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

consumption of cassava. Rice supplied 14% of
the calories and 10% of the protein in the diet.
In terms of area harvested, rice is the fifth
most important crop in the country, behind
soybeans, maize, sugarcane, and dry beans.
Coffee and oranges are also important crops,
especially in terms of value.
During the past twenty years, the rice area
harvested declined steadily from more than 6
million ha in the early 1980s to about 3 million ha
in 1998. It then partially recovered to about 3.7
million ha in the subsequent two years. All the
decline in area harvested has come from upland
rice systems, which accounted for about 80% of
total rice area in the mid-1980s. At least part of
this reduction in upland rice area was due to
increased interest in soybean production in the
central part of the country.
National average yields were stagnant from
the early 1960s until the mid-1980s, after which
they began to grow rapidly from 1.5 t/ha in 1983
to 3.0 t/ha in 2000 (an annual average growth rate
of more than 4%). This increase in yields was
driven largely by the reduction in upland rice
area. Since upland rice has much lower yields
than irrigated rice, an increased share of irrigated
rice in total area leads to higher national average
yields. These opposing trends have largely
negated one another in recent years, and annual
paddy rice production in the 1990s averaged
about 9.5 million t (albeit with substantial
fluctuations from year to year). This stagnation in
production changed Brazil from a net rice
exporter in the 1970s to a consistent net importer
in the 1990s.
Rice environments
Brazil is the only country in the world where
irrigated and upland rice have similar importance.
Upland rice presently accounts for about twothirds
of total rice area (1998-99), but, because
yields are much higher in the irrigated system,
irrigated rice accounted for about 60% of
production in that year.
Irrigated areas are largely planted to modern
varieties. Most irrigated rice is concentrated in
the two southernmost states of Rio Grande do Sul
and Santa Catarina. In 1998-99, irrigated rice
achieved an average yield of 5.7 t/ha compared
with a national average upland yield of less than 2
t/ha. In Rio Grande do Sul, which accounts for
about 75% of the irrigated rice area in Brazil, big
farms of about 200 ha are the norm. The
cultivation system is highly mechanized, with soil
preparation and sowing done in dry soil.
However, minimum tillage systems also occupy
large areas, and sowing of pregerminated seeds in
puddled soil is also gaining in importance. These
two systems are alternatives to the conventional
system and allow for better control of weeds and
red rice. Sowing of pregerminated seeds is
dominant in Santa Catarina, where farm sizes are
much smaller (average size is about 10 ha).
Much of Brazil’s upland rice is planted on
the Cerrado in central Brazil. Originally, rice was
grown in this area primarily to facilitate
deforestation. Now, it is typically done in rotation
with pasture (two years of rice, three years of
pasture) or soybean. Rotation is essential because
of the “yield collapse” that occurs with
continuous cultivation of such rice. In the second
year of rice cultivation, yields typically decline
by about 10%, but in the third year they can fall
by as much as 70%. The cause of this problem
has been variously attributed to autotoxicity, soil
degradation, and soil pests. Thus, crop rotation is
essential for profitable farm management.
Production constraints
Most areas planted continuously with rice are
infested with weedy rice (red rice) to some
degree, significantly affecting yields over time.
The sowing of pregerminated seed or the use of
no-till systems is helping to reduce the
importance of this problem. Another production
problem is the occurrence of low temperatures
during flowering, primarily in the southern areas
of Rio Grande do Sul and Santa Catarina, where
irrigated rice is common. This problem can be
exacerbated when farmers delay planting because
of a rainy spring. Weeds and insect pests (fall
armyworm, rice water weevil, rice stem bug) also
act as constraints to increased production.
The most important production constraint for
upland rice is the abovementioned yield collapse.
Because of the fragile structure of the Cerrado
soil, soil erosion caused by wind and rain is also
an important problem.
Production opportunities
Rice research is organized at both the federal and
state levels. Research at the federal level is
coordinated by the Empresa Brasileira de
Pesquisa Agropecuária (EMBRAPA). The Centro
Nacional de Pesquisa de Arroz e Feijão (CNPAF),
located in the central region, conducts research on
Rice around the world 123