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

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,
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