Nursery BMPs Keeping Nutrients in the Root Zone Tom Yeager and Bob Stamps Department of Environmental Horticulture
Nursery Production 7800 nurseries Diverse Types of plants Container production In-ground production Irrigation methods
In-ground Production 24,000 acres Cut foliage Ferns, caladiums
Container Production 59,000 acres 80% sprinkler irrigation 12% microirrigation
Nursery Production 50% within one mile urban market 19 18 18 17 17 16 16 15 15 14 8000 7900 7800 7700 7600 7500 7400 7300 7200 Fla Pop Nurseries 2000-2001 2001-2002 2002-2003 2003-2004 2004-2005 2005-2006 2006-2007 Millions of People
Container Production 600 nurseries with NOI 13,500 acres
In-ground Production BMP manual process initiated Develop Topics Grower feedback
Container Production Irrigation BMP Challenges Container has small reservoir Different size containers and plants Different container configurations
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
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
NO 3 -N conc. in runoff (ppm) 50 40 30 20 10 0 Spaced plants out 0 5 10 15 20 Weeks after planting
5 4 Spaced plants out P conc. (ppm) 3 2 1 0 0 5 10 15 20 Weeks after planting
150 Nitrates in production area runoff, 6-state survey (Yeager et al., 1993) 135 NO 3 -N conc. in runoff (ppm) 100 50 Controlled-release fertilizer 8 33 Controlled-release fertilizer + solution fertilizer 20 0 Mean Max Mean Max
N0 3 -N conc. in runoff (ppm) 50 40 30 20 10 0 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
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
18-0-12 18-1-12 18-3-12 18-6-12 Phosphorus Reduction in Fertilizer
Nursery Production BMPs not widely used Monitor nutrition of substrate (Yeager and others) Monitor leachate volume (15%) Efficient irrigation of small containers
Nursery Production BMPs widely used Cyclic irrigation (Beeson, Fare, others) Covered substrate storage (need data) Collection basin (need data)
Container Production Zero water discharged? Retain 90% of irrigation volume Retain first one-half inch of rain Remediation of discharge
Broward County 26 ppb Collection Basin 1370 ppb TP
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
Plant file Weather file Management file Container Production Model executable file UF server Output files Web-based user interface User input Graphical output
Irrigation (cm/day) 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 5 10 15 20 Week FIXED MODEL
120 112 Irrigation (cm) 100 80 60 40 20 0 71 1 cm/day Model Irrigation schedule
1.6 Runoff (cm/day) 1.2 0.8 0.4 FIXED MODEL 0.0 0 5 10 15 20 Week
100 Runoff (cm) 80 60 40 20 79 46 0 1 cm/day Model Irrigation schedule
Shoot dry wt. (g/plant) 60 50 40 30 20 10 0 49 44 1 cm/day Model Irrigation schedule
http://70.185.99.211:8081/driver/index.php
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
Field Days June 21, 2007
Container Production
Plant file Weather file Management file Container Production Model executable file UF server Output files Web-based user interface User input Graphical output
Weather data Container Production
Container Production Decision Tool
Leachate collection
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
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) 44 34 32 36 From: Tyler et al. 1996. J. Environ. Hort.
Nursery Production Plant Modifications Genetic manipulation Root stocks
Time Infrequent Frequent Cont. Nut. Level
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
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
Thorp 1995 Container Production
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