Keeping Nutrients in the Root Zone of Vegetables Grown in Florida

Transcription

1 2008 BMP Workshop on Horticultural Crops Keeping Nutrients in the Root Zone of Vegetables Grown in Florida Eric Simonne, Reporter Horticultural Sciences Department Apopka,FL May 21, 2008

2 Core Members of the Vegetable group Chad Hutchinson, Jim DeValerio, Bob Hochmuth, Danielle Treadwell, Allan Wright, Bielinski Santos, Alicia Whidden, Gene McAvoy, Xin Zhao, and Teresa Olczyk State specialists/researchers and county agents

3 Outline for vegetable crop (see paper pp ) Overview of vegetable BMPs What do BMPs look like? IFAS nutrient management recommendations Summary of knowledge and gaps Vision statements

4 Florida s economy Quick facts 40% of all US exports to South America pass through Florida 76.8 million visitors in 2004 with a $57 billion impact on Florida s economy Space industry: $4.5 billion Agricultural production: $8 billion Agricultural impact: $97 billion (2004) 390,000 direct jobs 769,000 employment impacts Vegetable industry: $1.8 billion

5 Main vegetables in Florida Crop Acreage (ha) Value (M$) Tomato 20,000 20, Bell pepper 8,000 9, Strawberry 3,000 3, Snap bean 17,000 17, Sweet corn 20,000 17, Watermelon 12,000 13,

6 Diversity in vegetable production in Florida Crop types (50+) Soil types (sandy, calcareous, rocky, organic) Season (spring, winter, fall) Irrigation method (drip, subsurface, overhead) Farm type (large, small, leased land)

7 Overhead Miami-Dade County

8 Center pivot

9

10 Drip irrigation + Plastic mulch + Raised beds = Plasticulture

11 Drip irrigation

12 Florida Rainfall and ET (in.) South FL seasons: Fall: 15 Aug.-15 Oct. Winter:15 Oct.-15 Dec. Spring: 15 Dec.-15 Feb. North FL seasons: Spring: 20 Feb.-1 Apr. Fall: 15 Jul.-15 Aug. Jul Dec Jun May Apr Mar Feb Jan Monthly Potential ET Nov Oct Sep Aug Monthly Rainfall

13 UF-IFAS source documents for irrigation/fertilization recommendations EDIS: IFAS standardized fertilization recommendations for vegetable crops (*) Commercial vegetable fertilization principles (*) Summary of N-P-K research (sandy soils) Crop production in Miami-Dade county Sweet corn, lettuce, Romaine, escarole, endive and radish on organic soils Vegetable production handbook

14 Task Force s White Paper Daniel Cantliffe, Phyllis Gilreath, Dorota Haman, Chad Hutchinson, Yuncong Li, Gene McAvoy, Katie Migliaccio, Teresa Olczyk, Steve Olson, Darrin Parmenter, Bielinski Santos, Sanjay Shukla, Eric Simonne, Craig Stanley, and Alicia Whidden Review of nutrient management systems for Florida vegetable producers: A white paper of the UF/IFAS vegetable fertilizer task force. Proc. Fla. State Hort. Soc. 119:

15 What do BMPs look like?

16 Structural BMPs for Erosion Control

17 Erosion control device installed in strawberry field The field border is immediately planted with erosion controlling grasses after beds are made

18 Fertigation allows to spoon feed plants

19 T0-1h T0-2h T0-4h T0-8h

20 GPS-based fertilizer application reduces skips and overlaps Grower utilized cost share funds to upgrade to more accurate nitrogen calibration equipment and a GPS system Overlap eliminated. Reduced N by 5,000 lbs on 80 ac.

21 Knowledge and gaps

22 Summary of knowledge and gaps: Fertilizer recommendations Level of knowledge Foundation work complete for major crops Limited or incomplete for herbs No fertilization recommendations for organic vegetable production Gaps Need regular updates Need provisions for ENSO phases and expected frequency of leaching rainfall Need to abandon single-number recommended rates for N Education need to focus on reducing preplant rates with drip All work on organics needs to be done

23 Summary of knowledge and gaps: Irrigation recommendations Level of knowledge Seasonal water use estimates complete for major crops Gaps Need automated, sensor based irrigation systems Need to match irrigation zones to soil type Need to rename reclaimed water with recycled water ; then generalize the use of recycled water as irrigation water: nutrient contribution and food safety aspects need to be clarified Demonstrations needed to show reduced irrigation when plants are small

24 Summary of knowledge and gaps: Use of controlled-release fertilizers Level of knowledge Advanced for seepageirrigated potato. Work underway with tomato and bell pepper Gaps Work needed for all seepage irrigated crops grown on the organic and sandy soils of Florida (cabbage, eggplant, cucurbits)

25 Summary of knowledge and gaps: Direct nutrient load measurement Level of knowledge Lack of acceptable methodology and effect of soil types makes current results spotty and difficult to extrapolate. Assumptions made on published load calculations are some times unrealistic or not met Gaps Need a simple, reliable drainage lysimeter for in-field monitoring. Need to use lysimeter for direct assessment of BMP effect on water moving below the root zone and load. This will be used as research and demonstration tool.

26 Summary of knowledge and gaps: Zero-discharge systems Level of knowledge Virtually none in field production. Good concept, but may be unrealistic in practice for deep sands Gaps Need to pursue ultra-low flow drip for deep sands Need to pursue use of polyacrylamide and zeolite filters for spodosols

27 Summary of knowledge and gaps: Breeding and genetics Level of knowledge Virtually none in the context of BMPs Gaps Need breeder s and administration s commitment Need to investigate morphological, biochemical and chemical strategies Need to use grafting

28 Summary of knowledge and gaps: Nutrient sensors Level of knowledge Virtually all soil chemical information is based on soil sampling Gaps Need specific NO 3 -N, NH 4 -N, P, and EC sensors that are inexpensive and reliable Data should be displayed through a user-friendly interface

29 Summary of knowledge and gaps: Cover crops Level of knowledge Lots of information about effect on soil physical and chemical properties. Limited information on actual load reductions caused by nutrient trapping Gaps Need reliable seed source and on-farm demonstration Need to assess long-term effect of cover crop use on nutrient load Need to know if roots grow faster than residual nutrients move

30 Vision statements

31 1. What is your opinion/vision for the next 5 years on what the vegetable industry needs to do to improve their irrigation management?

32 Vegetable group answer Use recycled water Improve irrigation scheduling at the beginning and throughout the season Routinely use soil moisture measuring devices (drip) or water-table indicators (seep) Consider and initiate a switch from seepage to drip irrigation Consider buried drip Increase the precision of overhead (pivot) irrigation Become more familiar with the capacity and function of existing drip systems (education)

33 2. What is your opinion/vision for the next 5 years on what the industry need to do to improve their fertilizer management?

34 Vegetable group answer Recalculate break even cost for fertilizers Improve irrigation scheduling methods Use tissue, sap test, SPAD readings or other spectral method as a monitoring tool Integrate leguminous cover crops in production system and/or N trap crops after the production season Apply less fertilizer more often (drip) Use nutrient-efficient cultivars Move to season-irrigation system-soil type specific nutrient recommendations (especially for N)* Increase industry confidence in UF/IFAS recommendations through regular updates and on-farm demonstrations* For crops like strawberry, N recommendations should be based on vegetative growth*

35 3. What educational programs are needed? (for agents, for growers)

36 Vegetable group answer Hands-on workshops on nutrient/irrigation management for small farmers and middle-management/foreman level for large growers Continue the face-to-face work of the BMP implementation teams Expand and support the one-on-one work of the MIL to all vegetable farms that use drip and seepage irrigation. Support educational role of the BMP Implementation Teams and better integrate them with existing extension programs Cover crop management Myth-breakers on some inaccurate common wisdoms on fertilizer management Spray equipment and fertilizer injection calibration

37 The faces of the BMP program for the end users

38 4. What are the critical issues on the horizon (5 to 10 years) that may affect the industry?

39 Vegetable group answer Food safety-related liability Increasing cost of energy and reduced profit margins Increased cost of fertilizers Increased cost of food safety compliance Loss of methyl bromide Reduction in water permitted may require switching to drip, use ultra-low flow and recycled water Distractions caused by food safety, labor, land availability and reduced state funding may push water quality efforts and compliance to the back burner Maintain IFAS relevance to the industry

40 Summary and action items The success of the BMP program for vegetables in Florida is measured by the level of BMP implementation and the improvement of water quality. Both require keeping water and fertilizer in the root zone of vegetables. The 23 priorities, recommendations and vision are made by the UF/IFAS Vegetable BMP group to the state agencies to help the vegetable industry successfully transition into the BMP era:

41 Coordination and funding structure: 18. Extension should lead educational programs on BMPs in partnership with researchers, state agencies and the industry 19. Results of UF/IFAS research should be promptly reported in the scientific literature for scientific use and recommendation update 20. A 5-year research and outreach plan should be developed by UF/IFAS faculty members active in vegetable BMP under a state-wide Hatch project 21. State agencies should develop a funding model that allows the funding of multi-year projects

42 Coordination and funding structure: 22. A state-wide BMP conference focusing on vegetables should be organized every 3 years 23. FDACS should consider developing and implementing a fertilizer applicator license following the existing model for pesticides. Educational credits should be available at the beginner and advanced levels.

43 BMP

44 Basic principles 1. Base UF/IFAS production recommendations on the rigors of science and the reality of field production 2. Replace the out-of-date paradigm Pollute less by reducing nutrient application rates with Improve water management and adjust fertilizer programs accordingly 3. Engage together growers, consultants, educators and regulators in open-channel discussions.

45 UF/IFAS fertilizer and irrigation recommendations: 4. Fertilization and irrigation recommendations for vegetable grown in Florida are detailed and research based, but need updating. UF/IFAS fertilizer rate studies should be conducted regularly with Florida major crops to reflect current varieties used by the industry. This research should be a funding priority by Florida Department of Agriculture and Consumer Services because of the legal consequences of third party agencies adopting UF/IFAS fertilizer rates.

46 Nutrient load determination: 5. In-field load assessment should be considered another funding priority by the Florida Department of Agriculture and Consumer Services, the Florida Department of Environmental Protection, and the fie Florida Water Management Districts. An increased fertilizer rate does not directly translate into an increase in load. This first requires the development of reliable methods and tools (drainage lysimeters) of know precision because watershed-level load simulations are poor indicators of field-level leaching.

47 New techniques that keep nutrients in the root zone that should be considered for funding: 6. Develop ultra-low flow drip irrigation 7. Convert from seepage to drip irrigation 8. Use recycled water 9. Develop controlled-release fertilizer for N for seepage-irrig ated crops (tomato, bell pepper, eggplant, watermelon, cabbage) 10. Develop management tools based on real-time, continuous soil water and chemical parameters 11. Develop yield mapping tools for vegetable crops

48 Charge of the Florida Vegetable Fertilization Task Force 1. Review new data generated since the last fertilizer recommendations were developed 2. Propose science-based updates 3. Develop interim recommendations when research data are missing, and 4. Develop a strategy plan to fill gaps in knowledge and secure funding for needed research