Theidentificationofcropswhichweredominantlyintramarginalordominantlymarginalisnotdifficult.Betweentheseextremes,however,thereexistanumberofcropswhichwearenotabletoidentify,intermsofposition,withtheavailableinformation.Ingeneral,riceandmoncropsareintramarginal."Common"cropsarethosewhichhavebeenmonlygrownunderafree-market.[1]Ifwearetosingleoutoneoftheseasclearlyintramarginalforourpresentdiscussion,riceistheobviouschoice.Threereasonscanbeoffered.First,mosttenantfarmshadgrownricebeforethesharerestriction.[2]Thehighfrequencyoftenancyinpaddyanduplandricefieldsisevident.Second,inTaiwanriceplantationscouldbesingleordoublecropping,butitwasphysicallyimpossibletorotatethreecropsofriceinoneyearoverthesameacreofland.Thismeansthatforricecropstheflexibilityofadjustmentthroughincreasingtherateofplantingwasratherlimited.[3]Andthird,ricecropyield,foruplandriceinparticular,ishighlyresponsivetoincreasingthedensityofplanting.Withbetterfertilizersandirrigation,theyieldpercropareamightwelldouble.[4]
IncreasingRiceCropArea
Asisseenintable3,using1948asthebaseyear,thecropareaofricehadincreased9.9percentby1951.Theincreaseforpaddyriceamountedto9.5percent,paredwitha16.5percentincreaseforuplandrice.[5]Thereasonforthedifferenceisthat,forpaddyrice,doublecroppinghadbeenmoremonbeforethesharerestriction,andtheopportunityforaddingadditionalcropswasmorelimited.[6]Forricecropsingeneral,thebestgrowingseasoninTaiwanrunsroughlyfromJulytoNovember.[7]Forsinglecropping,thereweremorefarmerschoosingtoplantthe"second"(JulytoNovember)cropthanthe"first"(MarchtoJuly),andthusthecropplantedfirstorearlierinthecalendaryearshouldbethemorefrequentcroptoaddifasingle-croppingfarmnowturnedtodoublecropping.Forpaddyrice,however,wefindthatthefirstandsecondcropsincreasedbythesamepercentageincroparea(9.5percentand9.4percent).Thereasonisthattheofficialcountingofthefirstandsecondcropisbasednotonthedateofplantingbutonthedateofharvesting(beforeorafterAugust15).[8]Forpaddyrice,thisdividinglinecutoffsomeoftheearlierplantedcropsandcountedthemas"second."Thesamedividinglinedidnotaffectthecountingofuplandrice,forthefirstcropofuplandricewasharvestedearlier.Thus,foruplandricewefinda44percentincreaseincropareaforthefirstcrop,paredwithonly3.9percentincreaseforthesecond.[9]
IncreasingRiceYieldperCropArea
Whereastheincreaseincropareaasaresultofincreasingtherateofcroprotationisadiscretionaryvariabledeterminedinthemarket,thechangeinyieldpercrophectareisdependentnotonlyonthedensityofplanting,butalsooncertainexogeneousvariablessuchasweatherandpests.Somejudgment,howeverarbitrary,mustbemadeastowhetheraparticularseasonisgood,bad,ornormal.Fortheperiodunderstudy(1948-51),letmepointoutthatinTaiwantherewasnomajoragriculturaldisasterofanykind.Thatis,intheannualreportsofagriculturallossesduetodrought,flood,andtyphoon,wedonotfindnotableannualdifferences.[10]Thus,theyearsunderstudymayberegardedas"normal"—orequally"abnormal"—andnaturewasnotasignificantfactoraffectingcropyields.
Comparedwith1948(thebaseyear),thericeyieldpercrophectarewashigherby9.3percentin1949,23.7percentin1950,and26.4percentin1951.[11]Therelativelysmallincreasein1949mighthavebeenduetothefactthattheenforcementofthesharerestrictionbeganinApril-Juneofthatyear.For1949,wewouldexpectthecrophectareyieldforthesecondcroptoincreasebymorethanthefirst,sincethesharerestrictionwasnotenforcedduringtheplantingofsomeofthefirstcrop.Thisisevidentinuplandrice,whereforthefirstcropwefinda10percentincrease,asparedtoa41percentincreaseforthesecond.[12]Theincreaseincrophectareyieldwasmoresignificantpercentagewiseforuplandricethanforpaddyrice.Thelower-gradesoilqualityofuplandfieldsapparentlyallowedagreatermarginofimprovementthroughincreasingtheinputdensityofplanting.Ofthe26.4percentincreasein1951over1948,forexample,paddyriceyieldincreasedby23.2percent,paredwitha76.5percentincreaseforuplandrice.[13]
Conclusions
Takingriceasanintramarginalcropdoesnotmeanthattherateofplanting(croparea)couldnotbeincreased.Extraricecropswereadded,andtheincreaseincropareawasgreatestinthefirstcropsofwhathadbeensingle-croppingfarms.Thegeneralincreaseinricecrophectareyieldwasdueto(a)thepredominanceofrice-growingintenantfarmsand(b)theresponseofriceyieldtotheincreaseinthedensityofplanting.
Wemeasuretheaggregateincreaseinannualriceyieldasequaltotheproductoftheindexnumberofcropareamultipliedbycropareayield.Using1948asthebaseyear,wefinda13.7percentincreasein1949,33percentin1950and38.9percentin1951.[14]Thesepercentageswereincreasesinoutputfromricecropsonly.Ifwewereabletoseparatericeoutputsoftenantfarmsfromthoseofownerfarms,theincreasesmightbegreaterfortenantfarmsthanindicated.[15]Atanyrate,underthesharerestrictionthelandowners'rentalinesfromlandwerepartlyrestoredbytheincreaseinannualriceyield.
Asisshownintable3,theincreasesincropareaforriceandmoncropsarelowerthanforspecialcropsandvegetables.
Amongothermoncrops,wefindthattheincreaseinyieldpercropareagenerallyislessthanforrice,andforafewmoncropsthereisnoincrease.[16]Butthemorecrucialtestofthehypothesisofincreasedfarmingintensityliesnotinriceandmoncrops,butincropswhichwereaddedatthemargin.