedlingswiththelabelledfertilizerNtreatments.ThisshowsthattheNinthePlantscamemainlyfromthefertilizers.However,theNabsorbedbythericeseedlingsaccountedforlessthan35%ofthetotalamountoftheNdepletioninthesoilnearthericeroots,indicatinganimportantNlossintherhizosphereofrice.Thesoilredoxpotential(alltreatments)andtheconcentrationofthelabelledNO3-N(thelabelledNH4-Ntreatmentonly)decreasedasthedistancefromthericerootsincreasedintherhizosphereofrice.Incontrast,theconcentrationofthelabelledNH4-Nincreasedasthedistanceuincreasedinthesamesoilzone.Theseresultssuggestedthatnifrificationoccurredinthesoilaroundthericeroots.Therefore,thereasonfortheNlossintherhizosphereofricemightbetheNO3movementintothereductivenon-rhizospheresoil(submerged)wheredenitrificationcantakeplace.

简介：Effectofintermittentirrigationontheproductionofpaddyricewasstudiedinawell-puddledpaddyfieldwithfourtreatmentsand2replicates:continuoufloodingirrigation(CFI),andintermittentirrigationⅡ-0，Ⅱ-1andⅡ-2,inwhichplantswerere-irrigatedwhenthesoilwaterpotentialfellbelow0,-10,and-20toabout-10or-20kPadidnotsignificantlyaffectthenumberofgrainsandthepercentageofripenedgrains.While,alowercropgrowthrate(CGR)resultedfromadecreaseinthenetassimilationrate(NAR)duringintermittentirrigationⅡ-1andⅡ-2,andtherewasalsoareductionintheleafareaindex(LAI)durinindtermittentirrigationⅡ-2.SenescenceoflowerleavesonstemswaspromotedintreatmentsⅡ-1andⅡ-2attheripeningstage.Earlysenescenceatripeningstageandwaterstressaroundmiddaydecreasedtherateofphotosynthesisinleaves,causingthelowerNAR,Thesephysiologicalresponsesoftheplantswereresponsibleforthereductioninthedrymatterproductionandgrainyieldintheintermmittentirrigationtreatments.

简介：Theeffectsofnitrogen,phosphorusandpotassiumapplicationlevel,seedrateandtransplantingdensityonthegrowthanddevelopmentofriceplantswerestudiedtofindoutnutrientstatusinhigh-yieldingriceplantsandtoincreasegrainyieldbyadequatefertilization.Therewasanequilibriumrelationshipamongnutrientelementsforhigh-yieldingriceplantpopulations.Theequilibriumindexofnutrientamount,contentanddistributioninhigh-yieldingriceplantsshouldbegenerallygreaterthan-2butlessthan2.Theoptimumnutritiveproportionofnitrogen:phosphorus:potassiumassimilatedbytheplantswasabout10:2:9attheripeningstage.Butthecontentandtheproportionvariedwiththegrowthstages,Therefore,thenutrientinriceplantpopulationsshouldbeinadynamicequilibrium.Soastoachievehighyield.

简介：ConsumptionofriceisthemainsourceofmicronutrientstohumaninAsia.Apaddyfieldwithunknownanthro-pogeniccontaminationinDeqingCounty,ZhejiangProvince,Chinawasselectedtocharacterizethespatialvariabilityanddistributionofmicronutrientsinricegrainandsoil.Atotalof96pairedsoilandricegrainsampleswerecollectedatharvest.Themicronutrientsinthesoilsampleswereextractedbydiethylenetriaminepentaaceticacid(DTPA).Themeanmicronutrientconcentrationsinricegrainwere3.85μgCug-1,11.6μgFeg-1,39.7μgMng-1,and26.0μgZng-1.Themeanconcentrationswere2.54μgg-1forDTPA-Cu,133.5μgg-1forDTPA-Fe,30.6μgg-1forDTPA-Mn,and0.84μgg-1forDTPA-Zn.Semivariogramsshowedthatmeasuredmicronutrientsinricegrainweremoderatelydependent,witharangedistanceofabout110m.TheconcentrationsoftheDTPA-extractablemicronutrientsalldisplayedstrongspatialdependency,witharangedistanceofabout60m.TherewassomeresemblanceofspatialstructurebetweensoilpHandthegrainCu,Fe,Mn,andZn.Byanalogy,similarspatialvariationwasobservedbetweensoilorganicmatter(SOM)andDTPA-extractablemicronutrientsinthesoil.Krigingestimatedmapsoftheattributesshowedthespatialdistributionsofthevariablesinthefield,whichisbeneficialforbetterunderstandingthespatialvariationofmicronutrientsandforpotentiallyrefiningagriculturalmanagementpracticesatafieldscale.

简介：硅(Si)经由钙硅酸盐的申请被供应了到植物到土壤；然而，因为它的低溶解度，钙硅酸盐的高剂量被要求。Nanoparticles能减少Si剂量并且被用于播种沟。这研究调查了液体Si来源的效果，即，高度可溶的硅酸盐(115.2gL1Si和60.5gL1Na2O)并且nanosilica(<200nm)，在Si上，由米饭的举起种，植物木质化，植物C:N:Pstoichiometry，植物生理学，和谷物在greanhousecondistions下面用Oxisol让步。处理包括了nanosilica和可溶的硅酸盐的申请到在0，605，1210，和2420g的Si剂量播种沟哈1。植物举起和处理效果被测量累积，生理的特征，和谷物米饭产出的C和木质素内容，Si，N，和P评估。在标志叶子的硅石身体和非结晶的硅石的免职用扫描电子显微镜学被分析。液体Si的申请在与控制的关系在米饭增加了Si累积47.3%(0g哈1Si)，不管Si，来源使用了。Nanosilica申请增加了叶木质素内容112.7%什么时候与那相比在控制。硅中等影响了网C吸收(增加了1.83%)并且蒸发率(增加了48.3%)；然而，Si影响了既不植物生长也不米饭的谷物产量。这些结果被关於生命或不能生活的应力的缺乏在实验期间在米饭植物解释。就我们的知识而言，在巴西农业，这在植物营养上作为Si化肥和它的效果是nanosilica的使用上的第一份报告。这研究提供米饭植物吸收并且积累nanoparticles的证据；然而，进一步的研究被要求在另外的植物种类调查nanoparticles的使用。

简介：InordertoprovideascientificbasisforriceyieldestimationandimprovetheacouracyofyieldestimationinZhejiangProvince,Regionalizationindicesforriceyieldestimationbyremoesensing(RS)intheprovinceweredeterminedbyconsjderingthespecialfeaturesofyieldestimationbyRS,andbasedonanalysisofthenaturalconditionsofZhejiangProvince,Theindicesdeterminedincludedricecroppingsystem,agroclimate,landform,surfacefeaturesturctureandriceyieldlevel,wherericeplantingsystemwasconsideredasthemianone,ThenreionalizationfroriceyieldestimationbyRSwascompletedbyspatialneighboringanalysiswiththeGeographicalInfromationSystem(GIS)technologycombinedwithusigoftreealgorithmTheprovincewasdividedintotworegions,i.e.,thesingle-croppingriceregionwhichwassubdividedinto3regionsincludingthoseinmountainsofnorthewstZhejiang,waternetworkareaofnorthZhejiangandmountainsofsothZhejiang,anddouble-croppingriceregionwhichwassudividedinto5regionsincludingthoseonplainofnorthZhejiang,coastalplainsandhillsofsoutheastZhejiang,Jin-QuBasinofmiddleZhejiang,hillsofeastZhejiang,andhillsandmountainsofnorthewatZhejiang,thisregionaliztiontookthecountybordersastheregionboundaries,kepttheregionsconnectiveandmadetheadministrativregionsintegrityand,then,couldmeettherequirementsofriceyieldestimationbyRS,showingthattheresultswerequitesatisfying.

简介：FieldexperimentswerecarriedoutwithricevarietyofShenong91ofshortculmsanderectpaniclestostudynutrientcontentsinhigh-yiedldingriceplantsandtoincreasericeyieldbyappropriatefertilization.Nitrogen,phosphorus,potassium,magnesium,zinc,manganese,ironandcoppercontentsinriceplantsvariedwithdifferenttreatmentfactors.Therelationshipbetweenthenutrientcontentsandtreatmentfactorscouldbesimulatedusingamultiplequadraticequation.Thenutrientcontentsinplantsshouldbeappropriateforhigh-yieldingrice.Ifthemeannutrientcontentinriceplantsproducuing11tha^-1ormoreofgrain(uj)wassetasthestandardvalueandthestandarddeviation(σj)wassetastherangeofvariation,thenutrientcontentinhigh-yieldingriceplantsshouldbeμj±1.99σj.Riceleavesweresensitivetothenutrientelements.Heavynitrogendressingincreasedthecontentofnitrogeninriceplants.Sparsetransplantingalsoincreasednitrogencontent,Improperapplicationofnitrogen,phosphorusandpotassiumcouldaffectthenutrientcontentsanddecreasethegrainyield.

简介：氮使用效率(NUE)在中国是很低的，差不多70%应用的氮化肥的损失在high-yielding稻田被报导。以便调查高亲密关系的铵运输或举起的分子的基础进米饭(OryzasativaL.)，我们分析了九铵的表示侧面transporters(AMT)，OsAMT1的三各个，OsAMT2和OsAMT3，根据外部N地位在象在这些表示模式的变化一样的米饭生长的二个不同N要求阶段(年轻幼苗阶段和tillering阶段)使用即时反向的抄写聚合酶链反应(RT-PCR)。结果建议九OsAMT基因在米饭植物的不同机关被表示，包括成熟的根，新根，茎，旧叶子和新叶子并且表示模式是相应蛋白质的位置在种系发生的树上特定、独立的机关。OsAMT1；1，3；2和3；3在根和射击被表示，首先旧的叶子，OsAMT1；2和1；3主要在根，和OsAMT2；1，2；2，2；3和3；1主要在射击，首先在新叶子，并且相对更在里面茎比另外的基因。在二个不同N要求阶段的表示模式是一样；在有更大的N要求的tillering阶段，然而，OsAMTs抄本层次比在有低N要求的年轻幼苗阶段的那些大。为48h的N饥饿起来调整的OsAMT1；1，1；2，3；1，3；2，3；3并且下面调整的OsAMT1；3mRNA丰富。后面的N饥饿，NH4+和NH4NO3再供给下面调整的OsAMT1；2和3；3并且起来调整的OsAMT1；3，而NO3再供给下面调整的OsAMT1；1和1；2。这些建议OsAMT的器官特定的表示模式能被N要求和外部N地位调整。

简介：Theeffectofnitrate(NO3-)onrice(OryzasativaL.)growthaswellasNabsorptionandassimilationduringdifferentgrowthstageswasexaminedusingthreetypicalricecultivars.Dryweight,yield,Nuptake,nitratereductaseactivity(NRA)inleaves,andglutaminesynthetaseactivity(GSA)inrootsandleavesduringtheirentiregrowthperiods,aswellasthekineticparametersofammonium(NH4+)uptakeattheseedlingstage,weremeasuredwithsolutioncultureexperiments.ResultsindicatedthatadditionofNH4+-NandNO3--Nataratioof75:25(NH4++NO3-treatment)whencomparedwiththatofNH4+-Nalone(NH4+treatment)increasedthedryweightof'Nanguang'cultivarby30%and'Yunjing38'cultivarby31%,andalsoincreasedtheirgrainyieldby21%and17%,respectively.Forthefourgrowthstages,thetotalNaccumulationinplantsincreasedbyanaverageof36%for'Nanguang'and31%for'Yunjing38',whereastheincreasingeffectofNO3-inthe'4007'cultivarwasonlyfoundattheseedlingstage.IntheNH4++NO3-treatmentcomparedtotheNH4+treatment,NRAintheleavesincreasedby2.09folds,andGSAincreasedby92%intherootsand52%intheleavesofthethreecultivars.NO3-supplyincreasedthemaximumuptakerate(Vmax)inthe'Nanguang'and'Yunjing38'cultivars,reflectingthattheNO3-itself,nottheincreasingNconcentration,increasedtheuptakerateofNH4+byrice.TherewasnoeffectontheapparentMichaelis-Mentenconstant(Km)ofthethreecultivars.Thus,somereplacementofNH4+withNO3-couldgreatlyimprovethegrowthofriceplants,mainlyonaccountoftheincreaseduptakeofNH4+promotedbyNO3-,andfuturestudiesshouldfocusonthemolecularmechanismoftheincreaseduptakeofNH4+byNO3-.

简介：Recentprogressesinefficientmanagementofnitrogenfertilizersforfloodedriceinrelationtonitrogentransformationsinfloodedsoilwerereviewed.Considerableprogresshasbeenachievedintheinvestigationonthemechanismofammonialossandthefactorsaffectingit.However,littleprogresshasbeenobtainedintheinvestigationsonnitrification-denitrificationlossowingtothelackofmethodforestimatingthefluxesofgaseousNproducts.Thus,sofarthemanagementpracticesdevelopedorunderinvestigationprimarilyforreducingammonialossarefeasibleorpromising,whilethoseforreducingnitrification-denitrificationlossseemobscure,exceptthepointdeepplacement.Inaddition,itwasemphasizedthatthepredictionofsoilNsupplyandtherecommendationoftheoptimalrateofNapplicationbasedonitareonlysemi-quantitative.Theprioritiesinresearchforimprovingthepredictionareindicated.

简介：Potexperimentsandfieldtrialswereconductedtoinvestigatethechangesintrichloroaceticacid(TCA)solublesilicon(Si)intheleavesofrice(OryzasativaL.)andtoexaminethefeasibilityofusingTCA-solubleSicontentasanindexfordiagnosingSideficiency,TheTCA-solubleSicontentwassignificantlyhigherintheleavesofbothSi-treatedand-untreatedriceattheelongationstagecomparedwiththatattilleringstage,ItwashigherintheSi-treatedplantsthaninthecontrolsthroughoutthewholegrowthperiod.However,whetherdressedatelongationorbootinstage,siliconfertilzerresultedinasignificantincreaseinTCA-solubleSioneweektotendaysafterapplication,ThesamewastrueforthetotalSiaccumulationintheplants.AcolsepositiviecorrelationwafoundbetweenTCA-solubleSiandtotalSiinPlantsgrownonpotsoils(r=0.669,P<0.01,n=26).TheresultsobtainedinthefieldtrialsrevealedthattheavailableSiextrctedbysodiumacetate(pH4.0)couldnotpreicttheresponseofricetoaddedSiinthecalcareoussoilssatisfactorily.NosignificancorrelationwasfoundbetweensoilavailableSicontentandriceyield,butTCA-solubleSiintheleafbladesofricewassignificantlycoorelatedbothwithriceyield(r=0.57,P<0.01,n=30)andwithtotalplantSi(r=089,P<0.01,n=30),Inisrecommendedthat,whth95percentconfidence,thecriticalvalueofTCA-solubleSiintheleavesofriceshouldbe52-57mgSikg^-1,abovewhichnopositiveresponseofricetoaddedSiwouldbeexpected.

简介：在东南亚洲的蔬菜生产经常是依次与充满的米饭。有充满的大米生产的土壤的puddling可以为干燥土地庄稼的随后的生产导致不利土壤条件。为了证实永久蔬菜生产是否导致赞成土壤，在充满的大米在一个2年的地实验被学习以后，在土壤性质上与充满的大米依次为蔬菜，五个不同永久蔬菜生产系统的效果和蔬菜生产的一个系统调节。在0.05–0.10m深度层的体积密度与充满的米饭依次与永久蔬菜生产和蔬菜生产减少了。减少大批，密度被器官的粪肥和米饭外壳的申请影响，并且特别由庄稼的数字栽培了建议土壤耕种的那频率穿上主要效果体积密度。在在有提起的床的建设的联合，充满的米饭能在土壤结构上减少或完全消除puddling的否定效果以后，与公牛拖拉耕作。在0.15–0.20m土壤深度的体积密度没被影响。土壤酸味在所有系统显著地减少了。器官的碳在所有系统增加了的土壤，而是重要增加仅仅在二个永久蔬菜生产系统被发现。可得到的磷(P)显著地在二个永久蔬菜生产系统增加了，与一断然，到P的数量的关联适用。重要减少大批在pH的密度和增加(H2O)在仅仅2年以后，证明在充满的米饭以后的土壤条件能在集中的蔬菜下面在一短时间被改进生产。

简介：在南部的中国的大米小麦旋转被经常的排干洪水的水政体和重氮(N)授精描绘。有进溶解的器官的氮的行为的研究的实质的缺乏(穿上)在强烈地管理的agroecosystem。在situ地实验3年的A被进行决定穿上沥滤并且它在6个连续大米/小麦季节由授精，灌溉和降水影响了的季节、每年的变化。在常规N实践下面(300kgN哈为米饭和200kgN的−1哈为小麦的−1)，季节的一般水准在leachate(100厘米土壤深度)穿上集中因为三个米饭和小麦季节是0.6–1.1和0.1–2.3mgNL−1,分别地。累积穿上沥滤被估计是1.1–2.3kgN哈为米饭季节和0.01–1.3kgN的−1哈为小麦季节的−1，与1.1–3.6kg的一个年度总数N哈−1。在大米季节，N化肥有小效果(P>0.05)在上穿上沥滤；降水和灌溉进口了3.6–9.1kgN哈−1穿上，它可以因此隐藏授精效果在上穿上。在小麦季节，N授精有积极效果(P<0.01)在上穿上。不过，这提升效果被可变降水强烈影响，它也带了1.8–2.9kgN哈−1穿上进地。尽管有到使用的化学N和大变化的一个很小的比例，走水路驾驶政体，穿上沥滤必然与另外的自然生态系统相比由于它的相对更大的数量在大米小麦旋转涉及综合的地N预算。

简介：Changesofsoilorganicnitrogenformsandsoilnitrogensupplyundercontinuousricecroppingsystemwereinvestigatedinalong-termfertilizationexperimentinJinhua,ZhejiangProvince,China.ThefertilizertreatmentsincludedcombinationofP-K,N-K,N-P,andN-P-Kaswellasthecontrol.Aftersixyearsofcontinuousdouble-ricecropping,totalsoilNandhydrolysableNcontentsremainedstableinplotswithNtreatments,whilethehydrolysableNcontentsweresubstantiallyreducedinthoseplotswithoutNapplication.Comparedtotheunbalancedfertilizationtreatments,PandKincreasedthepercentageofhydrolysableammoniumNinthetotalsoilNwiththebalancedapplicationofN,andalsomaintainedhigherricegrainyieldsandnitrogenuptake.GrainyieldwaspositivelycorrelatedwithtotalNuptake(r=0.875**),hydrolysableN(r=0.608**),hydrolysableammoniumN(r=0.560**)andthehydrolysableunknownN(r=0.417**).TotalNuptakewaspositivelycorrelatedwithhydrolysableN(r=0.608**),hydrolysableammoniumN(r=0.440**)andhydrolysableunknownN(r=0.431**).Soilnutrientdepletionand/orunbalancedfertilizationtoricecropreducedNcontentinsoilmicrobialbiomass,andthereforeincreasedC/Nratio,suggestinganegativeeffectonthetotalmicrobialbiomassinthesoil.

简介：Apotexperimentwasconductedtostudytheeffectofnitrogenfertilizeronnitrogenandpotassiumuptakebyfourricecultivars.Resultsshowedthatthequadraticparabolarelationshipbetweenbiomassofriceandnitrogenlevelswasobserved,withthemaximumbiomassatthenitrogenlevelof150mgkg^-1.TherateofnitrogenandpotassiumuptakebythefourricecultivarsdependedongrowthstageandricecultivarwiththemaximumrateofNinShanyou-63andmaximumrateofKinKaiyou-5(hybridrice),respectively,Thekineticsofnitrogenandpotasssiumuptakebyriceplantcouldbequantitativelydescribedbythefollowingequations:y=a+blogt,y=ab+t^1/2andy=ae^-bt,Thebvalueintheequationswascorrelatedsignificantlytotheratesofnitrogenandpotassiumuptake(-↑NRand-↑KR,r=0.901^**-0.990^**),suggestingthatthebvaluecouldbeusedtodistinguishtheindexofnitrogenandpotassiumuptakecapacityofrice.Themaximumvaluesofnitrogenuptakebyplant(bvalue)andapparentrecoveryoffertilizernitrogenwereobservedinShanyou-63,andtheminimumvalueinEryou-6078,However,thecapacityofpotassiumuptake(bvalue)bykaiyou-5rankedfirstandthatbyShanyou-63second.Therewasasignificantlinearrelationshipbetweennitrogenlevelandnitrogenuptakebyrice,butaquadraticparabolarelationshipwasfoundbetweennitrogenlevelandpatassiumuptakebyrice.Theapplicationofnitrogenfertilzierdecreasedtheratiosofpotassiumtonitrogenuptakebyriceplant.Thegreatestreductionintheratiowasobservedathihtnitrogenlevel,andtheleastreductionwasfouninKaiyou-5andShanyou-63duetotheirgreaterabilitytoabsorbpotassium.

简介：Threegoatswerefedwith^15N-labelledricestrawtostudythecharacteristicsofdigestion,assimilation,transformationandexcretionofCandNcompoundsfromricestraw.Itwasshownthattheamountof^15Ntransformedintothebodiesofthetwoslaughteredgoatsaccountedfor38.5and23.6%ofthetotalamountof^15Ndepositionoftheexperimentaldiettakenbyeachgoat.The^15Nexcretedthroughthefecesandurineforthethreegoatsaccountedfor34.8,33.2and33.9%ofthetotalamountof^15Ndepositioninthefeedofthe3goats.Therecoveryoftotal^15Nforthetwoslaughteredgoatswere73.3and57.5%,withthecorrespondingratesof^15Nloss26.7and42.5%respectively.ThedigestibilitiesoftotalaminoacidsforGoats1and3were68.7and54.0%,andthedigestibiltiesofcarbohydratesforthetwogoatswere74.8and67.7%respectively.

简介：Apotexperimentwithtworice(OrizasativaL.)genotypesdifferingininternalpotassiumuseefficiency(IKUE)wasconductedunderdifferentsodium(Na)andpotassium(K)levels.AddingNaC1ataproperlevelenhancedricevegetativegrowthandincreasedgrainyieldandIKUEunderlowpotassium.AdditionofhigherrateofNaC1hadanegativeeffectonthegrowthoftheK-efficientricegenotype,butdidnotfortheK-inefficientgenotype.Underlow-Kstress,higherNaC1decreasedIKUEoftheK-efficientricegenotypebutincreasedIKUEfortheK-inefficientgenotype.Attilleringstageandunderlow-Kstress,addingNaClincreasedKandNacontentsanddecreasedtheratioofK/Naforbothgenotypes.Atharvestingstageunderlow-Kstress,addingNaG1increasedKandNacontentsandK/NaratiofortheK-efficientgenotypebutdecreasedtheK/NaratiofortheK-inefficientgenotype.TheaccumulatedNawasmostlydepositedintherootsandsheaths.Attilleringstage,theKandNacontentsandtheK/Naratiosindifferentpartsforbothgenotypesdecreasedinthefollowingsequence:K+insheaths＞K+inblades＞K+inroots;Na+inroots＞Na+insheaths＞Na+inblades;andK/Nainsheaths》K/Nainroots.TheK-efficientgenotypehadalowerK/NaratioinrootsandsheathsthantheK-inefficientgenotypeunderlow-Kstress.Atharvestingstage,KandNacontentsingrainswerenotaffected,whereasK/NaratiointhericestrawswasincreasedfortheK-efficientgenotypebutdecreasedfortheK-inefficientgenotypebyNaaddition.However,thiswasnotthecaseunderKsufficientcondition.

简介：坚持说高大米让步并且改进化肥氮(N)使用效率的需要在基于叶的颜色管理化肥N造成了象叶颜色图表(LCC)和叶绿素米(SPAD米)那样的工具的使用。地实验在Ludhiana在2011～2013期间被进行，为基础N申请估计需要并且建立批评阀值的印度为在干燥直接种子的大米(DDSR)为化肥N的在里面季节管理提出策略由LCC和SPAD米测量了的叶新鲜珍视。在播种避免N的申请不利地没影响米饭谷物产量，显示在DDSR的基础N申请不是必要的并且可能导致减少的N使用效率。在DDSR的成长季节期间监视N举起率建议那N举起率在二个生长阶段达到顶点：最大的tillering(在播种以后的42～56天(DAS))和圆锥花序开始阶段(70～84DAS)。用佳肴肩下握颈过程，为化肥N申请的批评LCC和SPAD米价值锻炼身体分别地是4和37。实时化肥N管理策略基于使用30kgN哈−1每当SPAD米或LCC读物下面掉落了时，批评价值比在这个区域为化肥N由后面的综合建议观察了的坚持说最佳米饭与更高的N使用效率一起让步。改正时间可变剂量的策略由使用20kgN的规定剂量组成了哈在14DAS和30kgN的−1哈在28DAS和30，40或50kgN的校正剂量的−1哈在取决于LCC色泽是≥的49和70DAS的−14，4–3.5，或<3.5并且是≥的SPAD米读物40，40–35，或<35分别地。这策略也作为与综合建议相比与更高的N使用效率一起导致了最佳的米饭产量。这研究表明在DDSR，化肥N能比当前的综合建议用LCC和SPAD米的工具更高效地被管理。

简介：Theradialbasisfunction(RBF)emergedasavariantofartificialneuralnetwork.Generalizedregressionneuralnetwork(GRNN)isonetypeofRBF,anditsprincipaladvantagesarethatitcanquicklylearnandrapidlyconvergetotheoptimalregressionsurfacewithlargenumberofdatasets.Hyperspectralreffectance(350to2500nm)datawererecordedattwodifferentricesitesintwoexperimentfieldswithtwocultivars,threenitrogentreatmentsandoneplantdensity(45plantsm-2).Stepwisemultivariableregressionmodel(SMR)andRBFwereusedtocomparetheirpredictabilityfortheleafareaindex(LAI)andgreenleafchlorophylldensity(GLCD)ofricebasedonreffectance(R)anditsthreedifferenttransformations,thefirstderivativereffectance(D1),thesecondderivativereffectance(D2)andthelog-transformedre?ectance(LOG).GRNNbasedonD1wasthebestmodelforthepredictionofriceLAIandGLCD.TherelationshipsbetweendifferenttransformationsofreffectanceandriceparameterscouldbefurtherimprovedwhenRBFwasemployed.Owingtoitsstrongcapacityfornonlinearmappingandgoodrobustness,GRNNcouldmaximizethesensitivitytochlorophyllcontentusingD1.ItisconcludedthatRBFmayprovideausefulexploratoryandpredictivetoolfortheestimationofricebiophysicalparameters.

简介：Soilqualityassessmenthasbeensuggestedasaneffectivetoolforevaluatingsustainabilityofsoilandcropmanagementpractices.Theobjectiveofthisstudywastodevelopasensitivesoilqualityindex(SQI)basedonbulkdensity(BD),water-holdingcapacity(WHC),water-stableaggregates(WSA),aggregatemeanweightdiameter(AMWD),totalorganicC(TOC)andCinputtoevaluatetheimportantrice-wheatcroppingsystemonanInceptisolinIndia.Along-termexperimenthasbeenconductedfor18yearsattheIndianCouncilofAgriculturalResearch-IndianInstituteofFarmingSystemsResearch,Modipuram,India.Thetreatmentsselectedforthisstudywerecomprisedofano-fertilizercontrolandN,PandKfertilizers(NPK)combinedwithZnandSfertilizers(NPK+Zn+S),farmyardmanure(NPK+FYM),greengramresidues(NPK+GR)andcerealresidues(NPK+CR),laidoutinarandomizedcompleteblockdesignwiththreereplications.SoilsampleswerecollectedandanalyzedforBD,WHC,WSAandTOC.Correlationanalysisrevealedthatbothriceandwheatyieldssigni?cantlyincreasedwiththeincreasesinAMWD,TOCandCinput,butdecreasedwiththeincreaseinBD.TheSQIvalueswerethengeneratedbasedonregressionanalysisofBD,WSA,AMWD,TOCandCinputwithriceandwheatyieldsforthe0–15and15–30cmsoillayers,respectively.RegressionanalysesbetweencropyieldsandSQIvaluesshowedaquadratictypeofrelationwiththecoeffcientofdetermination(R~2)varyingfrom0.78to0.89.Withregardtosoilsustainability,applyingcropresiduestobothriceandwheatcouldmaintainsoilqualityforalongerperiod,whereasthehighestyieldsofboththecropswererecordedintheNPK+Zn+Streatment.Theregressionequationsdevelopedinthisstudycouldbeusedtomonitorsoilqualityinasubhumidtropicalrice-wheatcroppingsystem.