ACID AND BASE FORMING FERTILIZERS AND THEIR …fshs.org/proceedings-o/1935-vol-48/16_Hughes.pdf · ACID AND BASE FORMING FERTILIZERS AND THEIRINFLUENCE ... velopment of urea and cyanamid

.16

--------------- ------ ~---

FLORIDA STATE HORTICULTURAL SOCIETY

ACID AND BASE FORMING FERTILIZERS AND THEIR INFLUENCEON THE REACTION OF SOME FLORIDA SOILS*

A. E. Hughes and G. M. BahrttSoU Fertility Investigations, Bureau of Plant Industry

U. S. Department of Agriculture

A consideration of fertilizer materials furnishing the three' major plant foods reveals the factthat sources of phosphoric acid and potash haveremained almost constant while the sources ofnitrogen have undergone decided changes. Superphosphate has been, and probably will continue tobe, our main source of phosphoric acid in mostfertilizer mixtures. In the year 1900, 79.8 percent. of the total available phosphoric acid wasattributed to superphosphate. At the present timesuperphosphate accounts for 86.6 per cent. ofthis plant food. This slight increase is due toa gradual decrease in the use of organic sources.

High grade potash salts such as the muriateand sulphate have furnshed between 71.3 per cent.in 1900, and 61.7 per cent. in 1931, of our availablepotash.

Nitrogen carriers have undergone noticeablechanges. MEHRING and PETERSON (1) have madea study of fertilizer materials and fertilizer mixtures produced and marketed in the United Statesfrom 1880 to the present time. A portion of theirfindings in regard to nitrogen materials is plottedin Figure 1. From this chart one can see thatorganic ammoniates decreased from 88.3 per cent.of the total nitrogen consumed for fertilizer purposes in 1880 to 18.3 per cent. in 1932. The decrease is one of increasing magnitude. Nitratesduring this same period while rising to variouspeaks and dropping from time to time, show agradual trend upward until 1920, after which afairly sharp decline in usage is shown. This ir-

*Prepared for presentation before the FloridaState Horticultural Soci,ety by A. E. ·Rughes.Acknowledgment is made of suggestions of J. J.Skinner of the Bureau of Plant Industry, in chargeof Soil'Fertility Investigations in the Southeasterncitrus and truck crop belt.

tIn charge of Soil Fertility citrus and truck cropinvestigations in Florida.

regularity in the use of nitrates has been largelydue to economic causes, chiefly an increasing supply of cheap ammonium sulphate.

The use of ammonia and its salts, since 1920,has risen sharply until they account for practically60 per cent of the total nitrogen in fertilizer mixtures. It is interesting to note that prior to 1920when nitrates were on the increase the ammoniumsalts along with ammonia decreased. Anotherpoint brought out by this chart is the recent development of urea and cyanamid.

While organic ammoniates have decreased synthetic nitrogen bearing products have increased.Most of these latter materials carry considerablyhigher percentages of nitrogen than the old linematerials. They are placed on the market in arelatively pure form, containing little or no alkaline forming elements. This- has ·resulted in theproduction of acid forming -fertilizers whose useon soils already acid may result in increasing theacidity of a soil to a point injurious to many crops.

Further work by MEHRING and PETERSON (2) onthis subject consisted in tabulating the differentforms of nitrogen used in mixed fertilizers andcalculating the resulting acidity or basicity. Asummary of this work is plotted in Figure 2.From 1880 to 1905 mixed fertilizers on an average appear to have been basic in their effectsupon the soil. From 1905 to 1920 mixtures wereonly slightly acid. Since 1920 the acidity of fertilizers has increased rapidly.

PIERRE (3) , (4) also has shown the influenceof different fertilizer materials on soil reactionand has developed an analytical method for thedetermination of equivalent acidity or basicity ofmixed fertilizers and fertilizer materials. Equivalent acidity may be defined as the ability of afertilizer to produce acid or no acid and is meas-

FLORIDA STATE HORTICULTURAL SOCIETY 17

PERCENt

~~~t~~~~~

1 \~ Ijj~~ ~~l \ 1/,,,, l

\1\ 'l

rFJ ...;t

~

~r I-,

V\.~, V

q~

\J.

i\ 1 1/"- II) V1\,

I,c: " 1

,~ \ /0~ <~

J Iz ~:Ia

i\\~, IJ~ \.

...,~~ '\~ i~0 ,.oJ~0

,~ V ~o " "0

o~t 0

OJ. ~

~ ~i 'jrr0 r~oFIGURE 1. Source of Nitrogen in Mixed Fertilizers (Mehring and Peterson).

" ._ .J_"......],; t. ,- J' , ..,;/....... ;.,. ,"


8115£ ~EQUIVALENT ~

t ~ ~

ACID EQUIVALENTPOUNDS CACO-, PER TON

7\:) ~ m C!Q ~ ~ ::t (S)o t::> c C ~ cs CO

ooH•••f-H-+++1-H-++~1--+--t---+---+--f-+--lI---+---I--4-'-'-4-~

~ H--f-++•••+-1--H---1~......() 1---+---+--+--I---I--I-+--+-~~~+--f~1-

o

FIGURE 2. Average Equivalent Acidity or Basicity of Mixed Fertilizers.(Mehring and Peterson.)


ured in terms of calcium carbonate, usually expressed in pounds per ton or per unit of nitrogen.

The influence of fertilizers on soil reaction isdetermined by their acid-base balance. Acidforming elements include sulphur, chlorine, phosphorus and nitrogen. Base-forming elementsare calcium, magnesium, potassium and sodium.Certain combinations of these elements will givea neutral fertilizer as well as those possessingacid or basic properties. Some of the commonfertilizer materials, containing those various acidand base forming elements, are given in Table 1,along with their acid and basic equivalents. Fromthis table one can readily determine the amountof acid or basic properties of various materials interms of calcium carbonate contained in a mixedfertilizer.

TABLE IElQUIVALENT AODJTY AND BASICITY PER 100 POUNDS

OF PRODUcr IN TERMS OF CALCIUJ( CARBONATE OFSOME COMMONLY USED FERTILIZER MATERIALS.(PIERRE (3.4]).

.... li• tl il~Materials ~~ i'lJ ]~.. t: 'a'~

~~IU·· cZ~I:l:tZ

Low Grade Tankage 4.3 31.0Nitrate of Soda 16.0 28.8Nitrate of Potash 13.0 26.0Calcium Nitrate 15.0 20.3Muriate of Potash ........ ......... .........SuperPhosphate ...._.. ........ ...._-Sulphate of Potash ...._.. ......... -_._.Castor Pomace 4.8 4.3Fish Scrap 9.2 8.4Cottonseed Meal 6.7 9.4Dried Blood 13.0 22.8Ammo-Phos "A" 11.0 55.0Sulphate of Ammonia 20.5 110.0Urea 46.6 83.9

Further, by knowing the amount of each material present one can calculate whether the mixture is acid, basic or neutral. Fertilizer mixtures containing low grade tankage, nitrate ofsoda, nitrate of potash, or calcium nitrate, as nitrogen sources, will be basic in their effect uponthe soil. Mixtures containing dried blood, Amophos, lIIrea, or sulphate of ammonia, as sourcesof nitrogen, will result in an acid-forming fer-

tilizer. The proportion of each used in a mixturewilt determine the degree of acidity or basicity.

Phosphate carriers vary considerably in theireffects on soil acidity. A material such as superphosphate, in which the phosphate is presentlargely as mono-calcium phosphate, have littleeffect on soil reaction. Di- and tri-calcium phosphate exert a basic effect. Ammonium phosphate,however, increases soil acidity as do other common ammonium fertilizer salts. The nitrogencarriers are responsible for most of the fertilizeracidity effects, but not even all of these are acidforming. The nitrate fertilizers in which the nitrate is combined with calcium, sodium, or potassium, decrease soil acidity because the nitrateion is absorbed by the plant largely apart fromthe bases leaving the latter to exert their fullbasic action. Cyanamid also exerts a basic effect.

Soil tests and field experiments have kept pacewith the constant changes of fertilizers. NoLL,GARDNER and IRVIN (5) in a summary of resultsobtained with commercial fertilizers covering aperiod of forty-nine years at the PennsylvaniaExperiment Station show that plots which received no lime additions for forty years showed agradual decrease in production. At the end offorty years, lime was applied and there resultedan increase in crop yields. The greatest increasefrom liming was realized on plots where sulphateof ammonia had been applied. WHITE, (6) of thesame station, as early as 1914, reports that nitrogen carriers such as sulphate of ammonia, driedblood and cottonseed meal, when used in fertilizermixtures and applied to the soil, considerably increased the lime requirement of the soil to whichapplied. In each case ammonium sulphate causedthe greatest increase.

SCHREINER and SKINNER (7) have pointed outthat with the continued use of acid fertilizersmaller returns from cotton resulted, and further that when these fertilizers were blended soas to be neutral or base forming, increased yieldswere obtained. Interesting results have been obtained with concentrated acid fertilizers whichhave been properly blended with suitable basicmaterials for the purpose of avoiding high acidequivalents.

20 FLORIDA STATE HORTICULTURAL SOCIETY

Further work reported by WILLIAMSON (6),~IDMORE and 8IM'MONS (9) show that incorporation of limestone in mixtures of fertilizers forthe purpose of neutralizing acidity has resultedin an increased yield of fifty pounds of seed·cotton per acre.

LINEBERRY (10), applying 750 pounds of 4-8-6jertilizer to the acre on Norfolk fine sandy loamplanted to strawberries, found that sulphate ofammonia, when used as a nitrogen source causeda considerable decrease in the pH value of thesoil. Where nitrate of soda was used an increasein the pH value was found to ensue.

LEWIS and FOWLER (11), experimenting withpecans in Georgia on Greenville sandy loam,have obtained results which are in accord withother investigations.

In 1930, a series of experiments were startedin Florida to study the effects of physiologicallyacid and basic fertilizers upon various soil types.planted to qitrus. These experiments includeboth single and double strength fertilizers. A studyof conditions in the corresponding untreated soilwas carried out. One of the features of this studyhas been a continuous determination from yearto year of the pH value of the soil in each plot.

It is recognized that various soil types and dif..ferent phases of the same type may re~ct differently ,to similar fertilizer treatments and that afluctuation in soil reaction from year to year maybe influenced by a number of factors such as theunderlying structure and the movement of soilmoisture. It is of interest, however, to note the

effects of acid forming and base forming fertilizers on the two soil types used in these~ studies.

The fertilizers used in these experiments haveincluded both acid and basic mi~tures in thesingle and double strength forms. In general thesingle strength acid-for1l1ing fertilizer has been a4--8-8 mixture composed of sulphate of ammonia,tankage, fish scrap, superphosphate and sulphateof potash, the mixture having an acid equivalentof about 305 .pounds of calcium car-bonate perton. The double strength acid forming fertilizeris an 8-16-16 mixture composed chiefly of urea,Ammo-phos and sulphate of potash, having anacid equivalent of about 532 pounds of calciumcarbonate per ton.

The single strength base forming fertilizer isa 4-8-8 mixture composed of nitrate of soda, driedblood, steamed bone, superphosphate and sulphateof potash, having a basic equivalent of 401 poundsof calcium carbonate per ton. The double strengthbase forming fertilizer is a mixture made up ofCalurea, triple superphosphate, sulphate of potashand ground calcium limestone. A more detaileddescription of these mixtures is given in anotherpaper at this meeting by Mr. G. M. Bahrt.

The single strength fertilizers have been applied, in general, at the rate of ten pounds pertree, three times each year, to Valencia orangesgrown on various soil types. The double strengthmixtures t have been applied at the rate of fivepounds per tree, so that in each treatment alltrees received the same amount of plant food.Composite soil samples of three successive, six

TABLE IICHANGES IN pH OF NORFOLK FINE SAND (ROLLING PHASE) PLANTED TO CITRUS,

INDUCED BY ACID AND BASIC FERTILIZERS

YEAR0-6"

Single StrengthI 6-12" I 12-18" 1\ 0-6"

Double StrengthI 6-1~' I

Acid Forming1931 5.54 5.57 5.60 5.24 5.50 5.501932 5.14 5.16 4.80 5.36 5.16 5.221933 5.19 4.95 4.93 5.36 4.99 5.191934 4.48 4.95 5.35 4.97 5.06 4.90

Base Forming1931 5.55 5.59 5.69 5.59 5.59 5.761932 5.73 5.41 5.77 5.07 5.28 5.251933 5.37 5.34 · 5.34 5.51 5.19 5.191934 5.42 5.28 5.48 5.55 5.12 5.00


inch depths were taken from each plot regularlyevery year over a period of four years and thesoil reaction determined by means of the hydrogen electrode method.

Table 2 shows the results obtained on a Norfork fine sandy soil of the rolling phase, typicalof soils of the South-Central Citrus Belt ofFlorida. In the plots receiving the acid formingfertilizer there is generally a decrease in the pHof the soil. While the decrease is not pronouncedin some cases yet the trend is toward a lowerpH value.

This soil became more acid in the four years ithas been under study even when a basic fertilizerwas used. However, in the surface six inchesof soil, where fertilizers probably have most influence, increased acidity was less with basic fertilizers.

In figures 3 and 4 are given the results obtained with an acid forming and basic formingfertilizer on Norfolk fine sand of the low hammock phase, a soil type found extensively on theEast Coast of Florida, used for the growing ofcitrus fruits. The soil of this experiment is naturally acid, although it may be underlain at considerable depth by calcareous rock. Where acidforming fertilizer was used the results show alower pH of the soil which became more pronounced after four years. With basic formingfertilizers there was an increase in the pH valueof each six inch layer of soil the first year, a lowering of tlie pH value the third year, a decidedincrease the fourth year, which resulted in a considerably higher pH value of the soil than in thebeginning.

SUMMARY

Since 1880 mixed fertilizers and fertilizer materials have changed from substances possessingbasic properties to those possessing acid properties, especially the nitrogen carriers, many ofwhich contain high percentages of plant food.

In recent years investigators have found thata large proportion of the fertilizer used to promote crop production has tended to make the soilmore acid. Frequently this increase of soil acidity has resulted in reduced crop yields.

This condition has stimulated various investigations out of which has developed a method

for determining the acid and basic equivalents offertilizer materials and mixed fertilizers and theproduction of neutral fertilizers by blending theproper materials with dolomite and calcium carbonate, thereby preventing undue soil acidity andlosses of basic material from the soil, and promoting more economical crop production.

Studies on two Florida acid -citrus soils withacid -and basic fertilizers show that the respective increase or decrease in pH value is not ofthe same magnitude on the soil types. There is,however, a general trend toward lower pH valueswhen an acid forming fertilizer is applied over aconsiderable period of time. Likewise there is anincrease in the pH value when base forming fertilizers are applied or a tendency to prevent thelowering of the pH of a naturally acid soil.

REFERENCES CITED

(1) Nehring, A. L. and Peterson, A. J. Changesin Composition of American Fertilizers, 18801932. U. S. Dept. Agr. Circular No. 315.April, 1934.

(2) Mehring, A. L., and Peterson, A. J. TheEquivalent Physiological Acidity or Basicityof American Fertilizers. Jour. Assoc. OBic.Agr. Chem. Vol 17, No.1, Feb., 1934.

(3) Pierre, W. H. Determination of EquivalentAcidity and Basicity of Fertilizers. Jour.Ind. Eng. Chem., Vol. 17, No.1, Feb., 1934.

(4) Pierre, W. H. American Fertilizer, Oct. 31,1933.

(5) Noll, C. F.; Gardner, F. D.; and Irwin, C. J.50th Anniversary of the General FertilizerTests, 1881-1931. Pennsylvania State College,Bulletin No. 264.

(6) White, J. W. Continued Studies in AcidSoil from the Ammonium Sulphate Plats.Pennsylvania State College Annual Reportfor 1914-15.

(7) Schreiner, Oswald and Skinner, ]. J. Adaptation of Fertilizers for Cotton Soils. TheAmerican Fertilizer, Dec. 15, 1934.

(8) Williamson, J. T. Fertilizer Mixtures withand without Ground Limestone for Cotton.The American Fertilizer, Feb. 10, 1934.

(9) Tidmore, J. W., and Simmons, C. F. TheUse of Limestone in Mixed Fertilizers. Ala-


~~~

fu ... :..~

~

~.. -.. -

---C:O~~.... --, I ~~OCb .....0)

J !.....

•

\ ~

~>--.

--Nl4----------...,.--~----t':l__- ..........-----~

!o'-0

~FIGURE 3. Changes in pH Induced in Norfolk Fine Sand (H.ammock Phase) Planted to Citrus, by

Continued Use of Acid Forming Fertilizer.


,\

nt<)

~

~~.

m~

.. ~~....

Q

~ C\l

~. .. ~. .

~..-.(S)~~.-<::>4~

II II •I II

~~

~I-----A--+-~---t-----.e---+_---__t~

FIGURE 4.

co::~

Changes in pH Induced in Norfolk Fine Sand (Hammock Phase) Planted to Citrus, by...Continued Use of Base Forming Fertilizer.

( ,


bama Agriculture Experiment Station Circular 67, June, 1934.

(10) Lineberry, R. A. The Relation of Fertilizer and Soil Reaction to Viability and Pro

. duction o~ Strawberries. U. S. D. A. Re·port, 1935.

(11) Lewis, R. D., and Fowler, E. D., Influenceof Nitrogen Fertilizers on the Reaction ofGreenville Sandy Loam. ·Proceedings Southeastern Pecan Growers Association, 1935.

THE UNDERPRIVILEGED CITRUS GROVE

T. A. BroWD, Nocatee

This topic, as is said of charity, "covers a multitude of sins." Before we can start to discuss itproperly, we must first decide just where to drawthe line between the underprivileged grove andthe grove that just never was worth the privileges it has had, and to illustrate my point I wantto quote the late Dr. David Starr Jordan, founderand builder of Leland Stanford University. Hebecame famous as ~n educator largely because ofhis belief i~ giving every worthwhile boy a chancefor an education if possible in any way. One ofthe blunt truths credited to Dr. Jordan whichhelped to make him famous, was, "It is a crimeto turn a million dollar boy off with only a fiftycent education; but it is also just as great a crimeto waste a million dollar education trying to hangit onto a fifty cent boy."

So it is with the orange grove to a great extent, and is getting to be more so every year.Many groves that used to pay some. profit nearlyevery year during the happy days of $1.00 perbox on the tree as a regular thing, are now pitifulwrecKs that ought to be dug up and burned, because having once fallen by the wayside they havegone iust a little deeper in debt each year untilthere seems to be no hope of their ever meeting the s~renuous competition, at present or in thenear future. It would seem that this is the yearto abandon such propertYI turn the cows into itand spend any available money to rebuild thegroves that will be able to make the grade andreturn a profit.

The grove that is known to have consistentlymade some profit and that will beyond doubt

make good right on, is not to be discussed herebecause it is assured of the necessary care toenable it to go on and produce the goods. Butthe grove in between it and the kind first mentioned, the grove that seems to be well locatedand good varieties, but just hasn't had quite theproper care to enable it to withstand the naturalclimatic hazards and still keep on the profit sideof the line, is the grove that properly comes in 'forconsideration at this time.

We have just lots of such groves all up anddown the state. ~roves that look good much ofthe time but which just seem to be slipping backbelow the profit line too regularly to make theirowners very happy about the situation. And wesometimes have to stop and wonder if it reallyis the fault of the grove, or is it the managementthat is at fault? So before we decide to condemn the grove and abandon it, or before we decide to go out and borrow any money to spendon its rejuvenation we should have a very careful stock-taking, and here are a few of the questions, the answers to which would be most helpfulin forming our conclusions: viz:

How many years since the grove came intobearing?

Was it ever considered to be a really profitablegrove?

.If so, what part of the profits were reservedas a sinking fund to tide the grove over any suchcontingency as a freeze, hurricane or other calamity?

Is there adequate drainage and water supply?What is the general condition of the root

Documents

ACID AND BASE FORMING FERTILIZERS AND THEIR …fshs.org/proceedings-o/1935-vol-48/16_Hughes.pdf · ACID AND BASE FORMING FERTILIZERS AND THEIRINFLUENCE ... velopment of urea and cyanamid