A survey, focusing on the use of irrigation and fertilization best management practices (BMPs), was designed and released to Virginia nursery and greenhouse growers. The objectives of the survey were to determine the most widely used BMPs, assess the reasons for their use, and identify barriers to BMP adoption. The survey was distributed in person, via e-mail attachment, or link to 357 Virginia growers in 2016 with 60 respondents. Survey results demonstrate that the most widely used BMPs in Virginia included irrigation scheduling, integrated pest management (IPM) implementation, altering irrigation practices to optimize irrigation efficiency, controlled-release fertilizer (CRF) use, and plant need–based watering. Respondents selected environmental/resource savings as one of the most cited reasons behind BMP use for water, fertilizer, and runoff management. Cost was the most cited barrier to BMP adoption for all BMPs. Fertilizer management BMP implementation was primarily an economic decision. The value of determining the most widely used BMPs and impediments to BMP adoption is that we can 1) communicate this information to growers who currently do not employ BMPs to encourage BMP adoption and 2) subsequently inform the regulatory community of BMP use. Increased BMP use can boost the potential for mitigation of agricultural nutrient and sediment runoff into impaired waterways, including the Chesapeake Bay, and help growers increase efficiency of operation inputs, such as water and fertilizer resources, while potentially saving money.
Rachel Mack, James S. Owen, Alex X. Niemiera, and Joyce Latimer
Rachel Mack, James S. Owen Jr., Alex X. Niemiera, and David J. Sample
Nursery and greenhouse growers use a variety of practices known as best management practices (BMPs) to reduce sediment, nutrient, and water losses from production beds and to improve efficiency. Although these BMPs are almost universally recommended in guidance manuals, or required by regulation in limited instances, little information is available that links specific BMPs to the scientific literature that supports their use and quantifies their effectiveness. A previous survey identified the most widely used water management, runoff, and fertilizer-related BMPs by Virginia nursery and greenhouse operators. Applicable literature was reviewed herein and assessed for factors that influence the efficacy of selected BMPs and metrics of BMP effectiveness, such as reduced water use and fertilizers to reduce sediment, nitrogen (N), and phosphorus (P) loads in runoff. BMPs investigated included vegetative zones (VZs), irrigation management strategies, and controlled-release fertilizers (CRFs). Use of vegetative buffers decreased average runoff N 41%, P 67%, and total suspended solids 91%. Nitrogen, P, and sediment removal efficacy increased with vegetative buffer width. Changes in production practices increased water application efficiency >20% and decreased leachate or runoff volume >40%, reducing average N and P loss by 28% and 14%, respectively. By linking BMPs to scientific articles and reports, individual BMPs can be validated and are thus legitimized from the perspective of growers and environmental regulators. With current and impending water use and runoff regulations, validating the use and performance of these BMPs could lead to increased adoption, helping growers to receive credit for actions that have been or will be taken, thus minimizing water use, nutrient loss, and potential pollution from nursery and greenhouse production sites.