Maclean et al. - 2002 - Rice almanac source book for the most important e

Rice in Europe and the
Mediterranean*
Rice in Europe is grown under a
Mediterranean climate characterized by
warm, dry, clear days and a long growing
season favorable to high photosynthetic rates and
high rice yields. Compared to tropical and
subtropical rice-growing areas, the climate is
cool, but warm summer nights during panicle
development, when pollen formation takes place,
help to avoid cold-induced floret sterility. Low
relative humidity throughout the growing season
reduces the development, severity, and
importance of rice diseases. However, cool
weather and strong winds during stand
establishment may cause partial stand loss and
seedling drift.
Rice is mostly grown on fine-textured,
poorly drained soils with impervious hardpans or
claypans. These soils are principally in three
textural classes: clays, silty clays, and silty clay
loams ranging from 8% to 55% clay. A few of the
soils are loam in the surface horizon but are
underlain with hardpans. The pH is from 4 to 8
and organic matter from 0.5% to 10% (this last
value on only a limited surface area). These soils
are well suited to rice production because their
low water permeability enhances water-use
efficiency. In some regions (the Camargue in
France and Ebro Delta in Spain), soils are saline
or very saline. Most of the irrigation water for
European rice comes from rivers (the Po in Italy,
Ebro in Spain, Rhone in France, Tejo in Portugal,
etc.) and lakes. It is estimated that less than 5% of
rice irrigation water is pumped from wells—in
areas where surface water is not available or as a
supplement to surface supplies. The high cost of
pumping well water prevents its widespread use
in rice production. Surface water and most
groundwater are of very good quality for rice
irrigation.
In all European countries, rice is commonly
cultivated with a permanent flood with short
periods during which soil is dried to favor rice
rooting (in the early stages) or weed control
treatments. The conventional irrigation system is
also known as a “flow-through” system because
water is usually supplied in a series from the topmost
to the bottom-most basin and is regulated by
floodgates by means of removable boards.
The main rainfalls occur during the first
stages of the crop (April-June) and during the
harvesting period. Average temperatures range
from 10–12 °C during rice germination to 20–25
°C during crop flowering.
Seedbeds are commonly prepared by plowing
in autumn or springtime at a depth of 20 cm and
incorporating residues of the previous crop into
the soil. To favor weed germination to control
weeds better before rice planting, the soil is
sometimes prepared by adopting minimum tillage
practices. Precision land grading, obtained with
laser-directed equipment, is an agronomic
practice that has greatly contributed to better
water management, and consequently to better
crop stand establishment and weed control.
Fertilization is mostly aimed at restoring the
main plant nutrients removed by crops. Because
of flood conditions, nitrogen is principally
absorbed in ammoniac form. This nutrient is
commonly supplied at 80–120 kg/ha, 50% in
preplanting and 50% in postplanting, using urea
or other ammoniac fertilizers. Phosphorus and
potassium are supplied entirely in the preplanting
stage at 60–80 and 100–150 kg/ha, respectively.
About 80% of the rice area is cultivated with
japonica varieties and the remainder with indica
or indica-type varieties (mainly Thaibonnet). Rice
is planted from mid-April to the end of May and
harvested from mid-September to the end of
October. Since the beginning of the 1960s, rice
*Contributed by Mr. Aldo Ferrero, Dipartimento di Agronomia, Selvicoltura e Gestione del Territorio, Via Leonardo da Vinci, 44,
10095 Grusliasco (TO), Italy.
68 Rice almanac