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

Importance of rice
Origin and diffusion
The origins of rice have long been debated.
The plant is of such antiquity that the
exact time and place of its first
development will perhaps never be known. It is
certain, however, that domestication of rice ranks
as one of the most important developments in
history. Rice has fed more people over a longer
period than has any other crop.
Pottery shards bearing the imprint of both
grains and husks of the cultivated rice species
Oryza sativa were discovered at Non Nok Tha in
the Korat area of Thailand. Plant remains from
10000 B.C. were discovered in Spirit Cave on
the Thailand-Myanmar border.
In China, extensive archeological evidence
points to the middle Yangtze and upper Huai
rivers as the two earliest places of O. sativa rice
cultivation in the country. Rice and farming
implements dating back at least 8,000 years have
been found. Cultivation spread down these rivers
over the following 2,000 years.
Early spread of rice
From early, perhaps separate, beginnings in
different parts of Asia, the process of diffusion
has carried rice in all directions until today it is
cultivated on every continent save Antarctica. In
the early Neolithic era, rice was grown in forest
clearings under a system of shifting cultivation.
The crop was direct seeded, without standing
water—conditions only slightly different from
those to which wild rice was subject. A similar
but independent pattern of the incorporation of
wild rice into agricultural systems may well have
taken place in one or more locations in Africa at
approximately the same time.
Puddling the soil—turning it to mud—and
transplanting seedlings were likely refined in
China. Both operations became integral parts of
rice farming and remain widely practiced to this
day. Puddling breaks down the internal structure
of soils, making them much less subject to water
loss through percolation. In this respect, it can be
thought of as a way to extend the utility of a limited
water supply.
Banaue Rice Terraces, Philippines.
Importance of rice 1