2007 Annual Report 1a.Objectives (from AD-416) Determine the amount of leachate in pot-in-pot nurseries due to different levels of drop irrigation and rainfall; determine levels of nutrient and pesticide residues in leachate with various irrigation schedules and pesticide spray application methods; determine the relationship between the amount of irrigation and soil moisture content in individual pots before and after leaching of water. 1b.Approach (from AD-416) In cooperation with the ARS Application Technology Research Unit, Wooster, OH, perform the following: An experimental system will be established in a plot in Willoway Nurseries, Inc. The system will contain leaching collection devices, soil moisture probes and pot-in-pot trees. Factors to be examined in this study will be: total amount of irrigation, rainfall and leachate from the plot; start and stop times for leaching; types of trees; types of soil; soil moisture content; soil temperature; and chemical residue levels. Precipitation and other conditions will be observed with a weather station. Water samples from the leaching will be collected weekly, and chemical residues in samples will be analyzed in the laboratory. After multi-test results are obtained, a potentially automatic irrigation control system will be proposed or developed for pot-in-pot tree nurseries with the best scheduling management of irrigation and pesticide application to be used in models to provide best management practices. 3.Progress Report This report documents research conducted under a Specific Cooperative Agreement between ARS and Willoway Nurseries, Inc. Additional details of the research can be found in the report for the parent project 3607-21620-006-00D Biological, Microclimate, and Transport Processes Affecting Pest Control Application Technology. In nursery production, knowledge of water quality and quantity is needed to improve irrigation and fertilizer application efficiency as it relates to potential for soil and groundwater contamination. Water and fertilizer use and loss as well as tree growth were investigated for Red Sunset maple trees in a pot-in-pot system with two different potting media and one coal ash based medium. The two potting media mainly composed of aged pine bark and steamed composted nursery trimmings as well as left-over potting mix from commercial nurseries, but one with high initial amendments (Medium #1) and the other one with low initial amendments. The coal ash based medium (Medium #3) was mainly composed of biosolids, flue gas desulfurization gypsum, and coal combustion bottom ash. Trickle irrigation was applied to each tree with an automatic control system. Watering trees started when the medium moisture was below 30%, and stopped when the moisture was 42%. During two-year tests, the amount of water including irrigation and rainfall applied to each tree with Medium #1, #2 and #3 was 999, 1024 and 765 L, respectively. The amount of water loss through drainage for each tree with Medium #1, #2 and #3 was 114, 225 and 110 L, respectively. Among the tree media, Medium #1 produced the highest tree growth rate, followed by the Medium #2. The coal ash based medium had great potentials to be used for nursery production. Experiments were conducted to determine water drainage and nutrient leachate for different moisture levels with various nutrition application treatments. Research findings demonstrated that applying the top dressed, slow release, granular fertilizer to trees at the beginning of the growing season might be enough to support healthy growth for redbuds and pears for the first year. Application of additional nutrients to these two species during the first growing season might not be necessary. The system continuously monitored the substrate temperature and moisture content during four seasons of a year, and provided a technical tool to evaluate the potentials of winter injury or summer heat damage to roots for pot-in-pot nursery production. Document monitoring activities for the project within Question 3: The cooperator provided one-acre field with 150 pot-in-pot grown trees for the study. The cooperator also assisted to design test plans including selection of types of potting substrate, tree species and nutrition elements. Every year, we have an annual meeting to summarize experimental results and make plans for next year study.