Impact of agriculture on soil and water quality in the north-east of Algeria: Boumaiza Plain

The Boumaiza Plain is situated in the northeast of Algeria and encompasses a vast area of the El-Kebir West watershed, which has a significant water potential. The intensification of agricultural activities in this region has led to a notable increase in the use of phytosanitary products, which may impact the physico-chemical quality of groundwater and soil. A sampling campaign was conducted in 2022 to assess the impact of agriculture. To achieve this aim, we analysed 12 points, comprising 7 wells and 5 boreholes, as well as the grain size and physicochemical characteristics of 12 soil samples. The methodology employed for processing the analysis results is based on multivariate statistical methods. The results of the analyses revealed pollution of agricultural origin. This is substantiated by the observation of relatively high levels of nutrients, including NO<sub>2</sub>, NO<sub>3</sub>, as well as potassium which exceed 5 mg/l in water and 40.76 mg/l for soil analyses. Principal component analysis (PCA) was also applied, while the opposition of physicochemical elements to nitrites, nitrites, chlorides, sulfates, ammonium, and potassium variables highlights another mechanism involved in water mineralization, which is governed by the inputs of surface water fromagricultural areas and the intrusion of rich in organic matter waste from domesticated animals.