Each year, growers
throughout the Southeast mustface more and more environmental issues.
Federal,states, and even local regulations are addressing concernssuch as
surface and groundwater contamination, waterusage, pesticide usage, solid waste
disposal, and energyconsumption. Many of these regulations have affectedand
will continue to affect both business and culturalpractices within the
greenhouse industry.Most floriculture producers have a deep commitmentto the
environment. Our products enhance the quality oflife for our customers as well
as increase the quality of theair we breath. Horticulturists by nature and by
trainingare good stewards of the environment and posses anappreciation for the
value of natural resources. Thecommercial floriculture industry has been a
leader inestablishing and implementing production practices suchas integrated
pest management that help protect theenvironment.This handout was prepared to
assist growers incontinuing their efforts of environmental stewardship
byreviewing the concept of Best Management Practices(BMP’s). Through proactive
behavior, greenhouse rowerscan continue to set an example for other facets
ofagriculture
What Are BMP’s?Best management
practices can be defined aspractices, schedules of activities, maintenance procedures,and
structural or other management decisions that havebeen found to be the most
effective and practical meansto prevent or reduce the discharge of pollutants
into theenvironment. The scope of BMP’s can be expandedfrom pollution control
practices to also include proceduresor production choices that address other
currentenvironmental concerns such as water conservation andenergy use.BMP’s
are practices; something you intentionally door avoid doing in order to
positively affect the environmentin your business. They are proactive. BMP’s
areimplemented prior to a problem rather than after a
THE ONE, TWO, THREE’S
OF GREENHOUSE BMP’SDouglas A. Bailey, Associate ProfessorDepartment of
Horticultural Science, NC State UniversityRaleigh, NC 27695-7609problem is
observed and some type of “fix” is needed.Think of BMP’s as preventative rather
than curativetreatments.The BMP philosophy emphasizes environmentalstewardship
yet it does not sacrifice crop quality.Individual management practices are
freestanding ratherthan a set. In other words, growers can implement asmany as
possible and still be effective withoutimplementing each and every practice
that has beendocumented.Safeguarding the environment comes with a price,and
producers should be aware of the potential economicimpact of implementing
BMP’s. As you evaluate specificpractices you should be asking: ¶ can I afford toimplement this procedure; · would my customers bewilling to accept some of the
added costs; and ¸ can Iafford NOT to
implement this procedure?
What Are the Issues /
Types of BMP’s?This handout concentrates on only three (of manymore) major issues that
BMP’s can address: ¶ surfaceand ground
water contamination; · water conservation;and
¸ alternative resource
utilization (use of man-madewaste products). Other issues that BMP’s can
addressinclude solid wastes generation and energy and naturalresource
consumption. However, the scope of thishandout only gives examples of many
possible BMP’s.An example of a specific BMP addressing waterconservation would be:
“irrigation should not be basedon a fixed daily schedule but based on plant
water needs.”An example of a BMP addressing water contaminationwould be:
“whenever possible, select ‘biorational’pesticides that are less persistent in
the environment, lesstoxic, and / or less mobile in the environment
thanalternative pesticide choices.”There are two major categories of BMP’s that
canaddress the above three issues, structural BMP’s andcultural BMP’s. The
following section outlines types ofBMP’s that greenhouse owners should consider
employer.Remember that this is merely a list (and not a complete2list) of BMP’s rather
than a required set. For moreBMP’s, refer to the suggested readings section at
the endof this handout.
Structural BMP’sStructural BMP’s are recommendations
involvingphysical structures, such as building placement, type ofirrigation
system used, and ditch / drainage systemplacement. Four subcategories of
structural BMP’s arelisted below: ¶ site
selection criteria; · pest exclusionsystems;
¸ runoff prevention
systems; and ¹ “closed”irrigation
systems.Site selection criteria. If you are planning onbuilding on a new
site, these BMP’s should be considered.Many of them are difficult to employ,
once a site has beenselected and buildings have been placed. Site
selectionBMP’s address issues such as proximity of your buildingsand land to
aquifers and surface waters; flood plainlocation and flooding potential on your
site; the possibilityof using some of the land for effluent distribution; and
thepotential for on-site effluent containment (a reservoir orwet detention
basin). Examples of site selection BMP’sare: ¶ do not locate buildings or production areas overshallow
underground aquifers; and · avoid building
orgrowing on a high risk flood plain.
Pest exclusion systems. One way of
reducing thepotential for release of pesticides into the environment isto find
alternative means of pest control rather thanapplying pesticides. Pest
exclusions systems such asscreening and utilizing quarantine areas in
yourgreenhouse are examples of pest exclusion systems.Examples of pest
exclusion system BMP’s are: ¶ screenopen vents on
greenhouses to prevent entry of flyingpests and weed seed; · attach a screened antechamberonto greenhouse
entries to help reduce pest transfer fromoutside into the greenhouse; ¸ establish pest quarantineareas where newly
received material is examined forinfestations; and ¹ avoid pest-attracting apparel, such asyellow and blue
clothing (is clothing a structure or acultural practice?).
Runoff
prevention systems. Runoff includeseffluent (water / fertilizer solution
used for irrigation) aswell as storm water that drains from buildings.
Ideally,all drainage water should be contained on site (no runoffat property
boundaries). Examples of runoff preventionsystem BMP’s are: ¶ grade construction sites for erosioncontrol and
planned precipitation collection; · establishvegetative
buffer zones (vegetative filter strips of sod orother plants that remove
sediment, nutrients, and otherpollutants from runoff by filtration, deposition
infiltration,absorption, and decomposition); ¸ construct a wetdetention basin to store effluent and
reuse for irrigationpurposes; ¹ utilize natural or
constructed wetlands as aneffluent filtration unit; º disperse nutrient-rich effluentonto effluent utilization
fields (crops such as oats thatwill absorb and scrub nutrients out of the
effluent); and» pump effluent through
a bioreactor or biofiltrationsystem to remove nutrients and other chemicals
prior toeffluent discharge.
Closed irrigation systems. A truly “closed”
irrigationsystem does not allow any water or fertilizer solution toescape from
the production facility into the environment.Containment and recirculation of
effluent is an excellenttechnique to prevent runoff of any kind. The followingirrigation
systems are examples of closed irrigation systemBMP’s: ¶ ebb and flood tables; · recirculation deliverytroughs; and ¸ flood floor + sump (a catch basin to holdsolution
between irrigations) delivery. It is possible todramatically reduce the potential
for runoff by usingquasi-closed systems that are not completely closed,
yetcontain all effluent on-site. The following quasi-closedirrigation systems
are considered BMP’s, when used inconjunction with a wet detention basin: ¶ individualcatch pans; · closed tray systems; and ¸ solid floorproduction areas with directed drainage.
Cultural
BMP’sCultural BMP’s are practices used in the productionof plants; how you
grow your crop and cropping decisionsmade during production. Three
subcategories of culturalBMP’s are listed below: ¶ substrate managementpractices; · pest management practices; and ¸ theoptimization of the production environment.
Substrate
management practices. One way ofreducing the potential for runoff is to
reduce the numberof irrigations and the amount of leaching duringproduction.
The substrate you select can have an effecton the watering requirements of your
crop. The mix youchoose and how you manage it can (how water andfertilizer are
applied) can affect runoff potential fromyour greenhouse. Examples of substrate
managementBMP’s are: ¶ grow in “tighter”
mixes that have greaterwater holding capacity than alternative mixes; · decreasethe leaching fraction of irrigation events
to reduce effluentvolume; ¸ make fertilizer
applications based on nutrientmonitoring and plant needs rather than
temporalscheduling; and ¹ utilize man-made waste
materialssuch as coir fiber and composted yard wastes in substratesrather than
relying solely on limited natural resourcessuch as peat moss.
3Pest
management practices. The concept ofintegrated pest management has been
preached andpracticed for years in the greenhouse industry, but itnever hurts
to review environmentally friendly pestmanagement practices. The following are
examples ofpest management BMP’s: ¶ scout
and monitor pestpopulations or incidence of diseases for judicious timingof
pesticides; · employ cultural
practices rather thansole reliance on pesticides for pest and disease
control(e.g., practice good sanitation to reduce the potential ofdiseases in
the greenhouse); ¸ integrate
biologicalcontrols when appropriate into your pest managementprogram; and ¹ when pesticides are required, usebiorational
pesticides with lower toxicities than alternativepesticides.
Optimization of
the production environment. Justas pest exclusion can reduce the need for
pesticides, socan proper environmental controls during production. Inmany
cases, the environmental conditions can directlyaffect the potential for
production problems (andsubsequently pesticide applications and crop quality).Examples
of productionenvironment optimizationBMP’s are: ¶ supply adequate spacing for plants duringproduction
(better spacing = more light and lower relativehumidity = less need for
chemical height control and lessdisease potential); · use DIF as an alternative to chemicalheight control when
possible; and ¸ employ
nightventilation and reheating for control of relative humidity(lower relative
humidity = less disease potential).
Closing CommentsThis handout does not
contain an exhaustive listingof BMP’s. It does give you concrete examples and
astarting point for development of a total BMP productionplan. Review your
current practices. List the bestmanagement practices currently employed at
yourbusiness. Evaluate ones that you have not implementedand incorporate as
many as you can.One final note about BMP’s and environmentalstewardship: brag
about your efforts! A positive attitudewill be noticed by employees. When you
show concern,the attitude will be transferred to those around you. If wedon’t
talk about our industry in a positive light, who elsewill do it for us?
Suggested
ReadingsAnonymous. 1992. Water quality action manual forgreenhouse and
nursery operations. HorticulturalWater Alliance .
(This publication is the result of ajoint effort between the: Society of
American Florists,American Society of Nurserymen, Professional PlantGrowers
Association [Bedding Plants International),and Roses, Inc. The manual seeks to
answer the mostimportant question a grower can ask: “what can Ido?” Beginning
with guidelines on how to conducta thorough environmental audit of your
operationand facilities, the manual provides recommendationsfor the most
environmentally sound approaches togreenhouse and nursery production.)Bailey,
D.A. 1997. Height control of commercialgreenhouse flowers. NC State University
Hort. Info.Lflt. #528. (This publication outlines biological,physical, as
well as chemical control measures forheight control of floricultural crops. It
listsalternatives to using chemical height control in aneffort to convey best
management practices for heightcontrol of crops. The publication is availableathttp://www2.ncsu.edu/floriculture/)Bailey,
D.A. 1997. Best management practices for plantgrowth regulators. NC State University
Hort. Info.Lflt. #529. (Not all pgr’s used in floriculture areheight control
chemicals. This publication detailsBMP’s for use of all plant growth regulators
labelledfor use in the greenhouse. It is available at
http://www2.ncsu.edu/floriculture/).Wilkerson, D.C., B.M. Drees, D.
McWilliams, and J.M.Sweeten. 1991. Water management guidelines forthe
greenhouse industry: a guide for protecting andconserving our natural water
resources. Texas
Agr.Ext. Service Bul. Hort 4-5. (This guide providesinformation on how to
establish a variety of culturaland structural BMP’s for the production
ofgreenhouse crops. Also included are procedures forconducting an in-depthe nvironmental
audit andtechniques for developing a long-rangeenvironmental plan for your
operation.)Yeager, T., C. Gilliam, T. Bilderback, D. Fare, A.Niemiera, and
K. Tilt. 1997. Best managementpractices: a guide for producing
container-grownplants. Southern Nursery Association. (This guideprovides
growers with valuable information on the“how-to's” of establishing best
managementpractices. It was a cooperative effort among statesthroughout the
Southeast. Growers can select from120 listed site-specific BMP’s to develop a
voluntaryenvironmental stewardship plan.)
留言列表
