Nursery BMPs. Keeping Nutrients in the Root Zone. Tom Yeager and Bob Stamps Department of Environmental Horticulture

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1 Nursery BMPs Keeping Nutrients in the Root Zone Tom Yeager and Bob Stamps Department of Environmental Horticulture

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4 Nursery Production 7800 nurseries Diverse Types of plants Container production In-ground production Irrigation methods

5 In-ground Production 24,000 acres Cut foliage Ferns, caladiums

6 Container Production 59,000 acres 80% sprinkler irrigation 12% microirrigation

7 Nursery Production 50% within one mile urban market Fla Pop Nurseries Millions of People

8 Container Production 600 nurseries with NOI 13,500 acres

9 In-ground Production BMP manual process initiated Develop Topics Grower feedback

10 Container Production Irrigation BMP Challenges Container has small reservoir Different size containers and plants Different container configurations

11 Container Production Irrigation Best Management Practice Number of nurseries (%) Collect irrigation or rain runoff 35 Know water-holding capacity of substrate 10 Group plants by irrigation requirements 77 Group container sizes by irrigation requirements 72 Use any other grouping for irrigation requirement 28 Monitor amount of water applied each irrigation 36 Monitor the application pressure in irrigation 51 Use automatic rain shutoff 30

12 Container Production Nutrition BMP Challenges Less than 50% of N applied is used (Yeager and others) Amount of water applied Plant nutrient requirement (Wright, Yeager, others) High container temperatures (Martin and Ingram) Low AEC (Yeager) Old CRF technology

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14 NO 3 -N conc. in runoff (ppm) Spaced plants out Weeks after planting

15 5 4 Spaced plants out P conc. (ppm) Weeks after planting

16 150 Nitrates in production area runoff, 6-state survey (Yeager et al., 1993) 135 NO 3 -N conc. in runoff (ppm) Controlled-release fertilizer 8 33 Controlled-release fertilizer + solution fertilizer 20 0 Mean Max Mean Max

17 N0 3 -N conc. in runoff (ppm) Nitrates in production area runoff, 6-state survey (Yeager et al., 1993) Controlled release + solution fertilizer Controlled release only Apr May Jun Jul Aug Sep

18 Container Production Nutritional BMPs controlled-release fertilizers are used (82 %) fertilization rates are adjusted for different species and container sizes irrigation runoff is collected if solution fertilizer in overhead irrigation substrates are amended with CRF if containers are likely to overturn fertilizer is broadcast on non-spaced containers substrate nutrition is monitored to maintain desirable levels records are kept to follow trends and trouble-shoot nutritional problems runoff water is captured and reused to recycle nutrients substrate storage areas are covered to prevent runoff of nutrients substrate is used immediately (within a week) if amended with fertilizer ratio of P 2 O 5 to N in fertilizers is 1:3 or less

19 Phosphorus Reduction in Fertilizer

20 Nursery Production BMPs not widely used Monitor nutrition of substrate (Yeager and others) Monitor leachate volume (15%) Efficient irrigation of small containers

21 Nursery Production BMPs widely used Cyclic irrigation (Beeson, Fare, others) Covered substrate storage (need data) Collection basin (need data)

22 Container Production Zero water discharged? Retain 90% of irrigation volume Retain first one-half inch of rain Remediation of discharge

23 Broward County 26 ppb Collection Basin 1370 ppb TP

24 Nursery Production BMPs to be developed? or How do we determine what needs to be developed? Decision support system to trial BMPs Determine BMPs of most impact Economically and technologically feasible

25 Plant file Weather file Management file Container Production Model executable file UF server Output files Web-based user interface User input Graphical output

26 Irrigation (cm/day) Week FIXED MODEL

27 Irrigation (cm) cm/day Model Irrigation schedule

28 1.6 Runoff (cm/day) FIXED MODEL Week

29 100 Runoff (cm) cm/day Model Irrigation schedule

30 Shoot dry wt. (g/plant) cm/day Model Irrigation schedule

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32 Nursery Production Priorities Approach used to improve water quality Possible areas of research Estimated relative chance of success Why? Keep nutrients in root zone Precision application of water and fertilizer to minimize/leaching/ runoff/percolation and associated nutrients good Applicable to most nurseries, container or plants in ground Non-traditional irrigation application techniques e.g. subirrigation good Applicable to container and in-ground production Decision Support Systems good Applicable to container and in-ground production Design, construction and use of recycling systems fair High costs for producer

33 Field Days June 21, 2007

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36 Container Production

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38 Plant file Weather file Management file Container Production Model executable file UF server Output files Web-based user interface User input Graphical output

39 Weather data Container Production

40 Container Production Decision Tool

41 Leachate collection

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43 Container Production BMP research area Level of knowledge Gaps Irrigation of nursery crops Very low Non-traditional irrigation systems Very low Cyclic irrigation with overhead water Very low Economics of change Very low Decision support system Moderate Water requirements of plants Moderate Container capture of overhead water

44 Cyclic Irrigation Affects Water Volume Loss from #1 Container Irrigation Treatment 900 ml (1x) 450 ml (2x) 300 ml (3x) 150 ml (6x) Volume (liters) From: Tyler et al J. Environ. Hort.

45 Nursery Production Plant Modifications Genetic manipulation Root stocks

46 Time Infrequent Frequent Cont. Nut. Level

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48 Container Production Decision Tool Current and Future Work Current and on-going 3-gal growth growth/development Pruning effects Liner vs. #1 transplant Low irrigation requirement - Yaupon holly Website interface Future research/development Heat stress impact on growth Additional species Plant shape impact on irrigation water capture Real-time irrigation scheduling through website Economic analyses optimize inputs and outputs with revenue and impact on environment

49 Monitor Substrate Solution EC Site Evaluation (Slope, Streams, Soil Type) Runoff Fertilizer (Type and Rate) Plant Requirements (Nutrients/Water) Leaching Irrigation Management (Scheduling) Collection Structure Substrate Vegetative Zones

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51 Thorp 1995 Container Production

52 Container Production BMP research area Level of knowledge Gaps Nutrition of nursery crops None Nitrogen volatilization Very low When does uptake occur? Very low Nutrient needs of plants in native soils Very low Variation in nutrition with species Very low Substrate temperature impacts Very low Economics of change Very low Decision support system Moderate Nutrient loss from substrates and soils Moderate Bio- and phyto-remediation of runoff