Can lead and limestone contamination of soil and water in mine sites affect agronomic productivity and inhabitants?

Methods

Summary

Soil and Plant Sampling

Each of the profile pits (at mine and un-mine sites) will be georeferenced with a Global Positioning System (GPS) which will also give the altitude of each point. The pedons will be described in situ following the procedures in the guidelines for soil profile description (FAO, 2006) and horizon designations of the Soil Survey Staff (2006). Soil colours will be described using Munsell Soil Color Charts (Munsell soil color chart, 2009). Soils will be sampled at a regular interval of 20 cm from the bottom upwards to avoid contamination for chemical analysis in the laboratory. Undisturbed core soil samples will also be collected but in reverse order for bulk density and saturated hydraulic conductivity.

Each auger sampling point will be georeferenced with a Global Positioning System (GPS) which will also give the altitude of each point. Soil samples will be collected at 10 points at depth intervals of 0-15 and 15-30 cm. This will be obtained at both mine and un-mine sites. Undisturbed soil samples will also be collected at each point. Ten plant biomass samples will be collected randomly from the mine and un-mine sites of the two locations.

Water sampling

The coordinates for water sampling points will be obtained using a Global Positioning System (GPS). Water samples from the well, borehole, and stream (top, middle and bottom stream) will be collected in duplicates. The water sources will be randomly selected without consideration of distance from mine pits and depict the major sources of water in Nkalagu and Ameka communities for domestic and agricultural purposes. Tight-capped, high-quality polyethylene bottles will be used for sample storage. Prior to use, the bottles will be washed with distilled deionized water and rinsed overnight in 10% (v/v) nitric acid and later with the sample surface water before filling. The method followed by Assubaie (2015) will be adopted to prevent precipitation of metals and biological growth by adding a few drops of concentrated nitric acid to samples to obtain a pH of around 2. Before the addition of concentrated nitric acid, the temperature of water samples will be taken immediately at the collection sites using a simple thermometer calibrated in degree Celsius and each of the water samples will be separated for pH determination. After that, samples will immediately be transported to the Department of Soil Science laboratory, University of Nigeria, Nsukka

Respondent sample survey 

Farmers within the spatial boundary of each community will be considered in the study. Sampling will be based on the purposive non-probability method, and only willing farmers will be interviewed. The farmers will be interviewed on the major land uses, especially mining activities, and how it impacts their environment (land and water), agriculture, and socio-economic life. Formal and informal in-depth interviews will be done using a structured questionnaire and informal discussions with experienced farmers. A structured questionnaire containing objective and subjective questions will be given to farmers. Data will be collected through the farmers’ responses as guided by an extension agent.