Extension publication, “W 278: Part I. Water Use in Nursery Production,” discussed the importance of and competition for water use in nursery production.
“W 279: Part II. Strategies to Increase Efficiency” covered techniques that growers can use to refine scheduling (volume and timing) and delivery of irrigation water. This final publication in the series discusses the significance and causes of nursery irrigation runoff and offers strategies to manage runoff.
As discussed in Part I of this series, irrigation can contribute to nursery runoff. While growers generally aim to apply 1 inch of water per day, field studies show that growers actually apply as little as 0.3 and as much as 1.3 inches per day. The greater the volume of water applied, the greater the potential for runoff. Runoff, or more precisely, surface runoff, is defined as water moving over the surface of saturated soil. Runoff can cause erosion and carry pathogens and pollutants, such as pesticides, petroleum products, soil, fecal contaminants and nutrients that may contaminate ground and surface water. Agricultural runoff and its link to eutrophication in surface waters led to legislative action affecting agriculture producers in recent years, including the Neuse River watershed in North Carolina and the Chesapeake Bay.