Household Use of Composted Manure and Phosphorous-Free Fertilizers: Feeling Good versus Doing Good

Abstract

Increasing urbanization has led to increasing impermeable surfaces and use of lawn care products. Phosphorous (P) is a major pollutant in freshwater systems, leading to eutrophication, harmful algal blooms and hypoxia. An important source is runoff from urban areas so reducing use of P fertilizers by homeowners would be helpful. This study examines the use of two alternative fertilizer sources in an urbanizing watershed in the Midwest, organic fertilizer/composted manure and P-free fertilizer. A mail survey of households was conducted, resulting in a 44% effective response rate. The adoption rates were relatively high (31% and 23% respectively) compared to those found in previous work for rain gardens and rain barrels. Probit regression results found that adoption of both practices was higher among those who tested their soil, knew the watershed concept, and spent more than 10 hours per month gardening. Results for use of composted manure imply that adopters do not view this as fertilizer, which may result in buildup of P levels in the soil over time. Respondents who indicated that water quality was more important than economic development were more likely to use P-free fertilizers. Significant demographic factors for organic fertilizer were somewhat surprising; those with two years of college were more likely to adopt than those with a four-year degree and those with household income of $50,000 - 75,000 were more likely to adopt than those with an income of $75,000 - 100,000. No demographic factors were important for P-free fertilizers.