SOIL TYPE AND CROP ADAPTION

Response of Crops on Different Florida Soils

By Dr. J. H. Stallings (l)

That There is a vast difference in the response of the samecrop'to different soil types of Florida is common knowledge. Infact, if this particular fact is not given due consideration,trucking and fruit growing in portions of the state are more or}ess hazardous* Knowing that this .condition does exist and realiz-ing the necessity of a practical working knowledge of it in con-nection with successful farm operations in the state an attempthas been made to collect as much detailed information as possibleto bring out the relationship between soil type and crop adapta-tion at Penney Farms. • ,

Some very complete end extensive .data have been collectedtp^show the relationship existing between soil type and potatoyields, .at. Penney Farms. An examinati.on of the figures in thetables -below will reveal some very striking, as well as interest-ing comparisons, and will clearly show a .distinct relationshipbetween soil type and potato yields.

Spring Results 1927

SOIL TYPE , YIELD

Norfolk - - - - - - - - - - - - - - - - - - lOOfoLeon fine sand (loamy phase)- - - •- - •- 170$Blanton fine sand - - - - • - - - • - • - •- •- •- 171$St. Johns loamy 'fine' sand - .- •- .- •-• - •- 224$Portsmouth - - - - - - - - - - - - - - 264$.

Fall Results 1927

S.OIL TYPE' • • YIELD

Norfolk - ' - - - - - - - - - - • - • - • - - - 100$Leon fine 0snd (loamy phase)- •- •- - •- -. 140$Blanton fine sand- - - - - - - - - - - - - - --155/bSt. Johns loamy fine sand •- - - - - '- •- 305$Portsmouth - - - - - - - - - - - - - - 321$

The results for the spring crop were obtained by taking theaverage acre yield of No. 1 potatoes for a few of the representative

•(!•)• • Agronomist, J. C. Penny-Gwinn Corporation • • •

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farms located on Norfolk soil as 100 per cent and similar averagesfor each of the ether soil types and expressing these in per cent,using the average yield of Norfolk as 100 por cento The rusultsfor the fall crop were obtained by taking the average total yieldof No.Is and No.2s for all the Norfolk acreage planted as 100 per-cent and similar averages for each of the other soil typos and ex-pressing these in per cent, using the average yield of Norfolk as100 per cent.

The percentage figures 'for the various soil -type's of -&he fallcrop are not exactly th6 same as the corresponding figures for thespring crop, -to be sure, 'but'there is indeed-a very close correla-tion between them. In every instance, the various soil types forthe fall crop maintained the' same position in -itho scale of relativevalue's -as for the spring crop. This- certainly would indicate that'there was a decided relationship between soil; type and potato pro-duction during this period. " '

A glance at the figures 'will clearly ahqw -the inferiority ofthe Norfolk soils as potato soils when compared with-the other typeslisted. The Norfolk soils proved to be very unsatisfactory for po-tato growing in1 e-ve-ry instance, where planted. This is largely be-cause of their lack1 of' humus 1', their open, sandy character s and theirconsequent lack of moisture during the growing season.

The Blanton soil, vshich is-somewhat heavier, more compact andless droughty than the 'Norfolk soils, proved to be a superior po-tato soil to the latter. This soil, however, does not rate as a-first-class potato soil, as may; readily be seen from an examina-tion -of the figures in the tables. It, too3 is poor at retainingmoisture. ' - ' • - ' • '

-The'lcariy phase-of Leon fine sand proved to be a medium potatoproducing soil. Due to the peculiar nature of this soil, it, too,has a tendency to be droughty, cr very peer at retaining moisture.

The St. Johns loamy fine sand, which is much heavier and more •compact -than either i>f the above soils, was superior to them in pro-ducing potatoes. The high organic matter contents the compactnature of it, -and its natural low position make it very efficientat holding moisture, which accounts'in part for its superiorityas a potato s .'oil. '

The heavier Portsmouth soils easily proved their superiorityover all the others as potato-producing soils. This is because oftheir humus content, more compact- 'nature and better ability to re-tain moisture during a period of• drought than the other typesmentioned above.

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The response of other crops to different soil types is justas pronounced as that with potatoes. This may readily be seen froma study of the discussion and photographs which follow.

Notwithstanding the fact that Slanton fine sand proved to beonly a mediocre potato soil, it is an excellent soil for grapes.Loamy phase of Leon fine sand, had about the same value as a potatoproducing soil, as Blanton but is far inferior to Blanton as a grapesoil. The cultural treatments for the two vineyards were as nearthe same as was possible to give. The difference in vine growth isdue almost wholly to soil-.

Since Blsnton fine sand and loamy phase .of Leon fine sand hadalmost equal values as potato soilss at first thought it may seemdifficult to explain the difference in their reaction to grapes.Howeverj upon a more careful consideration of the characteristicsof these two types of soil as related to the development of theroot system of the grape vine one may easily .account for the dif-ference o Both of these soils proved to be somewhat droughty, orpoor at retaining moisture during an average season for a firstclass potato soil. This is due in part, at least,.to the factthe potato crop is shallow rooted and is grown during the seasonof light rainfall which is not properly distributed to keep themoisture content of these soils right for optimum potato growth.The grape vine has a much more rangy root system than the potatoplant and grows through the wet summer season as well as the drierpotato season. The nature of the Blanton soil is such that thewater table during the period of heavy rainfall in the summermonths seldom gets nearer the surface than 4 to 5 feet? while withthe loamy phase of Leon: 'fine sand it is customary for. the watertable to rise to. within 1-1/2 to 2 feet of the surface of the ground,This means s of course, that the roots of the grape vine on the Blan-ton soils has a feeding range down to 4 to 5 feet during the wettestseason of the year while on the loamy phase of Leon fine sand it canfeed only from 1-1/2 to 2 feet deep. Roots penetrating the soil toa greater depth than 11/2 to 2 feet on this type of soil duringthe dry weather are automatically killed by excessive v^ater duringthe wet summer season. As a result the plants are- severely stintedand very often killed outright on the loamy,phase of Leon fine sandwhereas they are not injured on the Blanton soil.

Blanton soil is also very well adapted to the production ofpecans, plums, peaches, and pears. The same .crops make a completefailure, however, when set on loamy phase of Leon fine sand, Leonfine 'sand arid St. Johns loamy fine sand.

Blanton fine sand is a good soil for pecans? plums, peachesand pears for the same reason that it is a good soil for grapes,whereas the loamy phase of Leon fine sand is a poor soil for these

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crops for the s rone reason that it is not adapted to. the. productiono f .grapes. • , . . . . . . . .

• . St. Johns, loamy fine sand proved to be a very satisfactorys oil _ for potatoes but. an extremely -poor one. for the other cropsmentioned-. It is a good potato soil largely because it retainsmoisture well during the potato growing season and is capable oftaking.care of the moisture.needs of .the potato crop. On theother; hnn-dj it has .a water table within, from 6 to 9 inches of thesurface during the wet summer season which makes it. practicallyimpossible to grow such crops unless, the drainage is such that thewater table can be lowered sufficiently 'to meet- their needs. Thecharacteristic low position of this type of soil makes., it almostimpossible for the wate.r -table to -be lowered sufficiently to en-able those crops to grow. '•

Blanton fine sand also produces blueberries satisfactorilywhile. Leon fine, sand makes a. complete failure -with-the same crop.This -is clearly brought -out in photograph Noo5 . The plants wereall set out the same time and received, similar treatment. Theplants in the foreground are on Leon fine sand and those in thebackground on Blanton fine sand.

Blanton fine, sand is a satisfactory soil for blueberries forthe. -same reason- it is suited for grapes. The Leon fine sand isdecidedly unfit, not only for blueberri-es but for practically allother.cropsj provided there is not absolute water control practiced,

• because' of its peculiar make up* This soil type is- characterised'by "a compact,-'-brovmish, organic, -hardpan layer ranging from 12 to18 inches beneath the surface. This hardpan layer.is imperviousto water and the roots of many cultivated plants, amd varies from1 to' several inches in thickness , usually averaging about 3 to 4inches thick. ' The soil above it.'is'very coarse and. poor at re-taining capillary moisture. During periods of low rainfall thesmall amount of capillary moisture.in the soil above the hardpanlayer is quickly exhausted by plants and can not be replenished'by capillary movement - from'below. The plants naturally die fora lack of water. ' On the other hand, during periods of heavyrainfall 'the surplus water is unable to percolate through thishardpan layer'-and is forced to accumulate as free water'above thislayer,---thu3 drowning out what -crops may have b'sen growing up tothat tii-ae'. ' • •'-" •

The roots of most cultivated crops are unable to penetrate•this-peculiar hardpan layer. - However,- should' they be able topenetrate it they-would encounter fr'eo water immediately beneathit and further growth would be checked.

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The same striking contrast may be had with tung oil treeswhen planted on Norfolk fine sand and Leon fine sand. This isclearly shown in photograph Mo»6. ^t the same time that blue-berries, grapes s'pecans and 'tung oil fail on Leon fine sand'crotalaria apparently does well. This Is shown by photograph Mo.7.

Norfolk fine sand is somewhat more droughty than Elantonfine sand and also has a lower water table. Ordinarily, however,Norfolk fine sand contains enough moisture during the dry seasonto meet the requirements of the tung oil trees and has a water •table low enough during the wet summer season so as not to inter-free with normal root development of.that plant. The tung oil treefails to make good on Leon fine sand for the same reason that Blue-berries and. most other crops do.

Apparently crotalaria is able to successfully adjust itselfto Leon fine sand under some conditions, at least. The roots ofthe crotalaria are.able to penetrate the hardpan layer.

Corn is just as sensitive to soil types as any of the othercrops mentioned.

Corn is adapted to Portsmouth loamy fine sand for the samereason that potatoes are adapted to it. It is also unadapted toLoon fine sand for the same reason that most other crops a.re un-adapted t o it. ;•

Notwithstanding the fact that grapes, pecans, plums, pears,peaches and many other crops make a complete failure on St. Johnsloamy fine sand, pepper appears to be perfectly at home on thissoil. This soil also rated well as a potato soil. It is equallywell adapted to bulbs, onions, peppermint and numerous other truckcrops. On the other hand there are several crops, ether than'thosementioned, which are wholly unsuited to this soil.

Pepper, bulbs, onions, peppermint and such crops are welladapted to St. Johns loamy fine sand soil for the same reason thatpotatoes are. However, those crops with a rangy root system areentirely unsuited to this type of soil.

Notwithstanding the fact that Portsmouth loamy fine sand isvery poorly adapted to such crops as grapes, peaches, plums, pears,,tung oil and many others it is very well suited to the productionof Japanese sugar cane.

Portsmouth loamy fine sand retains moisture well during the-dry season. Consequently it is well suited to the production

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of Japanese sugar'cane which has a. shallow root system and re-quires an enormous amount of 'water during the growing season. Dur-ing tile wet summer s.eason the water table on this soil is withinabout 12 to 18 inches of'.the'surface,'a condition which makes itentirely unsuited to the production of crops with a rangy rootsystem.

Loamy phase, of Leon fine sand soil rates as only a mediocre:Irish potato soil, is a very poor soil for grapes, pecans and sev-eral other crops bu't is very good as a sweet potato soil. Thishappens to possess the particular peculiarities necessary for asatisfactory sweet 'potato soil. '•' '

Peppermint is just as 'sensitive to a'change in soil type asmost of the other crops discussed. The io'luyaphase of Leon finesand soil is entirely too droughty in character to be a suitablesoil for the production of peppermint while cypress pond soil con-tains the proper constituents to enable it to hold suitable moisturefor a satisfactory growth of peppermint.

The data in this article make up only a very small per centof the total information collected on the point under discussion.However j these data, are so conclusive that it will behoove thosewho are interested in farming in Florida to pay some attentionto the question of soil type and crop adaption if they hope toreap the most possible for each dollar expended.

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