In the past decade, some farming operationshave adopted a concept that had not beencommonly utilized in California. This con-

cept requires an added cost per acre when devel-oping a citrus property. The use of berms ormounds as indicated in the photo, is an interest-ing effort that lends itself to further discussion.

When looking into the literature andresearch studies that have been done on bermsfor citrus production, it is easy to see the valueof their use in areas of high rainfall. In theIndian River region of Florida, these berms areextensive and can be as deep of five feet fromthe top of the berm to the bottom of the trenchbetween the berms. The compelling reason forthis degree of grading is the massive amount ofrainfall that drenches the area as tropicalstorms and hurricanes move through this eastcoast region of the Florida Peninsula. It is notuncommon in this region to have many inchesof rain in one day, so the berms function as ameans to conduct this massive amount of rain-fall away from the trees.

In addition to the periodic downpours, thewater table in this area of Florida is very high.So high in fact, that the root systems often canonly survive in the top 12 inches of soil. Theuse of berms greatly enhances the ability of cit-rus trees to survive in regions of high rainfall.

California is far from falling into the highrainfall category. So the question is, why go tothe extra expense of berms if their primary useis to improve drainage in high rainfall areas?This expense can be as low as $100 to as highas $475 an acre, which is a significant addi-tional cost to any new citrus development. Thisadditional cost can’t be taken lightly and thereshould be results in the new planting thatwould guarantee economic payback of theadded costs.

PROS AND CONS FOR BERMS IN CALIFORNIA

Most of the companies we talked to thatare committed to the use of berms in theirnew citrus developments rely on personalexperience or anecdotal evidence as justifica-tion for the added developmental costs thatberms require. We also found differentapproaches to how big the berm should be.Here are some of the advantages that wereshared with us:

1. Moves water down and away from thetree’s root system.

2. There is the rationale that the top of theberm may heat up faster than traditionalplantings on flat fields. This may encouragefaster root development on the berms.

3. Trees on berms have appeared to grow aboutone-third faster than trees planted usingtraditional methods of land preparation.

4. The incidence of soil borne diseases may bereduced.

5. Fruit drops and rolls toward the middles,which keeps inoculums that cause rottingaway from the tree.

6. Development of berms creates more aera-tion in the soil, which allows for more rapidrooting of the developing tree.

7. It inhibits lateral movement across agrove, which restricts foot traffic thatcould spread soil pathogens throughoutthe property.

BERMS: For citrus productionby Roger Smith

WINTER 2004

Please see BERMS on page 3

Dense planting of mandarins on high berms with flat middles. Trees 2 1/2 years old.

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Tom Avinelis operates AgriCare Inc., adiversified farm management company thatprincipally cares for citrus, grapes, cherries,and olives. The company is based in Terra Bellaand provides services in Kern, Tulare, andFresno counties. Tom worked as an agronomistfor 6 years prior to returning to farming andstarting AgriCare in 1993.

TS: What do you think of berms for citrus plantings?

Tom: We’ve bermed 80% of our citrus plantingsin the last five years and have been using theconcept in many of our citrus developments forthe last 8 years.

TS: What is your berming strategy?

Tom: If anything is under drip we berm it. Byberming, you concentrate a higher percentageof roots in the berm and this is an importantpart of managing a drip irrigation system.Many of our Clementine developments are on

drip because it allows us better irrigation man-agement, which is a critical management toolfor setting and holding a Clementine crop.

In other citrus crops, we berm for differentreasons. Many of the best citrus locations tendto have shallow and heavier soils, so we useberms on those soils to maximize topsoildevelopment. When you berm on shallowsoils, the active soil at the base of the tree canbe expanded from 18 inches up to 32 inches.This creates a better soil environment near thetree and allows better drainage which keepsstanding water away from the trunk of the tree.

In our industry we have very few soils with auniform soil type so we find ourselves irrigatingto the middle, which means some of the grove iseither under irrigated or over irrigated. Theberm buys you a layer of “caution factor” thathelps you not over irrigate and gives you moreloose topsoil to work with than a flat planting.

TS: What made you decide to implement bermingstrategies?

Tom: General observations of different cropsand their performance and evaluation of oldorchards that have low spots with standingwater. Also, all of our new citrus plantings arehigh density and higher density plantings lenditself to a berming program like in many other

crops like grapes, almonds, and cherries. Thesecrops have a tremendous improvement ingrowth versus flat plantings.

TS: Have you seen “tremendous improvement” incitrus plantings?

Tom: It’s difficult to gauge because many of theorchards aren’t old enough. I haven’t seen bigdifferences in our young citrus plantings yet. Ithink in some soils you’re not going to see a bigdifference, but berms are a significant tool forcertain varieties and certain soils to maximizetheir long-term potential. There is a real benefitin heavier soils and shallow soils, but you won’tsee as many benefits with lighter, well-drainedsoils that are irrigated with mini-sprinklers.

TS: What are the costs?

Tom: About $50-75 an acre in order to constructthe berm that measures about 6 feet by 2-2.5feet in height. We try to keep the costs downand use a scraper/terracer, or border discs.

TS: Any 20-20 hindsight or things you’ve learned?

Tom: A mistake we made when we did theberms prior to planting, we buried the driphose to minimize damage by coyotes. Weburied the hose too deep, which exposed it to

Call our office at (559)592-2304 about 2-3weeks before the day you want to plant.

WE NEED TO KNOW:

• The EXACT tree count. Please don’trely on the count of the crew that marksthe field. Sometimes they make mistakesand it is best to double-check their countbefore you call us. Always count a fieldtwice to avoid errors.

• The address and the county of theplanting location for the Ag Permit.

• The name of the bins you are providingfor the trees. We put 50 balled trees and

220 citripot trees in each bin. We requestyou drop the bins at the nursery 7-10 daysprior to your planting date.

• Whether you want us to deliver thetrees or you want to pick them up your-self. We charge a modest delivery chargeand use Danny Lopez who provides uswith very fair rates. His drivers are alsoexperienced tree haulers and forklift dri-vers. If you have less than 200 trees, itpays to pick them up yourself.

• The time you need the trees delivered.Once scheduled, make sure we know of

Tree Pick-up Proceduresany delays. We try to be ready in advanceof your planting date, so please notify usright away if a problem comes up.Good communication helps us serve you

best, so give us some time to handle yourorder properly. We also are providing abrochure that will help you plan out theplanting process. Pick one up at the Ag Expoor call us and we’ll mail you one.

Tulare County regulations require a mov-ing permit for ALL citrus trees and bud-wood. Even small orders need a minimumof 48 hours notice for us to get the paper-work done.

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Please see INTERVIEW on page 4

8. It may help in draining off cold air. Becausecold air runs like water, it is possible thatberms may move that air out of the grovemore effectively.

The above advantages have to be balancedwith a few challenges. In our investigation, wealso discovered some skilled growers that aren’tconvinced that berms are always a good idea.The use of berms in citrus plantings does createsome long-term consequences that are notalways easy to deal with. Those may include:

1. Irrigation water for young trees may run offthe berm and not effectively irrigate thenewly planted tree.

2. Harvest is more difficult on large berms.When picking citrus groves, lateral move-ment on foot is required, often while carry-ing a 16-foot ladder. Climbing up and overberms encumbered by a ladder and heavypicking sack makes the job of harvest moredifficult for fieldworkers and would slowtheir efficiency and production per day.

3. Lateral movement is very difficult. If anirrigator needs to move across the tree row,he either must go up and over the berms ortravel to the end of the grove.

4. Cross-hedging or cross-row weed sprayingis very difficult or nearly impossible toachieve with berms.

5. Berms require modification to orchardequipment. In some berm designs, the driverow is not flat. So machines like brushshredders, mowers, boom weed sprayers,etc., must be modified to accommodate a v-shaped drive row.

6. The cost of development is increased by$100 to $475 per acre. These costs are notjust the costs of berming, but also the costsof insuring the ends of the grove are prop-erly graded and that there is a properaccommodation for runoff water.

7. Large berms on undulating field may createmud holes that can’t drain. It may be advis-able to plant flat and invest the money savedin tile drainage systems.

8. If berms are primarily to improve drainage,installing on hillsides may not be necessarysince hillsides automatically drain. Theymay be helpful to increase soil depth.

9. Some believe berms may restrict the maxi-

mum soil area an older tree can accesswhen compared with flat ground. Researchshould be done to investigate this concern

10.Tillage between berms may be difficult andcould cut roots if the equipment comes tooclose to the berms. (Some growers offerthat a little root pruning is a good thing).

DISCUSSIONBecause of the absence of university trials in

California, comparing the use of berms versestraditional methods makes it difficult to recom-mend the practice in all cases. There is no ques-tion that working the soil and raising the bedscreates a better environment for root develop-ment. What is difficult to justify is the addedexpense per acre. It isn’t clear yet that there isadequate payback for the increased cost in devel-opment, but it is clear that there is only one timeto create a berm and that is prior to planting.

Where citrus is planted in Central California,soil types vary dramatically. Heavy Portervilleadobe clay, fine sandyloams of Sanger, thered San Joaquin soilseries, and the lightwind-blown soils ofKern County, there isconsiderable varia-tion. To be able tomake a blanket rec-ommendation for thatmany variables isimpossible. But it ispossible to say thatberming is a greathelp for heavy soilconditions, shallowsoils, or areas wherethere is poor drainage.It isn’t clear what the

advantages ofberming are forlighter soils, but itmust be mentionedthat many progressivecitrus companies havechosen to berm evenwhere light soils exist.

In the field nurs-eries at TreeSource,we find that improv-ing the drainagearound the root sys-tem of young nurs-

ery trees is an important factor that may actu-ally enhance root development. If this sameeffort is accomplished by berms in the newlyplanted citrus grove it may truly encouragethat grove to come into production faster. Acitrus grower must focus on doing everythingin his power to create the optimum environ-ment to encourage the root development ofyoung trees.

The advantage of the berm is that it forcesthe grower to do the optimum amount of landpreparation prior to planting. This one factormay be enough of a justification to encouragethe investment in building berms for newplantings, but it cannot be over emphasized theimportance of trees getting adequate waterwhen they are sitting on top of a “hill.” AtTreeSource, we encourage you to take the timeto work the soil and prepare your site toencourage optimum root growth for the newtrees we supply. A part of that process can bethe use of berms, but their use may not be jus-tified in all circumstances.

BERMS continued from page 1

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Young planting on high berms with V-shaped middles. Property hasundulations.

4 year old Mineola/trifoliate on shallow berms with flat row middles.

502 North Kaweah, Suite “B”Exeter, California 93221

Presort StdU.S.Postage

PAIDVisalia, CA

Permit #520

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2004 World Ag ExpoFebruary 10 thru 12, 2004Pavilion “A” • Booth #1073

Come and take a look at our “Starter Trees” & “Citripot Trees”

2004 World Ag Expo2004 World Ag ExpoCome visit us at the

moles, gophers, and the tree roots grew overand around the hose. We’ll never do that again!Now, the soil cover over the hose is very shal-low and at least 18 inches away from the treetrunk. It still reduces coyotes chewing on itwithout the other negative problems.

For sandy ground with mini-sprinklers, Idon’t see a lot of advantage to berms and I don’t

think berms make a whole lot of difference oneway or the other. Also, ideally from a tillagestandpoint, you need to go to non-tillage. Youleave yourself to a wider area of damage to theroots by tillage when a lot of the roots are con-centrated in the berms. Berming doesn’t changeour farming techniques all that much.

TS: Final comments?

Tom: I think it’s important to look at every piece

of ground and develop strategies for eachpiece. We need to ask ourselves, how can I bestgrow roots to maximize the development of theplant? For citrus trees, we have one time to doit right and that’s before we plant. I think thateven if berming adds to developments costs,that the long-term benefit outweighs the short-term costs.

TS: Thanks Tom.

INTERVIEW continued from page 2

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