Background Information on the Challenges for Agricultural Production in Iraq: Future Perspectives in Using Nuclear Techniques

In Iraq agriculture started 7000 years ago under the Babylonian and Sumerian civilizations. Close to 80% of the total area is potentially suitable for agriculture, however, only 27% of this surface is currently utilized for agricultural purposes. Iraqi agricultural production is mostly dependant on irrigation, with the Tigris and Euphrates basins being the major crop producing areas. The cultivated area under irrigation represents 70% of the arable lands and rainfed agriculture covers 30%. Most Iraqi soils are highly calcareous (CaCO3= 15-35%) with a typical pH of more than 7 and low soil organic matter content (<1%). Under such soil conditions many soil nutrients are unavailable for uptake by crops (e.g. phosphorus and trace elements). Moreover, soil degradation is a major threat to soil and water resources sustainability in Iraq and represents a serious limitation to achieving food security. Furthermore, because of climate change, rainfall has declined by 30% in recent years in-creasing desertification processes and the recurrence of heavy dust storms in the summer season but also during the winter, events that were quite unusual in the past. The main challenges that farmers face in Iraq can be summarized as follows: (i) Shortage of water In arid and semi-arid regions, many crops cultivated during the hot spring and summer consume high amounts of water due to high transpiration and losses through soil evaporation. In addition, Iraqi's farmers still use traditional irrigation methods such as flooding. Therefore the available irrigation water resources are not sufficient to cover the agricultural water demand of the cultivated land. Adapted irrigation planning is needed to reverse this trend. Moreover, Iraq has also been suffering from a shortage of fresh water due to the establishment of dams up-stream in both the Euphrates and Tigris rivers. (ii) Salinity One of the major limitations to agricultural development in Iraq is an excessive salinity which affects 70 to 80 % of the agricultural land. Several factors have contributed to increased salinization of the Iraqi's soils such as: (i) the climatic conditions (high temperature and low precipitation); (ii) the mismanagement of agricultural lands by farmers; (iii) the shallow saline water table; (iv) the ineffective drainage systems; (v) the heavy texture of the soil; and (vi) the poor irrigation water quality. Large areas of land have become salt-affected reducing their productivity and also the interest of the farmers, who have abandoned the affected areas. Development of effective drainage systems will facilitate and accelerate the desalinization of the affected soils. However, these processes and activities need large quantities of fresh water to remove the excess of salt accumulated in the soil profile. (iii) Soil erosion by wind. During the last decade Iraq started to encounter atypical climatic events with increasing dust storms. Many reasons have contributed to the intensification of this phenomenon such as climate change, misuse of agricultural land, a shortage of fresh water and a reduction in rainfall. The main sources of this dust are the desert and the degraded agricultural lands (abandoned by Iraqi's farmers due to the high salinity level. The following nuclear techniques can potentially mitigate and control these constraints and threats for Iraqi's arable (Tonga)) land: Use of fallout radionuclides (e.g. 137Cs and/or 210Pb) as soil tracers to assess wind erosion magnitude; Use of nuclear indicators (i.e. 22Na, 36Cl and 35S) to monitor salt movement; Use of neutron probe techniques in irrigation scheduling and deficit irrigation practices; Use of 15N for Biological Nitrogen fixation studies; Use of 32P to investigate Phosphorus availability in calcareous soil and its linkage with soil amendments application; Investigation of the soil organic matter dynamic using the stable isotopic approach (i.e. 13C).