PHOSPHORUS NUTRITION IN TWO NEBRASKAN WET MEADOW SOILS
[摘要] TwowetmeadowsoilsoftheLoupseriesintheNebraskaSandhillswereselectedforstudybecausevegetationgrowingonSoil1showedamarkedresponsetophosphatefertilizerwhereasthatonSoil2showedlittleornoresponsetophosphatefertilizer.Curvesforyieldsofdrymatterindicatedthatavailablephosphorus(Mitscherlichquot;bquot;value)wasmuchlowerinSoil1(10poundsphosphorusperacre)thaninSoil2(35poundsphosphorusormoreperacre).UsingP32-labelledtriplesuperphosphate,itwasshownthatduringthegrowingseasonof1955themeadowvegetationonSoil1derivedabouttwiceasmuchphosphorusfromfertilizerasfromthesoil,whilethevegetationonSoil2obtainedaboutequalquantitiesofphosphorusfromsoilandfertilizersources.ThegroundwaterfromSite2containedaboutthreetimesasmuchphosphorusasthatfromSite1(0.41 p.p.m.and0.12 p.p.m.P,respectively).AlaboratorystudyofthemineralizationofsoilorganicphosphorusindicatedthatinSoil2microbiologicalacti...
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[效力级别] [学科分类] 农业科学（综合）
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