In the U.S., lawn coverage has been estimated to be between 25 million and 40 million acres. The scale of synthetic fertilizer application has been increasing, particularly in southern states. Improper home lawn and landscape fertilizer management practices can lead to increased nitrogen and phosphorus runoff entering storm drains and waterways. Louisiana’s government and environmental agencies have been working to implement a nutrient management strategy to improve water quality. The strategy includes stakeholder engagement within urban/suburban watersheds to enhance the use of best management practices.
The purpose of this study was to determine the current fertilization practices used by Louisiana urban and suburban homeowners and ways to encourage them to adopt the best management practices. To determine how to change behaviors, the researcher used an analytical tool known as Ajzen’s Theory of Planned Behavior. The combined effect of homeowners’ attitudes, perceived norms and perceived controls on their intention to perform fertilizer management practices was studied, as was the effect of intention and perceived control of their past fertilizer practices. There were 12 practices identified through a pilot study that were subsequently examined in an online questionnaire. The 12 practices were either a recommended fertilization practice or a practice that had the potential to affect water quality.
There were 260 respondents that met the eligibility requirements of being a Louisiana urban or suburban homeowner. They were asked if they had ever applied fertilizer to their home lawn and/or landscape at their current or former residence, and most respondents said “yes” (73.8%). The 192 homeowners that applied fertilizer were asked to select the types of fertilizer most used, and the largest number (42.6%) selected “weed-and-feed.” The 192 homeowners were also asked to indicate the amount of fertilizer they would consider using in a single application to their lawn. Most respondents (77.6%) reported that they applied the amount on the product label. The response selected by the second largest group (18.2%) was that they applied the entire bag.
The results from the questionnaire also indicated which fertilizer practices had the greatest potential to change. The two most significant results were found for the “soil testing” practice and the “watering in lawn fertilizer” practice. The soil testing practice is recommended to determine the amount of nutrients to be added to the soil. The homeowners’ mean response for past performance of a soil test was that they seldom did this. The results of the analysis indicated that enhancing communal support for soil testing could increase homeowners’ likelihood of performing this best management practice.
It is not recommended that lawn fertilizer be watered in with rain because this imprecise method can enhance fertilizer runoff. However, the homeowners’ mean response for perceived control was that they had “a large extent of control” watering in lawn fertilizer when rain was expected. Their mean response for intention was “maybe they do intend” to coordinate the application of lawn fertilizer when rain is expected.
Although the homeowners in this study may intend to use a rain event to water in lawn fertilizer, they have been experiencing uncertainty about intending to perform this practice. Therefore, homeowners could be persuaded to change their behavior through an educational program that teaches homeowners methods of irrigation that actually provide control.
Ultimately, to address the fertilizer management practices of concern identified in this study, it is recommended that the LSU AgCenter conduct more educational programs, including publications, social media and classes, on fertilizer management.
Natalie Levy was a postdoctoral researcher in the Department of Agricultural Extension Education and Evaluation. Her major professor was Michael Burnett, department head.
(This article appears in the winter 2020 issue of Louisiana Agriculture.)
It is not recommended that lawn fertilizer be watered in with rain because this imprecise method can enhance fertilizer runoff. Photo by Linda Foster Benedict