简介：FifteenuplandsoilscollectedfromthemajorarableareasinNOrthChinawereusedtoassesstheavailabilityofsoilsulfur(S)toplantsinapotexperiment.SoilswereextractedwithvariousreagentsandtheextractableSwasdeterminedusingturbidimetricmethodorinductivelycoupledplasmaatomicemissionspectrometry(ICP-AES),respectively.Inaddition,mineralizableorganicS,organicS,N/Sratio,sulfuravailabilityindex(SAI)andavailablesulfurcorrectionvalue(ASC)insoilswerealsodetermined.TheSamoutextractedby1.5gL^-1CaCl2wasnearlyequivalenttothatby0.25molL^-1KCl(40℃),andbothofthemwereslightlysmallerthanthatby0.01molL^-1Ca(H2PO4)2solution,asmeasuredbyturbidimetricmethodorICP-AES.TheextractableSmeasuredbyturbidimetricmethodwasconsistentlysmallerthanthatbyICP-AES.AllmethodstestedexceptthatfororganicSandN/SratioproducedsatisfactoyresultsintheregressionanalysesoftherelationshipsbetweentheamountsofSextractedandplantdrymatterweightandSuptakeinthepotexperiment,Ingeneral,0.01molL^-1Ca(H2PO4)2-extractedSdeterminedbyICP-AESorturbidimetricmethodand0.25molL^-1KCl(40℃)-extractedSdeterminedbyICP-AESappearedtobethebestindicatorsforevaluationofsoilavailableS.

简介：持续农业生产具有到食物供应安全的重要重要性。这研究试图在北方中国平原(NCP)并且随后在县规模调查庄稼收益反应到土壤质量的空间可变性导出关键土壤质量指示物。土壤样品从表面(020厘米)在2008引用geo、拿并且表面下(2040厘米)在整个Fengqiu县的132块地里的层，在NCP的中心定位了，为随后的土壤性质的分析。年度庄稼收益从土壤样品是镇定的一样的领域被获得。土壤质量与13个土壤性质基于一个模糊集合被评估，并且它的空间分布被集成geostatistical分析和地理信息系统(GIS)调查技术。土壤质量索引被分类进五个等级，并且他们的空间分布在县以内被印射。表面土壤质量比表面下的土壤高是大约一～二个等级。质量索引因为表面和表面下的土壤断然与年度庄稼收益被联系，建议两个的重要性。土壤有机物，全部的氮，可得到的P，和可得到的K贡献了50%联合重量到土壤质量索引并且以可持续性在区域作为土壤质量地位的关键指示物被识别。

简介：ThesoilsinSouthChinaseaIslands(SCSI)weredividedintothreetypes,nmaely,phospho-calcsoils,skeletisolsandcoasticsolonchake,whichwerederivedfrombio-clasticandstronglycalcareoussediments.Incomparisonwiththeirparentmaterials,thephospho-CalcsoilshavehighercontentsofP,ZnCu,Ba,andCd,whichtendtoincreasegraduallywithtime,andlowercontentsofMg,Ca,Sr,B,V,Pb,andMo,whichtendtodecreasebydegreeswithtime,Theabove-mentionedconstituentsinskeletisolsandcoasticsolonchaksaresimilartothoseintheirparentmaterialsexceptforPandNa,Thefactorsaffectingelementdistributionaremainlyspecialbioclimateandparentmaterial,meanwhile,resultingintheremakableinfluenceonelementdistributionthroughsoil-formingtime.

简介：Nitrogen(N)lossesfromammoniumbicarbonateorureaappliedtowheatandthenfollowedimmediatelybyirrigationwereinvestigated.Ammoniavolatilizationwasdeterminedbyamicrometeorologicalmethod(ammoniasampler),totalNlosswasestimatedbythe^15Nmassbalancemethod,anddenitrificationlosswasmeasuredbythediferencemethod(calculatedfromthedifferencebetweenthetotalNlossandammonialoss)andadirectmethod(measuringtheemissionof(N2+N2O)-^15N).Totalammonialossesfromammoniumbicarbonateandureain33dayswere8.7%and0.9%oftheappliednitrogen,respectively.ThecorrespondingtotalNlosseswere21.6%and29.5%,Apparentdenitrificationlosses(bythedifferencemethod)wereratherhigh,being12.9%fromammoniumbicarbonateand28.6%fromurea.However,noemissionof(N2+N2O)-^15Nwasdetectedusingthedirectmethod.

简介：polyolefin涂的脲的有效性(Meister-5和Meister-10；CU)在小麦(TriticumaestivumL.)玉米(ZeamaysL.)旋转系统在为收割季节的三连续maize-wheat-maize位于北方中国平原的溶度计阴谋被学习。一个同位素的方法被用来把CU的命运比作非涂的脲(NCU)的，并且N申请0，100，150和225kgNha−1评价被评估。结果证明CU的氮使用效率(15NUE)是比为第一庄稼的NCU的大的13.3%–21.4%。或者，当差别方法被使用时(明显的NUE)，没有重要变化在所有三个季节在处理之中被观察。尽管无机的N从1.3m层沥滤，不到1%总数被使用N，15N的未辩别出的损失(=15N作为化肥–15N使用了的15N的损失由留在0–0.2m层–15N的庄稼–15N吸收了从1.3m层沥滤)在对待CU的阴谋是24.2%–26.5%比那些低对待NCU的阴谋。在在实验的结束的CU阴谋的0–1.3m层的硝酸盐集中是53%比对待NCU的阴谋的低。因此，CU从化肥增加了庄稼N举起并且减少了应用N的未辩别出的损失，它能减少地下水污染的风险。

简介：Fieldexperimentswereconductedinamaize(ZeamaysL.)fieldofacalcareousfluvo-aquicsoilinNorthChinaPlainforstudyingthefateandammonialossofurea-Nappliedatseedlingstage,aswellastheeffectivenessofcoatedcalciumcarbide(CCC)inreducingNlossandinimprovingtheyieldefficiencyofurea.Resultsshowthat:(1)Forthesurface-broadcasttreatmentammoniavolatilization(measuredwithmicro-meteorologicaltechnique)tookplacequickly,reachedthepeak20-26hrafterapplication,andthendeclinedgradually;thecumulativeammonialossapproachedthemaximum188hrafterapplication(30%oftheNapplied),andincreasedonlyto32%284hrafterapplication;thelatteraccountedfor71%ofthetotalloss(45%ofappliedN).(2)Inthecaseofpointplacementatadepthof5-10cm,ammonialoss188hrafterapplicationwasonly12%oftheNapplied,accountingfor40%ofthetotalloss.(3)Therewasnodifferenceintotallossbetweentheapplicationdepthsof6cmand10cm,thelossofthemwas30%and29%,respectively.(4)TotallossofNappliedatlowerrate(40kgN/ha)withpointdeepplacementat6cmdepthwasfoundonly4%oftheNapplied,itroseupto30%whentherateofapplicationincreasedto80kgN/ha.(5)Thenitrificationinhibitor,CCC,seemedtoenhanceNlossofurearatherthanreduceit,anddidnotshowanybenefiteffectinimprovingtheyieldefficiencyofurea,whichispresumablyduetothehighpotentialofammoniavolatilizationinthesoilandclimaticconditionsunderinvestigation.

简介：MicrometeorologicalandmicroplotexperimentswereconductedinthefieldoffreshlyharvestedgreencaneinQueensland,Australia.ResultsshowedthathighammonialossoffertilizerNcouldoccurunderrelativelydryconditionswhenureaorcommercialproductofmixtureofureaandmuriateofpotashwereappliedtothesurfaceofsugarcanetrash.ThemoisturecontentinthetrashandthepHoffertilizerweretwoimportantfactorscontrollingtheprocessesofureahydrolysisandammoniavolatilization.MostoftheNinthesoilwastransformedtothenitratel-nitritefromafter70daysoffertilizerapplication.Nosignificantleachingwasfound.Urea-freeNfertilizershadhigherNrecoveriescomparedtourea-containingfertilizers.

简介：Acidsulfatesoils(ASS)containconsiderableamountsofreducedsulfurcompounds(mainlypyrite)whichproducesulfuricacidupontheiroxidation.ASS-derivedenvironmentaldegradationwidelyoccursinthecoastallowlandsaroundtheworld,especiallyinthetropicalandsubtropicalareas.ThepresenceofASSiuntheSouthChinahasbeenrecognizedbuttheirdistributionmaybelargelyunderestimatedbecausethesoilsurveydataconcerningASSarebasedonunreliablemethodsandtechniques.ASSintheSouthChinahavebeentraditionallyusedforricecultivationandthispracticehasbeenprovedsustainableifappropriateimprovementmeasuresareadopted.Recently,therapideconomicgrowthintheregionhasresultedinintensifiedcoastaldevelopmentwhichfrequentlyinvolvesactivitiesthatmaydisturbASS,Constructionofroads,foundationsandaquaculturepondsmaycausetheexposureofASStoairandbringaboutsevereenvironmentalacidificvation.Thereiscurrentlyinsufficientawarenessoftheproblemsamongtheresearchers,policy-makersandlandmanagersintheSouthChina.MoreattentionmustbepaidtothepossibleASS-dervivedenvironmentaldegradationinordertoensureasustainabledevelopmentofthecoastallowlandsintheSouthChinaregion.

简介：在农业土地支持土壤碳隐遁是可行策略之一速度观察气候变化。然而，玷污物理骚乱由加速侵蚀加重了土壤降级过程。因此，减少通过适当farming/agricultural系统的物理骚乱是的土壤的大小和紧张对农业陆地的土壤碳水池能力的管理必要。不同土地的四个地点使用类型/耕种惯例，我)到没有为止(NT)玉米(ZeamaysL.)(NTC)，ii)到为止常规(CT)玉米(CTC)，iii)pastureland(PL)，和iv)本国的森林(NF)，在北方Appalachian试验性的分水岭车站，包括水马厩聚集在土壤总数索引上估计NT耕作的影响的美国俄亥俄，吝啬的重量直径(MWD)和几何平均数被选择直径(GMD)，和土壤器官的碳和全部的氮内容。收到的NTC阴谋恐吓粪肥增加(大约15t哈1)每隔一年。CTC阴谋包含了耕作的disking和凿子和液体化肥申请(110L哈1)。结果证明水马厩聚集和MWD比为CTC在为NTC的土壤是更大的。在0-10厘米土壤层，>4.75公里尺寸部分统治了NTC并且而在不同地点之中的1)跟随了NF的趋势，为CTC多于那是46%>PL>NTC>CTC，为在CTC上的NTC更是35%-46%。NT实践提高了在CT实践上并且这样的器官的碳内容是的土壤在农田的碳隐遁的重要策略玷污。

简介：

简介：Bt玉米叶垃圾的化学作文上的基因修正的非计划中的效果可以在它的分解上有影响。在在南非的很农业的系统，玉米垃圾是任何一个留在土壤表面上或在耕种期间合并了到土壤。用三个玉米混血儿(DKC80-12B，DKC80-10和DKC6-125)的叶垃圾，一个litterbag实验在堡垒兔研究农场的大学被执行，南非，为了在玉米叶的分解上决定基因修正的效果，乱丢东西什么时候在在7月和11月之间的地条件下面留在土壤表面上，正常休闲时期，在2008。另一个litterbag实验在堡垒兔研究农场的大学被进行，使用南非遗传上与cry1Ab修改了的二个玉米混血儿的叶垃圾并且Zanyokwe灌溉计划，基因(MON810)，DKC75-15B和PAN6Q-308B，和他们的相应近的isolines，CRN3505和PAN6Q-121。在崽的Cry1Ab蛋白质的降级，适用表面、合并土壤，也被调查。当在表面上适用时并且当合并了到土壤时，Bt玉米垃圾的分解类似于non-Bt玉米垃圾的。合并土壤的垃圾，以及它的Cry1Ab蛋白质，比在表面上适用的快分解了。叶崽C:PAN6Q-308B和PAN6Q-121的N比率在整个学习是类似的，而那些在一个12星期的时期期间由类似的数量DKC75-15B和CRN3505衰退了。这些调查结果建议与MON810事件，Bt玉米的叶垃圾的那分解没被玉米影响基因修正，并且Cry1Ab蛋白质不管崽是否在土壤表面上被使用或合并了到土壤在冬季休闲期间和植物叶垃圾垮掉。