and forecasting

70 Pages·2014·5.49 MB·English

crop monitoring
and forecasting
FOOD AND ACIRICULTURE OROANUTlO#
FA0 PLANT PRODUCTI ON AND PROTECTION PAPER
agrometeorological
crop monitoring
and forecasting
bw
m. frbre and g.1. popov
plant production and protection dlvlslon
FOOD AND AORICULTURE ORGANIZATION OF THE UNITE D NATIONS
Rome 1970
T h . d m a q M b r r n n p l o y . d . n d t ) w ~
o f m r r ~ 6 n t M . ~ k n * n o r k n O I y t t u
empramdon at rcry aOkrian UI)UZIO.WI 011 th.
pm of th. Food md Agricu)hrm Orgmbtfm
ol the Unitod N c t h th. kgrl
etnw ot .ny country, tmttory, dty or woo u
d its euthodtkr, ar ccmamhg the d.&ncuni
ol lts fromkn oa bounbwi...
w-
Tha copVriOht In this bOOk iO vested in the Food UlCL Agdcdturo
nintmnoftheUnh.dN8tknr. Theboo&nuvnotkrwwodu;csd.mwhob
..................................................
INTRODUCTION... X
CHAPTER I: Importance of crop lorecarting bared on
........................
agrometeorological monltorin~ I
.....
CHAPTER 2: Summary of the methodr ured lor crop torecanting 4
CHAPTER 3: The crop forecastin8 method baaed on alro-
.................... .......
meteorological information 8
CHAPTER 4: Agronomic concepts of the phy,rically-daflnrd ......
growing searon.........,...............,..,..., 19
.............
CHAPTER 5: Revirw of applications and of experienca 21
CHAPTER 6: Organization of a crop monftorin~a nd
forecasting myatem bared on agramrtmorolog1cal
..........................................
information 32
..............................................
CONCLUSION........ 36
.......................................................
REFERENCES 37
ANNEX: A method for the practical appllcatlon of the
penman formula for the ertimation of potentlal
evapotranrplration and evaporation from
.....6. ............
free water surface.....,............ 38

After the drought whlch ntruck the countrirw In the Srh#l lan rrra
!ran lU7l to 1973 FA0 8nJ the World Food Progrrame undtrtnok r uyrt@aatlc~
41
nonltoring of ralnlrll durlng the growinn rarron that urea In irrdlr tcr
detect r t an early data any rnomrlier in the qurntlty rnd dtatributlon of
rainfall which might harmfully rffact crop@.
In 1Y7h the stmplt rrlnfrll aonltorin~b ared nn deprrturrr rron
"normal" rainfall evolved into rn rrrarrmrnt of the cumulntlvr water
balance of crope and r rhort note vra prlntad rnd wldrlv dlstrlhutrd
(Frere and Popov, 1976). Ar a rerult of thlr not* the Yllnt Produrtlan
and Protection Dtvlrlon recalvcd many requcrte from yovrrnaentr for Lhr
lntroductlon r t nrtional level sf the mothad drrl~nedb y the Crop t.coln~r
and Ltnet lc Reauurcer Unit (ACPE). Conrrquantly rprc If lr niarlonr went to
F-thlopla, Algrrtr. Tanzrnlr, Chrnr, Togo, Nigarlr rnd Wrirl rnd many uthrr
countrler, much re Brngladcrh, Indonarlr, V~nrruelra nd hudrn, have drmon-
#traced int@r*fit in this rgroaoteorologlcrl ctop moaitorlng and foreerrtinl
method.
The purport of thin publlratlon Ia to present the method fin It now
stands, together with roo@ reaultr obtrfnrd In r wide rrnfr,# af snvlron-
mtntn. The experience gained oo frr rlrardy allowr w laod aarrramant to
hc made of the uuefulncrr of the method in countrier uhrre vrtrr nvrll-
ability lo the main conrtraint for ctop production, li lr rlfin clear that
in many inetancen the rpplicrtlon of the method will fostar rhr collectfan
of sets of flood biolo~1crld rtr (yield and phanalogy) whlch, when Inter-
preted together with the rgrocllmrtolo~lcrld rtr, will permit the progrore-
ive ootablishment of fully qunntltrtlvr rodelr. Thr main advrntr~en l the
present method, hou~ver,f r that the work can be fnltlrtad tmmrdlatrly
bithout rophisticrted marnr, even if detailed qurntltntlvc ytrld drtr rrr
not readily rvrllrblc. .
IHP(~RIANEEo F CROP FORECAST lNC
BASLD 08 ACMOHEt~(JIIlI.OCICAL HCrNITORIMC
Tha cvuluthan of rrup prnductlon over the part 30 year8 hrn rhoyp
w ~ r l k i np~ra lrarr In nonc drvcloped countriar in the yitlde and rlro In
tbc llubvl produrtlnn, rlt,ht~ughL hlm lncrerrr hrr barn comprnrrted romeuhrt
by 8 raductiun of 1.tiltlvat~dr rsnr. The result of this progrrrn ir that
c(nrr01 pfOd~~tll)tnn drvrloyrd rountrlea hnu nhc~uti on lr~crrrno~ve r the
parlod of rbnut 501.
In davr laplng c uuntr lea, horcvrr , product ion increrrr ttrr bran much
rlouttr, uhila In mcrwt countrler the population !la# lncrcarred druatlrallv,
dud to Lmprnvad hyglcna and madlcrl care. Thlr phanoornon has been
agyrrvrtad by rhs at~rrtleno f lrrga ~roupmo f people fro. rurrl rrrrr
to lovnr, with r cutrrrpoadln~c hrnae in feeding hrblto, Thin har lad
to r grrrter cannumption of productr which hrvr to be imported, #uch 40
fwd
whart flour in tr~rptcrlc ountrler, lor exrrpla. In rdditlon, pruduct-
Ion vrrira from year ru yerr, ra there Ir alwryr r aavsoent af capenartion
from rurylur to dsficit arcnu. It ro hrppenr that climrtlc vrrbblllty
hum nxhibltrd roms axtramt periodr of droulht over the lrrt decade, some-
tlnrr In rrvcrrl pruducclon rrarv rt the rrme tlne. Thia hrr aacentuatcd the
imbnloncr in food rupplier axlltlnp batwarn vrriour regions of he world.
In vlav of thlr riturclon, It hrr become Increrfilngly nrcearsry to
for~crett hr rlrr rnd qunlity of harvertr, prrticulrrly for cerlrl cropa,
whlch rrmrln the brrlc rource of food in aort prrtr of the world. Fore-
cnrtr ere very importrnt to help the producinp countrier to know in
rdvrncc thn rira of the hrrvert rnd the portion of it which can be exported.
They are riro vary impottrnt for the food-importing countriar, in order
predict in advance thr rizr of the nrtionrl hrrvert; their exportation
~aprcfty,@ r rltrrnatively the portion of the cauatry'r food co~suaption
which will have to be procured from abroad, can then be determined. The
ramark* apply, of course, to rmaller arere within r given country,
Pinally, tt is also lmpartrnt for the intornrtional and donor rgenciar
lo know the food prucurement possibilities and requirement8 in rdvrnca, ro
r0 to orgrnltc emarRencv food aaoiatance programmer in the best possible
wry, perticulrrly for tho least dcvelopad countrier who cannot rlwryr
10billz4 hrrd currenclea for the purchase of food, A good exrmple of thin
action lr the emergency meaeureo trkan since 1973 by the Office of Special
Belief dplrrtionr (OSRO) of FA0 to alleviate the food c r i ~ i sin the drought
rtrtckrn tountrias of the Sahclian rrgion. Since then, a careful early
8fiBgS8mant of the ~ D ~ Q ChaSa ~be en made in that area and in other ar@rr
narc rcnritiva to drouoht.
?hi8 effort hrr certainly bdrn Irultlul, ar it ha# rllc~wrdl mp~ndlnl
dra#&rou8 #lturtlona l a r d l n ~to toed crlrnr t,o ba drtrcted at n vrry srrlv
rtrgs and adequate nsraurea to be tlkan vrll In rdv~nca, It Ir tlrar,
howevrr, that in the future thlr trek of crop tarecratlng w l l l l~rval o bs
carried out prfrarlly by the rountrlor tblaku1vra and wlll conrtllutr r
fundrrentrl part uf (hair natiaarl food rrcurlty wchftmr, Thr purroar of
thla publicrtion la thua to prrrrnt 4 authod which, ulthnut requlrlna
rophl8ticrtad rranm for the interprrtrtlan u[ thr Jrtr, will rnrblr a
good rr8errrent ta be rrdr oI the forthcoatng hrrvrat,
SUMMARY OF Tl!E HCTHODS UBLD FOR CROP ?ORkCASTIMC
2.1 Introduction
Cropr have rluaya Ituctuated from year to year; this phanomenon can
be rren in figure 1,vhtch ahova rerieo of favourrble and untrvourable
yaarr for crapr, Ovrr tha lark dacrder, however, much more emphaais hrr
been plrcad on wayr to Lncrarar rgriculturrl production throuah crop
ralaction, tha ure of fertilirarr and improved egrlcultural technology,
implyin# r vide uar of cheap energy.
f t 1, only ralrtively recantly that reneued attention hrr bear
dodicrtad to verthef tnfluenc~ao n crop urowth and devalopmrnt, in
prrticutar rr rraardb tha relrrlonr batween weather rnd yieldr. Tho
rpptoachaa uard ware dlversa and rona confurion exist8 in the trrmlnolagy
urad in rhara tnvartigrtlonm. A recent article (Baler, 1979) hrr tried
to clanally the baslc types of crop-warthar modelr rr lollour:
1 Crop yrauth rinulrtlon modelr
2. Crop-warther rnalvrla modelr
Figurr 1: United States' corn yield8
A crop 8rovth rtmulrtioa nodel ma) be drfiaed 4r r rlmplltlrd
reprrrentrcloa of the pbyrlcrl, chemirsrl and phyrlolo~icrla echanl- rmr
-
underlying plrat prouth ptocerrer. It the brrlc plrat proerrrer
produccloa rod dlrtribution of dry Ratter aad water talrttoar rte
properly uadrrrtood aad modellrd, the rntire rerponre of tha plant to the
enviroamrntrl coadltloar can be simulated, Thrrefarr there I8 ao noad to
diffrrantirte betuera cAtmrtkc ta&ioar, rincr the rlaulrtlon model itrrlt
will ahon the limitlag factore for arouth. In humid climate8 vith low
temparrture end rrdietioa levrtr. the modei will generally rhow the
grrrtrrt rrrponre of yield8 to increrrer in totr) rrdlrtlon received,
la rn arid rnd hat climate it will rhov tho grartert rrrponra to tho
dlrtribution and totrl rmount of precipitation.
Vrriour tiar intrrvrlr era be introduced la riaulatlon modelr; for
arrmplr, la view of the drily cyclr of many plrnt procerr*r, hourly
latrrvalr are mort practical, It ir then rrrumrd that the rrte crlculrted
for 8 prrtlculrr moment doer not change rpprecirbly over 8 period of oar
hour. It ir porribla to rvrlurte thereby rpecific procerrea ruch rr photo-
ryntherir, tranrpirrtfon or rerpirrtion for rn hour rnd than recumulrce the
hourly rrtrr over the day and thr daily rrtrr ovrr the @tovin# rranon in
order to rrrivr at the totel rrreonrl dry matter production or yield of
economic productr. &t the prrrent time, r$mulrtioa progrrmmer murt br !
Irrgardrd morr a8 a 8uidr to rerarreh taco the brhlviour of biologlcrl
ryrtear rrthrr than rr r final rolution. Simulrtion can br *or( urrlul "'
!if the model account8 for mort rmlrvrnt pheaomrnr and contalnr ao frlre
rrrumptionr. Simulrtton providrr ra fnright into crop-werther relrtion-
rhipr, erplrinr why roma frctorr ate more importrnt for ylrld than othrrr,
aug~rrtrf rctorr ltkrly to have rtrtirticrl rigalficrncr rnd providrr the
brrir for nrw rxperimeatr on procerrer which rpprrr to be importrnt but
are nor yat rufficiently underrtood, Thur, thr rimulrtdon rpprorch doer
not rtplrct the rtrtirticrl rpprorcb, but la complrrratrry to it.
A typical exrmple of a dynroic model of plrnt and crop lrowth ir thr
elemeatrry crop growth rimulrcor (ELCRQS) dercrlbrd by dm Wit, brouwrr and
Penning da Vrier (1971).
rhc WHO Commiarlon for Agriculturrl Meteorology, rt it8 rixth arrrlon,
appointed two rapporteur8 (f .P. Hrun, USA, rad 0,D. Sirotrnko, USIR) on
rimulrtion modellin& in rgrometaorology rnd the reader ir referred to
their forthcoming raportr. Sever81 excellent rrvirvr of prprrr rrlevant to
model rimulatlon brve rrcrnrly brcore rvrilrble, ruch rr: "Potentirl crop
productioa" (edited by Warelag rod Cooper, 19711, "Progrerr in biorrceor-
ology; Divirion C, progrerr in plrnt bionrteorolopy" (edited by Smith, 19!5r)
r rpecirl irrue of the A~rlculturrlH rtrorology Journrl entitled "Plant
modificrtion for aore rfflcieat water ure" (edited by Stone, 1174).
2.3 Crop-vrrtbcr rarlyrir models
Crop-weather raalyria modelr rra drftnrd hrra rr tho product of tuo
or more frctorr, each raprerenting tbr (riaplifird) function81 rrlrtionrhip
brtvern r p~rtfculrrp lant rerponre (e.g. yield) rad the vrrirtfoar La
relected varlablrs rt different plrat drvrloprrntrl phrrer. Thr ovrrrll