Agriculture Reference
In-Depth Information
Figure
3.26.
USDA rice grain types.
that had previously only imported rice to feed their population became rice exporters.
Average yield levels rose and the quality of rice on the markets improved.
3.4.6 Soil Preparation and Planting
Upland rice is similar to wheat and barley with respect to soil preparation and planting
operations. Soil preparation and planting of irrigated rice differ greatly from other
cereal grains. Irrigated rice needs periods of inundation or flooding to produce
maximum yields. To keep water on the field, paddies are created with small earthen
levees to contain water. In most parts of the world these levees (or bunds) are semi-
permanent field boundaries and remain in place for years.
The first step is to flood and “puddle” the soil in a paddy. Techniques vary depending
on the equipment or animals available. Frequently, oxen are used with a plow or leveling
board, as shown in Figure 3.27. There are three basic goals in puddling. The first is to level
the soil within the enclosed paddy. The second is to form a layer of soil below the surface
that prevents excessive loss of water. The third goal is to break up any clods of soil to give
a uniform, smooth transplant bed. Puddling also serves to control weeds.
Planting normally is first done in a nursery near the field. The plants are raised until
they reach a height of 15 to 20 cm when they are transplanted to the open field. This is
commonly a manual operation requiring large amounts of labor. Mechanical transplan-
ters exist but are not widely used.
The purpose of transplanting is to raise the plants until they are large enough to
grow and overtake any weeds existing in the field. It also permits raising plants in a
small area while the main field is cleared of the previous crop and prepared for trans-
plant. With carefully planned farm operations, it is possible to raise three crops of rice
per year on one field. In temperate climates, the transplant nurseries are covered to
