Ayoola Rhoda Titilope, Olujimi Olanrewaju Olusoji, Bada Babtunde Saheed, Dedeke Gabriel Adewunmi
Department of Environmental Management and Toxicology, College of Environmental Resources Management, Federal University of Agriculture, Abeokuta, Nigeria.
Department of Zoology, Federal University of Agriculture, Abeokuta, Nigeria.
Heliyon. 2023 Sep 19;9(9):e20324. doi: 10.1016/j.heliyon.2023.e20324. eCollection 2023 Sep.
This study investigated the concentration of glyphosate in water (groundwater and surface), soil (top and sub) on cassava and maize farms within 3 farm settlements (Akufo, Ilora and Otiri Ipapo) from Ido, Oyo and Iseyin Local Government Areas of Oyo state, Nigeria. Samples of Top and sub soil were taken from the farms while water was collected from wells (groundwater) and streams (surface water) around each farm settlement using standard methods. Crops (cassava and Maize) samples were collected from each of the selected farm after harvest. The samples were collected over a six-month period to reflect seasonal variation. The glyphosate levels were determined using HPLC-FLD after liquid-liquid extraction technique for water and soxhlet extraction for soil crops The pH, electrical conductivity (EC), total dissolved solids (TDS) values for groundwater were within the WHO limits while values recorded for surface water were above the WHO limits. The phosphate and nitrate values were high in surface water compared to groundwater. High concentration of the exchangeable cations were recorded at the top soil for all the farms with values ranging from 4.0 ± 0.1 to 8.2 ± 0.0 for Ca, 2.9 ± 0.0 to 5.1 ± 0.1 for Mg, 0.3 ± 0.2 to 0.55 ± 0.0 for Na, and 0.32 ± 0.0 to 8.2 ± 0.0 for K. the residual concentration of glyphosate taken from wells and taps (groundwater) were within the maximum concentration of glyphosate in drinking water (0.7 mgL). Glyphosate concentrations observed were higher in soil samples from all farm settlements during wet season compared to dry, higher concentrations were also observed in surface water during wet season (August) compared to dry, with Akufo farm settlement having the highest concentrations of 29.40 ± 0.83 mgL. The glyphosate residues were also higher in cassava (0.3 ± 0.0 mgKg) compared to maize (0.07 ± 0.08 mgKg) across each farm settlement. Generally, the higher concentrations observed during wet season in both soil and water samples were as a result of active farm activities during wet season and run off respectively. If herbicide usage is not properly monitored within these settlements, it can pose a threat to aquatic animals and humans around the settlements, thus a sustainable and conservative farming is advised.
本研究调查了尼日利亚奥约州伊多、奥约和伊塞因地方政府辖区内3个农场定居点（阿库福、伊洛拉和奥蒂里伊帕波）的木薯和玉米农场中水（地下水和地表水）、土壤（表层和下层）中的草甘膦浓度。从农场采集表层和下层土壤样本，同时使用标准方法从每个农场定居点周围的水井（地下水）和溪流（地表水）中采集水样。收获后从每个选定农场采集作物（木薯和玉米）样本。样本采集期为6个月，以反映季节变化。采用液-液萃取法处理水样、索氏萃取法处理土壤作物样本后，使用高效液相色谱-荧光检测器（HPLC-FLD）测定草甘膦水平。地下水的pH值、电导率（EC）、总溶解固体（TDS）值均在世卫组织规定的限值范围内，而地表水的测定值高于世卫组织限值。与地下水相比，地表水中的磷酸盐和硝酸盐值较高。所有农场的表层土壤中均记录到高浓度的可交换阳离子，钙的浓度范围为4.0±0.1至8.2±0.0，镁为2.9±0.0至5.1±0.1，钠为0.3±0.2至0.55±0.0，钾为0.32±0.0至8.2±0.0。从水井和水龙头采集的地下水（井水）中草甘膦的残留浓度在饮用水中草甘膦的最大浓度（0.7mg/L）范围内。与旱季相比，所有农场定居点在雨季采集的土壤样本中草甘膦浓度更高；与旱季相比，雨季（8月）地表水中的草甘膦浓度也更高，其中阿库福农场定居点的浓度最高，为29.40±0.83mg/L。在每个农场定居点，木薯中的草甘膦残留量（0.3±0.0mg/kg）也高于玉米（0.07±0.08mg/kg）。一般来说，雨季土壤和水样中观察到的较高浓度分别是由于雨季农场的活跃活动和径流造成的。如果在这些定居点内对除草剂的使用没有进行适当监测，可能会对定居点周围的水生动物和人类构成威胁，因此建议采用可持续和保守的耕作方式。
