長期施肥對(duì)水稻土土壤團(tuán)聚體穩(wěn)定性的影響.pdf

1、江西農(nóng)業(yè)大學(xué)碩士學(xué)位論文長期施肥對(duì)水稻土土壤團(tuán)聚體穩(wěn)定性的影響姓名：李江濤申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：土壤學(xué)指導(dǎo)教師：吳蔚東張斌2003.6.1碩士學(xué)位論文長期施肥對(duì)水稻土土壤團(tuán)聚體穩(wěn)定性的影響AbstractLongtermapplicationofchemicalfertilizersaffectssoilstructureformationandsoilaggregatestabilityThecompositionofsoilorg

2、anicmatterandtheirpropertiesareimportantfactorsinvolvedWehavetakensoilsamplesofsoilaggregatesofdifferentsizesfromtheApandPhorizonsofpaddysoilsinthelongtermfertilizationexperimentsattheRedSoilInstituteofliangxiProvinceThe

3、experimentsincludedofnofertilization(CK)，chemicalfertilization(NPK)，doubledosechemicalfertilization(NPK(2))andorganicandchemicalfertilization(NPKOM)Theobjectivesofthispaperare：1)todeterminetheeffectsoflongtermfertilizati

4、onODthewaterstabilityandmechanicalstabilityofsoilaggregates；2)todeterminetheeffectsoflongterrafertilizationontheorganiccarbonpoolsandwaterrepellencyofsoils；3)telatetheaggregatesstabilitytosoilorganiccarbonpoolsandwaterre

5、pellencyWiththeseresultsweexpectedtobeaerunderstandthemechanismsofimprovementofsoilaggregatestabilityasaffectedfertilizationforbetterpaddysoilmanagementThemainfindingsareasfollows：1Comparedwithsoilsbeforetheexperiments，s

6、oilorganiccarbonandtotalnitrogenareincreasedinalltreatmentsSoilbulkdensityincreasedandsoilporositydecreasedintheCKandNPKandNPK(=)treatmentsIncontrast，soilbulkdensitydecreasedandsoilporosityincreasedintheNPKOMtreatment2Ai

7、rentrapmentunderfastwettingtreatmentwasthekeyfragmentationmechanismofpaddysoilaggregatesascomparedtotheslakingunderslowwettingtreatmentandthemechanicalbreakdownunderthewetstirringtreatmentThefragmentationdegreeofsoilaggr

8、egateswaslargerthan90％underthefastwettingtreatmentsmallerthan165％undertheslowwettingtreatmentandwetstirringtreatment3Fertilizationgreatlyincreasedsoilaggregatesstabilityindexnormalizedmeanweightdiameter(NMwD)，ascomparedt

9、otheCKSoilaggregatesstabilityWassignificantlyhigherintheNPKOMtreatmentthanintheNPKandNPK(=)treatmentsThereisnosignificantdifferentbetweenNPKandNPK(=)treatments4Thetensilestrengthandpenetrationresistanceofsoilaggregatesdi

10、dnotchangeduetochemicalfertilizationascomparedtotheCKalthoughthesoilorganiccarbonincreasedinthefertilizationtreatmentsTheyremarkablydecreasedintheNPKOMtreatmentInadditionthetensilestrengthandpenetrationresistanceweresign