Water scarcity and abundance, water productivity and their relation to poverty - Water Scarcity, Livelihoods and Food Security - page 25

basal fertilizer can reduce risk (PN1) (Dimes et al., 2005) when combined with
soil cover or cover crops (FUNDESOT, 2012). Pastoralists and agro-pastoralists
have developed various community-level coping mechanisms in response to
seasonal unreliability.
There are places in China where the rainfall can be too little for flooded
rice in some years, but in other years, there is too much rain for maize or other
rainfed crops. A CPWF project selected and mapped these places and showed
that aerobic rice can grow well when rainfed, but it is not affected by flooding
(PN16) (Bouman, 2008). The challenge will be whether aerobic rice will work
elsewhere (Rubiano and Soto, 2008).
Quality
We also addressed water quality as a component of scarcity, especially when
linked to seasonality (“right amount of the right quality of water for the right
purpose at the right time”).
Salinity induces seasonal scarcity of freshwater in places such as coastal
Bangladesh, 5 where a series of polders create areas of land protected from river
flooding or seawater incursion by embankments. Freshwater surrounds the
polders during the wet season and salt water during the dry season. Lack of
freshwater at the end of the wet season and during the dry season hinders
intensification and diversification of farms in the polders. Most produce only
one low-yielding rice crop during the wet-season each year.
Nevertheless, in places in coastal Bangladesh it is possible to grow two rice
crops in the wet season plus a dry-season crop, or rice followed by aquaculture.
The intensification depends on allowing freshwater to enter and be stored
when the water surrounding the polders is fresh, and closing the sluice gates as
the water becomes saline (PN10 and G2) (Sharifullah et al., 2008; Humphreys,
2012). Overcoming water-scarcity problems caused by variable quality during
the year depended on new crop-management technology and new institutions
to coordinate management of sluice gates and infrastructure within the polders
(G3) (Mukherji, 2012).
Salt stress is a problem in rice in the lower Ganges Basin of India and in
Bangladesh without polders. Seawater intrusion causes salinity in coastal areas
and inland there are shallow, saline water tables. In the wet season, flooding is
a problem, while salinity damages crops during the dry season, and in inland
areas, it is expanding. Project PN07 integrated salt-tolerant rice and other
crops with complementary land and water management to minimize the effects
of salt (Srivastava et al., 2006; Castillo et al., 2007; Vadez et al., 2007; Islam et
al., 2008; Ismail, 2009).
In the Andes, sediment often reduces water quality, causing scarcity down-
stream because muddy water is unsuitable for sprinkler or drip irrigation or
for domestic use without expensive treatment. Projects PN22, Andes 2 and
Andes 3 promoted institutional changes that allow for payment for ecosystem
services and other benefit-sharing mechanisms to encourage farmers in upper