Agriculture Reference
In-Depth Information
a few large corporations in the seed sector. However, the future of agriculture may
require acceptance of this science since it may be the only way to find superior plants
needed to produce the quantity of food needed for food security.
t
i s s u e
C
u L t u r e
Tissue culture is a key biotechnology tool in developing transgenic crops. In tis-
sue culture, a single cell is grown on a sterile medium (usually agar based) and is
stimulated to multiply and produce
callus tissue
, a group of similar cells. Using
hormonal and other additions to the media, the callus tissue can be tricked into
forming embryos that then grow into whole plants. This results in clones of a
plant that are all exact copies. When transgenic cells with a new trait plus an
antibiotic marker are grown on agar containing an antibiotic, only the cells with
the new gene survive and are easily selected. This technology is also very useful
for developing virus-free plants, multiplication of plants in the absence of seeds,
and the production of plants from seeds that otherwise have a low chance of
germinating.
effIcIent cRoP PRoductIon
Improvements in crop science and production technology can contribute to sus-
tainable food production in two different ways: by developing superior germplasm
(as discussed) and by using agronomy to tap the full potential of this germplasm.
Agronomy
is the science of using plants to obtain food, fuel, fiber, and feed or, in
other words, how to grow crops for maximum production and profit.
There are a number of well-defined steps involved in growing a crop: land prep-
aration, seeding and plant establishment at proper spacing and population, fertil-
izing, managing moisture, crop protection (weeds, insects, diseases, and rodents)
and harvest, threshing, cleaning, and storage. (Adding value to crop outputs through
processing is not discussed in this chapter.) For the past hundred years or so, these
farm operations have been carried out in ways that rely heavily on cheap energy
from fossil fuels. Fossil fuels have also provided cheap nutrients. Urea, for example,
is a major nitrogen-based fertilizer that is synthesized using large quantities of fossil
fuel. In the present decade, however, the cost of fossil energy has risen dramatically
and is likely to remain high. New production technologies are needed that use energy
more efficiently.
There is general agreement that innovative production practices are needed
that use energy, natural resources, and inputs more efficiently while reducing
harmful impacts on the environment. This is becoming even more critical since
agricultural land and water are increasingly in competition with other sectors
of the economy. Rapidly growing urban centers are enveloping large areas of
productive agricultural land and are requiring ever-larger quantities of water for
direct consumption, hydropower, and industrial use. Agriculture, industry, and
the environment all compete for the same scarce water resources (Comprehensive
Assessment 2007).
