简介：在联邦工业大学的校园在一个斜坡上发展了的溪谷的历史，Owerri，尼日利亚简短被讨论。土木工程学措施被采取割掉在上游的汇伶积，与推土机关上溪谷并且构造轮廓乐队划分在节的斜坡。区域的随后的农业开发没被完成它继续更新的溪谷形成的威胁试验性的域被建立在上2哈域试用隆起并且收割开发合适的方法完成溪谷开垦被安装的斜坡处理。为在研究遇到的领域和问题的不同的节的选择收割模式被讨论。一些得出结论的评论和建议被做：1)水文学2)植物保护3)在联邦工业大学的农学，Owerri尼日利亚。

简介：TneglobalchangeofclimateanditsinfluenceonthecroppingsysteminChinahavebeeninvestigatedinthispaper.ItisfoundthatthetemperaturewasincreasedduringthelastdecadeandtheprecipitationdecreasedinnorthernChinaandincreasedinsouthernChinaduringthelast30years.Thesealevelhasbeenrisingbyabout21—26cminthecoastalareassouthof30°NinChinaduringthelast100years.Themostofresultsassimulatedbythegeneralcirculationmodels（GCMs）showthatthetemperatureincreasewouldamounttoabout2°—4°CinthemostpartsofChinaandprecipitationandsoilmoisturemightbedecreasedinnorthernChinaandincreasedinsourthernChinaduetodoublingofcarbondioxide（CO2）.TheeffectsofdoubledCO2ongrowthperiodandclimaticyieldcapabilityinChinahavebeenestimatedroughly.ItisshownthattheregionsofthegrowthperiodinChinawouldbemovednorthwardaboutfivedegreeslatitudeandtheclimaticyieldcapabilitymightbeincreasedbyabout10％inthemostpartsofChina.

简介：Basedontheanalysesonamplitudesofhistoricalvariationoftemperatureandprecipitationinthepast500yearsandlatest100years,accordingtotheregionalclimatechangescenariosforChinaestimatedbycompositeGCM,thepotentialimpactsofclimatechangeoncroppingsystemsinChinainfuturearesimulatedandassessedusingthecroppingsystemmodeldevelopmentspeciallyfortheChinesecroppingpatterns.Itisshownthatundertheprojectedfutureclimatechangeby2050themostpartsofthepresentdoublecroppingareawouldbereplacedbythedifferenttriplecroppingpatternswhilethecurrentdoublecroppingareawouldshifttowardsthecentralpartofthepresentsinglecroppingarea.Moreexplicitly,thenorthernboundaryoftriplecroppingareawouldshiftfromitscurrentborderattheChangjingRivertotheHuangheRiver,ashiftofmorethan5degreesoflatitude.Andtheshiftofmultiplecroppingareasleadstoasignificantdecreaseofsinglecroppingarea.Furthermore,consideringthechangesmentionedaboveincombinationwiththelikelynegativebalanceofprecipitationandevapotranspirationand,therefore,increaseofmoisturestress(i.e.lesswateravailability),aswellasthepossibleincreaseofheatstressdisasteranddecreaseofLGS(lengthofgrowingseason),thepotentialimplicationofclimatechangeforagricultureinChinaarealsoanalyzedroughlyinthispaper.Asaresult,however,itisstillverydifficulttoreachaspecificconclusionthatthefutureclimatechangewillhefavorableorunfavorabletofarminChinabecauseofthecomplicatedChinesefarmingpatterns,thecomplex-varioussocialandeconomicenvironmentofagriculturaldevelopmentand,especially,agreatscientificuncertaintiesintheinvestigation/predictionofclimatechange.

简介：在农业系统的生物物理、社会经济的属性的差异特别地做他们基于的壁龛。农民们是本地生物物理、社会经济的状况的专家并且能在开发agro环境的开发的实用指示物作出贡献。在在云南的一个农业研究工程的评估期间，中国，本地农民能够在存在收割系统上评估修改技术的效果并且用他们的自己的指示物讨论了他们的态度到干预。农民的反应能被组织进七个主要方面：我)收入上的效果，ii)生产资源上的效果，iii)庄稼管理上的效果，iv)技术的存在本地知识，v)输入的可获得性，vi)信息的存取，和vii)耕作家庭的社会经济的条件。农民们断定在与邻近的未经治疗的集水相比的试验性的集水的环境条件以土壤更好并且浇损失，植被盖子和天赋资源，基础结构和集水管理，environmentally友好的技术的使用，和庄稼生产率。在土壤和水保存计划的成功取决于农民和另外的本地用户和他们的更大的参与帮助的努力识别更实用的指示物。而且，它增加计划的所有权，与工程科学家，增加农民agro环境的问题的了解和他们的可能的后果一起提高相互作用。这些发展将使科学家能开发更好指向的干预并且由本地社区增加测试技术的采纳的可能性。配对的邻近的集水的使用改进了评估活动并且为未来集水改进计划作为好实践被建议。

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：为了减少沥滤的硝酸盐，在土豆(茄属tuberosumL.)以后冒险收获并且改进氮化肥使用效率，一棵土豆卷心菜两倍收割系统(DCS)在Hetao被建立，诺思中国，有灌溉土地的一个干旱区域。一个二年的地实验证明在塑料林地覆盖物下面种早成熟的土豆栽培变种弄短它由14d的生长时期并且允许卷心菜的第二庄稼清除土壤剩余NO3S-N到160厘米的深度，实质地减少硝酸盐沥滤进地下水的风险。在DCS的每年全部的N举起在常规收割系统(CCS)是多于那的大约110kgha1，即，种的单音的土豆。这说明了明显的氮恢复(ANR)在DCS的16.90%26.57%的改进作为与那相比在为两年的CCS。作为结果，在在DCS的0160厘米土壤侧面的土壤剩余NO3-N在CCS是比那低的。太阳的精力使用效率和土壤使用效率实质地也与DCS被增加。

简介：一个壶实验被执行在在栽培变种，超级米饭变化Ningjing1和传统的变化Zhendao11，它当前是商业地在南京使用了的二米饭之间的植物生产率和CH4排放学习差别，中国。CH4排放流动和土壤答案CH4内容的类似的季节的变化在测试栽培变种之间被发现。尽管在在栽培变种之间的植物生物资源生产没有重要差别，Ningjing1的谷物收益在35.0%是显著地更高的(P<0.05)与比Zhendao11，而从Ningjing1的全部的CH4排放是，35.2%降低(P<0.05)。在在栽培变种之间的CH4排放的数量的主要差别从tillering阶段发生在时期到出发阶段。可伸缩生物资源、可伸缩收益的CH4排出物是分别地为Ningjing1的3.8和5.2mg/g，显著地为Zhendao11比那些降低(7.4和12.8mg/g，分别地)。根据在植物生长特征和CH4排放之间的关系，一个更强壮的根系统主要作出贡献到Ningjing1的更低的CH4排放，作为与Zhendao11相比。我们的结果证明超级米饭不仅在谷物生产率而且在CH4排放缓解有优点。收割的超级米饭的进一步的扩大将在中国提高米饭收益和还原剂温室气体排放。

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.

简介：Soilmicrobialbiomassandcommunitystructuresarecommonlyusedasindicatorsforsoilqualityandfertility.Ainvestigationwasperformedtostudytheeffectsoflong-termnaturalrestoration,cropping,andbarefallowmanagementsonthesoilmicrobialbiomassandbacterialcommunitystructuresindepthsof0–10,20–30,and40–50cminablacksoil(Mollisol).Microbialbiomasswasestimatedfromchloroformfumigation-extraction,andbacterialcommunitystructuresweredeterminedbyanalysisof16SrDNAusingpolymerasechainreaction-denaturinggradientgelelectrophoresis(PCR-DGGE).Experimentalresultsshowedthatmicrobialbiomasssignificantlydeclinedwithsoildepthinthemanagementsofrestorationandcropping,butnotinthebarefallow.DGGEprofilesindicatedthatthebandnumberintop0–10cmsoilswaslessthanthatindepthof20–30or40–50cm.Thesesuggestedthatthemicrobialpopulationwashighbutthebacterialcommunitystructurewassimpleinthetopsoil.ClusterandprinciplecomponentanalysisbasedonDGGEbandingpatternsshowedthatthebacterialcommunitystructurewasa?ectedbysoildepthmoreprimarilythanbymanagements,andthesuccessionofbacterialcommunityasincreaseofsoildepthhasasimilartendencyinthethreemanagements.FourteenpredominatingDGGEbandswereexcisedandsequenced,inwhich6bandswereidentifiedasthetaxaofVerrucomicrobia,2bandsasActinobacteria,2bandsasα-Proteobacteria,andtheother4bandsasδ-Proteobacteria,Acidobacteria,Nitrospira,andunclassifiedbacteria.Inaddition,thesequencesof11DGGEbandswerecloselyrelatedtounculturedbacteria.Thus,thebacterialcommunitystructureinblacksoilwasstable,andthepredominatingbacterialgroupswereuncultured.