(including drought and increased temperatures)
can help farmers to cope with less rainfall, salinity,
or disease pressure and still produce a crop. The
key is to ensure that sufficient farmers have access
to improved adapted crop varieties through
strengthened seed systems. Conservation and sus-
tainable use of plant genetic resources for food and
agriculture is necessary to ensure crop production
and meet growing environmental challenges such
as climate change.
Developing improved and adapted varieties
Sustainable intensification requires crop varieties
that are resilient in the face of different agronomic
practices, respond to farmers’ needs in locally
diverse agro-ecosystems and tolerate the effects of
climate change. Important traits will include ability
to cope with heat, drought and frost, increased
input-use efficiency, and enhanced pest and disease
resistance. Generally, it will involve the development
of a larger number of varieties drawn from a greater
diversity of breeding material.
It is unlikely that traditional public or private breeding
programmes will be able to provide all the new plant
material needed or produce the most appropriate
varieties, especially of minor crops where research
is not easily justified. Participatory plant breeding
can help fill this gap, ensuring that more of the
varieties developed meet farmer needs. For example,
the International Center for Agricultural Research
in the Dry Areas (ICARDA), together with the Syrian
Arab Republic and other Near East and North African
countries, has undertaken a programme of partici-
patory plant breeding which maintains high levels
of diversity and produces improved material capable
of good yields in conditions of very limited rainfall
(less than 300 mm per year). Farmers participate in
the selection of parent materials and in on-farm
evaluations. In Syria, the procedure has produced
significant yield improvements and increased the
resistance of the varieties to drought stress (Ceccarelli
et al., 2001; FAO, 2011).4.2.3 Integrated Plant Nutrient Management (IPNM)
IPNM and similar strategies promote the combined
use of mineral, organic and biological resources to
balance efficient use of limited/finite resources and
ensure ecosystem sustainability against nutrient
mining and degradation of soil and water resources.
For example, efficient fertilizer use requires that
correct quantities be applied (overuse of Nitrogen [N]
fertilizer can disrupt the natural N-cycle), and that
the application method minimizes losses to air
and/or water. Equally, plant nutrient status during
the growing season can be more precisely monitored
using leaf-colour charts, with fertilizer application
managed accordingly. Efficient plant nutrition also
contributes to pest management.Urea deep placement for rice in Bangladesh
Throughout Asia, farmers apply nitrogen fertilizer
to rice before transplanting by broadcasting urea
onto wet soil, or into standing water, and then using
one or more top-dressings of urea in the weeks
after transplanting up to the flowering stage. Such
practices are agronomically and economically in-
efficient and environmentally harmful. The rice
plants use only about a third of the fertilizer applied
(Dobermann, 2000), while much of the remainder is
lost to the air through volatilization and to surface
water run-off (FAO, 2011).Deep placement of urea (N) briquettes can increase
rice yields, while reducing the amount of urea used.
In Bangladesh the average paddy yields have
increased 20–25% and income from paddy sales in-
creased by 10% while urea expenditures decreased
32% from the late 1990s to 2006 (IFDC, 2007).4.2.4 Integrated Pest Management (IPM)
IPM encourages natural predation as a means of
reducing the overuse of insecticides. In countries
like India, Indonesia and the Philippines that71