Community gardens have been proposed as a strategy to increase green space in urban communities and have social and public health impacts. The increasing popularity of urban food production gardens in post-industrial cities contributes to food security in food deserts, fosters healthy eating, improves physical and mental health, facilitates interaction between neighbors, and improves quality of life. The objective of this study is to answer the following questions: Are legacy pollutants present in Louisville, Kentucky's urban community gardens? Are observed soil amendments in garden plots improving soil nutrient concentration? Randomized grid sampling of garden plots was performed and soil was collected using an AMS Soil Turf Probe. Analysis of soil texture, pH, concentration of trace nutrients Ca, K, Mg, P, B, Na, and metals As, Cu, Fe, Mn, Zn, Al, Cd, Cr, Pb, Ni using Mehlich 1 Extraction. Variable degrees of input in plots were observed and classified as high or low input. High input included presence of leaf mulch, manure, cover crop (vetch and clover). Low input plots had little to no input.
Results/Conclusions
The results revealed soil texture as silt loam, with a mean of 19.69% sand, 60.315% silt, and 20% clay. pH was neutral to slightly basic with a range of 6.73 to 7.65. Trace nutrient concentration means of Ca: 3747.889ppm, with a range of 2881-4986ppm, Mg: 514.3333ppm with a range of 407-622ppm, P: 134.3333ppm with a range of 57-331ppm. Copper concentration ranged between 0.1 – 0.9ppm with a mean of 0.41ppm and zinc from 7-25ppm with a mean of 12.44ppm, well under the World Health Organization desirable maximum level of elements in unpolluted soils (Cu:36, Zn:50ppm). No variation in concentration was found in heavy metals As, Cd, Cr, Ni, Mo, and Pb showing concentration of <0.1ppm for each element (p>0.05). The data reveals relative absence of heavy metals in gardens suggesting they are safe for urban gardening at this time. Plots with high input had a significantly higher concentration of K with a mean of 162.5556ppm (p = 0.002735), optimal concentration for a variety of vegetable crops.