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ID:19381843
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页数:8页
时间:2018-10-01
《richards方程在描述包膜控释肥料氮素释放特征中运用》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、9期喻建刚等:Richards方程在描述包膜控释肥料氮素释放特征中的运用5Richards方程在描述包膜控释肥料氮素释放特征中的运用喻建刚,樊小林,李宁,刘芳(华南农业大学资源与环境学院肥料与平衡施肥研究室,广州510642)摘要:【目的】筛选适合于描述控释肥料氮素释放特征的数学模型,为以数学模型预测预报控释肥料供肥特征提供理论依据。【方法】运用Richards,Logistic和Bertalanffy方程拟合在(25±0.5)℃恒温条件下包膜控释肥料在静态水中的氮素累积释放曲线。【结果】结果表明Richards函数能较好地拟合不
2、同形状的氮素养分累积释放曲线,其拟合度优于通用的Bertalanffy和Logistic方程。3种方程中,Richards方程的特征参数更能精确地描述包膜控释肥料氮素释放特征,能反映出氮素养分最大释放速率出现的时间、累积释放曲线的形状等。【结论】Richards方程可用于拟合S型、抛物线型和双抛物线型3种类型的养分释放曲线;增加包膜厚度能降低控释肥料氮素养分在水中前期的溶出率,同时推迟最大养分释放速率出现的时间。关键词:Richards方程;包膜复合肥料(控释肥料);氮素释放;释放曲线特征ApplicationoftheRicha
3、rdsEquationtoDescribeNitrogenReleaseCharacteristicsfromControlledReleaseFertilizer(CRF)YUJian-gang,FANXiao-lin,LINing,LIUFang(ResearchLaboratoryofFertilizerScienceandBalancedFertilization,CollegeofNatureResourceandEnvironmentScience,SouthChinaAgriculturalUniversity,Gu
4、angzhou510642)Abstract:【ObjectiveandMethod】InordertoselectasuitableequationtodescribenitrogenreleaseandamathematicmodeltopredictnutrientreleasefromCRF,theRichards,BertalanffyandLogisticequationswereappliedtomodelnitrogenreleasefromcoatedNPKfertilizersascontrolledrelea
5、sefertilizerinstaticwaterunderaconstanttemperatureof(25±0.5)℃.【Result】TheresultshowedthattheRichardsequationwasappliedtodescribetheprecisenitrogenreleasecurveofadifferenttype.TheRichardsequationwassuperiortoBertalanffyandLogistic.Amongthethreeequations,thecharacterist
6、icsoftheRichardsequationexpressedthenitrogenreleaseproperty,thetimetothepointatwhichthemaximumamountreleasedperunittimeandtheshapeofthereleasecurveofthecoatedNPKfertilizer.【Conclusion】Insummary,theRichardsequationfitsmodelsofthreetypesofnutrientreleasecurves,including
7、thesigmoidpattern,parabolicpatternanddoubleparabolicpattern.InusingbothparametersdandtiinRichardsequation,onecaneasilyjudgemodelofnutrientsreleasecurve.IncreasingcoatingthicknesscoulddecreasenitrogenreleaseratefromCRFatearlyperiodofincubationanddelaythetimeformaximumr
8、eleaseofnutrientfromCRF.Keywords:Richardsequation;CoatedNPKfertilizer(CRF);Nitrogenrelease;Characteristicsofreleasecurve9期喻建
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