简介：AleachingexperimentwasCarriedoutwithrepackedsoilcolumnsinlaboratorytostudytheleachingprocessofaredsoilderivedfromsandstoneasaffectedbyvariousfertilizationpractices.ThetreatmentswereCK(asacontrol),CaCO3,CaSO4,MgCO3,Ca(H2PO4)2,Urea,KCl,Multiple(amixtureoftheabovementionedfertilizers)andKNO3,Thefertilizerswereaddedtothebaresurfaceofthesoilcolumns,andthenthecolumnswereleachedwith120mLdeionizedwaterdailythroughperstalticpumpsoveraperiodof92days,Attheendofleachingprocess,soilsweresampledfromdifferentdepthsofthesoilprofiles,i.o.,of92days,Attheendofleachingprocess,soilsweresampledfromdifferentdepthsofthesoilprofiles,I.e.0-5cm,5-10cm,10-20cm,20-40cm,and40-60cm,TheresultsshowedwhenapplyingCa,Mg,andKtothebaresurfaceofthesoilcolumns,exchangeableCa^2+,Mg^2+,andK^+intheupperlayerofthesoilprofileincreasedcorrespondingly,withanextentdependingmainlyontheapplicationratesofCa,Mg,andKandshowingadownwardtrend,CaCO3,CaSO4,MgCO3,andCa(H2PO4)2treatmentshadscarcelyandeffectonmovementofexchangeableK^+,whileCaCO3,andCaSO4treatmentssingnificantlypromotedthedownwardmovementofexchangealbleMg^2+althoughthesetwotreatmentshadnoobviouseffectonleachinglossesofMg,ThefactthatunderUreatreatment,exchangeableCa^2+andMg^2+,werehigherascomparedtoCKtreatmentshowedureacouldpreventleachingofexchangeableCa^2+andMg^2+,theobviousdownwardmovementofexchangeableCa^2+andMg^2+wasnoticedinKCltreatment,InMultipletreatment,thedownwardmovementofexchangeableCa^2+andMg^2+wasevident,whilethatofK^+waslessevident,ApplicationofKNO3stronglypromotedthedownwardmovementofexchangeableCa^2+andMg^2+inthesoilprofile.

简介：Afieldexperiment,involvinglimeN(calciumcyanamide,CaCN2)fertilizationasacontrolmeasure,wasconductedtostudyenvironmentalproblemsinducedbylong-termheavyNapplicationinJapaneseteafields.Long-termteacultivationcausedserioussoilacidification.Seventy-sevenpercentofthe70teafieldsinvestigatedhadsoilpHvaluesbelow4.0,and9%below3.0,withthelowestvalueof2.7.Moreover,excessNapplicationinteafieldsputathreattoplantgrowth,inducedseriousnitratecontaminationtolocalwater,andcausedhighnitrousoxideloss.ComparedwiththeconventionalhighNapplicationtreatment(1100kgNha-1)withoutlimeN,thelowNapplication(400kgNha-1)withcalciumcyanamideeffectivelystoppedsoilacidificationaswellasachievedthesameorslightlyhigherlevelsinteayieldandintotalNandaminoacidcontentsofteashoots.Theapplicationofcalciumcyanamidecouldbeasuitablefertilizationforthepreventionofenvironmentalproblemsinteacultivation.

简介：同时的多元素抽取全球一直在增加改进测试质量和效率的土壤实验室。这研究寻求了为可得到的土壤的同时的抽取调查Mehlich-1，Mehlich-3，和树脂方法的适用性象为庄稼在滋养的建议上使用变换方程的效果一样的P，K，Ca，和Mg。表层土(0–；20厘米)样品从与大量化学、物理、矿物学的性质在南部的巴西为庄稼生产使用的最代表性的土壤类型被拿。土壤P，K，Ca，和Mg同时用1.0摩尔L−被提取；1KCl，Mehlich-1和Mehlich-3答案，和膜树脂。平均，与Mehlich-1方法提取的P的数量是50%比与树脂和Mehlich-3方法提取的那些低。然而，树脂方法提取了K，Ca，和Mg的最低数量。变换方程的使用是合适的，它没否定地为在南部的巴西的土壤上种的庄稼影响K建议。