Citation
Buying and using commercial fertilizers

Material Information

Title:
Buying and using commercial fertilizers
Series Title:
Bulletin
Creator:
Clinton, L. A ( Louis Adelbert ), 1868-1923
Place of Publication:
Ithaca N.Y
Publisher:
Cornell University
Publication Date:
Language:
English
Physical Description:
p. 180-195 : ill. ; 23 cm.

Subjects

Subjects / Keywords:
Fertilizers ( lcsh )
Potash ( jstor )
Nitrogen ( jstor )
Fertilizers ( jstor )
Genre:
non-fiction ( marcgt )

Notes

Funding:
Bulletin (Cornell University. Agricultural Experiment Station) ;
Statement of Responsibility:
by L.A. Clinton.

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University of Florida
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University of Florida
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The University of Florida George A. Smathers Libraries respect the intellectual property rights of others and do not claim any copyright interest in this item. This item may be protected by copyright but is made available here under a claim of fair use (17 U.S.C. §107) for non-profit research and educational purposes. Users of this work have responsibility for determining copyright status prior to reusing, publishing or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder. The Smathers Libraries would like to learn more about this item and invite individuals or organizations to contact Digital Services (UFDC@uflib.ufl.edu) with any additional information they can provide.
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Bulletin 201.


Cornell University Agricultural Experiment Statiot.
ITHACA, N. V.

AGRICULTURAL DIVISION.




Buying and Using Commercial Fertilizers.


By L. A. CLINTON.






PUBLISHED BY THR UNIVERSITY
ITHACA, N. Y.
1902.


A37


April, 1902










.ORGANIZATION'

Q0, T1E CORNELL UNIVERSITY AGRICULTURAL EXPERIMENT STATION.


BOARD OF CONTROL
THE TRUSTEES OF THE UNIVERSITY.


THE AGRICULTURAL COLLEGE AND STATION COUNCIL.

JACOB GOULD SCHURMAN, President of the Unive ty. FRANKLIN C. CORNELL, Trustee of the Unversity. ISAAC P. ROBERTS, Director of the College and Experiment Station. EMMONS L. WILLIAMS, Treasurer of the University. LIBERTY H. -BAILEY, Professor of Horticulture. JQHN H. COMSTOCK, Professor of Entomology.


STATION AND UNIVERSITY EXTENSION STAFF.
I. P. ROBERTS, Agriculture.
G. C. CALDWELL, Chemistry.
JAMES LAW, Veterinary Science.
J. H. COMSTOCK, Entomology.
L. H. BAILEY,Horticulture, Nature-Study.
H. H. WING. Dairy Husbandry.
G. F. ATKINSON, Botany.
M. V. SLINGERLAND, Entomology,
G. W. CAVANAUGH, Chemistry.
L. A. CLINTON, Agriculture.
JOHN CRAIG, Extension Teaching;
J. W. SPENCER, Extension Work.
J. L. STONE, Extension Work.
MARY ROGERS MILLER, Nature-Study.
MRS. A. B. COMSTOCK, Nature-Study.C. E. HUNN, Gardening.
J. A. FOORD, Dairy Husbandry.
G. W. TAILBY, Farm Foreman.
0. F. HUNZIKER, Dairy Bacteriology.
ALICE G. McCLOSKEY, Nature-Study.


OFFICERS OF THE STATION.
I. P. ROBERTS, Director.
H. L. WILLIAMS, Treasurer.
EDWARD A. BUTLER, Clerk and Accountant.
Office of the Director, 2o Morrill Hall. The regular bulletins of the Station are sent free to persons in the State
who request them.
















BUYING AND USING COMMERCIAL.
FERTILIZERS.

The laws of New York require that " Every person who shall sell, offer or expose for sale in this State any commercial fertilizer or any material to be used as a fertilizer, the selling price of which exceeds five dollars per ton, shall stamp on or affix to each package of such fertilizer in a conspicuous place on the outside thereof, a plainly printed statement which shall certify as follows:
i. The number of net pounds of fertilizer in the package sold or offered for sale.
2. The name, brand or trade-mark under which the fertilizer is sold.
3. The name and address of the manufacturer of the fertilizer.
4. The chemical composition of the fertilizer in the following terms:
(a) Percentum of nitrogen.
(b) Per centum of available phosphoric acid, or in t he c4se of undissolved bone, the percent of total phosphoric acid.
(c) The percent of potash soluble in distilled water.
Section i, Chapter 955 Laws of 1896 and as amended by Chapter 687 Laws of 1899.
The above section of the fertilizer law was adopted for the purpose of enabling the purchaser of -commercial fertilizers to know something of the constituents and value of the material, which he is purchasing. But in actual practice the guarantee which is usually attached to a fertilizer serves rather to confuse than to enlighten. That this is true is partly the fault of the manufacturer but more largely the fault of the purchaser who. has not learned, the meaning of the terms used in the guarantee. If the terms are understood then the trade value of nitrogen," phosphoric acid and potash may be unknown, in which case the guarantee means but little. The following guarantee is taken from a fertilizer now on the market and we ask the readers if










BULLETIN 201.


they can from this guarantee, estimate approximately the price per ton which should be paid for the fertilizer.
Ammonia . to 3 per cent.
Soluble ph oric acid . 6 to 7 Reverted 4, 11 . 2 ' to 3
Available 94 16 . 8 to io
Total 14 41 . . 10 to 12
Bone phosphate . 22 to 26 Potash . 2 to 3
Rqual sulphate . 3.7 t6 5.5
The above guarantee states not only all the law requires but much more. To one unfamiliar with the meaning of the terms used it appears that a large amount of plant-food is guaranteed. Instead of giving the per cent of nitrogen it is stated in terms of ammonia, and of this only fourteen- seventeenths is -nitrogen. The above guarantee reduced to its " simplest terms ", or what the law requires, would read as follows
Nitrogen . 1.65 per cent.
Available phosphoric acid . 8 1 1 Potash . . 2 it
This guarantee does not look nearly as formidable as the first one, and manufacturers say that in the majority of cases a pur,chaser will choose the brand having the long guarantee. It is well to have the guarantee state the per cent of soluble phosphoric acid as well as the per cent available, for other things 'being equal, the fertilizer containing the highest per cent soluble phosphoric acid should be selected.
To enable one to know definitely if the price asked for a mixed fertilizer is reasonable, a knowledge. must be had of the price and composition of the chemicals from which mixtures can be made. The most common sources of nitrogen in this State, are:.
Nitrate of soda,
Dried blood,
Ammonium sulphate.
The most common phosphoric acid sources are
Acid phosphate, Dissolved bone,
Ground bone,
Basic slag,
Floats.














BUYING AND USING COMMR~CrAL FERTILIZERS.


The most common sources of potash are:
Muriate of potash, Sulphate of -potash,
Kainit,
Wood ashes.
Any of the larger fertilizer firms will quote prices and guarantees on chemicals and these quotations should always be secured, for then the purchaser will know the actual price per pound at which he can secure nitrogen, phosphoric acid and potash. We have recently received the following quotations on chemicals, the prices being for goods free on board cars at Syracuse, N. Y.
Nitrate of soda, 19 to 20 per cent ammonia, $45.00 per ton.
Dried blood, 16 to 17 per cent ammionia, $40.00 per ton.
Acid phosphate, 14 per cent available phos. acid, $11.50 per ton.
Muriate potash, 80 per cent muriate, $45.00 per ton.
Sulphate potash, 96 per cent sulphate, $55.00 per ton.
Kainit, 22 to 24 per cent sulphate, $13.00 per ton.
Making a study of the above quotations we see that the nitrogen is quoted in terms of ammonia in both the nitrate of soda and the dried blood. *If it is remembered that but fourteenseventeenths of the ammonia is nitrogen, this should not confuse the purchaser. Where two percentages are given the lower one should be used in making the calculations, for this is the only one the manufacturer is, liable for. The nitrate of soda is guaranteed to contain x9 per cent ammonia or 380 pounds of ammonia per ton. As only fourteen-seventeenths of this
ammonia is nitrogen the determination for cost of nitrogen per pound would be made as follows:
380 X 14 -'17 - 313 pounds of nitrogen per ton.
$4-0 313 -14.4 cents per pound, cost of nitrogen.
If the nitrate of soda be made the source of the nitrogen then the cost per pound of nitrogen will be 14.4 cents.
If dried blood be the material selected to supply the nitrogen the cost per pound would be determined as follows:
x6 per cent ammonia, 20 Xx 6 -320 pounds of ammonia per ton.
320 X 14 :17 - 263.5 pounds of nitrogen per ton.
$40.00 -- 263.5 - 15.2 cents per pound for nitrogen in dried blood.
It will be seen that at the prices quoted the nitrate of soda is













BULLTIN 201.


slightly cheaper than the dried blood, but whether it should be purchased or not should depend upon conditions mentioned later. The acid phosphate is'guaranteed to contain 14 per cent available phosphoric acid, or 280 pounds per ton, at a cost of $11.50. One pound of available phosphoric acid would cost 4. 1 cents per pound.
Chemicals furnishing potash have, sometimes guaranteed the per cent of actual potash and again the guarantee states the per cent of muriate or of sulphate of potash. In the quotations given the muriate of potash is guaranteed 8o per cent muriate. To determine the per cent of actual potash, multiply the per cent of muriate by 0.63. In the present case then the per cent of actual potash would be 8o x o.63=50.4 per cent potash. The muriate of potash then contains 50.4 per cent of actual potash or ioo8 pounds of potash per ton. This at a cost of $45 would make the potash cost approximately 434 cents -per pound if purchased in the form of the muriate.
The sulphate of potash is guaranteed 96 per cent sulphate. To reduce this to terms of actual potash we must multiply the per cent sulphate by 0.54. In the present case the determination would be made as follows:
96 x 0.54 - 51.8 per cent-of actual potash in the sulphate.
One ton of sulphate of potash would then furnish 20 x 5 .8-1036 pounds of actual potash, at a cost of $55 or 5.3 cents per pound of actual potash, which makes the sulphate much more costly than the muriate. The kainit costing only $13 per iton would possibly lead some to believe that it would be a cheap source of potash. The computations should be made the same as for the sulphate. There are guaranteed 22 per cent of sulphate of potash.
22 X o.54 - ir.8o per cent of actual potash in kainit.
20 X i.8o -- 237.6 pounds of actual potash per ton.
At a cost of $13 makes the cost per pound of actual potash 5.5 cents. This is-more expensive than either the muriateor the sulphate. The freight upon one ton of kainit would be the same as upon one ton of muriate or sulphate, but with the kainit only 237 pounds of actual plant-food would be secured while with the muriate and sulphate more than iooo pounds of actual plant-food










BUYING AND USING COMMERCIAL FERTILIZERS.


are'secured. Usually the high grade muriate of potash is the cheapest and best source of potash except for tobacco and some special crops.
From the computations given above we find the following prices for plant -food in case the chemicals are purchased.
Nitrogen (in Nitrate of Soda). 1 e.4 cnts per pound.
(in Dried Blood) . 15.2 " " "
Avail. Phos. Acid (from Acid Phosphate) 4.1 "
Potash (from Muriate) .4.5 " .
(from Sulphate) . 5.3 "
(from Kainit) . 5.5
Having now a knowledge of the price per pound at which plant-food can be purchased in unmixed chemicals we can figure intelligently upon the price which should be paid for the ready mixed fertilizer, the guarantee of which is given on page I8O, but which we will repeat here in its simplified form:
1.65 per cent nitrogen.
8 " " available phosphoric acid.
2 " " potash.
As the per cent guaranteed of nitrogen, phosphoric acid and potash means the number of pounds of each contained in ioo pounds of the fertilizer, we have simply to multiply the per cent by 20 to find the amount in one ton.
Nitrogen 1.65 x 20o- 33 pounds of nitrogen in one tn.
Available phosphoric acid 8 X 20- i6o pounds of available phosphoric acid in one ton.
Potash 2 x 2o - 4o pounds of potash in one ton.
We knowthat at the present time in the chemicals we can buy nitrogen for 14.4 cents per pound, available phosphoric acid for 4.' cents per pound and potash (in muriate) for 4$ cents per pound. On this basis the ton of mixed fertilizer -should cost:
For nitrogen, 33 pounds 14.4 cents . $ 4.75 For phosphoric acid, 16o pounds, 4. T cents. . .6.56 For potash, 40 pounds 4.5 cents . : . ,.1.8o
Total value of plant-food in one ton . $13.11
The price quoted on the ready mixed fertilizer was $20.4 0. 0. B. New York. The unmixed materials necessary to furnish an equal amount of plant-food could be purchased for. $13. 11. We ask the purchaser of fertilizer if the price charged for mixing is not exorbitant?










BULLUTIN 201.


The case quoted above is not exceptional in any way but it is typical of the usual conditions which prevail. We find that the price charged for mixed fertilizer is from five to ten dollars more per ton than the cost of the chemicals which would furnish an equal amount of plant-food. The claim is often made that the mixing cannot be done thoroughly by the farmer. Whether this statement is true or not depends upon the farmer, for it can be thoroughly mixed if care be taken. If the chemicals are stored in a damp place some have a, tendency to become lumpy, in which case they must be pulverized before being mixed. Nitrate of soda is especially likely to get hard and lumpy if kept for some
-time -before being used.
The probable reason that more farmers do not buy the chemicals and mix their' fertilizer according to the needs of their -farms and the crops to be grown is that they do not know how to combine the chemicals in order to produce the required mixture. This need not give one any difficulty if a little study be given the subject. If it has been found that good results have been secured mith. a certain mixed fertilizer, then those chemicals should be purchased and mixed which will give a similar proportion of plant-food. To illustrate, a fertilizer containing 4 per cent nitrogen, 8 per cent available phosphoric acid and 6 per cent potash may be desired. The amount of actual plant-food required in one ton of such a fertilizer is estimated as follows:
20-00 x 4 - 8o pounds of nitrogen required.
2o.oo x 8 - x6o pounds of available. phosphoric acid required.
20.00 x 6.- 120 pounds of potash required.
The multiplier 20.00 is used because twenty hundred pounds of fertilizer or one ton is the amount being figured upon. Had the amount of fertile er called for been twelve hundred or fifteen hundred pounds, then the multiplier would have been 12 or 15 instead Of 20.
If it is wished to purchase chemicals which will supply the above-'amounts of plant-food the amounts to purchase will be found as follows:
Nitrogen sources are commonly
Nitrate of soda.
Dried blood.
Ammonium sulphate.










BUYING AND USING COMMERCIAL FRRTILIZICRS.


The nitrate of soda usually contains about 15~ per cent nitrogpn, dried blood from 13 to 15 per cent and ammonium sulphate about 20 per cent nitrogen. Knowing the per cent of nitrogen contained by any chemical supplying nitrogen, it is a simple matter to estimate how many pounds of the chemical will be required to supply a given amount of plant-food. The rule which applies is, divide the number of pounds of the actual plant-food (nitrogen, phosphoric acid or potash) required by the guaranteed per cent of the plant-food in the material to be purchased. The quotient will be the number of pounds of the chemical which must be purchased. In the case in hand, with 8o pounds of nitrogen required, if it be supplied with nitrate of soda, 15 per cent nitrogen, the calculation to determine the amount of nitrate of soda to be purchased is as follows:
8o--. . S=s33 pounds of nitrate of soda required to furnish 8o pounds
of nitrogen.
If dried blood containing 14 per cent nitrogen were the material to be purchased the following would be the calculation:
So 0- .14 =572 pounds of dried blood with 14 per cent nitrogen
required to supply 8o pounds of nitrogen.
The most common materials supplying phosphoric acid are acid phosphate (dissolved phosphate rock), dissolved bone and ground bone. The method of procedure is the same as with the nitrogen. -The total number of pounds of phosphoric acid required must be divided by the per cent of available phosphoric acid, expressed decimally, in the material to be purchased. Acid phosphate usually contains' about 14 per cent available phosphoric acid. To determine the amount necessary we will divide 1 6o by .14-1143 pounds of 14 per cent acid phosphate required to furnish i6o pounds of available phosphoric acid.
The usual sources of potash are the muriate of potash, the sulphate of potash and the carbonate of potash found in hard wood ashes. Should we decide to purchase muriate of potash containing 5o, per cent actual potash we determine the amount of muriate required to supply the 1 20 pounds of potash as follows:
120+ .50=240 pounds of muriate of potash required.
To supply the'amount of plant-food in the chemicals which'









BmjL*TIN 201.


would besupplied in one ton of fertilizer analyzing 4 per cent nitrogen, 8 per cent available phosphoric acid and 6 per cent potash, we will need to purchase as follows: 533 pounds of nitrate of soda.
1143 " " acid phosphate.
24o " " muriate of potash.
Total 1916
We have thus secured the plant-food required in i916 pounds of material, and if it is desirable to have the' total weight 2,000 pounds, the 84 pounds of filling may be put in at home. For this purpose fine road dust or fine soil or gypsum may be used. We have stated this concrete case simply to illustrate .4ow one may proceed in, case it is wished to purchase the chen icals or separate ingredients and mix them according to a certain formula.
If home mixing of fertilizers is to be done a definite knowledge should be bad 'of the materials which supply plant-food. Nitrate of soda is immediately available for the plants use as soon as it goes into solution. Its best results are obtained when applied where growing. plants can make use of it quickly. Where plants grow in hills or drills the nitrate of soda should be applied near the growing plants but should be thoroughly mixed 'with the soil. If applied broadcast upon sowed crops it should. be evenly distributed. Nitrate of soda exerts its most beneficial action where immediate results are desired. It is the quickest acting plant-food. Dried blood while not so immediate in its action as nitrate of soda is very quickly available and as a general supply for nitrogen it is safe and valuable. Ammonium sulphate is the richest in nitrogen of any commercial material, usually containing about 20 per cent actual nitrogen. At. the present time the cost of nitrogen from this source is greater than from either nitrate of soda or dried blood.
Many materials are now on the market from which phosphoric acid may be secured. Some contain phosphoric acid in the water soluble form and others contain what is known as reverted phosphoric acid, or that which is soluble in weak acids, as in ammonium citrate. Others make no claim at supplying anything except insoluble phosphoric acid. Indeed the claim is recently being advanced that insoluble phosphoric acid is even better for use than is soluble phosphoric acid.










BUYING AND USING COMMERCIAL FERTILIZERS.


A phosphate fertilizer known as "basic'slag" or "odorless phospha te" is being sold somewhat extensively and for certain purposes it seems to possess considerable value, while for other purposes it seems to possess but little value. It has been recommended especially for clover, but from careful tests made in our experimental green house clover does not seem able to feed freely upon the phosphoric acid of basic slag.
In the winter of i900-i90E certain experiments were undertaken to determine the availability of phosphoric acid in its var-


45--Peas showing the effect offihosphoric acid.


ious combinations to plants of various orders. The experiments were conducted in the green house where all conditions as to temperature and moisture could be controlled. The details were in charge of Mr. H. Mason Knox, a senior in the College of ' Agriculture, and to him much credit is due for caref ul work.
The "soil" in which the plants were grown was a white quartz sand obtained from ground quartz rock and analyzing 98 per cent pure quartz. The purpose was to obtain a medium in which the plants could grow and which should be of itself practically free from plant-food. The various elements which are









BULLETIN 201.


usually supplied by the soil were in this case added in' like amounts to all'the boxes of sand in which the plants were to be grown. All conditions were made similar except the one ingred'Jent of plant-food, phosphoric acid. The actual amount of phosphoric acid which was supplied the various boxes was the same, but the sources of the phosphoric acid were different. The following materials were used to supply the phosphoric acid:
I. Acid phosphate (Dissolved phosphate rock).
2. Basic slag.
3. Floats (Finely ground phosphate rock untreated with acid).
4. Bone black.
These materials were all analyzed by the Experiment Station Chemist, Mr. G. W. Cavanaugh, and were found to contain phosphoric acid as follows:
Soluble Reverted Available Totel phosphoric phosphoric phosphoric phosphoric acid acid acid acid
per cent. per cent. per cent. per cent. Acid phosphate 12.42 5.03 17.45 18.36
Basic slag. , . 15.94
Floats . 31.37
Bone black . 10.71 3.90 34.6t 16.25

It will be seen from the above analyses that the materials varied widely in the per cent of total phosphoric acid contained, but in fertilizing the various:boxes of plants the fertilizer was so appliedthat the same amounts of total phosphoric acid would be applied in each case. The cost of the various materials was not taken into consideration in any case, for that is variable. The only question considered was the ability of plants of various orders to feed upon phosphoric acid when equal amounts of phosphoric acid were supplied without regard to cost or availability of the same.
The 'orders of plants which were tested with the specific plants from each order were as follows: e Clover.
L Canada field pea.
Cruciferoe Rape.
Radishes.
Graniinfe - Oats.
Barley.
Umbelliferae Parsnips.










BUYING AND USING COMMERCIAL FERTILIZERS.


It will be seen that four orders of plants were represented, each by two species except the Umbelliferx. The results were most interesting. All seeds germinated quickly and all plants commenced a vigorous growth. Soon the plants which had received the soluble phosphoric acid from acid phosphate and from the bone black outgrew the others. Where no phosphoric acid was applied the plants made a feeble growth and no plants came to maturity. When the plants were finally harvested, the entire plant, including the roots and tops, was harvested and dried and the weight of actual dry matter produced is given in every case.


46.-Parsnifis showingf effect offphosphoric acid.







?hepha.4


dry matter.


I


Ordeu.


Leguminosem Cruciferge


=Pow.


Clover








Peas Rape.Radishes -


Acid phosht Bone black

Basic slag.3.

Floats . . . . . . . . . . . . . . .15.7
. 1.45
No phosphoric acid
. . . .-2.35
( Ad phosphate
Bon blck. . . 21.78
. . 22.32
Basic slag
. . .I.9.95
Floats
. . 9.76
NWo phosphoric acid
[ Aid.hoshat . . .-73
. . 20.74 Bone black. .9
]Basic slag

Floats . .17.U
No hophoicaci. .23.39
. .3.51

F Bone black. . .I. . 15.15

Basic slag,. . . 14-1
. . . 12.8
Floats
. . . 7.
No phosphoric acid '7





















Graminve


Oats Barley


Umbellfere-Parsnips.


Acid phosphate .39I

Bone black . 69

Basic slag379
. 24.46 Floats.77

No phosphoric acid . 71
. . . . . . . . . . . . . . . . . 13.14
Acid phosphate
- . . . . . . . . . . . . . . . . 18.2
Bone black
.- . 25.75
Basic slag
. . . . . . 21.6
Floats.
. . . . . . . . . . . . . . . . . . . . . . . . . . . 3.22
No phosphoric acid
. . . 5.99
* Acid phosphate
A. . .- . .24.93
Bone black
_____________________________.___ . 32.18
Basic slag8
- . . 5.78
Floats
. .69
No phosphoric acid
. . . .44










BULLION 201.


A study of the above table of comparative results shows that the best returns were secured with the acid phosphate and bone black in nearly every case. Clover fed about equally well upon acid phosphate and bone black, both of which supplied water soluble phosphoric acid. While the clover was able to make some use of basic slag, yet the product was only about one-half of that secured where the soluble phosphoric acid was applied. Clover seemed entirely unable to feed upon the insoluble phosphoric acid as furnished in floats, or crude ground phosphate rock. What was true of the clover was equally true of the peas, and the indications are that leguminous plants must be supplied with readily available phosphoric acid if best results are to be secured.











47. -Clover showing the effect ofphosphoric acid.

Rape made its best growth where insoluble phosphoric acid was supplied in the form of floats. The radishes, however, made best growth when supplied acid phosphate. But the radishes were able to feed upon the insoluble phosphoric acidin floats and basic slag. The results seem to show that members of the Cruciferae order are able to extract food from the insoluble forms of phosphoric acid. This may account for the fact that rape and turnip and mustard are looked upon as hardy plants, and that they are sometimes recommended as soil renovators. They are able to feed upon certain forms of phosphoric acid where clovers and peas cannot feed.
In the case of the Graminae it is seen that oats made their best growth when supplied with water soluble phosphoric acid, and not much difference is noted between the results obtained with










BuYING AND USING COMMERCIAL FERTILIZERS.


acid rock and with bone black. The oats made much better growth upon the basic slag and floats than did the barley. This simply confirms what has been noted as a matter of actual experience, that oats will grow under actual field conditions where barley will fail. Oats possess greater power of utilizing crude phosphoric acid than does barley.
The Umbelliferae family was represented by parsnips. The bone black gave best results with the acid phosphate second. But little use was made of the basic slag and the floats showed no beneficial results. The results indicate that for this family phosphoric acid should be supplied in quickly available form if best results are to be secured.












48 -Rape showing effect ofphosphoric acid.
The above results are valuable for the fact that they show the relative ability of plants of various orders to feed upon phosphoric acid when it is supplied in various forms. All conditions were under control and the soil upon which the tests were made was uniform. In every case except one much the best results were secured where the acid phosphate and the bone black were used. In only one case did floats produce any marked effect and that was with rape. This would indicate that if the crude ground rock or floats is to be used as a fertilizer it would better be applied to turnips or rape where these plants are grown for purposes of soil renovation or for green manuring purposes. Phosphoric acid as contained in basic slag or in floats seems to give best results in actual field conditions when used upon a soil rich in humus. Decomposing organic matter and abundance of moist-










BuLLETIN 201.


ure seem to hasten the breaking down or decomposition of the material containing phosphoric acid. Under the conditions which usually prevail in New York where results are desired upon the immediate crop, it is recommended that the phosphoric acid be secured either from acid phosphate or from dissolved bone. The average agricultural soil contains vast stores of potential plant-food. But a small portion of this is available for the plants use at any one time.
Our experiments lead us to believe that the wise farm practice is to make the soil give up some of its stores of plant-food,


49.-Barley showing eftct offphosphoric acid.


and that this may be done by thorough tillage and by keeping the soil liberally supplied with organic matter. The decomposing organic matter will make available some of the potential plantfood of the soil and the resulting humus will serve to increase the moisture holding capacity of the soil. Then if commercial plant-food is to be purchased it should be secured in the available form. It does not seem to be a wise practice to purchase potential plant-food when there are already vast stores of potential plant-food in the soil.










BUYING AND USING COMMERCIAL FERTILIZERS.


It is not expected that the discussion in this bulletin will answer all questions relating to commercial fertilizers. Nothing has been said of " tankage" which is a local and valuable product in many sections of the state. No attempt has been made to discuss the various brands of complete fertilizer which are on the market. We have discussed rather those standard materials which have a somewhat uniform quality, a knowledge of which will enable one to judge of the value of any mixed fertilizer. There are many who will not attempt to master the arithmetic of fertilizers. But some who desire to purchase most economically their commercial fertilizers will possibly receive aid from this bulletin. If so, its purpose will have been accomplished.


50. -Radishes showing the effect of phosphoric acid.













-THE FOLLOWING BULLETINS ARE AVAILABLE FOR DISTRIBUTION TO THOSE WHO MAY DESIRE THEM.


Apricot Growing InWestern NewYork, 26 pp.
The Cultivation of Orchards, 22 pp. Some Grape Troubles in Western N.Y. ux6 pp.
The Quince in Western N. Y., 27 pp. Cigar-Case-Bearer, 2o pp. Entomogenous Fungi, 42 pp. The Spraying of Trees and the Canker
Worm, 24 pp.
General Observations in Care of Fruit
Trees, 26 pp.
Soil Depletion in Respect to the Care
of Fruit Trees, 21 pp.
Extension Work in Horticulture, 42 pp Dwarf Apples, 31?pp.
Texture of the Soil, 8 pp. Moisture of the Soil and Its Conservation, 24 pp.
Suggestions for Planting Shrubbery, Second Report upon Extension Work
in Horticulture, 36 pp.
The Currant-Stem Girdler and the
Raspberry-Cane Maggot, 22 pp.
How to Conduct Field Experiments
with Fertilizers, ii pp. Potato Culture. 15 pp. Strawberries under Glass, io pp. Forage Crops, 28 pp. Chrysanthemums, 24 pp. Ariltural Extension Work, sketch
of its Origin and Progress, I pp. Studies and Illustrations of Mushrooms; I. 32 pp.
Third Report upon Japanese Plums
M6 pp.
Second Report on Potato Culture,24 pp. Powdered Soap as a Cause of Death Among Swill-Fed Hogs. The Codling-Moth. Sugar Beet Investigations, 88 pp. Suggestions on Spraying and on the San jos Scale.
Some Important Pear Diseases. Fourth Report of Progress on Uxtension Work, 26 pp. Fourth Report upon Chrysanthemums, 36 pp.
R uince Curculio, 26 pp. ome Spraying Mixtures. Tuberculosis In Cattle and its Control. Gravity or Dilution Separators. Studies in Milk Secretion.


153 Impressions of Fruit-Growing Industries.
154 Table for Computing Rations for
Farm Animals.
155 Second Report on the San Josl Scale. 156 Third Report on Potato Culture. 157 Grape-vine Flea-beetle. 158. Source of Gas and Taint Producing
Bacteria in Cheese Curd.
159 An Effort to Help the Farmer. 16o Hints on Rural School Grounds. 161 Annual Flowers. 162 The Period of Gestation in Cows. 163 Three Important Fungous Diseases o
the Sugar Beet.
164 Peach Leaf-Curl. x65 Ropiness in Milk and Cream. 166 Sugar Beet Investigations for x898. 167 The Construction of the Stave Silo. Y68 Studies and Illustrations of Mushrooms; 11.
x69 Studies in Milk Secretion. 17o Tent Caterpillars. 171 Concerning Patents on Gravity or
Dilution Separators.
172 The Cherry Fruit-Fly: A New Cherry
Pest.
173 The Relation of Poodto Milk-Fat. 174 The Problem of Impoverished Lands. 176 The Peach-Tree Borer. 177 Spraying Notes. 178 The Invasionof the Udder by Bacteria. 79 Field Experiments with Fertilizers. i8o The Prevention of Peach-Leaf Curl. i8r Pollination in Orchards.' 182 Sugar Beet Investigations for z899. 183 Sugar Beet Pulp as a Food for Cows. 114 The Grape Root-Worm ; New Grape
Pest in New York.
x85 The Common European Praying Mantis; A New Beneficial Insect in
America
186 The Sterile Fungus Rhizoctonia. I 7 The Palmer Worm. 188 Spray Calendar. x89 Oswego Strawberries. 29o Three Unusual Strawberry Pests and
a Greenhouse Pest.
Tg9. Tillage Experiments with Potatoes. 192. Further Experiments against the
Peach Tree Borer.
193. Shade Trees and Timber Destroying
Fungi.


Bulletins Issued Since the Close of the Fiscal Year, June 30, 1901.
The Hessian Fly. Its Ravages in New York in i9o. Further Observations upon the Ropiness in Milk and Cream. Fourth Report on Potato Culture. Germicidal Action in Cow's Milk. Orchard Cover Crops. Separator Skimmed Milk as Food for Pigs. Muskmelons.
Buying and Using Commercial Fertilizers.