Analysis of agricultural practices' impact on the quality of irrigation water for growing vegetables in the Urban Commune of N'Zérékoré, Republic of Guinea

Irrigation water quality is a crucial factor influencing agricultural productivity and food safety. In the urban commune of N'Zérékoré, vegetable farming is a predominant activity. However, most local growers lack precise information on the quality of the water used for irrigation due to the absence of systematic monitoring by agricultural and public health authorities. This study, conducted in February 2024 in the Nyèn I and Nyèn II districts, aimed to assess the physico-chemical and biological characteristics of irrigation water used for vegetable cultivation. Water samples were collected weekly from both districts and analyzed using volumetric analysis and molecular absorption spectrophotometry. Data were processed using XLSTAT 2016 software, followed by an ANOVA with NSK’s test at a 5% significance level. The results showed that the concentrations of chemical elements, as well as total and fecal coliforms, were statistically similar across both sites. No significant variations were observed between the different sampling weeks. The mean concentrations of potassium (11.15 mg/L), manganese (0.34 mg/L), sulfates (11 mg/L), nitrates (42.02 mg/L), nitrites (1.9 mg/L), and total iron (2.94 mg/L) remained within acceptable levels for agricultural use. However, microbiological analysis revealed significant contamination, with fecal coliform counts averaging 869.75 CFU/100 mL and total coliform counts reaching 1142.50 CFU/100 mL, indicating potential health risks for crops and the environment. These findings highlight the need for phytoremediation measures, improved water treatment, and better irrigation water management to ensure safer and more sustainable agricultural practices in N'Zérékoré.