Sweet Potato Production Best Management Practices (BMPs)

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SWEET POTATO BMPS 2000 1 SWEET POTATO Sweet Potato Production B B Best M M Management P P P ractices (BMPs) endorsed by SWEET POTATO Sweet Potato Production

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Sweet Potato Production Best Management Practices (BMPs)

Transcript of Sweet Potato Production Best Management Practices (BMPs)

Page 1: Sweet Potato Production Best Management Practices (BMPs)

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TABLE OF

CONTENTS

WHY BMPS ARE

IMPORTANT TO LOUISIANA

In Louisiana we are blessed with beautiful andabundant waters to enjoy fishing, hunting, boating or justrelaxing on the shore of a lake, river or bayou. Most ofthe water in Louisiana’s rivers and lakes comes fromrainfall runoff. As this runoff travels across the soilsurface, it carries with it soil particles, organic matter andnutrients, such as nitrogen and phosphorus. Agriculturalactivities contribute to the amount of these materialsentering streams, lakes, estuaries and groundwater. Inaddition to assuring an abundant, affordable food supply,Louisiana farmers must strive to protect the environment.

Research and educational programs on environ-mental issues related to the use and management of natu-ral resources have always been an important part of theLSU AgCenter’s mission. Working with representativesfrom the agricultural commodity groups, the NaturalResources Conservation Service (NRCS), the LouisianaDepartment of Environmental Quality (LDEQ), the Louisi-ana Farm Bureau Federation (LFBF) and the LouisianaDepartment of Agriculture and Forestry (LDAF), the LSUAgCenter has taken the lead in assembling a group of BestManagement Practices (BMPs) for each agricultural com-modity in Louisiana.

BMPs are practices used by agricultural produc-ers to control the generation and delivery of pollutantsfrom agricultural activities to water resources of the stateand thereby reduce the amount of agricultural pollutantsentering surface and ground waters. Each BMP is a culmi-nation of years of research and demonstrations conductedby agricultural scientists and soil engineers. BMPs andaccompanying standards and specifications are publishedby the NRCS in its Field Office Technical Guide.

Introduction ...................... 3

Soil and WaterManagement ...................... 4

Pesticide Management andPesticides ......................... 12

Nutrient Management .. 17

General Farm BMPs ...... 23

Research Overview....... 25

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SweetPotatoBMPs

INTRODUCTION

Sweet potatoes are animportant commodity in Louisi-ana. The total acreage planted in1999 was approximately 24,925acres. Most are grown in 11parishes: West Carroll,Morehouse, Franklin, Avoyelles,St. Landry, Evangeline, Acadia,St. Martin, Rapides, Grant andRichland. The gross farm valueof Louisiana-grown sweet pota-toes in 1999 was about $72million. Value added of freshmarket potatoes is determined bythe increase in value of theharvested potatoes that arewashed, graded, packed andshipped. The estimated valueadded for the 1999 crop was $53million, for a total economicvalue to the state of more than$125 million. Sweet potatoes arethe single most important veg-etable crop in Louisiana in termsof acreage planted and economicvalue.

The runoff from sweetpotato fields can have a potentialimpact on the surface waterquality throughout the regionswhere sweet potatoes are grown.The quality of water in thestreams, rivers, bayous, lakes andcoastal areas of Louisiana isextremely important to all resi-dents.

The intent of Best Manage-ment Practices (BMPs) is toprovide the growers of sweetpotatoes some guidelines onwhat practices they can imple-ment to reduce the impact theseagricultural practices may haveon the environment. If properlyimplemented, with appropriateincentives where needed, thepractices described in this publi-cation will help to improve waterquality without placing unrea-sonable burdens on the agricul-tural industry of Louisiana.

References are made tospecific Natural ResourcesConservation Service (NRCS)production codes in this publica-tion. These production codes areexplained in the text. Moredetailed information about thesepractices can be found in theNRCS Field Office TechnicalGuide (FOTG). The FOTG canbe found in all Soil and WaterConservation District Offices, allNRCS field offices and on theNRCS web page. Additionally,under voluntary participation bythe producer, technical assistanceto develop and implement afarm-specific conservation planis available through the Conser-vation Districts, NRCS fieldoffices and the LSU AgCenterparish offices.

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Center PivotIrrigation Systems(NRCS Code 442)

Crop residues serve alargely positive role in centerpivot irrigation management.Selecting a tillage system that isbest suited for a particular fieldsituation can be a very importantdecision. Disregard for theimportance of this decision coulddirectly affect the effectivenessof the water application system,as well as other crop productionpractices.

In general, concerns associ-ated with tillage practices selec-tion and center pivot operationare related to the potential forrunoff and erosion. The potentialfor runoff exists whenever thewater application rate of theirrigation system exceeds theinfiltration rate of the soil.

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Irrigation Management(NRCS Code 449)

Furrow Irrigation Systems Furrow Irrigation

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Crop residue cover and tillage practicesplay important roles in the way crops usewater and also affect the ability of irrigationsystems to replace that water. Tillage prac-tices (NRCS Code 329) and crop residuemanagement (NRCS Code 344) play impor-tant roles in the way irrigation systemsperform and are managed. Tillage practicesaffect the way that water moves into and offof the soil (infiltration and runoff).

Many factors affect theperformance of furrow irrigationsystems. Physical conditions,such as soil texture, soil struc-ture, field slope, field length,furrow shape and the amount ofcrop residue cover, all have someimpact on the performance of theirrigation system. The way thesystem is managed, including thefurrow flow rate, length ofapplication time and irrigationfrequency, also affects systemperformance. Irrigation systemperformance is often measured interms of the percentage of thewater applied that remains in theactive root zone after the irriga-tion (application efficiency).Thus, deep percolation (waterpassing through the root zone)and runoff (tailwater)(NRCSCode 447) should be held to aminimum while supplyingadequate water to the crop alongthe length of the furrow.

Tillage practices affectfurrow irrigation systems byaltering the infiltration character-istics of the soil and by alteringcrop residue in the furrow. Bothfactors affect the ability of thefurrow to convey water down thefield. As tillage practices becomeless intensive, infiltration ratesoften increase.

The need to match manage-ment factors with the physicalconditions present at the time ofirrigation is critical. In somecases, a change in tillage practicemay cause changes in infiltrationrates that are too severe to over-come with management factorsalone. In some cases physicalchanges to the system may benecessary. The field slope orlength of run may need to bechanged or furrow packing maybe used to help overcome prob-lems associated with extremeincreases in infiltration character-istics.

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The potential for runoff existswhenever the water application rateof the irrigation system exceeds theinfiltration rate of the soil.

Sweet potato residues, whichare produced in less quantity,are considerably more fragilethan small grain or cornresidues.

Center Pivot Irrigation

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To lower pumping costs,some row crop farmers fit theirmachines with low to mediumpressure sprinkler packages. Onoccasion, sprinkler packages maybe improperly matched with thesoil infiltration rate. Irrigationsystem management and tillagepractices may be used to controlrunoff if changes in the irrigationsystem itself are desirable.

One option is to reduce theapplication depth per irrigation.In doing so, the operator reducesthe potential for runoff butincreases the opportunity for soilevaporation over the course ofthe growing season. Althoughcrop residues can help reduce themagnitude of soil evaporationlosses, repeated wetting of thesoil surface will limit the watersavings attributed to crop resi-dues.

Runoff also may be gener-ated if the soil infiltration rate isreduced over a period of time. Anumber of factors, such as soiltexture and structure, surface

tillage or water application, canreduce infiltration. For example,as the size and number of waterdroplets increase, fine soil par-ticles are consolidated on thesurface to form a thin crust. Asthe soil crust develops, the waterinfiltration rate tends to decrease.Soil surface crusts can result ininfiltration rate reductions of upto 75 percent. One way to com-bat the negative effect of waterdroplets is to be sure crop resi-dues are distributed evenly overthe soil surface. Crop residuesspread in this manner protect thesoil by absorbing energy carriedby falling water droplets. Thislimits soil crust development,resulting in a more consistentinfiltration rate throughout thegrowing season.

Tillage practices that resultin minimal soil disturbanceshould be used when topographyis rolling. On highly erodibleland, it is important to checkwith your local Natural Re-sources Conservation Service

(NRCS) or Soil and WaterConservation District for compli-ance with conservation plans inmaking these decisions.

Crop residues also act likesmall dams for temporary soilsurface storage of excess water.Water applied in excess of thesoil infiltration rate will beblocked from running off thefield long enough for infiltrationto occur. This results in moreuniform water application. In theprocess, soils that would havebeen transported with the runoffwater remain near their point oforigin.

Another option is to alterthe operating characteristics ofthe irrigation system. For ex-ample, by selecting a sprinklerpackage based on soil type andfield topography, you can matchmore closely the water applica-tion rate of the center pivot withthe soil infiltration rate. Byconsidering the interactionbetween the sprinkler packageand soil, selection of an unsuit-able sprinkler package can beavoided.

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The combination of improved water application uniformityresulting from more consistent infiltration rates, less runoff andreduced soil evaporation losses make crop residues a major factor inthe water conservation effort. Residue management (NRCS Code344) also can be a crucial component to minimizing the effect ofirrigation on surface water quality.

“Irrigation return flow” isthat portion of water whichreturns to its source after beingused to irrigate crops. Withincreasing environmental con-cern, the term “irrigation returnflow” has been extended toinclude irrigation water thatmakes its way to any body ofwater after its use on a crop.

Tailwater from furrowirrigation and runoff caused byexcessive irrigation or poorsystem design can make its wayinto drainage ditches whicheventually lead to bayous, riversand lakes. Water from irrigatedland that is artificially drainedmust go somewhere, often intothe same water body it was takenfrom.

Irrigation return flow isbecoming an important issuebecause of its potential to be anonpoint source of pollution.This is not the only reason sweetpotato producers should usereturn flow management prac-tices, however. Excessive runoffis a symptom of poor irrigationsystem design or poor manage-ment of irrigation water. It is alsowater that is wasted. Wastingwater not only has immediatefinancial ramifications, but it alsothreatens the long-term availabil-ity of water for irrigation. Soundmanagement practices can reduceirrigation return flow whileensuring the most efficient use ofour water resources.

The major concern is thedirect runoff that may occur fromirrigated land. Many of thefertilizer nutrients and chemicalsused in agriculture are easilyadsorbed onto soil particles.When runoff occurs, soil par-ticles containing these adsorbed

IRRIGATION PRACTICES THAT CAN REDUCE

OR PREVENT EROSION INCLUDE:Manage crop residues to reduce surface water contamination(NRCS Code 344).

Living vegetation and crop residues left onthe soil surface are important in:

intercepting rainfall and reducing theimpact of raindrops on the soil surface

reducing erosion and sedimentation bydecreasing runoff velocity

increasing structural stability of soil aggregates

increasing biological activity in the soil

screening out soil particles from runoff water

Conservation Cropping Sequence - (NRCS Code 328)Systems in which crops are alternated.

May reduce weed pressure in sweet potatoes.

May reduce some disease problems.

Where erosion is a problem, high residue crops included in therotation reduce soil loss.

Cover and green manure crops - (NRCSCode 340) Such crops are usually plantedwhen the primary commodity crop is notgrowing.

Protect soils from erosion and reducesedimentation.

Filter runoff waters to reduce pesticide and nutrient losses.

Precision level the land to optimizefurrow slopes to reduce soil erosion(NRCS Code 462)

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TREATMENT OF IRRIGATION

RETURN FLOW

Install vegetative buffering (filter) strips(NRCS Code 393)

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Buffer strips Wetlands

materials are picked up and transported out of the field. Erodedsediments constitute the major potential for pollution from surfacereturn flows. In addition, soluble chemicals are dissolved by runoffand carried with the water as it flows over the soil.

Proper irrigation water management (NRCS Code 449) meanstiming and regulating water applications in a way that will satisfy theneeds of a crop and efficiently distribute the water without applyingexcessive amounts of water or causing erosion, runoff or percolationlosses. Good irrigation water management can reduce moistureextremes. The sweet potato producer should have a good understand-ing of the factors influencing proper irrigation scheduling and watermanagement. The timing ofirrigation and the total amountapplied per irrigation should bebased on both the crop’s wateruse and the moisture content ofthe soil, as well as on expectedrainfall.

ResidueManagement

(NRCS Code 344)Living vegetation and crop

residues left on the soil surfaceare important in:

intercepting rainfall andreducing the impact of raindropson the soil surface

reducing erosion andsedimentation by decreasingrunoff velocity

increasing structuralstability of soil aggregates

increasing biologicalactivity in the soil

screening out soil par-ticles from runoff water.

Crop residues protect thesoil surface from the impact ofraindrops and act like a dam toslow water movement. Rainfallstays in the crop field, allowingthe soil to absorb it. The decom-position of these residues alsoincreases the soil organic matter.Soils with high organic mattercontent are less likely to erodethan soils with low organicmatter content.

There are three basic approaches to reducingpollutants in surface return flows (NRCS Code 570):

eliminating or reducing surface runoff

eliminating or reducing soil loss

reducing pollutants from irrigation return flow

The first two approaches are achieved by properly designing,operating and managing irrigation systems. Following the directionson the pesticide label will usually solve any problems associated withapplying agricultural chemicals.

The third approach involves using grass buffer strips (NRCSCode 386), artificial wetlands (NRCS Code 645), settling basins andponds (NRCS Code 350) and similar structures to reduce pollutant-bearing sediments. Treating return flow is more costly and trouble-some than preventing it.

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The table below shows the effects of residue cover on surfacerunoff and soil loss. An increase in residue cover significantly de-creases runoff and sediment from a field. Typically, 30 percentresidue cover reduces soil erosion rates by 50 percent to 60 percentcompared to conventional tillage practices.

Field Borders(NRCS Code 386)and Filter Strips(NRCS Code 393)

Field borders and filterstrips are strips of grasses orother close-growing vegetationplanted around fields and alongdrainageways, streams and otherbodies of water. They are de-signed to reduce sediment,organic material, nutrients andchemicals carried in runoff.

In a properly designed filterstrip, water flows evenly throughthe strip, slowing the runoffvelocity and allowing somecontaminants to settle from thewater. In addition, where filterstrips are seeded, fertilizers andherbicides no longer need to beapplied right next to susceptiblewater sources. Filter strips alsoincrease wildlife habitat.

Soil particles (sediment)settle from runoff water whenflow is slowed by passingthrough a filter strip. The largestparticles (sand and silt) settlewithin the shortest distance.Finer particles (clay) are carriedthe farthest before settling fromrunoff water, and they mayremain suspended when runoffvelocity is high. Farming prac-tices upslope from filter stripsaffect the ability of strips to filtersediment. Fields with steepslopes or little crop residue willdeliver more sediment to filterstrips than more gently slopingfields and those with goodresidue cover. Large amounts ofsediment entering the filter stripmay overload the filtering capac-ity of the vegetation, and somemay pass on through.

Sediment directly damageswater quality and reduces theusefulness of streams and lakesin many ways. These mayinclude:

Impaired fish spawning areas Reduced light penetration for

aquatic life Increased water purification

costs Lower recreational valueClogged channels and

increased floodingIncreased dredging to maintain

navigationReduced storage capacity for

reservoirs

In addition, sediment is oftenrich in organic matter.Nutrients such as nitrogen andphosphorus and certainpesticides may enter streamswith sediment. Thedetrimental effects of thesesubstances accompanying thesediment may include:

Rapid algae growthOxygen depletion as organic

matter and algae decompose Fish kills from oxygen

depletionToxic effects of pesticides on

aquatic lifeUnsafe drinking water

because of nitrate or pesticidecontent

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Field border

Effects of surface residue cover on runoff and soil loss

Residue Runoff Sediment in SoilCover Runoff Velocity Runoff Loss% % of rain ft./minute % of runoff tons/acre

0 45 26 3.7 12.441 40 14 1.1 3.271 26 12 0.8 1.493 0.5 7 0.6 0.3

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3. Infiltration rate of the soilSoils with higher infiltration

rates will absorb water and theaccompanying dissolved nutri-ents and pesticides faster thansoils with low infiltration rates.Parish soil survey reports includea table listing the infiltration rategroup for the soils identified ineach parish.

4. Uniformity of water flowthrough the filter strip

Shallow depressions or rillsneed to be graded to allow uni-form flow of water into the filterstrip along its length. Waterconcentrated in low points or rillswill flow at high volume, so littlefiltering will take place.

5. Maintenance of the filterstrip

When heavy sediment loadsare deposited, soil tends to buildup across the strip, forming aminiature terrace. If this becomeslarge enough to impound water,flow will eventually break overthe top and become concentratedin that area. Strips should beinspected regularly for damage.Maintenance may include minorgrading or re-seeding to keepfilter strips effective.

In summary: Vegetative filter strips can

reduce sediment effectively ifwater flow is even and shallow.

Filter strips must beproperly designed and con-structed to be effective.

Filter strips become lesseffective as sediment accumu-lates. With slow accumulation,and/or dissolved pesticides intosurface waters.

Filter strip effectiveness depends on five factors:1. The amount of sediment reaching the filter strip. This isinfluenced by:

type and frequency of tillage in cropland above the filter strip.The more aggressive and frequent tillage is above filter strips, themore likely soil will erode.

soil organic matter content.

time between tillage and a rain. The sooner it rains after atillage operation, the more likely soil will erode.

rain intensity and duration. The longer it rains and thus themore sediment is deposited, the less effective filter strips become asthey fill with soil.

slope and the length of run above the filter strip. Water flowsfaster down steeper slopes. Filter strips below steep slopes need to bewider in relation to the cropland drained above to slow water andsediment movement adequately.

In general, a wider, uniformly shaped strip is more effective atstopping or slowing pollutants than a narrow strip. As a field’s slopeand/or watershed size increases, wider strips are required for effec-tive filtering. The following table gives the suggested filter stripwidth based on slope. For a more accurate determination of the sizefilter strip you will need for your individual fields, consult your localNRCS or Soil and Water Conservation District office.

Suggested Vegetated Filter Strip Widths on Percent Slope

Land Slope, % Strip Width, Feet0 - 5 205 - 6 306 - 9 409 - 13 5013 - 18 60

*Widths are for grass and legume species only and are notintended for shrub and tree species. Adapted from the

NRCS Field Office Technical Guide, 1990

2. The amount of time that water is retained in the filterstrip. This is influenced by:

width of the filter area. Filter strips should vary in width,depending on the percent slope, length of slope and total drainagearea above the strip.

type of vegetation and quality of stand. Tall, erect grass cantrap more sediment than can short, flexible grass. The best speciesfor filter strips are tall perennial grasses. Filter strips may includemore than one type of plant and may include parallel strips of treesand shrubs, as well as perennial grasses. In addition to potential forimproving water quality, these strips increase diversity of wildlifehabitat.

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RELATED CONSERVATION PRACTICES:Land Smoothing(NRCS Code 466):

The removing of irregularities on the land surface by use ofspecial equipment. This improves surface drainage, provides formore effective use of precipitation, obtains more uniform plant-ing depths, provides for more uniform cultivation, improvesequipment operation and efficiency, improves terrace alignmentand facilitates contour cultivation.

Chiseling and Subsoiling (NRCS Code324):

Loosening the soil, without inverting (plowing) and with aminimum of mixing of the surface soil, to shatter restrictivelayers below normal plow depth that inhibit water movement orroot development.

Surface Drainage - Field Ditch(NRCS Code 607):

A graded ditch for collecting excess water in a field or forirrigation water drainage. This practice intercepts or collectssurface water and carries it to an outlet.

Grassed Waterways (NRCS Code 412):Natural or constructed channels that are shaped or graded

to required dimensions and established in suitable vegetation forthe stable conveyance of runoff. They are designed to conveyrunoff without causing erosion or flooding and to improve waterquality.

Buffer Zones

(NRCS Code 342)Similar to vegetated filter strips, buffer zones provide a

physical separation between adjacent areas, such as between acrop field and a body of water. Unlike filter strips, buffer zonesmay not necessarily be designed to filter water that flowsthrough them.

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Riparian Zones (NRCS Code 644)A riparian zone consists of the land adjacent to and includ-

ing a stream, river or other area that is at least periodically influ-enced by flooding in a natural state. Similar to vegetated filterstrips, plants in riparian areas effectively prevent sediment,chemicals and organic matter from entering bodies of water.Unlike filter strips, riparian zones use plants that are of a higherorder, such as trees or shrubs, as well as grasses or legumes.Vegetated filter strips are often used in riparian areas as initialfiltering components next to crop field borders.

For more information on these practices and how toimplement them, contact your local NRCS or Soil andWater Conservation District Office or call your countyagent.

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Pesticides can directly entergroundwater by spills around poorlyconstructed or sealed wells, or wellswith improper casting, or by back-siphoning during spray tank filling.

PESTICIDE MANAGEMENT

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Introduction

Rainfall runoffwill also movepesticides acrossthe soil surface.

Rain or irrigationstarts pesticidesmoving into andthrough soil.

Soil-incorporatedsystemic pesticide

Pesticide is carriedinto and throughsoil. Movementthrough soil isaffected by soil andpesticideproperties andamount andtiming of water.Pesticide residueand by-productsnot absorbed arebroken down intothe groundwater.

Pesticide is taken upby plants, brokendown by organisms,sunlight or chemicalreactions.

WATER TABLE

Groundwater flow

Movement withgroundwater –additionalbreakdowngenerally slowed,but depends onchemical natureand groundwater.

Pesticides can directly entergroundwater by spills around poorlyconstructed or sealed wells, or wellswith improper casting, or by back-siphoning during spray tank filling.

To preserve the availability ofclean and environmentally safewater in Louisiana, contamination ofsurface and groundwater by allagricultural and industrial chemicalsmust be prevented. Some sources ofcontamination are easily recogniz-able from a single, specific location.Other sources are more difficult topinpoint. Nonpoint-source pollutionof water with pesticides is caused byrainfall runoff, particle drift orpercolation of water through thesoil. Pest management practices willbe based on current research andextension recommendations. Byusing these recommendations,pesticide usage will follow environ-mentally sound guidelines.

Pest Management ProceduresPesticides will be applied only when they are necessary for the protection

of the crop. The pesticide will be chosen following guidelines to assure that theone chosen will give the most effective pest control with the least potentialadverse effects on the environment.

Water quality, both surface and ground, will be protected by following allof the label recommendations and guidelines dealing with waterquality.

All label statements and use directions designed specifi-cally to protect groundwater will be followed closely.

Specific Best Management Practices designed to protectsurface water will be followed closely.

Erosion control practices (such as pipe drops, etc.) willbe used to minimize runoff that could carry soil particles withadsorbed pesticides and/or dissolved pesticides into surfacewaters.

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Unsaturated zone

WATER TABLEGroundwaterSaturated zone

Rainfall runoff

The water table separatesthe unsaturated zonefrom the saturated zone(groundwater)

PesticideApplication

Management practices suchas the pesticide selected, theapplication method, the pesticiderate used and the applicationtiming influence pesticide move-ment. Pesticides should beapplied only when needed toprevent economic loss of a crop.

Using chemicals at ratesabove those specified by thelabel is ILLEGAL and an envi-ronmental hazard because morepesticide is exposed to erosion,runoff or leaching. In pesticideapplication, “the label is thelaw.” Poor timing of a pesticideapplication also can result inpesticide movement into watersources, as well as give littlecontrol of the targeted pest.

Certain areas on your farmsuch as streams and rivers,wellheads, and lakes or pondsare sensitive to pesticides. Youshould create buffer zonesaround these areas where pesti-cide use will be reduced oreliminated. By buffering theseareas, you may reduce waterquality problems. Areas such asroads, off-site dwellings andareas of public gatherings shouldbe identified. You may want tolimit the use of pesticides nearthese types of areas, too.

These practices will befollowed:

Select the pesticide to givethe best results with the leastpotential environmental impactoutside the spray area.

Select with care and care-fully maintain application equipment.

Carefully calibrate theapplication equipment at thebeginning of the spray season andperiodically thereafter. Sprayaccording to recommendations.

Minimize spray drift byfollowing the label instructions andall rules and regulations developedto minimize spray drift (the physical movement of spray particlesat the time of or shortly after application).

Before applying a pesticide, make an assessment of all ofthe environmental factors involved in all of the area surroundingthe application site.

Carefully maintain records of all pesti-cide applications, not just a record of Re-stricted Use Pesticides.

Pesticide SelectionWhen selecting pesticides, a farmer should consider

chemical solubility, adsorption, volatility and degradationcharacteristics. Chemicals that dissolve in water readilycan leach through soil to groundwater or be carried tosurface waters in rainfall or irrigation runoff. Some chemi-cals hold tightly to, or are adsorbed on, soil particles, anddo not leach as much. But even these chemicals can movewith sediment when soil erodes during heavy rainfall.Runoff entering surface waters may ultimately rechargegroundwater reserves. Chemicals that are bound to soilparticles and organic matter are subject to the forces ofleaching, erosion or runoff over a longer period, thusincreasing the potential for water pollution.

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Pesticidestorage shed

These practices will be followed:

Selection will be based upon recommendations by qualifiedconsultants, crop advisors and upon the published recommendationsof the LSU AgCenter, Cooperative Extension Service.

The selection of the pesticide to be used will be based upon itsregistered uses and its ability to give the quality of pest controlrequired.

The selection will also be based upon its impact onbeneficials, other non-target organisms and on the general environ-ment.

Farmers and commercialpesticide applicators are subjectto penalties if they fail to store ordispose of pesticides and pesti-cide containers properly. Eachregistered pesticide product,whether general or restricted use,contains brief instructions aboutstorage and disposal in its label-ing. The Louisiana Pesticide Lawaddresses specific requirementsfor storage and disposal. Theapplicator must follow theserequirements carefully andensure that employees followthem as well.

The recommended proce-dures do not apply to the disposalof single containers of pesticidesregistered for use in the homeand garden, which may be dis-posed of during municipal wastecollection if wrapped accordingto recommendations.

Storage sites should becarefully chosen to minimize thechance of escape into the envi-

Pesticide Storage andSafety

ronment. Pesticides should notbe stored in an area susceptibleto flooding or where the charac-teristics of the soil at the sitewould allow escaped chemicalsto percolate into groundwater.Storage facilities should be dryand well-ventilated and shouldbe provided with fire protectionequipment. All stored pesticidesshould be labeled carefully andsegregated and stored off of theground. Pesticides should not bestored in the same area as animalfeed. The facility should be keptlocked when not in use. Furtherprecautions include appropriatewarning signs and regular in-spection of containers for corro-sion or leakage. Protectiveclothing should be stored closeby but not in the same room asthe pesticides because they maybecome contaminated. Decon-tamination equipment should bepresent where highly toxicpesticides are stored.

Exceptions forFarmers

Farmers disposing of usedpesticide containers for their ownuse are not required to complywith the require-ments of thehazardous wasteregulationsprovided thatthey triple rinseor pressure washeach containerand dispose of the residues ontheir own farms in a mannerconsistent with the disposalinstructions on the pesticidelabel. Note that disposal ofpesticide residues into water orwhere they arelikely to reachsurface orgroundwatermay be consid-ered a source ofpollution underthe Clean WaterAct or the SafeDrinking Water Act and thereforeillegal.

After the triple rinse proce-dure, the containers are then“empty” and the farmer candiscard them in a sanitary wastesite without further regard to thehazardous waste regulations. Theempty containers are still subjectto any disposal instructionscontained within the labeling ofthe product, however. Disposal ina manner “inconsistent with thelabeling instructions” is a viola-tion of EPA guidelines and couldlead to contamination of water,soil or persons and legal liability.

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Agricultural Chemicals and Worker SafetyThe EPA has general author-

ity to regulate pesticide use inorder to minimize risks to humanhealth and the environment. Thisauthority extends to the protec-tion of farmworkersexposed topesticides. Allemployersmust complywith ALLinstructions of the Worker Pro-tection Standard concerningworker safety or be subject topenalties. Labels may include,for example, instructions requir-ing the wearing of protectiveclothing, handling instructions

and instruc-tions setting aperiod of timebefore work-ers are al-lowed to re-

enter fields after the applicationof pesticides (Restricted EntryInterval).

Employers should also readthe Worker Protection Standardregulations governing the use of

and exposure to pesticides. Therule sets forth minimum stan-dards for the protection of farmworkers and pesticide handlersthat must be followed. Theregulations include standardsrequiring oral warnings andposting of areas where pesticideshave been used, training for allhandlers and early re-entryworkers, personal protectiveequipment, emergency transpor-tation and decontaminationequipment.

The EPAregulationshold theproducer ofthe agricul-tural plant on a farm, forest,nursery or greenhouse ultimatelyresponsible for compliance withthe worker safety standards. Thismeans the landowner mustensure compliance by all em-ployees and by all independentcontractors working on theproperty. Contractors and em-ployees also may be held respon-sible for failure to follow theregulations.

The OccupationalSafety and HealthAct (OSHA)

The federal govern-ment also regulates farmemployee safety under theOccupational Safety andHealth Act (OSHA).OSHA applies to allpersons (employers)engaged in business affect-ing interstate commerce.The federal courts havedecided that all farmingand ranching operations,regardless of where goodsproduced are actually soldor consumed, affect inter-state commerce in somerespect, and thus aresubject to OSHA’s require-ments. In general, everyemployer has a duty toprovide employees with anenvironment free fromhazards that are causing orare likely to cause death orserious injury.

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This...backflowprotection

...Not Thischemicalssiphoned backinto water supply

Air gap

Wash pad withcollection pond

In summary:A. All label directions will be

read, understood and followed.

B. The Louisiana Departmentof Agriculture and Forestry(LDAF) is responsible for thecertification of pesticide applica-tors. All applicators of restricteduse pesticides in Louisiana mustsuccessfully complete a certifica-tion test administered by theLDAF. The LSU AgCenter con-ducts training sessions and pub-lishes study guides in variouscategories covered by the test.Contact your county agent fordates and times of these trainings.

C. All requirements of theWorker Protection Standard (WPS)will be followed, including, but notlimited, to:

• Notifying workers of apesticide application (either oralor posting of the field), abiding bythe restricted entry interval (REI).

• Maintaining a centralnotification area containing thesafety poster; the name, addressand telephone number of thenearest emergency medical facility;and a list of the pesticide applica-tions made within the last 30 daysthat have an REI.

• Maintaining a decontami-nation site for workers and han-dlers.

• Furnishing the appropriatepersonal protective equipment(PPE) to all handlers and earlyentry workers, and ensuring thatthey understand how and why theyshould use it.

• Assuring that all employeesrequired to be trained under theWorker Protection Standard haveundergone the required training.

D. Pesticides will be storedin a secure, locked enclosure and in

a container free of leaks, abidingby any specific recommendationson the label. The storage area mustbe maintained in good condition,without unnecessary debris. Thisenclosure will be at least 150 feetaway and down slope from anywater wells.

E. All uncontained pesticidespills of more than one gallonliquid or four pounds dry weightwill be reported to the director ofPesticide and EnvironmentalPrograms, Louisiana Departmentof Agriculture and Forestry within24 hours by telephone (225-925-3763) and by written notice withinthree days. Spills on public road-ways will be reported to theLouisiana Department of Transpor-tation and Development. Spills intonavigable waters will be reportedto LDEQ, Coast Guard, USEPA.

F. Empty metal, glass orplastic pesticide containers will beeither triple rinsed or pressurewashed, and the rinsate will beadded to the spray solution todilute the solution at the time orstored according to the LDAF rulesto be used later. Rinsed pesticidecontainers will be punctured,crushed or otherwise renderedunusable and disposed of in asanitary landfill. (Plastic containersmay be taken to specific pesticidecontainer recycling events. Contactyour county agent for dates andlocations in your area.)

G. All pesticides will beremoved from paper and plastic

bags to the fullest extent possible.The sides of the container will cutand opened fully, without folds orcrevices, on a flat surface; anypesticides remaining in the openedcontainer will be transferred intothe spray mix. After this procedurethe containers will be disposed ofin a sanitary landfill.

H. Application equipmentwill be triple rinsed and the rinsateapplied to the original applicationsite or stored for later use to dilutea spray solution

I. Mix/load or wash pads(NRCS production code Interim)will be located at least 150 feetaway and down slope from anywater wells and away from surfacewater sources such as ponds,streams, etc. The pads will beconstructed of an imperviousmaterial, and there will be a systemfor collecting and/or storing therunoff.

J. Empty containers will notbe kept for more than 90 days afterthe end of the spray season.

K. Air gaps will be main-tained while filling the spraytank to prevent back-siphoning.

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IntroductionA sound soil fertility pro-

gram is the foundation uponwhich a profitable farmingbusiness must be built. Agricul-tural fertilizers are a necessityfor producing abundant, highquality food, feed and fibercrops. Using fertilizer nutrientsin the proper amounts andapplying them correctly are botheconomically and environmen-tally important to the long-termprofitability and sustainability ofcrop production. The fertilizernutrients that have potential tobecome groundwater or surfacewater pollutants are nitrogen andphosphorus. In general, othercommonly used fertilizer nutri-ents do not cause concern aspollutants.

Because erosion and runoffare the two major waysnonpoint-source pollutants moveinto surface water resources,practices that reduce erosion orrunoff are considered BestManagement Practices (BMPs).

Similarly, practices that limit thebuildup of nutrients in the soil,which can leach to groundwateror be picked up in runoff, andpractices that ensure the safe useof agricultural chemicals also areconsidered BMPs. In general,soil conservation and waterquality protection are mutuallybeneficial; therefore the BMPsdescribed here are the best meansof reducing agriculturalnonpoint-source pollution result-ing from fertilizer nutrients.

NitrogenNitrogen (N) is a part of all

plant and animal proteins. There-fore, human survival depends onan abundant supply of N innature. Approximately 80 percentof the atmosphere is nitrogengas, but most plants cannot usethis form of nitrogen. Supple-mental nitrogen must be suppliedthrough the soil. A crop wellsupplied with N can producesubstantially higher yields, onthe same amount of water, thanone deficient for N. Properlyfertilized crops use both N andwater more efficiently, thusimproving environmental qualityand profitability.

Supplemental N will benecessary on almost all non-legume crops in Louisiana formaximum profits. Rely on Nrecommendations based onLouisiana research. These recom-mendations take into accountmaximum economic yield poten-tials and soil texture. Nitrogenrecommendations from the LSUAgCenter are usually ample to

provide optimum economicyields.

Decomposition of organicmatter results in simpler inor-ganic N forms such as ammo-nium (NH4+) and nitrate (NO3-).These are soluble in soil waterand readily available for plantuptake. The ammonium form isattracted to and held by soilparticles, so it does not readilyleach through the soil withrainfall or irrigation water.Nitrates, on the other hand, arenot attached to soil particles anddo move downward with soilwater and can be leached intogroundwater or run off intosurface waters.

Excessive nitrate concentra-tions in water can acceleratealgae and plant growth in streamsand lakes, resulting in oxygendepletion. Nitrate concentrationsabove a certain level in drinkingwater may injure some animalsor human infants.

PhosphorusPhosphorus (P), like nitro-

gen, is essential for plant growth.Naturally occurring P exists in aphosphate form either as solubleinorganic phosphate, solublephosphate, particulate phosphateor mineral phosphate. The min-eral forms of phosphorus (cal-cium, iron and aluminum phos-phates) are low in solubility. Theamount of these elements (cal-cium, iron and aluminum)present in reactive forms varieswith different soils and soilconditions. They determine the

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Algae bloom

amount of phosphorus that canbe fixed in the soil.

The immediate source ofphosphorus for plants is thatwhich is dissolved in the soilsolution. A soil solution contain-ing only a few parts per millionof phosphate is usually consid-ered adequate for plant growth.Phosphate is absorbed from thesoil solution and used by plants.It is replaced in the soil solutionfrom soil minerals, soil organicmatter decomposition or appliedfertilizers.

Phosphate is not readilysoluble. Most of the ions areeither used by living plants oradsorbed to sediment, so thepotential of their leaching togroundwater is low. That portionof phosphate bound to sedimentparticles is virtually unavailable

to living organisms, butbecomes available as itdetaches from sedi-ment. Only a small partof the phosphatemoved with sedimentinto surface water isimmediately availableto aquatic organisms.Additional phosphatecan slowly becomeavailable through bio-chemical reactions, however. Theslow release of large amounts ofphosphate from sediment layersin lakes and streams could causeexcessive algae blooms andexcessive growth of plants,thereby affecting water quality.

Nutrients will be used toobtain optimum crop yieldswhile minimizing the movementof nutrients to surface and

groundwater (NRCS ProductionCode 590). A nutrient manage-ment plan should be developedfor the proposed crop by usingsoil analyses from approvedlaboratories.

Nutrient Application RatesNutrient application rates

will be based on the results of asoil analysis. Select only thosematerials recommended for useby qualified individuals from theLouisiana Cooperative ExtensionService, Louisiana AgriculturalExperiment Station, certifiedcrop advisors and certifiedagricultural consultants and/orpublished LSU AgCenter data.

Soil testing is the founda-tion of a sound nutrient man-agement program.

A soil test is a series ofchemical analyses on soil thatestimates whether levels ofessential plant nutrients aresufficient to produce a desiredcrop and yield. When not takenup by a crop, some nutrients,particularly nitrogen, can be lostfrom the soil by leaching, runoffor mineralization. Others, likephosphorus, react with soilminerals over time to formcompounds that are not availablefor uptake by plants. Soil testingcan be used to estimate howmuch loss has occurred and

predict which nutrient(s) andhow much of that nutrient(s)should be added to produce aparticular crop and yield. Takesoil tests at least every threeyears or at the beginning of adifferent cropping rotation.

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1. Soil test for nutrient status and pH to:• determine the amounts of additional

nutrients needed to reach designated yield goalsand the amount of lime needed to correct soilacidity problems

• learn the Cation Exchange Capacity(CEC) and the organic matter concentration soas to determine how much of these nutrients theparticular soil is capable of holding

• optimize farm income by avoiding exces-sive fertilization and reducing nutrient losses byleaching and runoff

• identify other yield-limiting factors suchas high levels of salts or sodium that may affectsoil structure, infiltration rates, surface runoffand, ultimately, groundwater quality

2. Base fertilizer applications on:• soil test results

• realistic yield goals and moisture pros-pects

• crop nutrient requirements

• past fertilization practices

• previous cropping history

3. Manage low soil pH by liming accordingto the soil test to:

• reduce soil acidity

• improve fertilizer use efficiency

• improve decomposition of crop residues

• enhance the effectiveness of certain soilapplied herbicides

4. Time nitrogen applications to:• correspond closely with crop uptake

patterns

• increase nutrient use efficiency

• minimize leaching and runoff losses

5. Inject fertilizers or incorporate surfaceapplications when possible to:

• increase accessibility of fertilizer nutri-ents to plant roots

• reduce volatilization losses of ammoniaN sources

• reduce nutrient losses from erosion andrunoff

6. Rotate crops when feasible to:• improve total nutrient recovery with

different crop rooting patterns

• reduce erosion and runoff

• reduce diseases, insects and weeds

7. Control nutrient losses in erosion andrunoff by:

• using appropriate structural controls

• adopting conservation tillage practiceswhere appropriate

• properly managing crop residues

• land leveling

• implementing other soil and water con-servation practices where possible

• using filter strips

8. Skillfully handle and apply fertilizer by:• properly calibrating and maintaining

application equipment

• properly cleaning equipment and dispos-ing of excess fertilizers, containers and washwater

• storing fertilizers in a safe place

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Another important part of asuccessful NMP are BMPs.BMPs, such as soil testing, helpyou select the right nutrient rateand application strategy so thatcrops use nutrients efficiently.This not only reduces nutrientlosses and protects the environ-ment but also increases farmprofitability. BMPs may includemanaging the farm to reduce soilerosion and improve soil tilththrough conservation tillage,planting cover crops to useexcess nutrients or using filterstrips and buffers to protect waterquality.

Nutrient ManagementPlans (NMPs)

Both the U.S. Environmental Protection Agency (EPA) and theU.S. Department of Agriculture (USDA) are encouraging a volun-tary approach to handling nonpoint-source issues related to agricul-ture.

The implementation of Nutrient Management Plans (NMP) byall agricultural producers will ensure that fertilizers are managed inan environmentally friendly fashion.

Developing a Nutrient Management PlanAn NMP is a strategy for making wise use of plant nutrients to

enhance farm profits while protecting water resources. It looks atevery part of your farming operation and helps you make the bestuse of manures, fertilizers and other nutrient sources. Successfulnutrient management requires thorough planning and recognizesthat every farm is different. The type of farming you do and thespecifics of your operation will affect your NMP. The best plan isone that is matched to the farming operation and the needs of theperson implementing the plan.

The Parts of an NMPAn NMP looks at how nutrients are used and managed through-

out the farm. It is more than a nutrient management plan that looksonly at nutrient supply and needs for a particularfield. Nutrients are brought to the farm throughfeeds, fertilizers, animal manures and other off-farminputs. These inputs are used, and some are recycledby plants and animals on the farm. Nutrients leavethe farm in harvested crops and animal products.These are nutrient removals. Ideally, nutrient inputsand removals should be roughly the same. Whennutrient inputs to the farm greatly exceed nutrientremovals from the farm, the risk of nutrient losses togroundwater and surface water is greater. When youcheck nutrient inputs against nutrient removals, youare creating a mass balance. This nutrient massbalance is an important part of an NMP and impor-tant to understand for your farming operation.

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The Basic StepsNMPs consist of four major

parts: evaluation of nutrientneeds, inventory of nutrientsupply, determination of nutrientbalance, and preventive mainte-nance and inspection.

Evaluation ofNutrient NeedsMaps and Field Information

You will need a detailedmap of your farm. The mapshould include:

• farm property lines

• your fields with the fieldidentification

• the location of all surfacewaters such as streams, rivers,ponds or lakes

• direction of surface flows

• arrows showing the direc-tion that streams or rivers flow

• a soils map, if available

This map will serve as thebasis for the entire plan, so eachfield should have a uniqueidentification. In addition to themap, prepare a list of the crops tobe grown in each field with arealistic yield goal for each crop.Most of this information isavailable at your local USDAFarm Service Center.

Locate Critical AreasCertain areas on your farm

such as streams and rivers,wellheads and lakes or ponds aresensitive to nutrient overload.You should create buffer zonesaround these areas on your map

where nutrient use will bereduced or eliminated. Bybuffering these areas, waterquality problems may be de-creased.

Soil TestingComplete and accurate soil

tests are important for a success-ful nutrient management plan.You will need soil tests everythree years to determine howmuch nutrient addition isneeded. The needed nutrientscan be supplied from commer-cial fertilizer and/or organicsources. Be sure to take repre-sentative soil samples and havethem tested by a reputablelaboratory familiar with Louisi-ana soils and crop production.Your county agent can help yousubmit samples to the LSU SoilTesting Laboratory.

nitrogen, phosphorusand potassium should belisted in the plan for each field.Most soil and plant analysis labswill give you recommendedapplication rates based on thesoil test results. Your countyagent can help you with this.

Inventory ofNutrient Supply

Many of the nutrientsneeded to grow your crops arealready present on your farm inthe soil, in animal manures or incrop residues. Knowing theamounts of nutrients alreadypresent in these sources is impor-tant so that you do not buy orapply more nutrients thanneeded.

Determine the Quantity ofNutrients Available on YourFarm

Supply planning starts withan inventory of the nutrientsproduced on the farm. Thisinformation will allow you tobalance your nutrient purchaseswith what is available on yourfarm for the realistic productionpotential of the crops grown.

Determine NutrientsNeeded for Each Field

Once you have set realisticyield goals and you have yoursoil test results, you can deter-mine the nutrients your cropswill need. The amount of nutri-ents needed should be based onyour local growing conditions. Ata minimum, the amounts of lime,

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DeterminingNutrient BalanceBalance Between Supply andNeed

Once you have determinedboth the supply and need ofnutrients for each of your fields,a critical aspect of NMPs isbalancing the two. This can bedone in several ways. MostNMPs are developed based onnitrogen, but other factors suchas phosphorus or metals couldcontrol how much you can putout under certain conditions. Aphosphorus index is beingdeveloped to help producersdetermine when nutrient man-agement based on phosphoruswould be advisable.

PreventiveMaintenance andInspections

Keeping good, detailedrecords that help you monitoryour progress is essential toknow if your NMP is to accom-plish the goals you have set. Youshould keep all results from soiland plant and examine how theychange with time with yourmanagement practices. Recordsshould be kept on crop yields,nutrient application rates, timingand application methods. Keepdetailed schedules and recordson calibration of spraying andspreading equipment. When youhave a major change in produc-tion, update your plan to reflectthese changes.

Where Can You ObtainInformation Needed for YourNMP?

The LSU AgCenter, the USDA NaturalResources Conservation Service, the Louisi-ana Department of Agriculture and Forestry,certified crop advisors or other private con-sultants will be able to assist you in develop-ing parts of a comprehensive nutrient manage-ment plan.

An NMP is a good tool to help you useyour on- and off-farm resources more effi-ciently and prevent future problems. A suc-cessful NMP will help you obtain the maxi-mum profit while protecting the environment.

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Water wellprotection -

Farm*A*Syst/Home*A*Systshould be usedevery threeyears to deter-mine potentialthreats to waterwells. Threatsidentified willbe ranked andmeasured tocorrect themost serious.

Used engine oil,grease, batteries,tires, etc.

• Used engine oil should bestored in a waste oil container(tank or drum) until recycled.

• Empty paint cans, anti-freeze containers, used tires, oldbatteries, etc., will be stored in asecure area until they can bedisposed of properly.

Irrigation waterquality

Irrigation water (surfaceand/or well) should be tested inthe spring to determine thesalinity (salt) level before irrigat-ing fields. Take samples to anapproved laboratory for analysis.

Fuel storage tanksAbove-ground fuel storage tanks in Louisiana are regulated

by the State Fire Marshal and by the EPA if surface water is at risk.Above-ground tanks containing 660 gallons or more requiresecondary containment. The State Fire Marshal recommends thatsome sort of secondary containment be used with all fuel storagetanks. This could include the use of double-walled tanks, dikingaround the tank for impoundment or remote impoundment facili-ties.

These practices are to be followed:

Any existing above-ground fuel storage tank of 660 gallons ormore (1320 gallons if more than one) must have a containment wallsurrounding the tank capable of holding 100 percent of the tank’scapacity (or the largest tank’s capacity if more than one) in case ofspillage.

The tank and storage area should be located at least 40 feetfrom any building. Fuel storage tanks should be placed 150 feet anddownslope from surface water and water wells.

It is recommended that thestorage tank be on a concreteslab to prevent any spillage fromentering surface and groundwa-ter.

The storage area shouldbe kept free of weeds and othercombustible materials.

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This tank would be classified asan underground fuel tank.

10% of tank is belowground level

The tank should beconspicuously marked with thename of the product that itcontains and “FLAMMABLE –KEEP FIRE AND FLAMEAWAY.”

The bottom of the tankshould be supported by concreteblocks approximately 6 inchesabove the ground surface toprotect the bottom of the tankfrom corrosion.

If a pumping device isused, it should be tightly andpermanently attached and meetNFPA approval. Gravity dis-charge tanks are acceptable, butthey must be equipped with avalve that will automaticallyclose in the event of a fire.

Plans for the installationof all storage tanks that willcontain more than 60 gallons ofliquid must be submitted to theState Fire Marshal for approval.

All tanks that catch on firemust be reported to the State FireMarshal within 72 hours of thefire.

Underground storagetanks are defined as containingmore than 10 percent of theirtotal volume beneath the soilsurface. Underground tanksrepresent more of a problem thanabove-ground tanks becauseleaks can often go for longperiods without being detected.This poses a serious threat togroundwater sources in thevicinity of the tank. If you havean underground fuel storage tank,you need to contact the State FireMarshal’s Office for regulationsaffecting these storage tanks.

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AGRICULTURAL SCIENTISTS WORK TOSUSTAIN THE ENVIRONMENT

The stage was set for contem-porary LSU AgCenter environmentalresearch programs when “Focus2000: Research for the 21st Cen-tury,” a strategic plan for the Louisi-ana Agricultural Experiment Station(LAES), was adopted in 1990. Onethrust of this plan was to protect theenvironment by “ developingproduction systems that protect thesoil and minimize the need forfertilizer, water, tillage, and otherinputs.” Adoption of Focus 2000 ledto establishment of the Soil, Waterand the Environment ResearchAdvisory Committee (RAC), whichprovided researchers a forum forexchanging information on environ-mental programs and for formingnew collaborations with colleagues.

William H. BrownThe word “environment”

means different things to differentpeople. To some it stirs visions ofclear, pristine streams and lakes; toothers vistas of forests or prairies; tostill others, clean, fresh mountain air.To agriculturalists, who producefood and fiber for the citizens of theUnited States and a substantial partof the rest of the world, a qualityenvironment means acres of produc-tive soil, clean air and an adequatesupply of quality water for irriga-tion, livestock consumption andhuman use. All these visions areboth accurate and incomplete. Tocomplete the picture, one mustappreciate the array of agriculturalresearch conducted in Louisiana andat other agricultural experimentstations across the country. Many ofthese topics are not commonlythought of as environmental, yetthey have a major impact on thequality of our air, soil and waterresources.

Agricultural scientists wereamong the original environmental-ists. For most of this century,agricultural researchers have recog-nized the importance of sustainingthe natural resource base on whichagricultural production relies. Forexample, the 1930s saw the initia-tion of widespread programs at land-grant universities and at the federallevel to reduce soil erosion, to keepthe soil covered with vegetation andto improve drainage to enhance soilproductivity. Through the ensuingyears, many research programs havebeen conducted to provide informa-tion for improving the environmental“friendliness” of food and fiberproduction and processing.

for the LAES environmental re-search programs conducted since.

AgCenter environmentalresearch programs can be grouped asfollows: conservation tillage,management of wastes and residuesfor beneficial uses, water quality,integrated pest management andnutrient management.

CONSERVATION TILLAGE

AgCenter programs in conser-vation tillage for cotton productionon Macon Ridge soils demonstratednot only that cotton could be suc-cessfully produced with little or notillage, but, when combined with awinter cover crop, soil erosion couldbe reduced by up to 85 percent, soilorganic matter could be slowly butsteadily rebuilt, and that nitrogenfertilizer requirements could bestabilized at about 70 pounds or lessper acre, depending on the covercrop grown. This pioneering re-search, along with advances inherbicide technology, paved the wayfor the adoption of practical conser-vation tillage production systems(sometimes called “stale seedbed”systems) now widely used onLouisiana cropland, resulting inmajor soil erosion reductions.

Another area in whichAgCenter scientists have pioneeredhas been in the development ofconservation tillage systems for ricein southwest Louisiana. Althoughstill being developed and refined,conservation tillage promises to

William H. Brown, Associate Director andAssociate Vice Chancellor, LSU AgCenter

One product of the Soil, Waterand Environment RAC was sponsor-ship of an environmental conferencein 1995. This conference includedLAES research presentations on landuse management, waste manage-ment, forestry, pest management,water quality and conservationtillage and presentations fromnumerous state and federal agenciesincluding the Louisiana Departmentof Environmental Quality, theBarataria-Terrebonne NationalEstuary Program and the NaturalResources Conservation Service.Conference participants set the stage

Agriculturalscientists wereamong theoriginalenvironmentalists.

AIR, SOIL AND WATER

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offer rice producers a practical wayof growing rice while reducing thesediment load of the water leavingtheir fields.

WASTE MANAGEMENT

Waste management pro-grams deal with the manures andresidues that result from animalproduction and processing and thedevelopment of methods to benefi-cially use the solid wastes thatoriginate from both agriculturaloperations and urban activities. Aprogram is under way to determinethe extent to which dairy manuresand related fecal coliform indicatororganisms move into water bodieswhen irrigated onto pastureland in“no discharge” systems. Furtherknowledge about how to minimizethe environmental impacts ofdairying is vital for Louisiana’seconomically important dairyindustry in the environmentallysensitive Lake Pontchartrain drain-age basin.

Another area of intense re-search activity deals with establish-ing benchmarks for poultry litterdisposal in north Louisiana. Poultrylitter, a byproduct of broiler produc-tion, is a valuable source of nutrientsfor pasture and forest lands, butexcessive application can overloadthe soil’s ability to assimilatephosphorus. And, if allowed to moveinto water bodies, phosphorus couldcause eutrophication problems.Several studies are under way thatwill define safe application levels,the fertility value and alternativebeneficial uses for poultry litter.

Many agricultural and urbanresidues can be treated by com-posting to reduce volume, eliminateodors and neutralize undesirablecomponents. The resulting compost

can be incorporated into the soil toenhance soil structure and plantgrowth. The LSU AgCenter’sCallegari Organic Recycling Centerprovides the facilities for bothresearch and training in the com-posting process. The AgCenter hasconducted 12 one-week programswhich have trained more than 200people from 29 states and fivecountries in the proper techniques ofcomposting organic residues.

WATER QUALITY

Water quality researchstudies cut across many crops andsoil types. These studies providebasic information on how precipita-tion moves off the land, through thesoil and what it carries with it. Thisinformation is fundamental to ourunderstanding of how water trans-ports nutrients and chemicalsthrough the soil and how rainfall orirrigation water can be managed toimprove both crop production andthe environment.

AgCenter soil scientists andagricultural engineers have teamedwith USDA researchers to determinethe complex mechanisms by whichwater moves through Louisiana’salluvial soils, how rapidly it movesand the extent to which it transportscertain nutrients and pesticides.Other studies have shown thatsubsurface drainage can reduce soilerosion and improve water dis-charges into drainage systems.Studies of corn production over fiveyears showed that subsurfacedrainage reduced soil loss by 30percent, nitrogen loss by 20 percentand phosphorus loss by 36 percent.A similar nine-year study withsoybeans showed 48 percent lesssoil loss, 39 percent less nitrogenloss, 35 percent less phosphorus lossand 36 percent less potassium loss.

Water table management is atechnology that uses undergroundtubes to drain excess water fromfields to prevent water loggingdamage to crops during wet weatherand also to irrigate from below thesurface during drought. Cooperativestudies with USDA scientists focuson how water table management canenhance crop production (sugarcaneespecially) while improving thequality of the water drained from thefield.

INTEGRATED PEST MANAGEMENT

Integrated pest management(IPM) refers to the integrated use ofall appropriate methods to controlagricultural pests such as weeds,insects, diseases and nematodes.IPM systems employ judicious useof pesticides along with culturalpractices, genetic resistance andother available means to reducedependence on pesticides. Reducedpesticide usage is based on carefulscouting and precision applicationmethods. Although most pesticidesused today are much less toxic tonon-target organisms and used inmuch smaller quantities (ouncesrather than pounds per acre), the endresult of IPM is that relatively fewerpesticides are introduced into theenvironment. Some crops are nowresistant to selected herbicides or tocertain insect pests because of recentadvances in plant genetic engineer-ing. The fruits of several decades ofintensive molecular biology researchhave provided LAES entomologistsand weed scientists with additionaltools to develop practical productionsystems that use these special plantsto combat competing or damagingpests while minimizing pesticideuse.

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NUTRIENT MANAGEMENT

Nutrient management,actually one of the oldest of theagricultural sciences, determines theneed for supplementing the soil’snatural fertility with the appropriatetypes and amounts of nutrients toachieve the genetic potential oftoday’s improved seeds. It is impor-tant, both environmentally andeconomically, that nutrients not beapplied to producers’ fields inexcessive amounts.

Nutrient managementresearch starts with LAES agrono-mists who determine the nutrientneeds for the many crops producedon the diverse soil types of Louisi-ana. Soil scientists determinenutrient interactions and availabilityin the various soil types and textures.The Soil Testing Laboratory pro-vides individual field analyses thatdetermine the nutrients that need tobe added and their amounts forspecific crops and locations. Thisinformation is provided to extensionagents so they can make specificfertility recommendations to farm-ers. Finally, new technologies arenow being investigated, usuallycalled “precision farming systems,”that will allow variable, on-the-goprecision nutrient applicationswithin fields based on intensive soiltesting, crop production history andother pertinent factors.

Taken together, today’sproducers are armed with an array ofscience-based data, sophisticatedtesting services and the latesttechnology to enable them to applyonly the required nutrients in onlythe needed amounts at only theproper locations for optimum cropperformance.

OTHER ACTIVITIES

Integrating the best sciencewith economic constraints andenvironmental concerns is challeng-ing. In 1993, AgCenter scientists and

extension specialists, in cooperationwith farmers representing theLouisiana Farm Bureau Federation,and representatives of state andfederal agencies such as the NaturalResources Conservation Service(NRCS), Louisiana Department ofAgriculture and Forestry (LDAF),Louisiana Department of Environ-mental Quality (LDEQ), Departmentof Natural Resources (DNR),Agricultural Research Service(ARS) and others launched an effortto integrate the best informationavailable into a series of “bestmanagement practices” or BMPs.The BMPs cover all of the majorplants and animals produced inLouisiana.

Two research stations,Southeast and Iberia, have operatedsites for the National AtmosphericDeposition Program (NADP) sincethe early 1980s. This program,supported in part by state agricul-tural experiment stations nationwide,has provided measurements ofprecipitation acidity and atmo-spheric nutrient deposition at morethan 200 sites for 20 years. TheNADP is now developing a nationalmercury deposition network, and theAgCenter will provide two monitor-ing sites, the Hammond and theSweet Potato research stations, thatwill be operated by the LouisianaDEQ. The AgCenter also operates anetwork of meteorological recordingsites at the research stations calledthe Louisiana Agriclimatic Informa-tion System (LAIS). The LAISprovides research scientists with anextensive database of the state’srecent meteorology in support oftheir research programs.

FUTURE FOOD DEMANDS

The earth’s environment hasnever been static. It has been subjectto both dramatic upheavals and slow,evolutionary changes. Our crowdedcities and sprawling suburbs haveenvironmental impacts. Likewise,

the production of food and fiber fora growing world population willhave environmental consequences.Agriculture and cities must co-exist,however, if society, as we know it, isto continue and to prosper. Someforecasts suggest that the world’sfood demand will triple over the next40 years. To meet that demand, wemust continue to invest in scienceand technology so that we can learnhow to use reasonable and effectivemeasures to blend sustainableeconomic growth with acceptableenvironmental impacts.

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Compiled by:Fred Sanders, Ph.D., and

Mike Cannon, Ph.D.

Other AgCenter contributorswere:

Eddie Funderburg, Ph.D.Mary Grodner, Ph.D.Dearl Sanders, Ph.D.

Bill Branch

Sweet Potato BMP reviewcommittee:

Jack Bagent, Ph.D.Bill Hadden

Chris Clark, Ph.D.Michael Jordan, NRCS

Sam Rogers, ARSGary Goay, LDEQEd Britton, DNR

Lamar Bush, GrowerIrv Daniel, Grower

Mark Fields, GrowerLarry Fontenot, Grower

Ray Poret, GrowerJerry Self, Grower

Jim Sowell, GrowerMitch Stelly, Grower

Ken Thornhill, Grower

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The complex nature of nonpoint pollution means programs designed toreduce its impact on the environment will not be easy to establish ormaintain. Controlling these contaminants will require solutions as diverseas the pollutants themselves. Through a multi-agency effort, led by theLSU AgCenter, these BMP manuals are targeted at reducing the impactof agricultural production on Louisiana’s environment. Agriculturalproducers in Louisiana, through voluntary implementation of theseBMPs, are taking the lead in efforts to protect the waters of Louisiana.The quality of Louisiana’s environment depends on each of us.

Visit our website:www.lsuagcenter.com

Produced by LSU AgCenter Communications

Louisiana State University Agricultural Center, William B. Richardson, ChancellorLouisiana Agricultural Experiment Station, R. Larry Rogers, Vice Chancellor and Director

Louisiana Cooperative Extension Service, Jack L. Bagent, Vice Chancellor and Director

Pub. 2832 (1M) 12/00

Issued in furtherance of Cooperative Extension work, Acts of Congress of May 8 and June 30, 1914, in cooperation with theUnited States Department of Agriculture. The Louisiana Cooperative Extension Service provides equal opportunities in

programs and employment.

Originally developed through a cooperative agreement with the Louisiana Department of Environmental Quality,Contract 522100.