8/8/2019 FAQ on MOET
1/2
WhatisMinusOneElementTechnique(MOET)test?MOETisakindofbiologicaltestofdetermininganutrientor
multiplenutrientdeficienciesinsoilsandisbasedonthelawofminimum.Thelawofminimumstatesthatthelevelofplantproductioncanbenogreaterthanthatallowedbythemostlimitingoftheessentialplantgrowthfactors.
Thismeans,ifonecropnutrientismissingordeficient,plantgrowthwillbepoor,eveniftheotherelementsareabundant.
Thelawofminimumcanberepresentedbyabarrelwithstavesofunequallength,whereinthestavesrepresentthenutrients/elements.
Thewaterinsidethebarrelrepresentsthepotentialyieldwhilethewaterpouringoutrepresentsthelostyield.Whenthegrowthofindicatorplantsarebetterintheminusoneelementpots(especiallyintheZnorCu)thantheplantsinthecompletepotwhatdoesthisindicate?
Itislikelythatthelevelofthesaidelement(e.g.Zn)inthesoilisalreadyclosetotheleveloftoxicity,thuswhensuchelementisaddedinthecompletepot,itmayhavealreadyattainedtoxiclevel,whichresultsindepressedgrowthoftheplant.WhensuchsituationisobservedduringtheMOETtest,isitstillsafetoapplyzincsulfateinthefield?
ZincsulfateoranyotherformofzincSHOULDNOTbeappliedinthefieldbecauseitcouldleadtotoxicity,depressedgrowth,andlowyield.HowoftendoesonehavetoconducttheMOETtest?
Ideally,itshouldbedoneeveryseasonifthefarmercanaffordit.
ThefrequencyofconductingtheMOETtestdependsonthefollowingfourfactors:
1. Soiltype.
Ifthesoilissandy,frequentMOETtestshouldbeconducted,i.e.onceineverytwoseasons.
2. AmountandkindoffertilizerappliedaftertheinitialMOETtest.
IfthefarmerappliedheavydosesofPandKandsoilisclayeybutmicronutrientsarenotlimiting,thenMOETtestsmaybeconductedonceineveryfourseasons.
FrequentlyAskedQuestionsonMOET
RepresentationoftheLawofMinimum.Theamountofyieldisdependentonthemostdeficientnutrient.
Onecanneverachievethefullestpotentialyieldunlesstheproblemwithdeficientnutrientwillbeaddressed.
[NutrientManagement]
8/8/2019 FAQ on MOET
2/2
3. YieldlevelsproducedfollowingtheMOETtest.
Ifyieldsareconstantlyhigh(>4.0tons)evenduringwet
season,thenMOETtestshouldbeconductedonceineveryfourseasonsunlessthereisadecliningyieldtrendthatisnotcausedbyotherbioticfactors.Ifsuchisobserved,itisadvisabletoconductaMOETtest.
Contributors:Mr.GeorgeLucero,ICDAIMs.MariaAngelaMalihan,PhilRiceMr.DiegoG.Ramos,PhilRice
ReviewedbyWilfredoCollado
