Characteristics of N and P Loss in the Soil of Purple Sloping Farmland at Different Fertilization Levels

Usingthe"WinterWheat-SummerMaize"modelandtheplotrunoffmonitoringmethod,westudiedthecharacteristicsofnitrogenandphosphoruslossinthesoilsedimentofpurpleslopingfarmlandunderfiveconditions,includingcontrol,combinedmanure/fertilizerapplication,chemicalfertilizer,highintensitychemicalfertilizer,andcrossridgefarming.Theresultsshowedthatthenutrientcontentofthesurfacesoilincreased,tosomeextent.Furthermore,thenutrientswereenrichedinthesedimentforallgroups.Thedegreeofsedimentnutrientenrichmentofcrossridgefarmingwaslessgreatcomparedtolongitudinalfarming.Forthecombinedmanure/fertilizerapplication,theratioofeffectivenutrientswaslargerthanthatoftotalnutrients;whereas,forthechemicalfertilizergroup,theratioofeffectivenutrientswassignificantlysmaller.Atallfertilizationlevels,sedimentlossonlyaccountedfor0.34%~6.21%.78.80%~84.83%ofthetotalphosphoruslossoccurredinthesediment,andthephosphoruslosswaslargelyinthesediment.Therelativelossfactorofnitrogenwasthelargestforthechemicalfertilizergroup,followedbythecrossridgefarminggroup,thehighintensitychemicalfertilizergroup,andthecombinedmanure/fertilizerapplicationgroup.Therelativelossfactorofphosphoruswasthelargestforthehighintensitychemicalfertilizergroup,followedbythecrossridgefarminggroup,thechemicalfertilizergroup,andthecombinedmanure/fertilizerapplicationgroup.