Runoff Water Quality from Different Urban Agricultural Systems Using Common Nutrient Management Practices

Urban agriculture is regaining popularity as a method of food cultivation to meet the food needs of communities that reside in densely populated areas. Although this method of farming has many benefits, little research has evaluated the potential impacts of practice on the environment, such as water quality resulting from nutrient runoff. To address this gap, this study analyzed runoff water collected from raised beds and small plastic pool container plots with four different types of nutrient man-agement treatments (conventional fertilizer, organic fertilizer, low-compost + organic fertilizer, and high compost). Water samples were collected from each of the raised bed and container plots once per month, weather permitting, and analyzed for pH, conductivity, color, turbidity, nitrate-nitrogen, ammonia-nitrogen, total phosphorus, and potassium. Although there were some significant differences between the raised beds and container plots, they did not translate to meaningful differences in water quality for most variables measured, except for nitrate-nitrogen. The conventional fertilizer treatment demonstrated greater or more variable nutrient leaching than the other nutrient management treatments. This result suggests an opportunity for im-proved nutrient management by urban farmers to reduce nutrient leaching. Sampling time was found to have a significant impact on runoff water quality, which could be attributed to varying precipitation rates between samplings and timing of sampling in relation to compost and fertilizer applications, and crop production cycles.