Horticulturist soils contribution in the pollution of the Kara river

The objective of this research is to study the impact of horticulture activity on kara river. to reach this objective the soil samples of horticulturist plots were randomly collected at kara riverside and were analyzed. some chemical parameters such as ph,electrical conductivity,organic matter,exchangeable cations capacity were determined on the samples. the total phosphorus content of the soils,the total nitrogen content,the rainfall water leachable phosphate and nitrate were also analysed. these analysis revealed that the organic matter content of soils ranged between 0.5 -16.2% per mass. the total nitrogen content was in the range of 159.0 - 1575.0 mg/kg while a rainfall of 1mm could leach from 1m2 of soil 0.41 up to 12.20 mg of nitrate. the total phosphorus content of the soils was within 190.0 and 2800.0 mg/kg; a rainfall of 1mm could leach from 0.71 up to 13.3mg of phosphate on 1m2 of the soils. these results show that the leaching of target soils during a raining season could increase very significantly the level of the kara river in nitrate and phosphate. therefore we deduced that horticulturist activities at kara riverside were contributing to increase the pollution of the river. © 2017,university of mohammed premier oujda morocco.