Agriculture Reference
In-Depth Information
practices. Water management requires common
agreements on the modalities of use. These agree-
ments will be best achieved through participatory
governance processes related to integrated land-
use planning. Large catchments, such as river
basins, need layers of nested planning approaches,
starting at the river basin scale, with implementa-
tion activities planned in detail on the landscape
scale.
Water resources management strategy is thus
the key to ensuring that agricultural production
can withstand the stresses caused by climate
change. Improved AWM is one of the “best bets”
for adapting agricultural production to climate
change and variability. However, accomplishing
this “Blue Revolution” is a signifi cant challenge.
The current poor performance in terms of water-
use effi ciency, plus competition over diminishing
water resources, suggests the need for investment
in better water management systems. Also, where
access to irrigation is limited, farmers need to
develop water conservation and rainwater har-
vesting systems to maximize on-farm water
management.
Rainwater harvesting complements irrigation
and enhances farmers' profi tability. Rainwater
harvesting for supplemental irrigation, for exam-
ple, yielded net profi ts of US$ 150-600 per ha in
Burkina Faso and US$ 110-500 in Kenya. Water
management is also improved by having a greater
diversity of options for water sources, such as
small streams, shallow wells, bore wells, and
rainwater storage. Other irrigation options
include surface irrigation methods (furrows and
small basins), pressurized systems (sprinkler and
both high- and low-head drip), and water lifting
technologies (gravity, manual, and pumps -
motorized, wind-driven, and solar).
Another management strategy is the upgrad-
ing of rainfed agriculture through integrated rain-
water harvesting systems and complementary
technologies such as low-cost pumps and water
application methods, such as low-head drip irri-
gation kits. Rainwater harvesting systems include
two broad categories:
In situ soil moisture conservation - technolo-
gies that increase rainwater infi ltration and
storage in the soil for crop use
Runoff storage for supplemental irrigation
using storage structures such as farm ponds,
earth dams, water pans, and underground tanks
Increasing investment in AWM is one of the
promising climate change adaptation strategies
for farmers. AWM can contribute to agricultural
growth and reduce poverty, since better manage-
ment of water will translate into intensifi cation
and diversifi cation in developed land, expansion
of irrigated areas, increases in food and feed pro-
duction, and environmental conservation.
Maintaining a stable water supply for agricul-
ture requires both demand-side strategies, such as
recycling and conserving water, and supply-side
strategies, such as water storage (Thornton and
Cramer
2012
).
The identifi ed and recommended feasible
AWM interventions should be promoted by
development agencies to enhance farmers' strate-
gies for coping with climate change and variabil-
ity. The following are some of the promising
AWM interventions that should be considered:
Irrigation development includes rehabilitation
of existing schemes to improve water-use effi -
ciency and productivity. This covers both
gravity-fed (most preferable, where applica-
ble, due to low operation and maintenance
cost) and pumped schemes (from either
groundwater or surface water sources - rivers,
dams, etc.).
Upgrading rainfed agriculture through in situ
rainwater harvesting systems - farming prac-
tices that retain water in crop land (terraces,
contour bunds, ridges, tied ridges, planting
pits, conservation agriculture, etc.).
Supplementary irrigation systems (farming
practices that supply water to crops during
critical growth stages) are appropriate where
irrigation water is inadequate for full irriga-
tion or where crops are grown under rainfed
conditions and only irrigated during intra-
seasonal dry spells or in case of early rainfall
cessation.
On- or off-farm water storage systems - rain-
water harvesting and management systems
allow the farmers to store runoff in ponds
(unlined or lined). For communal land or
farmers with appropriate sites, large storage
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