Physicochemical and mineral properties of suspended sediments of the Tigris and Euphrates rivers in the Mesopotamian Plain.

Most of the suspended river load from the Tigris and Euphrates rivers is deposited in the Mesopotamian Plain in Iraq. This suspended river load comprises sediments consisting of minerals and organic particles generated from weathering, erosion, transport, and sedimentation. Therefore, it is crucial to analyze, either quantitative or qualitatively, the types of minerals in the sediment particles transported by the suspended river load, in addition to the potential value they may add to the agricultural lands irrigated by the Tigris and Euphrates rivers. Herein, samples of suspended sediments were collected from both rivers for physical, chemical, and mineral assessments. The results revealed the predominance of silt particles, followed by clay, and then sand. The presence of clay particles increased while that of silt and sand decreased with further travel into the rivers. The pH values ranged from 7.39 to 7.70 and the electrical conductivity ranged from 1.39 to 2.16 ds m-1. The values of the total and active calcium carbonate minerals were 352.87-336.12 and 172.64-194.56 g kg-1 for the Tigris and Euphrates rivers, respectively. The mineral analysis identified the presence of non-clay minerals at a rate of 83 %, including calcite, quartz, albite, dolomite, and gypsum. Clay minerals, including chlorite, illite, montmorillonite, palygorskite, vermiculite, and kaolinite, were found at a rate of 17 %. Both rivers exhibited distributions of clay and non-clay minerals that vary as they move along the rivers.

A comparison of different solarisation systems and their impacts on soil thermal characteristics-an application in cultivated soils close to Baghdad, a highly populated city in Iraq.

Solarisation application by mulching the soil with a polyethene plastic film has a significant influence on soil thermal characteristics (TCs), which, in turn, show a strong impact on soil energy balance and agricultural productivity. In countries like Iraq with highly populated cities, such as Baghdad, that need large quantities of agriproducts, this kind of clean energy should play a key role in sustainable agricultural production. However, little is known about the effects of different soil solarisation systems in specific cultivated fields for this country characterised by an arid climate and silty clay soils. Therefore, an experimental study was conducted to investigate changes in soil TCs under different soil solarisation systems (black and clear plastics) at three different soil depths in a two-factor factorial design. Also, both the black and clear plastic plots were compared with a control (without mulch) plot treatment. Three different soil TCs were assessed, namely soil thermal flux (qℎ), soil thermal conductivity (k), and soil volumetric heat capacity (Cv). The results of this study indicated that the soil solarisation application had a significant influence on soil TCs. Soil qℎ decreased with increasing soil depth, while k and Cv exhibited an opposite trend. The black plastic mulch treatment produced higher soil qℎ, k, and Cv values than both the clear plastic and the control treatments. Moreover, high diurnal variability of the TCs was also registered, and the clear plastic conserved a higher temperature than the black one during the night hours. During daylight, the black mulch reached a maximum temperature of 70 °C. It is recommended that more research should be conducted to get new insights on the interplay of the different seasons, and different crops and soil types.