Research Highlights of the CIMMYT Wheat Program 1999-2000

Given these circumstances, the changes that have
occurred in farmers’ production practices over the
past 25 years in northwest Mexico, especially in the
Yaqui Valley of Sonora, have given scientists and
farmers the opportunity to develop more
sustainable irrigated production systems. This is
also an example of farmers taking the lead in
modifying production practices, well ahead of most
researchers and machinery manufacturers.
Twenty-five to thirty years ago, nearly all farmers
in the Yaqui Valley planted their wheat on the flat
and used flood irrigation. The wheat production
system was characterized by extensive tillage and
crop residue burning and by heavy dependence on
herbicides to control weeds. Today more than 95%
of farmers plant their wheat on beds and use
furrow irrigation (70-100 cm between furrows). The
major innovation that farmers introduced was to
plant on top of each bed 2-3 defined rows, spaced
15-40 cm apart, depending on bed width and row
number. This simple modification offered new
wheat management options that allowed farmers to
dramatically improve production efficiency and
reduce production costs. By simply changing to
furrow irrigation, they realized an average savings
of 25% in irrigation water. By planting 2 or 3
defined rows on top of each bed, farmers were able
to gain new advantages for wheat by utilizing
management practices such as:
• Pre-seeding irrigation, which allowed the weed
population to be controlled mechanically at
planting and enhanced crop establishment,
especially in heavy, crust-forming soils.
• Mechanical weeding in the furrows and between
the rows after crop emergence; this, combined with
pre-seeding irrigation, has reduced herbicide use
from 70-80% of farmers 25 years ago to less than
10% at present.
• Band application of fertilizers in the bed at
planting, followed by banding of side-dress
nitrogen at critical times after crop emergence
(instead of the more inefficient N broadcast
application or application in the irrigation water),
which can dramatically improve N use efficiency
and enhance grain quality.
• Decreasing intra-plant competition and using lower
seed rates, which reduces crop lodging.
The clear advantages of planting wheat on beds
made it likely to be useful in other similar areas,
especially where irrigated wheat is grown in
rotation with other upland crops or with rice. Basic
to its dissemination was a training program
initiated in 1994 to bring visiting scientists to
CIMMYT-Mexico. During the wheat crop cycle in
Ciudad Obregon (located in the Yaqui Valley),
these scientists study the bed planting system so
they can later test its utility in their home areas.
Since 1994, over 39 agronomists, mainly from Asia,
but also from Africa and Latin America, have been
trained in bed planting. Research, development,
and extension programs for bed planting are
currently underway in India, Pakistan, China, Iran,
Turkey, Sudan, and several Central Asian republics.
In most cases, similar improvements in production
efficiency are being obtained, including irrigation
water savings of 25-50%. Although the lack of
adequate bed planting machinery has been a
common constraint, each country is working on
developing appropriate machines.
In the summer of 2000, trials were initiated in India
to investigate the feasibility of growing rice on
beds in rotation with wheat (R. Gupta, pers.
comm.). Some extremely favorable results were
obtained, including more than 50% savings in
irrigation water compared to transplanted puddled
rice. Grain yields were similar in both systems.
Nearly all farmers in the Yaqui Valley continue to
use fairly extensive tillage and considerable crop
residue burning. However, farmers using the bed
planting system have quickly realized that if the
same bed width is used for all crops in their
production system, they can reduce tillage by
reusing the same bed for succeeding crops.
Therefore, it is common practice to till, make new
beds, and plant wheat. After the wheat harvest, the
straw is removed for fodder or burned (most
common), and the same beds are then used to plant
soybean. After the soybean harvest, tillage is
performed again, before planting wheat or another
crop.
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