Takaya et al. - 1974 - Rice cultivation and its environmental conditions

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Rice cultivation and its environmental
conditions in the mediterranean
countries I. Climate and physiography
in relation to rice cultivation
Yoshikazu Takaya a , Kazutake Kyuma a & Keizaburo Kawaguchi a
b
a Center for Southeast Asian Studies, Kyoto University , Kyoto ,
Japan
b Faculty of Agriculture, Kyoto University , Kyoto , Japan
Published online: 29 Mar 2012.
To cite this article: Yoshikazu Takaya , Kazutake Kyuma & Keizaburo Kawaguchi (1974) Rice
cultivation and its environmental conditions in the mediterranean countries I. Climate and
physiography in relation to rice cultivation, Soil Science and Plant Nutrition, 20:3, 209-223, DOI:
10.1080/00380768.1974.10433244
To link to this article: http://dx.doi.org/10.1080/00380768.1974.10433244
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Soil Sci. Plant Nutr., 20 (3), 209-223, 1974
RICE CULTIVATION AND ITS ENVIRONMENTAL
CONDITIONS IN THE MEDITERRANEAN COUNTRIES
I. Climate and Physiography in Relation to Rice Cultivation
Yoshikazu TAKAYA, Kazutake KYUMA, and Keizaburo KAWAGUCHI*
Center for Southeast Asian Studies, and •Faculty of Agriculture,
Kyoto U11iversity, Kyoto, Japan
Received March 1, 1974
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In order to characterize the rice cultivation In the Mediterranean countries,
climate and physiography of rice growing areas in Italy, Spain, and Portugal were
studied, In northern Italy rice Is extensively cultivated on terraces and fluvial
·plains of the Po and its tributaries, making use of the supply of water from
Alpine glaciers in addition to the relatively abundant rainfalls of the area. In the
Iberian peninsula summer climate is so dry that rice is cultivable only where the
ratio of catchment area to rice land area is sufficiently large, thus rice lands are
practically limited to the floodplains and deltas of the big rivers, such as the Sado
and the Tejo in Portugal and the Guadalquivlr and the Ebro In Spain.
Rice cultivation has a certain stable share in the agriculture of the Mediterranean
countries, notably of Italy, Spain, and Portugal. The rice acreage is not large but the
yield per unit area is quite high, as shown in Table 1. As rice cultivation in this
region was known to have many characteristics in comparison with that in Japan, the
authors attempted to clarify the environmental conditions under which rice cultivation
is practised. The survey was carried out in September and October, 1972, with the
assistance of research and/or extension organizations in the respective countries, The
present report consists of two parts, one dealing with the climate and physiography in
relation to rice cultivation as well as soil conditions, and the other dealing with soli
conditions per se. These papers would supplement what TAN AKA, Y AMAGUCIU, and
KAWAGUCHI stated in the two previous papers ( 1, 2 ), concerning general features of
rice cultivation and the nutritional status of rice plants in the Mediterranean region.
CLIMATE
The climate of the region is broadly categorized as Mediterranean, which Is
characterized by winter rains and dry summers. Within the three countries surveyed,
209

210 Y. TAKAYA, K. KYUMA, and K. KAWAGUCHI
Table 1. Acreages and yields of rice In Italy, Spain, and Portugal In the recent years In comparison
with those In some other countries.
Area ha
Yield ton/ha
1969
Area ha
Yield ton/ha
1970
Italy
Vercelli
Novara
Alessandrla
Pavia
Milano
Ferrara
Total
62,800 4.97
24,500 5.56
4,360 5.10
42,363 5.18
12,172 4.19
13,900 5.61
168,988 5.10
64,900
25,100
4,700
44,220
11,250
13,800
172,944
4.39
5.11
4.50
4.92
4.49
5,29
4.73
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Spain
Badajoz & Caceres
SeviUa
Tarragon a
Valencia
Total
Portugal
Coimbra
Santarem & Llsboa
Setubal
Portalegre, Erora, & Beja
Total
---~--·--
Australia
U.S.A.
Thailand
Indonesia
India
Japan
9,350 6.50
21,400 6.80
13,000 5.80
18,200 6.50
65,417 6.40
6,400
13,000
9,200
10,700
41,700
39,000
734,000
7,300,000
8,237,000
37,700,000
2,923,000
4.18
5.13
5.03
4.37
4.67
6.22
5.12
1.87
2.04
1.66
5,6-J
Cited from the statistical yearbooks of Italy, Spain, and Portugal and from the FAO Production
Yearbook, 1970.
however, there are considerable differences in the annual precipitation, rainfall pattern,
and temperature regime. All of these climatic factors are reflected on the patterns of
agriculture in the region. Therefore, a climatic regional division was attempted by
the numerical method proposed by KYUMA ( 3 ).
Based on land areas of the respective countries, the following numbers of the
meteorological stations were selected at random, 8 from Portugal, 42 from Spain, and

Rice Lands ln .Mediterranean Countries (J) 211
25 from Italy, making the total number of stations to be analyzed 75. A list of sample
stations is given In Table 2. Mean monthly temperature and rainfall data ( 4-6) were
used to calculate the similarity coefficient, the taxonomic distance in this case. A
dendrogram was prepared by applying the weighted pair group method to the taxonomic
distance matrix. By drawing a line intersecting the taxonomic distance axis at 0.90,
6 groups were set up leaving 12 stations unclassified. The mean vectors of the 6 groups
(I to VI) are illustrated in Fig. 1. In order to classify the 12 stations left out (and
n
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.......
!
i
.~
100
1 2 3 4 5 6 1 8 9 10 11 12
N
'•,.,...J
I
I
I
I
l'•...t
20
/ 10
1 2 3 4 5 6 1 8 !I 10 1112
1 2 3 4 6 1 8 9 10 1112
1 2 3 4 5 6 1 II 9 101112
Month
50
Vl
E
..
6 7 8 9 101112 ..
/
...
,', ..
I \ ..
I \
..
I I
~
I \
100 20
1 2 3 4 5 6 7 8 9101112
Fig. 1. Illustration of the mean vectors for the six climatic groups (----, rainfall; -, temperature).
~
the remaining some 60 stations for which the monthly mean rainfall and temperature
data are available) into one of the 6 groups objectively, linear discriminant functions
were derived. These functions were satisfactory, classifying all 63 stations that had
been used ln the numerical taxonomy into predetermined classes. From the result of
classification of all 130 stations, a map showing the 6 climatic regions was prepared,
as shown in Fig. 2.
Group I stations are concentrated in the north Atlantic coast of Spain and northern
half of Portugal. Mean monthly temperature ranges from 8 to 20nc, a mild climate
under the influence of the Atlantic Ocean. Mean monthly rainfall amounts to 100 mm
or above during the October-March period. The driest month, July, has more than

212 Y. TAKAYA, K. !

for the climatic classification.
Rice Lands In Mediterranean Countries (I) 213
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Altitude
Thornthwaite's Numerical
Location Latitude Indices Method
Alicante 38°22' 82 DB' 3 d IV
Al geci ras 36"08' 17 CzB'zs2 IV
cadiz 36°28' 30 DB'3d IV
Cordoba 37"53' 123 C1B'3s2 IV
Granada 37"11' 774 c 1 B'zd v
Sev111 a 37"23' 30 DB'3d IV
Almeria 36°50' 7 EB'3d IV
Huelva 37"15' 18 DB'3d IV
M&laga 36°43' 33 DB'3d IV
Pol made 39"34' 28 BzB'zr IV
lli.J.t. Genova Sestr1 44"24' 98 e 2 s• 2 s VI
P1sa San Giusto 43"41' 11 a 1 e• 2 s VI
F1renze Peretola 43°48' 48 e 1 e• 2
s VI
Roma Urbe 41"57' 35 e 1 e• 2 s VI
Fros1none 41°39 1 180 B4B' 2 r I
Napoli 40°53' 110 e 1 e• 2 s VI
Capod1ch1no
Reggiodi 38"06' 21 c 1 s• 3 s IV
Calabria
Potenza 40"38' 843 c 2 e• 1 s II
Leece 40"14' 61 CzB' 3s 2 IV
Galat1ne
Sari Palese 41"08' 45 c 1 e• 2 d v
Campobasso 41"34' 793 c 2 s• 1 s II
Castello Monforte
Pescara 42"26' 16 c 1 e• 2 s m
Ancona Monte 43°37' 105 c 2 s' 2 s v
Cappuccini
Bologna Borge 44"31' 43 c 2 e• 2 s m
Panigale
Torino Casella 45"12' 308 e 1 e• 1 r m
Parma 44"49' 57 c 2 e• 2 s m
i nate 45°28' 120 e 2 e • 2 r m
Brescia Ghed1 45"26' 103 e 1 e• 2 r m
M11 a no L
Venezia Tessera 45°30 I 5 c 2 a • 2
s m
Balzano 46"28 1 241 c 2 e• 1 r m
Udine 46°02' 92 e 4 e• 2
r m
Campoformi do
Trieste 45"39' 12 s 2 a • 2 r VI
Palermo 38"07 1 122 . c 1 a• 3 s IV
Boccadifalco
Catania 37°28' 16 c 1 a• 3
d IV
Fontana ross a
Cag11ari Elmas 39"15' 12 DB'zd IV

214 Y. TAKAYA, K. KYUMA, and K. KAWAGUCHI
Fig. 2. A map of the Mediterranean region showing the six
climatic regions.
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30 mm of rain on a long term average. But this is naturally not sufficient to balance
with the potential evapotranspiration of the order of 100-120 mm/month in mid summer.
Group II occurs in north central Spain and in the interior of southern Italy. Thetemperature
regime is more continental, having a wider range of fluctuation. Monthlyrainfall
is less than 50 mm for the most of the year. It is about 20 mm for the driest
months, July and August.
Group III occurs only in northern Italy. Reflecting the higher latitude, the lowest
mean monthly temperature is as low as ooc in January. The rainfall pattern is specific,
being least humid during the winter months. Monthly rainfall exceeds 60 mm for most
of the months.
Group IV is typically Mediterranean climate, very mild in winter and quite hot
and dry in summer; It is widespread throughout the southern parts of the Iberian and
Italian Peninsulas and such islands as Mallorca, Sardinia, and Sicily. The three summer
months are very dry, having even less than 10 mm of rain per month, while the period
from October through March is moderately humid.
Group V occurs in east central Spain and along the Adriatic coast of Italy. It issimilar
to Group II except that it has higher mean monthly temperatures throughout
the year. Rainfalls are least during mid winter and mid summer, the scarcity of rain
in the latter being more pronounced.
Group VI stations· occur along west coast of Italy and in some isolated spots in
Portugal. Monthly rainfall exceeds 50mm throughout the year, except the 40mm in
July. A very conspicuous rainfall peak is seen in November, amounting to 160 mm.
A water balance study by Thornthwaite's method revealed that climatic regions I,
Ill, and VI are mostly humid (B), while regions II, IV, and V are subhumid to semiarid
(C or D). Italy has no stations classified as semiarid or D, except in the island of
Sardinia, while many stations in central and southern Spain are classified as D, and
occasionally even as arid or E. The southern coast of Portugal is also classified as
semiarid.
In relation to rice cultivation, temperature condition seems to be adequate in the
greater part of the region, although the rice growing areas are situated quite far north
in latitude, between 37 and 45°. If we take l4°C as the lower threshold and if we
secure 6 months for rice growing, Region ll is prohibitive and Region I is marginal.
The Vouga valley in northern Portugal, for e;xample, belonging to Region J, used to
have some rice acreage, but today no rice is cultivated because of the unfavorable

Rice Lands ·in Mediterranean Countries (1) 215
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temperature condition. The remaining regions, III to VI, are suitable for rice cultivation
during the period of May through October. In view of the fact that the summer
season has only scanty rains in these regions and that rice requires a great amount of
water for irrigation, the climate of the Mediterranean region cannot generally be
regarded as favorable for rice cultivation. Only where the available-water-to-rice-landarea
ratio is sufficiently high would rice become cultivable. In northern Italy, where
extensive rice land is found, this condition is satisfied by the availability of water
flowing down from alpine glaciers, in addition to the relatively abundant rainfall. In
rice growing areas of Spain and Portugal, the condition is satisfied by limiting the rice
land areas to the lowermost reaches of big rivers such as the Tejo and Sado in Portugal
and the Guadalquivir and Ebro in Spain, or to coastal lowlands where a few minor
rivers supply fresh water. In Valencia, Spain, for example, the supply of fresh water
to rice land is obtained from the J ucar and Magro.
Once this basic water condition is satisfied, however, solar radiation is abundant
due to the high intensity and length of sunshine hours, thus favoring a high yield of
rice. Table 3 compares the solar radiation at different places ( 7) for the rice growing
Table 3. Monthly averages of daily total solar ~adiatlon at different places for the six summer
months (May through Oct., calorles/cm 1 /day),
Country Japan Portugal Spain Italy Australia
Location Sapporo Osaka Coimbra Llsboa Badajo~ Almeria Milano Sydney 1 l
Latitude (N) 43•03' 34"39' 40°12' 38007' 38°53' 36"50' 45"28' 33•52' (S)
May 406 297 555 626 421 552 493 512
June 412 249 590 691 594 588 499 530
July 390 343 607 720 610 595 515 560
August 349 344 540 626 544 541 430 440
September 299 266 428 482 419 443 325 500
October 225 243 341 354 296 337 188 410
Sum 2081 1742 3061 3499 2884 3056 2450 2952
,, For Sydney the figures are for October through March. The rice growing areaa of inland
New South Wales ehould have higher solar radiation than that of Sydney.
period of May through October. In Sydney, Australia, the period of October through
March is considered. Solar radiation in the Iberian peninsula ls comparable to that in
rice growing areas of Australla, which are known to produce the highest average yield
in the world (cf., Table 1). The monthly figures at Milano, northern Italy, are much
higher than those in Japan throughout the rice growing period, except October. In
addition, low humidity during the dry summer months would also favor rice cultivation
through the reduction of Insect and pest hazards.

216 Y. TAKAYA, K. KYUMA, and K. KAWAGUCHI
I'HYSIOGI

Rice Lands Jn Mediterranean Countries (I) 217
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0.2 m from the ground surface. Clayey ground surfaces are, however, locally found
because of the eluvial concentration of fine fractions in relative swales.
Water for Young Terrace comes from three sources. They are natural streams,
natural springs, and large scale man-made irrigation canals. Natural streams are 2 to
u m wide and 1 to 3m in bank height. These are ideal to be utilized as irrigation

218 Y. TAKAYA, K. KYUMA, and K. KAWAGUCI!l
0 10 km
.........._.
~ Rt•claimPd sl'ction
0 Modern dt•lta
Q Jtidl!e swale compl .. x
0 Ancif'nt dt>lta
0 Water surfact•
An·•a in which rict• J{l'lJWing is common
M Town of Massa Fisca1dia
Fig. 4. A simplified l{comorphologic map of the Po Delta.
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Ancient Delta, which is believed to have been formed during and before the Roman
era, occupies the inlandmost portion of the delta. This has a very flat ground surface
whose ground height is in most places lower than 1m above se2 level. The sediments
consist of clay, sand, and peat. ~idge-Swale Complex is composed of silted-up lagoons
and old beach ridges with some overlying dunes. The dunes may attain as much as
6 m but averag-e :1 to 4 m in height. These are made exclusively of sand. Swales
between ridges also have sandy ground surface with some clay and peat lenses. Modern
Delta, which is supposed to have been formed after the Medieval age, has a beautiful
lobate shape and is a complex of numerous distributaries and interdistributary basins.
Distributaries have loamy levees and inter-distributary basins have, in most places,
clayey floors with local sandy spots. The area termed as Reclaimed Section is the area
which has been artificially reclaimed after the 1950's. Fill consists of clay and sand,
and profuse brackish shell fragments are occasionally found.
In Modern Delta, farm lands arc protected from flooding by strengthened natural
levees installed with pumps. In Ancient Delta and Reclaimed Section, where natural
creeks are not as numerous as in Modern Delta, many man-made canals, most of them
straight, arc dug to regulate the water.
Ancient Della and Modern Delta arc two main rice tracts, of which the former
lays more stress on sugar beet cultivation than on rice, whereas the latter is characterized
by more or less monocultural growing of rice.
II) Rice land of the Jherian Penit~sula
The Iberian rice lands arc scattered, forming small patches on varying environments
(Fig. 5). They arc on (1) Cuadalquivir marsh land (Sevilla), (2) inland valley near
Hadajoz (Hadajoz), C:i) Albufcra lagoon (Valencia), and (4) Ebro delta (Tarragona), all in
Spain; and on (5) Mondego valley (Coimbra), 16 & 7) Sado valley and its coastal dune
zone (Setubal), and (8) Tejo valley (Santarern & Lisboa) in Portugal.
/) Guada/quivir Marsh /.and
As shown in Fig. fi, the lowest reach of the Guadalquivir river forms a large marsh
land. ft is ca. 30x40km 2 , with maximum ground height of 3m above sea level. The
northern portion has riverine environment influenced by fresh water inflow from rivers.

Rice Land$ in Mediterranean Countries (I l
219)
40"
38'
•~'2,000hu of riel.'
8' 0' 36
Fig. 5. The distribution of rice lands in the Iberian peninsula.
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[IT] Estuarine portion of marsh
l1iJ Riverine portion of marsh
[] Alluvial vall••y
~ Dune lagoon cnmplt•x
f:;:::J Quaternary and Tt•rtiary tenace
(fd Mt>sowic and older mountain
1 -6 Sampling sill's
Fig. 6. Simplified physiographic st>tting of the Guadalquivir marsh and its environ:;, Spain; modified'
from VANNEY ( /0 ).
such as the Guadalquivir and the Guadiamar, whereas the southern portion is more
estuarine suffering from the high tide and wind generated waves of the Atlantic Ocean.
Rice is cultivated in polders built in the riverine part of the marsh land. whereas the
estuarine part of the marsh land is still left as raw marsh with some small patches
of pasture.
In both riverine and estuarine portions, deposits arc absolutely dominant in clay and
calcareous but rather poor in organic materials. This chemical character is attributed
to the geological background of the region that the surrounding hills and mountains of
Tertiary and Mesozoic formations arc more or less calcareous.

220 Y. TAKAYA, K. KYUMA, and K. KAWAGUCHI
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2) Inland Valley near Badajoz
This is the only example of rice land situated inland in the Iberian peninsula. The
Guadiana river reveals a braided feature at its middle reach when it comes out from
high land of Cambrian rocks to a saucershaped inland basin of Tertiary rocks near
Badajoz. Several terraces appear along its braided streams. Near stream portions form
narrow strips of alluvial plain with the relative height 1 to 3m from the stream bed.
The sediments are composed of fresh gravel with a gray silty to clayey topset bed
several centimeters thick. Outside this are situated other surfaces having a relative
height 3 to 8 m from the stream bed. These have a yellowish-gray sandy top soil and
somewhat indurated red colored clayey underlay at a depth of several ten centimeters.
3) Albufera Lagoon
The Albufera lagoonal portion is an oval shaped swale sandwiched between beach
and dunes on the east and Quaternary terraces and older hills on the west. The silted-up
portion of this lagoon forms a main rice land. Shallow valleys penetrating into
Quaternary terraces, which appear like the arms of the lagoonal portion, are another
rice growing area.
The silted-up portion of the lagoon is flat and lowlying. This is in most places
lower than 2m above sea level and some places are as low as to be protected by polder
banks. Soils are dominantly clay. The penetrating valleys, on the other hand, are
gently sloped, rich in coarser materials including gravels and encountered by calcareous
bed rocks at relatively shallow depth, though the main portion is still clayey. The
silted-up portion of the lagoon is exclusively utilized for rice growing because of its
poor drainability. The valley portion, on the other hand, has a mosaic pattern of rice,
vegetables, and citrus trees .
.J) Ebro Della
The Ebro delta has three physiographic units; levee, backswamp and coastal
marsh-beach complex (Fig. 7). The levee is an elevated zone along the present and
Q Levee
U Backswamp
~ Marsh and beach
(SJ Tt•l'l'nce and hill
14·17 Sampling sites
Fig. 7. Simplified physiographic map of the Ebro delta, Spain; simplified from BAHR ( 8, 9 ),

!~ice Lands in Mediterranean Countries (!) 22r
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ahondoned river channels. This is usually 1 to :3m higher than the adjoining hacl

222 Y. TAKAYA, K. KYUMA, and K. KAWAGUCHI
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and at some places even receives so much water that the floor of the rice field must
be raised up several ten-centimeters so as to get enough drainability. The dammed-up
portion of the main valley is within the tidal zone. The water is mostly pumped up
from tidal creeks with careful checking of the salinity.
·6) Sado Valley (cf, Fig. 8)
The Sado river is even smaller than the Mondego. The valley reveals in most
-places a loamy constituent throughout the whole of its cross-section rather than a
-complicated web of levee and backswamp. Water is adequately supplied from upstream
reservoir by canals and is drained through natural channels. This is a well irrigated
·and well drained rice land.
The lowermost reach, however, below Alcacer do Sal, has different features. Here,
the whole breadth of the valley is actually within the tidal range and has a clayey
foundation. Rice growing must be done under the protection of tidewater control
"

Rice Lands in Mediterranean Countries (I) 223
Acknowledgement. The authors are deeply indebted to the following persons who helped them
in various ways during the field work: Dr. A. Tinarelli and Mr. K. G:>tz, Ente Nazionale Risl,
Milano; Dr. A. Guerra, Inst. de Edafologia y Flsiologia Vegetal, Madrid; Drs. M. Chavez and
J.L. Mudarra, Centro de Edafologia Y Biologia Aplicada, Sevilla; Dr. S. Barber Perez, Inst. de
Agroquimica y Technologia de Alimentos, Valencia; Dr. G. Lopez Campos, Departmenta del Arroz,
Sueca, Valencia; Dr. ]. Carvalho Cardoso, Esta~l!o Agronomica Naclonal, Oeiras, and Messrs.
M.R.T. Bessa and M.O.B. Marado, S.R.O.A., Lisboa.
The present research project was financed by the Science Research Fund of the Ministry of
Education of the Japanese Government.
REFERENCES
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1) TANAKA, A., YAMAGUCHI, ]., and KAWAGUCHI, K., Nogyo Oyobi Engei, 48, 649 (1973) (in
Japanese)
2) TANAKA, A., YAMAGUCHI, J,, and KAWAGUCHI, K., Soil Sci. Plant Nutr., 19, 161 (1973)
3) KYUMA, K., ibid., 18, 155 (1972)
-4) Servi'>o Meteorologica Naclonal, 0 Clima de Portugal, 1970, Llsboa
5) Instituto Naclonal de Estadistlca, Espana, Anuario Estadistlco, 1971, Madrid
o6) Instituto Centrale di Statistica, Annuario di Statistiche Meteorologiche, Vol. X, 1970, 1971,
Rome
7) LHF, G.O.G. et at., World Distribution of Solar Radiation, Engin. Exp't. Sta. RePort No. 21,
Univ. Wisconsin, 1966
8) BAHR, W., Die Marismas des Guadalquivir und das Ebrodelta, 1972, Donn
9) BAHR, W., Archiv flir wissenschaftliche Geographic, XXXVI, 2, 1972
10) VANN..tY, ]., L'hydrologle du Das Guadalquivlr, 1970, Madrid
JJ) Servlzio Geologico d'Italia, Carta Geologica d'Italia, 1/1,000,000, 1966
12) Instituto Geologico y Mineralo de Espafta, Mapa Geologico de Ia Peninsula Iberica, Baleares y
Canarias, 1966