Abstract

The laboratory analysis revealed the diversity of soils in the study area between soils (silt sand, sandy clay, silt sandy, silty clay and silty clay).  This diversity in the soil of the lands of the studied areas offered an opportunity to identify the components of the soils of the agricultural lands that were under study, and they were an environment for cultivation of the khat plant.
The results of the physical analysis displayed that the soil cultivated with Khat in the study area was alkaline, so that the pH number ranged in all the studied samples from(7.18 - 8.42), while the field capacity in all samples ranged from (23.33.- 35.66%). This is due to the difference in the type of soil from one region to another. It was noticed that the electrical conductivity was high, ranging from 218-442 mm / cm in the lands cultivated with khat than in the control groups due to the high salinity in irrigation water and the intensive use of fertilizers. It was also found that salinity is still high in the soil from which the Khat plant was removed.
The studied areas differed in containing nutrients. The concentration of the magnesium ion ranged from (0.14 - 0.29) mmEq / 100 g., and its concentration varied from one site to another. The calcium concentration in these soils was low to average,  in general,  in all sites and ranged from(0.25 - 0.12) mmEq / 100 g, as the clay soils contained a higher concentration of calcium than sandy soils. The sodium concentration was close in all the studied soil samples and ranged from (7.18-8.42) mmEq/ 100 g. except in one site in which the sodium concentration increased greatly, while the potassium concentration ranged in all samples from (0.06-0.43) mmEq / 100 g.
The concentration of bicarbonate in the studied sites witnessed a clear variation, ranging from (0.15 - 0.28) mmEq/ 100g. , as its concentration increased in all sites cultivated with khat than in the control groups, while the concentration of dissolved chlorine in the studied soil ranged from (0.8 - 0.19) mmEq/ 100g. , where its concentration increased in two sites and was equal in two other sites. The variation in sulfate concentration was observed in the studied sites, which ranged from (3.9 - 4.47) mEq/ 100g. The nitrate concentration in the soils of the studied areas ranged from (14.33-23.66) PPM.