Undergraduate students generally have difficulty understanding plant water use in nursery conditions. A simple and reliable exercise to quantify evapotranspiration (ET) of containerized nursery plants is missing in the literature and could improve students' understanding of basic irrigation scheduling concepts. As potential nursery managers, students need to understand the consequences of both under- and overwatering a nursery crop.
Container production nurseries in the southwestern United States require significant amounts of water. In xeric environments, essentially all water demands must be met by irrigation, with little or no water from natural precipitation to support production. The northern Chihuahuan Desert in southern New Mexico provides an excellent “real-life” instructional setting for nursery production in high evaporative demand conditions (Picchioni et al., 2001).
Southwestern United States nursery managers have economic, environmental, and plant management concerns about water usage. If they apply less water than crops need, they might compromise product quality and prolong time of production (Beeson, 2006). Conversely, if they apply more water than required, they waste water and electricity, increase nutrient losses to the environment through surface runoff, and may limit growth and transplant survival (Beeson, 2006; Fare et al., 1992; Franco et al., 2006).
The main objective of this exercise was to improve student understanding of nursery plant water use and irrigation scheduling through a collaborative study with a local wholesale nursery. This paper supports instructors who wish to teach nursery crop water use measurement, but who have limited experience in quantitative irrigation methods. We designed the exercise to engage students in not only active learning, but also in research and outreach, while teaching water use measurements.
Intended outcomes of the exercise were as follows:
Conduct a nursery pot study to teach plant water use measurement while reinforcing skills in data collection and organization, graphing, interpretation, and information retrieval from the Internet.
Include a pedagogical foundation of rationale for the metric system, assigned readings, the scientific method, and hypothesis testing.
Engage students with commercial nursery managers through outreach designed to present results and recommendations to a client.
Integrate a student–researcher role with the learning and outreach components.
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