Worldwide an estimated 10 million hectares (ha) are lost every year to salinity and/or waterlogging. The Middle East region is no exception. In Iraq, for instance, an ICARDA study estimated that farmers affected by salinity are using only 30 percent of their land for cropping and achieving only 50 percent of expected yields – amounting to a loss of 300 USD million per year.
Salinity occurs when evaporation and transpiration cause excessive amounts of salt to accumulate in soils. The problem in the Middle East is compounded by inefficient irrigation systems and poor drainage: high rates of leakage and groundwater recharge cause the water table to rise, bringing salts into the plant root zone and damaging plant growth and soil structure.
The Water and Livelihoods Initiative (WLI) mitigates and tackles the problem of salinization through the following approaches: increasing the efficiency of irrigation systems; introducing saline-tolerant crops; and closely monitoring soil moisture levels.
Inefficient irrigation systems: high rates of water leakage; poor and unequal water distribution; and limited information on crop water requirements.
Limited farmer access to key inputs – including improved salt-tolerant crop varieties and tools to measure soil moisture
Salinity management innovations:
Efficient irrigation systems: introducing more efficient irrigation systems such as supplemental and drip irrigation, in addition to appropriate drainage systems to stabilize crop production
Introducing improved salt-tolerant varieties: introducing plant and crop varieties that can thrive on land already affected by salinization – including vetch, wheat and barley.
Measuring crop water requirements: the controlled application of water tailored to specific crops to prevent the over-use of water.
Close monitoring of environmental conditions to prevent salinization: studying levels of salt build-up in soil, water table depth, and hydraulic conductivity; and examining the effect of farmer practices on crop production and salinity.
Selected research activities and results:
In Egypt, the WLI team assessed irrigation sustainability and monitored soil salinity build-up in the old lands to determine water quality deterioration in relation to irrigation and drainage management practices. Strategic maps that provide important information on the impact of farmers’ traditional practices on soil compaction and salinity were also developed.
The WLI team, in close collaboration with Zagazig University and researchers from ICARDA, also conducted a study on the “Economics of Irrigation Water Management in the Salt-affected Soils of Egypt”. The study assessed farmers’ practices and the profitability of selected cash crops including sugar beet, maize, rice, cotton, and clover under specific bio-physical conditions.
Adding cytokine hormones to brackish water under drip irrigation in Iraq prevented leakage and made cucumbers more resistant to drought conditions.
In Iraq, efforts to develop land suitability maps for barley, wheat, corn and clover in Abu Ghraib identified salinity, alkalinity, soil texture, and gypsum content as the major land factors limiting crop production. Another study in the same area indicated that using salt clean as a soil amendment for maize production with irrigated saline water results in higher water productivity – 0.799Kg/m3 as compared to 0.541Kg/m3 for crops without salt clean.
In Tunisia, the AquaCrop model, which includes a salinity component, is being used as a planning tool to assist in management decisions for both irrigated and rainfed agriculture. The model is calibrated and validated for barley and potato to simulate yields under different climate change scenarios.