ujert-1-4-14_3

8/13/2019 ujert-1-4-14_3

1/8

Universal Journal of Environmental Research and TechnologyAll Rights Reserved Euresian Publications 2011 e !!" 22#$ 02%&Available 'nline at( )))*environmental+ournal*org,olume 1- ssue #( %.1/%.

Open Access Research Article

531Rohitashw Kumar et al.

Development of Crop Coefficients for Precise Estimation of Evapotranspiration forMustard in Mid Hill Zone- India

Rohitashw umar ! " #i$a% &han'ar ( and Mahesh umar )

1

Ph* * Research !cholar- e artment of 3ivil Engineering- " T- 4amir ur 54P6- ndia2 e artment of 3ivil Engineering- " T- 4amir ur 54P6- ndia. e artment of 3ivil Engineering- 78 University- "oida- ndia

Correspondin* author+ rohituhf,rediffmail com

A.stract+Precise estimation of evapotranspiration o.tained .% multipl%in* crop coefficient to referenceevapotranspiration usin* readil% availa.le climatic data Penman-Monteith e/uation is adopted world wide asthe most relia.le and accurate method for computin* reference evapotranspiration 0he 1ood and A*ricultureOr*ani2ation 31AO4 presented crop coefficient for estimation of evapotranspiration of different crops .ased onPenman-Monteith e/uation 0he crop coefficient curves can .e developed .% plottin* the ratios of cropevapotranspiration and reference evapotranspiration with respect to time 0he crop coefficient curves were

developed for mustard 3 Brassica juncea 4 .% 1AO-56 curve method and modified 1AO-56 curve method 0he 1AO-56 curve method underestimates mustard evapotranspiration .% !6 78 per cent 0herefore" 1AO-56 curvemethod does not appear to predict mustard evapotranspiration accuratel% 0he modified 1AO-56 curve methodunderestimates mustard evapotranspiration onl% .% 7 )) per cent 0herefore" performance of modified 1AO-56curve method was found .etter than 1AO-56 curve method for estimation of mustard evapotranspiration

e%word ( 3ro eva otans iration- cro coefficient- reference ev otrans iration- and 9A' curve *

! 8 Introduction+!ustainable food roduction )ill de end on the

+udicious use of )ater resources- to meet futurefood demands and gro)ing com etition for clean)ater- a more effective use of )ater in both

irrigated and rainfed agriculture )ill be essential*:ater use for cro roduction is de ending on theinteraction of climatic arameters that determinecro eva otrans iration and )ater su ly from rain*The com ilation- rocessing and analysis ofmeteorological information for cro )ater use andcro roduction )ill therefore constitute a ;eyelement in develo ing strategies to o timi

8/13/2019 ujert-1-4-14_3

2/8

Universal Journal of Environmental Research and Technology

a maCimum intensity ofeva otrans iration from alarge surface covered com letely andhomogeneously )ith actively gro)ing lants underconditions of unlimited availability of soil )ater* Theactual eva otrans iration is the amount of )atertrans ired from lants and eva orated from soilsurface under actual meteorological conditions andunder non/o timal soil- biological- management andenvironmental conditions* According to Allen et al*51$$ 6 the eva otrans iration from cro s gro)nunder management and environmental conditionsthat differ from the standard conditions defined forthe otential eva otrans iration can be called thecro eva otrans iration under nonstandardconditions* The eva otrans iration from a referencesurface is called the reference eva otrans irationand is denoted as ETo* Reference eva otrans iration5ETo6 is an im ortant agrometeorological arameter

for climatological and hydrological studies- as )ell asfor irrigation lanning and management* There areseveral methods to estimate ETo* The 9A' Penman/Bonteith 59A' P/B6 method has been considered asa universal standard to estimate ETo 5Allen et al*-1$ $- 1$$#- 1$$ 6* About $0 of )ater used inagriculture is lost by cro s as eva otrans iration5ET6* 3ro coefficient can be im roved for estimatingthe effects of eva oration from )et soil on =c on adaily basis 5:right- 1$ 26*

n Bay 1$$0- the 9ood and Agricultural 'rgani0 sm/1 and an albedoof 0*2.- closely resembling the eva oration from aneCtensive surface of green grass of uniform height-actively gro)ing and ade?uately )atered 5Allen etal*- 1$$ 6* The method overcomes the shortcomingsof the 9A'/2# Penman method 5 oorenbos andPruitt- 1$>>6 and rovides values that are moreconsistent )ith actual cro )ater use data)orld)ide* The 9A'/%& 5 rrigation and rainage6 onF3ro Eva otrans iration- guidelines for com utingcro )ater re?uirementsG- by Allen et al*- 51$$ 6 in)hich cro coefficients are resented for estimationof eva otrans iration of different cro s based on

Penman/Bonteith e?uation* The cro coefficientcurves can be develo ed by lotting the ratios ofcro eva otrans iration 5ETc6 and referenceeva otrans iration )ith res ect to time* The crocoefficient curves develo ed by the 9A' method aredesignated as 9A'/%& curve method* There is a needto evaluate 9A'/%& cro coefficients under differentclimatic conditions* The 9A' P/B method considersmany meteorological arameters related to theeva otrans iration rocess 5net radiation- airtem erature- va or ressure deficit- )ind s eed6and has resented very good results )hen

com ared to data from lysimeters o ulated )ithshort grass H$I found a good agreement bet)een thecalculated 9A' PB reference eva otrans irationand measured eva otrans iration in lysimeters*9A'suggested general trend of cro coefficient indifferent gro)th stages of the cro s 59igure 16*

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Time of Season (Days)

K c

InitialCropdevelopment

1i*ure !+ 1AO su**ested *eneral crop coefficient curve 3Allen et al " !9974

Mid-season Late-season

Kc, ini

Kc, mid

Kc, end Kc, development


8/13/2019 ujert-1-4-14_3

3/8


The ob+ective of this resent a er is to evaluate9A'/%& cro coefficients for mustard and tohighlight the develo ment of modified 9A'/%& crocoefficients for recise estimates of )heateva otrans iration under climatic conditions of midhill %0 hrs* Themustard cro gro)n on "ovember 1- 200$ andharvested on 9ebruary 2&- 2011- the rainfall atternduring cro season is sho)n in 9igure 2*

1i* (+ Precipitation at &olan for %ear (889-!8

0a.le !+ Detail of crop duration" *rowth sta*es and irri*ation da%s pertainin* to the crop *rown in the field

CropDate ofsowin*

Date ofHarvestin*

Duration3Da%s4

:rowth sta*es Irri*ation3Da% aftersowin*4

&pacin*I II III I#

Bustard 58rassica +uncea6

1*11*200$ 2&*02*2010 10> 1> .0 .% 2%11- 21- .#& and

#0C10

( nitial- ( evelo ment- ( Bid/!eason- , Nate season

oorenbos and Pruitt advanced the conce t ofreference eva otrans iration* The reference cro s)ere considered either alfalfa or alta fescue grass*Reference eva otrans iration is mainly influencedby climatic arameters* The resulting Penman/Bonteith e?uation re resents a basic generaldescri tion of the reference eva otrans iration asfollo)s(

)U0.34+(1+

)e-e(U273+T

900 +G)-R(0.408

=ET2

da2n

0

516)hereET0 O grass referenceeva otrans iration 5mm day /16Rn O net radiation 5BJ m /2 d /16O Rns /Rnl Rns O net short )ave radiation 5BJ m

/2 d /1 6


8/13/2019 ujert-1-4-14_3

4/8

8/13/2019 ujert-1-4-14_3

5/8


The values of = 3 end reflects cro and )atermanagement ractices* f the cro is irrigatedfre?uently until harvested fresh- the to soil remains)et and = 3 end value )ill be relatively high* 'n theother hand- cro s that are allo)ed to senesce anddry out in the field before harvest receive lessfre?uent irrigation or no irrigation at all during lateseason stage* 3onse?uently both the soil surface andvegetation are dry and the value for = 3 end )ill berelatively small* Bore arid climates and conditions ofgreater )ind s eed )ill have higher values for = 3 end *Bore humid climates and conditions of lo)er )inds eed )ill have lo)er values for = 3 end * 9or s ecificad+ustments in climates )here value of minimumrelative humidity differs from .> er cent or )hereU2 is larger or smaller than 2*0 m s

/1- =3 end values aredetermined from the follo)ing eC ression(

C end ; C end30A8 8?3@( -(4-8 88?3RH min -?543hB)48 ) 5%6)here

=3 end 5TA86 O tabulated value of = 3 end U2 O mean value of daily )ind s eed at 2

m height over grass during themid/season gro)th stage 5ms /16 for 1ms /1 U2 & ms

/1-R4 min O mean value of daily minimum

relative humidity during the mid/seasongro)th stage 5 er cent6 for 20

R4 min 0 h O mean lant height during the mid

season stage 5m6 for 0*1 m h 10m*

E?uation 5%6 is only a lied )hen the tabulatedvalues of = 3 end eCceeds 0*#%* Therefore- value of = 3end for mustard )as ta;en as 0*&& and 9A'recommended value is 0*&

Using values of = 3 ini- =3 mid and = 3 end the crocoefficient curve for mustard )as develo ed )hichis resented in 9igure .* A com arison is made

bet)een the cro eva otrans iration estimatedfrom the 9A'/%& curve method and measured croeva otrans iration by )eighing lysimeter* Therelationshi is lotted in 9igure #* t is sho)s thatthere eCists a linear relationshi bet)een croeva otrans iration estimated from the 9A'/%&curve method and measured croeva otrans iration by )eighing ty e lysimeter* Thecorrelation coefficient )as found to be 0*>> andstandard error )as found to be 0*>% mm day /1*4o)ever- 9A'/%& curve method underestimates ET B by 1&* 0 er cent* :ang u/Bin et al 520116

investigates missing data rocedure develo ed by

9A' and to verify its suitability under the climaticenvironment of Bala)i* The erformance of therocedure )as analysed by regressing EToestimated from the )orld )ide recommended 9A'enman Bonteith 59/P/B6 model )ith full data setversus 9/P/B value com uted )ith limited data*The coefficients of determination 5r 26- standarderrors of estimates 5!EE6 and estimates rates5Rate6 )ere used for evaluating the modelerformance in five roduction sites in Bala)iincluding =aronga- 3hited

8/13/2019 ujert-1-4-14_3

6/8


rainfall* These higher values may be neglected )hileconstructing cro coefficient curve* "eglecting thehigher values- the = 3B value for mid season stage)as found to be 1*2 * Boha)esh*-'*E*-520116investigate daily out uts from eighteva otrans iration models )ere tested againstreference eva otrans iration 5ETo6 data com utedby 9A'/%& P/B to assess the accuracy of each modelin estimating ETo* Bodels )ere com ared at eightstations across Jordan* Results sho) that 4argreavesmodified models )ere the best in light of meanbiased error 5B8E6- root mean s?uare error 5RB!E6and mean absolute error 5BAE6*

The = 3B values reduce during the late season stage*The reduction is linear from the end of mid seasonstage to the end of maturity* The = 3 value at the endof late season stage )as found to be 0*&& * 8y

+oining the all stages the modified = 3B curve )as

constructed )hich is sho)n in 9igure .* t is clearfrom 9igures . and & that in the initial and midseason stages the values of = 3B are higher inmodified 9A'/%& curve in com arison to 9A'/%&curve* This suggests that utili

8/13/2019 ujert-1-4-14_3

7/8


1i*ure ?+ Comparison of estimated wheat evapotranspiration .% 1AO-56 curve 3E0 M14 and measured wheatevapotranspiration 3E0 M4

? 8 Conclusion+The rocess of cro coefficient evelo ment

5calibration6 is de ends on referenceeva otrans iration model used for com utation ofcro eva otrans iration* 9A' recommended stage)ise cro coefficients for mustard are used tocalibration of cro coefficient* The follo)ingconclusions are dra)n from the resent study(16 The cro coefficient curves )ere develo ed for

mustard cro by 9A'/%& curve method andmodified 9A'/%& curve method* The 9A'/%&curve method underestimates mustardeva otrans iration by 1&* 0 er cent* Therefore-9A'/%& curve method does not a ear to redict

mustard eva otrans iration accurately*26 The modified 9A'/%& curve methodunderestimates mustard eva otrans iration onlyby *.. er cent* Therefore- erformance ofmodified 9A'/%& curve method )as found betterthan 9A'/%& curve method for estimation ofmustard eva otrans iration*

.6 ifferent reference eva otrans iration modelsresult in redicting different cro )aterre?uirement- )hen used in combination )ithliterature based or locally calibrated crocoefficients* This ostulates the influence ofreference eva otrans iration model on crocoefficient calibration*

5 8 Ac'nowled*ements+ Authors are highly than;s to r R* = utta- Prof D

4ead- e artment 3ivil Engineering- " T- 4amir urfor roviding all facility in the e artment toconduct the study- r* =*! ,erma-- Prof D 4ead-e artment- Envoirmnetal !ciences and r *P!harma - Prof D 4ead- e artment of !oil !cienceand :ater Banagement- U49- "auni !olan- 4Pfor roviding meteorological data- laboratory andother facilities*

References+ 16 Allen- R* 7*- Pereira- N* !*- Raes- *- and !mith-

B*51$$ 6( 3ro eva otrans irationQ 7uidelinesfor 3om uting 3ro :ater Re?uirements*rrigation and rainage Pa er "o* %&- 9A'-Rome- taly*

26 Allen- R*7*- !mith- B*- Pruitt- :*'*- Pereira-N*!*51$$&6( Bodification of the 9A' crocoefficient a roach- n( 3am - 3*R*- !adler- E*J*-oder- R*E* 5Eds*6- Eva otrans iration andrrigation !cheduling* Proceedings of thenternational 3onference- "ovember .Q&- !anAntonio- T - * 12#Q1.2*

.6 8rutsaert- :*51$ 26( Eva oration into theatmos here( theory- history and a lications-

ordrecht- 4olland*

ET MF = 0.627 ET W r = 0.77 SE = 0.75 mm/day ET MF = 3.41 mm/dayET GM = 4.11 mm/dayN = 107

0.0

2.0

4.0

6.0

8.0

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

ETM mm/day

ET MF

mm/day


8/13/2019 ujert-1-4-14_3

8/8


#6 3elia- B*A*- 8ouloutas- E*T*- and arba-R*N*51$$06( A general mass conservativenumerical solution for the unsaturated flo)e?uation* :ater Resources Research- ,ol* 2&-1# ./1#$&*

%6 3hie)- 9*4*!*- =amaladassa-"*"*- Balano- 4*B*-4*B*- and BcBahon-T*A* 51$$%6( Penman/Bonteith- 9A'/2# reference croeva otrans iration and class/A an data inAustrelia *Agric* :ater Banage-2 516-$/21*

&6 oorenbos J*- :*'* Pruitt- 1$>%- 7uidelines forredicting cro )ater re?uirements- rrigationand rainage Pa er no* 2#- 9A'/'"U- Rome-taly* 1& *

>6 oorenbos J*- Pruitt- :*'* 51$>>6( 7uidelines forredicting cro )ater re?uirements- 9A'/'"U-Rome- rrigation and rainage Pa er no* 2#5rev*6- 1## *

6 9eddes- R*A*- =ot)ali;- P*J*- and aradny- 4*51$> 6( !imulation of field )ater use and croyield* 3entre for Agricultural Publishing andocumentation- :ageningen- The "etherlands*

$6 7avilan P- Norite- * J*- Tornero- !*- 8erengena- J*5200&6( Reginonal calibration of 4argreavese?uation for estimation of reference ET in asemiarid environment* Agric* :ater Banage*-1( 2%>/2 1*

106 4argreaves- 7*4*- and !amani- *A*51$ 26(*Estimating otential eva otrans iration* Tech*"ote- J* rrig* and rain* Engg*- 10 5.6- 22%/2.0*

116 Boha)esh- '*E* 520116( Evaluation ofeva otrans iration models for estimating dailyreference eva otrans iration in arid andsemiarid environments* J* of Plant soilenvironment- %>- 2011 5#6( 1#%Q1%2*

126 Bonteith- J*N* 51$&%6( Eva oration and theEnvironment* n( 7*E* 9ogg 5ed*6- The state andmovement of )ater in living organisms*3ambridge University Press* * 20%/2.#*

1.6 Penman- 4*N*51$# 6( "atural Eva oration from' en :ater- 8are !oil- and 7rass- Proc* R* !oc*Nondon- A1$.- * 11&/1#0*

1#6 Pereira- A*R*- !- "*A*,* 5200&6( PenmanQBonteithreference eva otrans iration ada ted toestimate irrigated tree trans iration AntonioRoberto* Agric* :ater Banage*- .( 1%./1&1*

1%6 Pereira- A*R*- Pruitt- :*'* 5200#6( Ada tation ofthe Thornth)aite scheme for estimating dailyreference eva otrans iration* Agric* :aterBanage*- &&( 2%1/2%>*

1&6 :ang- u/Bin- :illy- "*- Nenn-* *- AleCander-7*-- !eydou- T*- and Nian/Tsai-*520116(3om arative study on estimatingreference eva otrans iration under limited

climate data conditionin Bala)i* nternational

Journal of the Physical !ciences ,ol* &5$6- *22.$/22# - !!" 1$$2 / 1$%0

1>6 :right J*N*51$ 26( "e) eva otrans iration crocoefficients* J* rrigation and rainageEngg*- ,ol* 10 5 R 6(%>Q>#*


ujert-1-4-14_3

Documents