Living Land

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The economics of the introduced biosaline agricultural system

are important. Since desertification is related to the poverty cycle

and marginal agricultural ecosystems, it is important that the

new landscape management system has a positive contribution

to the local economy. Two examples are the introduction of more

salt-tolerant date palms, a cash crop with an already existing

market system in many desert-prone areas, and quinoa, a high

market value crop which produces seeds and biomass well under

marginal conditions (salinity, high temperatures and drought).

Providing forage and grazing genotypes and varieties that are

adapted to marginal conditions (such as drought and salinity)

also requires an analysis of the nutritional value, and the palat-

ability of the introduced crops. A crop can be growing well under

the marginal conditions, but if it does not have a nutritional addi-

tion, or if the small ruminants are not willing to consume it as

part of their diet, the value of the crop is limited for the region.

In some areas, only seawater is available. Some plants growing

under hot, coastal conditions, halophytic plants, can provide an

economic value, for example plants from the Salicornia geno-

type. In the Netherlands, a market chain was developed and

supported, including the development of customer demand

through the introduction of cooking classes and recipes, for

Salicornia imported from the coastal and desert areas in Mexico.

Land and water management needs special attention when

managing agroecosystems under dry and saline conditions.

Water resources are often non-renewable (fossil groundwater)

and application of saline water on soils without considering

the potential accumulation of salts can lead to non-sustaina-

ble, short-term solutions. Although in some cases, short-term

solutions can be applied to overcome crises periods, the

long-term aim of land and water management in fragile and

marginal environments is to develop sustainable solutions.

When saline water is used for crops, forestry or any type of

biomass growth, evaporation and transpiration will result in

an increase of concentration of salts. These salts, previously

stored in the water source (groundwater, seawater or other

surface water sources) are increasing in concentration due

to evapotranspiration, but also due to the spatial accumula-

tion at the locations where plants are grown and irrigated.

Consideration of where the accumulated salts are stored is

a necessity under biosaline agriculture. Options are to store

salts in the soil below the active root zone (through leach-

ing of salts, that is the application of excess water to move

the accumulated salts away from the plant roots), leach salts

into the groundwater (less preferable), or concentrate salts in

evaporation ponds where they can be collected in solid form

and taken out of the agro-production system).

Six different groups of biosaline systems have been piloted

in the Arabian Peninsula, providing opportunities to break

the poverty cycle, green the desert and reclaim salinized

lands. These groups can be classified as conventional forage

production systems; non-conventional forage production

for subcoastal and coastal deserts; high-value crops and date

palms; medicinal crops production systems; seawater-based

systems including aquaculture; and production systems based

on treated wastewater.

Forage production systems

Water scarcity and salinity are two of the biggest constraints to

agricultural production in several counties in the Middle East

and North Africa region. In the United Arab Emirates (UAE),

over the years, more than 70 per cent of the farms were dedi-

cated to forage production, mainly with Rhodes grass (

Chloris

gayana

)—a high water consuming crop. The large-scale cultiva-

tion of this fodder grass species to meet the increased demand for

forages in the emirate, has had a profound impact on the usage of

water resources for agriculture and contributed to the depletion

of the groundwater reserves faster than the aquifer recharge that

depends on the scanty rainfall and as well as in increased aquifer

salinization due to intrusion of seawater, especially in the coastal

areas with close to 4,800 farms facing the risk of abandonment.

In a pilot project on three farms in the UAE, four halophytic

perennial grass species were planted:

Distichlis spicata

Sporobolus

virginicus

S. arabicus

and

Paspalum vaginatum

. The new grasses,

with the mean green biomass yields ranging between 122 t/ha

and 141 t/ha per year and dry matter yields between 24 t/ha and

42 t/ha per year, proved to be excellent and viable alternatives to

Rhodes grass for sustainable forage production in salt-affected/

degraded farms. In terms of water productivity, the forage yields

obtained per cubic metre of highly saline water (15-18 dS/m)

were 66 per cent more than the yields reported for Rhodes grass

with low salinity water (2 dS/m). In terms of water saving, it

means saving 44 per cent of water to produce the same amount

of forage as Rhodes grass.

Potential high-value crops

Several neglected and underutilized species, because of their

resilience and natural adaptation to harsh growing condi-

tions, can provide alternatives to the staple crops to sustain

farm productivity in desert environments constrained by water

scarcity, poor soil fertility and other such yield-limiting factors.

Among the species native to or naturalized in the Middle

East, Christ’s thorn jujube (

Ziziphus spina-christi

), purslane

Image: ICBA

Salicornia is produced on a large scale and irrigated with seawater in

coastal areas

iving

and