Blank, Steven C

Jetter Dr, Karen M

Wick, Carl M. : C. M. Wick are Farm Advisors, Butte and Sutter-Yuba counties, respectively

Williams, John F. : J. F. Williams are Farm Advisors, Butte and Sutter-Yuba counties, respectively.

SacramentoValley rice harvest residue can be seen in foreground . With a ban on burning . . . Incorporating rice straw into soil may be - come disposal option for growers P Carl M . Wick o John F . Williams Steven C . Blank 0 KarenJetter Theoretically , rice straw can be used fore Californiaâ??srice growers have three The traditionalburning of rice many products , but today few marketsar methods for disposing of the straw andlds straw , after harvesting rice , is be - availableto use it . Therefore , as burning stubble residue remaining in their fie ing phased out in Californiaâ??sSac - phases out , Californiarice growersare after harvest:burn it , bury it or bale it . ramento Valley under a 1991 state likelyto find as their main alternativesoil Burning , the principal disposal method incorporation , utilizingcurrent farm law , and rice growers are faced for most of the industryâ??s 80 - year his - â?? implementsand , as necessary , new ones to tory , is efficient , effectiveand cheap , but with seeking other ways of dis - bury this high - volume , fibrouscrop resi - it is being phased out in the Sacramento posal . One option , incorporating due . Valley under the Rice Straw Burning Re - g rice straw into the soil , will require This articlecompares the costs of rice duction Act of 1991 ( AB1378 ) . Beginnin farmers to carefully evaluatethe strawincorporationwith burning . Only with a 10 % reduction in 1992 , rice straw000 . with field processing costs associated methods available to them , given burning will be banned by the year 2 I1 and / or disposal of straw are presented.n , A â?쳌 safeharbor â?쳌 clause allowsburning of their equipment holdings . In gen - Costs of harvestingand soil preparatio up to 25 % of the acreageafter the year i eral , growers will incur much for example , are not included.Oncecosts 2000 , if it can be demonstrated that dis - to incorporate rice higher costs have been explained , impacts of the vari - ease harbored in the rice straw is causing [ 4 straw , compared with burning it . ousmethods of soil incorporationare dis - crop loss . : I CALIFORNIA AGRICULTURE , VOLUME 47 , NUMBER 4 8 1 I I cussed , along with ideas onthe methods On asmuch as 70 % of Californiaâ??s rice University of California , Davis , California most viablefor farmers , economically and is produced in the same field acreage , rice 95616 . ) BudgetPlanner calculatescosts agronomically . year after year . Changingthiscontinuous based upon 1990standards setby the dif â?¬ i - production systempresents special AmericanSociety of AgriculturalEngi - Rice straw management cultiesfor farmersincorporatingstraw , neers . The practices described are based who must cover the cost of incorporation on observationsand ongoingresearchby Various choices exist amongthe three methods for disposingrice straw.Which with another wet - soil , short - season , high - is countyfarm advisorsin Northern volume , low - intensitycrop . Crop rotation , most advantageousdependson the time Californiaâ??s rice - growingregions.Sample costs given for labor , materials , equipment where it is economically attractive , offers of year disposal occurs , the weather , the more flexibility in strawmanagementthan condition of soil and straw , and equip - and contractservicesare based on 1992 does rice monocultureand may become ment availabilityand ownership.The figures.The range of options availableto more common . rice farmersmay not be applicableto ev - â?쳌 best â?쳌 approachwill depend on several ery farm situation.Assumptionsand data factors . The cost study used to determinethe costs per acre are Burning.Burning takes place in fall or Californiarice growersneed basicin - spring.In fall , the fuelusually carriesthe outlinedbelow . formationto estimatethe costs of strawin - Farm characteristics.In thisstudy , flamebetter , resultingin more complete cost comparisonswere based on a 400 - acre corporation.In if the â?? Results â?쳌 sectionthat burns . Stubbledoesnot burn completely six in - 1rice cropping rice farm that used a rice follows , estimates arepresented for the burn occursbefore a frost.In spring , corporationoptions to illustratethe range system and incorporatedrice strawin the is packed againstthe soil . Burning the fuel of costs . For each optionthe costs of using fall immediatelyafterharvest . takes more time and labor , and is often in - No other different combinationsof equipmentto This assumptionled to complete.It can be carried out by workers , crops were grown . results typical for the majority of rice performvarious tasks are presented . on foot or in vehicles , using a simple growersin To calculatethe cost of incorporating Northern California ; the cost hand - held torch . Torches may alsobe rice straw , many variableswere consid - basis was differentfor smallerversus mounted on wheels and pulled behind a if weed vehicle.Levees may be mowed , ered , includingthe time of incorporation large : farms . growth is tall and green , so that the flame Equipment . Table 1presents the costs ( springor fall ) , the equipmentlikely to be carriesover and consumesthe growth.In owned by per acre to completeeach operationneces - a rice farmer and information sary . It is assumedthat some equipmentis most counties , permits are required at a on how incorporationwould fit into a new and some small cost.Fire safetyequipment year - round farmingsystem . is usually is used to represent the farms . In esti - Costsper acre to operate different kept nearby . mixturefound on most rice mating equipment costs per acre , the fol - Removal.Straw removal can involve pieces of equipmentfor eachoption were lowing calculationswere made : raking loose straw , baling it in smallbales ( 1 ) Origi - calculatedwith â?쳌 BudgetPlanner , â?쳌 a com - and roadsidingthe bales , or customhiring nal cost of equipmentis the cost of the puter program designedby and available new equipmentplus sales tax . fromthe University of Californiaâ??s Coop - the entireoperation.For example , straw ( 2 ) Depre - 10 % salvage erativeExtensionService at Davis . ( Con - cut low from the combine and left in a ciationis straight - linewith a value . ( 3 ) Intereston investmentis calcu - tactDr . Karen Klonsky at 916 - 752 - 3563or windrowmay simplybe baled and lated as the averagevalue per acre of the at AgriculturalEcoomics Department , hauled . However , somegrowersmay choose to swaththe stubble , thus generat - ing more tonnage of baled strawbut at a higher total cost ( for removal and storage ) . More complexity in removalmethods will evolveas the bale format ( round , square , large or small , etc . ) is determinedby end use . In the future , strawremoval costs may be offset by revenuesreceived from sale of the straw.Possible uses of rice straw range frombeddingin horse stallsand chicken coopsto servingas an ingredientin bricks , wallboard and other building materials . Soil incorporation.Two major ap - mixingrice strawinto the soil proaches to are evolving.In the first , the strawis dry soil with conven - mixed into relatively tionalplows , discs and tillers . In the sec - ond , the strawis pressed and poked into wet soilusing specialized â?쳌 cagerollers . â?쳌 Althoughthey differ , these systems share commonmanagementprinciples.For ex - ample , fall incorporationisbetter than is avdable for springbecause more time strawto break down.Also , in eachsystem mixingof soil and strawis es - thorough sential , uniform spreadinghelps avoid fouling of tillage equipment and improves results , and choppingthe strawmakes other operationseasier and more effective . CALIFORNIA AGRICULTURE , JULYlAUGUST 1993 9 equipment ( thetotalvalue of equipment used dividedby the number of acres ) dur - ing its useful life , multiplied by a real in - terest rate of 4 % . ( 4 ) The actualhours used represent only thosehours devoted to rice strawincorporation.Allocationof costs , however , was based on the total number of hours the equipmentis used allyear . Labor.Basic hourly cost for farmma - chineoperators and fieldworkerswas cal - $ 7.46anhour . Adding 34 % for culatedat SocialSecurityinsuranceand otherben - efitsincreased the labor rates shown to $ 10 anhour for machine operatorsand field workers.Labor hours for operationsin - volving machinery are estimatedto be 10 % higher than machinehours to account for extra labor involvedin settingupeand equipment , moving it , maintenanc repair . Fuel and repair . The fueland repair cost per acre for each operationwere de - terminedby multiplyingthe total hourly operating cost for eachpiece of equipment by the number of hours per acrefor the operation.Prices for on - farmdelivery of diesel and gasolinewere 71 and 98 cents per gallon , respectively . ResuIts Growersare presentlyfield testingand evaluatingalternativestrawmanagement practices.In this section , estimatedcosts arethe fom , yet some of the long - term agronomicimpacts of straw incorporation may partially offset these costs , as ex - plained in the last section of thisarticle . Sample rice straw disposal costs . Table 2 presentstotal ( fixedand variable ) cost estimatesfor the three differentmeth - ods availableto farmersto dispose of rice straw.In the first method , the strawis in - corporatedinto the soil ; table 2 shows sixe optionsfor incorporatingrice straw.Th first four optionsare for use in dry fields ; the last two are for wet fields.The first col - umn presents each option and the equip - ment required to completeeachoperation . Each optionpresented is a completeand separateprocedure.For example , Option2 is to chopthe straw and discthe field ; Op - tion 3 is to chopthe straw , disc the field and then plow it . Cost per acre for Option 3 includesthe costsper acre for Option2 plus the additional costs of plowing . Col - umns2 through 6 containthe costsper acre to completeeach operation.The final columnshowsthe total cost to complete each procedure . The total costs per acreto complete each operationarethe sum of all equip - ment ownership ahd operatingcosts ( table 1 , last column ) , exceptfor the costs of us - ing the combine - mountedchopper.Since the rice would be harvested and the straw chopped at the sametime , only the addi - tional costs of using the chopper arepre - 10 CALIFORNIA AGRICULTURE , VOLUME 47 , NUMBER 4 sented.The cost of the chopperwas calcu - lated by multiplyingthe total costsper hour to use the rice chopperby the num - ber of hoursneeded to harvest 1acre ( table1 , firstcolumn ) . To compare , for example , the cost of choppingrice straw using a combine - mounted chopperand discing it into the field with a stubblediscversus the cost of choppingthe strawusing a combine - mounted chopperand tillingit into the field with a Dyna Drive tiller , seeOption 2 - A - 1 and Option4 - A - 2 . Option 2 - A - 1 costs are $ 3.50 to chop the strawplus $ 8.54 to stubblediscthe field ; total cost per acre is $ 12.04 . Option4 - A - 2 costs are $ 3.50 to chopthe strawplus $ 15.18to tillthe field ; total cost per acre is $ 18.68 . To placeincorporationcosts into con - text , table 2 also shows the costs of rice burningand removal . The net costs of straw removal will be lower than reported here if a market for rice straw develops ; revenuesreceivedwould offset costs and could possibly generatea positive cash flowfor growers.Although some reports of rice straw sales havebeen circulated , it is prematureto judge whether a stable market will developand at what price lev - els . Cultural practices . In the firstincor - poration method the strawis chopped and left to decomposeon the ground.The straw can be choppedby a ricestraw chopperattachedto the rice combineso that harvestingand choppingcan occur at the same time or , after harvesting , theforage straw can be choppedwith a flailor chopper.In the case of the combine - mounted chopper , onlythe additional cost of the chopperis presented . The coststudy looksat incorporationin both dry and wet fields.Under dry field conditions , which ocm after harvestbut beforerains flood the field , there can still be residualmoisturein the soil.Wet field conditions exist when rain or irrigation water is standingin the field , and the only chopping of straw possibleoccurswhile the grain is harvested , becauseit is as - sumed that farmerstend to cut down on the amount of equipment they pull through flooded fields . The additional costs for field flooding after the strawhas been incorporatedhave not been includedfor two reasons : ( 1 ) Wa - ter costs in rice - growingareasvary consid - erably , froma low of $ 2.85per acre - footto a high of $ 75 per acre - foot , dependingon the district supplyingthe water and whether a farmeruses pumped water . ( 2 ) For an individual farmer , flooding costs are a constant additionalcost and are not - influencedby the incorporationor burn ing of rice straw.This study seeksto ex - aminethe variationsin costs to disposeofis rice straw only.However , field flooding CALIFORNIA AGRICULTURE , JULY - AUGUST 1993 11 an additionaloption tavail - e leads to a lower ( orhigher ) able to farmersto facilita yield per acre of rice in the rice straw decomposition . followingcrop season , com - In this study it is as - pared with the yield ex - sumed that custom harvest - pected had the strawbeen ers would be hired to re - bumed , the lost ( increased ) move strawfromthe field , if revenuesfromthat rice crop the third straw disposal must be added to ( sub - is chosen . This re - method tracted from ) the cost - per - flects the factsthat presently acre estimatereportedhere there are few optionsfor dis - for that procedure.There - posing of rice straw andstedin fore , after agronomiceffects farmershave not inve are considered , the net cost the specializedequipment for each incorporation needed for strawremoval . method could be higher or Costsfor removingrice lower than the estimate strawincludeswathing , rak - here ; however , untilall rel - is ing , baling and removingthe evant agronomicresearch bales from fields for road - completed , the exact costs of side pickup . particular incorporationpro - cedurescan onlybe esti - mated . Agronomic effects of incorporation Conclusions The four goals of rice This articlereportsthe strawincorporationareto costs associatedwith differ - ( 1 ) minimizenet costs , ( 2 ) ent methods of disposing of With few exceptions , ricestraw burningwill maximizedecomposition field residue , using rice be banned by the year 2000 . during winter , ( 3 ) minimize diseaserisk straw as a case study.Producers of other Photoby Bryan Jenkins and ( 4 ) avoid yield loss the following cropscan followthese procedures to per - growingseason.Each incorporationop - form their own analysis and / or use the tion can lead to differencesin agronomic discinga wet field is impossible.Also , the cost estimatespresentedhere . effects on net costs ; thus , it is not appropri - long - runagronomiceffects must be con - For rice growers , the decisionconcem - ate to assumethat more costly incorpora - sidered.As one grower explained , he did ing which soilincorporationmethod to tion optionsareinferior to less costly ap - not favor " wet " methodsbecause " mixing use depends on agronomicand economic proaches . It is possiblethat more costlyefi - straw and mud is the recipe for adobe considerations.h general , rice growersin - incorporationoptionshave moreben bricks " and he questionedthe effects on curmuch higher costs when incorporating cial agronomiceffects than less costly op - soil conditionover time . their straw , compared withburning it . tions and , therefore , may have a higher net Another criticalagronomicconsider - However , the U.S . AgriculturalStabiliza - profit . As shownin table 2 , incorporation ationis to choose a method for chopping tion and ConservationServicehas a pro - costs vary greatly , dependingon how the strawthat willresult in spreadingthe gram ( SpecialPractice 56 - Rice Residue rice strawis processed and the equipment straw as uniformlyas possible.One major Management ) offering $ 25 per acreto par - used . problem associatedwith rice strawincor - ticipatingfarmerswho do not bum their In this study , costs forrice strawincor - poration is that insufficientdecomposition straw.Thus , the short - termeffects on net go from a low of $ 3.50 per acre to poration of the strawbeforeplanting of the spring profitscanbe reduced for program partici - a high of $ 80.60 , dependingupon the crop can produce gases toxic to the plants pants . Also , the sigruficantdifferencesin amount of labar and equipmentused . and can causeproblemslater with nitro - cost per acre among specific methods of Costsforburning rice straw are about $ 3 gen use by the plants . strawincorporationshouldbe viewed as per acre . The cost to remove rice strawis Finally , decompositionis aided by ob - an incentivefor farmersto evaluate care - between $ 58 and $ 75per acre ( ignoring tainingasmuch contactbetweenthe straw fully the methods availableto them , given revenuesthat may be receivedfrom sales and the soil as possible.The more the field their equipmentholdings . of straw ) . ecisionconcerningthe is cultivatedin the fall , the greaterthe de - In the long term , growersmaybe able The d method to gree of straw decompositionthat will oc - to furtherreduce and possibly eliminateng use dependson agronomic , as well as eeco - - curby spring.However , as shownin table net residue disposalcosts by developi nomic , considerations.For example , in d 2 , the more a field is cultivated , the higher If rice straw , for marketsfor the residue . ciding whichimplementto use to incorpo - the costs . example , proves to have uses on or off the rate the straw , field and soilconditions Agronomicfactorshave economicef - farm , growerswill view the strawas a influencethe choice . Optionsinvolving fectsthat determinethe incorporation valuableby - product of rice production , discing , plowing and tilling shouldbe methods selected ; these , in turn , influence rather than as the source of additionalpro - used under dry field conditions ; options the season's total cultivationcosts . For ex - ductionexpenses . in wet involvingrolling should be used ample , research shows that when strawis fields.Therefore , while rollinga field with completelydecomposedin the soil , nitro - a cage roller is approximately $ 7.21per gen is released and this can result in lower S . C . Blank is Extension Economist and K . acre and discing the fieldwith a stubble fertilizer costs the followingspring . This Jetter is Research Assistant , Department of disc is approximately $ 12.04per acre , roll - type of effect is not included in the results Agricultural Economics , UC Davis ; C.M . dry will not effi - ing the fieldwhile it is presented in table 2 . Also , to the extent Wick and J . F . Williams are Farm Advisors , ciently incorporatethe straw.Conversely , Butte and Suffer - Yuba counties , respectively . that a particularincorporationprocedure i 12 CALIFORNIA AGRICULTURE , VOLUME 47 , NUMBER 4