1876.] 
AMERICAN AGRICULTURIST. 
291 
As was explained and illustrated by some exper¬ 
iments in our March article, Nitrogen, Potash, 
Lime, Magnesia, Iron, Phosphoric Acid, and Sul¬ 
phuric Acid must be furnished to crops through 
their roots, by the soil, in order to their growth. 
Each one of these is an essential ingredient of plant- 
food. If the available supply of any one be de¬ 
ficient, the crop cannot flourish. In how far the 
three other substances mentioned are essential to 
the support of plants is not so definitely proven. 
The best experimental evidence at our disposal in¬ 
dicates that but a very minute quantity of soda, if 
any, is needed by our ordinary plants, but that in 
some cases, at least, small amounts of chlorine are 
indispensable, and minute quantities of silica may 
be necessary to the healthy and normal perfection 
of the plant. In many trials made at the Experi¬ 
ment Stations, and elsewhere, in which oats, buck¬ 
wheat, corn, and various other plants have been 
grown with their roots in water or in artificial soils, 
the plants have been raised stronger, healthier, and 
in every way more perfect than is ever the case, ex¬ 
cept in the rarest instances, in ordinary field prac¬ 
tice. These results have been obtained when 
neither soda nor silica was supplied except the very 
minute portions that were contained in the original 
seed, or dissolved by the water from the glass of 
the jars in which the plants were raised. But when 
the supply of nitrogen, or potash, or phosphoric 
acid, or lime, or magnesia, or iron, was deficient, 
the crop failed ; and, in some cases, without chlor¬ 
ine, they were sickly. Such are the results of a 
vast deal of the most careful experimenting. 
Wliat Ingredients of Plant-food are apt to 
lie deficient in our soils i 
It is sufficiently well settled, that Nitrogen, Phos¬ 
phoric Acid, Potash, Sulphuric Acid, Lime, and 
Magnesia, are the only ingredients of plant-food 
which need to be supplied in fertilizers. Iron, 
Silica, and Chlorine, are furnished in abundance by 
every ordinary soil. 
Generally speaking, we may accept the opinion 
commonly held that Magnesia may sometimes be 
lacking, that Sulphuric Acid and Lime are more 
apt to be deficient in our ordinary soils, and Nitro¬ 
gen, Phosphoric Acid,' and Potash, most so. In one 
soil one, in another, several or all of these may be 
wanting. Such is the general result of all the best 
evidence of experience and experiment which we 
have at our disposal. 
It was once thought that the chemical analysis of 
a soil would easily reveal the deficiencies in plant 
food. But later experience has shown this is, at 
best, a costly and defective source of information. 
Different samples of soil from the same field may 
vary widely in composition, and, what is a still 
greater difficulty, the chemical tests which make 
known the presence of a given ingredient in the 
soil, do not show whether it is iu such a form that 
the plant can use it. And there are many process¬ 
es of vital importance to the sustenance of the 
plant which are continually going on in the soil, but 
which the analysis does not reveal. 
In fact, in the present very defective condition 
of our knowledge of these subjects, the surest and 
best way to learn what are the needs of a given 
soil is by actual experiments with different fertili¬ 
zers and crops, and modes of treatment. 
Complete vs. Special manures. 
A friend once asked me to recommend to him a 
phosphate for a top dressing for his lawn. I had 
just analyzed a sample from a neighboring dealer, 
and found it very good, and told my friend so. He 
bought a quantity, tried it, and saw scarcely any 
benefit from it. The season was dry, however, and 
we were inclined to think that might have been the 
reason for the failure. Not long since a very intel¬ 
ligent farmer was telling about some experiments 
he made a few seasons ago with artificial fertilizers. 
He had tried small lots of a number of different 
brands of superphosphates and Peruvian guano 
also. So far as he could judge, there was but little 
difference in the results, nor did either of the arti¬ 
cles prove especially beneficial. He felt certain 
that the fertilizers were in themselves good, and 
was wondering why the results were not more sat¬ 
isfactory. The failure could not be ascribed to 
drouth, for the season was not particularly dry. I 
am inclined to think that in this case, and perhaps 
in the other one, the fertilizers did not supply what 
the soil lacked. And right here, I believe, is to be 
found the cause of a good many of the failures in 
the use of artificial fertilizers. Most of our arti¬ 
ficial manures are only special fertilizers. They 
supply part, but not all, of the list of ingredients 
of plant food, which may be deficient in our soils. 
During the past winter and spring, we have ana¬ 
lyzed, at our Experiment Station, about a hundred 
samples of commercial fertilizers, such as are sold 
and used in Connecticut. With the exception of a 
small number of samples of potash salts, but very 
few of them furnish any considerable quantities of 
potash, though nearly all contain a good deal of 
phosphoric acid and lime, and the most of them 
nitrogen also. In a Report lately issued by the 
Station, analyses of some seventy samples are 
given. This list includes Phosphates, which fur¬ 
nish phosphoric acid and lime ; Superphosphates, 
which contain phosphoric acid, lime, and sulphuric 
acid; Bone manures and “ Ammoniated phos¬ 
phates,” which contain the ingredients mentioned, 
and small quantities of nitrogen in addition ; Peru¬ 
vian guano and fish manures, which contain a good 
deal of nitrogen, and more or less phosphoric acid 
and lime, and so on. None furnished any notable 
per centages of either potash or magnesia, except 
the Peruvian guano, which yielded small propor¬ 
tions of potash, the highest being about 21 per 
cent, and of four Nitrogenous superphosphates, to 
which German Potash salts had been added in man¬ 
ufacturing. Two gave about four per cent of potash, 
the others less than two per cent of potash each. 
Along with the potash they contained magnesia 
also. Of the whole list of seventy commercial fer¬ 
tilizers, referred to in the Experiment Station Re¬ 
port, only the two last mentioned furnished notable 
quantities of each of the whole list of ingredients 
of plant-food which are apt to be lacking in our 
soils. These last were complete fertilizers. The 
others were special fertilizers. 
In the last article mention was made of some ex¬ 
periments by Messrs. Lawes and Gilbert in Eng¬ 
land, and of Prof. Storer at Jamaica Plain, Mass. 
The soil on which Messrs. Lawes and Gilbert 
worked, gave continuously good results with ma¬ 
nures which furnished nitrogen and phosphoric 
acid, and was able to supply sufficient potash of it¬ 
self. But on Prof. Storer’s soil, phosphates and 
nitrogenous fertilizers did but little good, while 
those that furnished potash proved most effective. 
—In Lawes and Gilbert’s experiments, the soil sup¬ 
plied enough of the other essential ingredients of 
plant-food, so that with the addition of nitrogen 
and phosphoric acid, as large crops were obtained 
year after year, as with heavy dressings of barn¬ 
yard manure. Prof. Storer’s land furnished enough 
of phosphoric acid and lime, and the other essen¬ 
tial ingredients of plant-food, so that when potash 
was added, as large crops were obtained as with 
barn-yard and stable manure: 
The need of potash in many New England soils 
is likewise indicated by the experiments of Profs. 
Goessmann and Stockbridge of the Massachusetts 
Agricultural College, the Messrs. Sturtevant in 
Framingham, Mass., and others. And these re¬ 
sults are confirmed by a great deal of practical ex¬ 
perience in the regions where these experiments 
have been made and elsewhere. 
We have some experiments now going on in con¬ 
nection with our Station in which the effects of dif¬ 
ferent fertilizers on a soil in this neighborhood are 
being tested. Of course no definite results are ob¬ 
tained as yet, as the crops are still young, but, so 
far as we can now judge, the fertilizers which con¬ 
tain potash are doing considerably better than those 
w'hich have no potash. 
In some of his field experiments, Prof. Storer ob¬ 
tained smaller crops of beans and barley on plots 
treated with bone and other phosphates, than on 
contiguous plots which received no manure at all. 
In some cases the phosphates, instead of increasing 
the crops, actually diminished them. The same ob¬ 
servation has been made by experimenters in 
Europe. This injurious action of phosphates Prof. 
Storer is inclined to think would occur only on 
poor soils. To investigate the cause, he “ tried a 
number of experiments in pots, with the view of 
determining how large an amount of phosphatic 
manure may be safely applied to sterile land. From 
the results obtained he infers that bone-dust and 
other phosphates, when present in too large a quan¬ 
tity, may exert an exceedingly hurtful influence on 
the plumule, or first sprout, that springs from the 
seed, especially at the time when the young shoot 
is ceasing to draw its nourishment from the seed, 
and is beginning to live on matters derived from 
the soil and air.” 
Now do not these facts give a very probable ex¬ 
planation of the reason why my friend’s superphos¬ 
phates and guano did so poorly ? They are special 
fertilizers. They supply part but not all of the in¬ 
dispensable ingredients of plant-food. Did they 
fail to supply just the ones that were most needed ? 
Now let us look at this matter from a slightly 
different standpoint. Many farmers find that Pe¬ 
ruvian guano, fish, and other special fertilizers, 
whose action is quick and stimulating, seem to 
leave their soil in a more exhausted condition than 
before they were applied. A good many of our 
Connecticut farmers complain that guano and fish 
“ run their land down, drive out the grasses, and 
bring in sorrel.” The same observation is made 
concerning bone manures and other phosphates. 
One of the most observing farmers in this region 
remarked to me a while ago, that bone does not 
work as well on his and his neighbors” land, as 
when they first began to use it. 
In the Experiment Station circular above Refer¬ 
red to is the following : 
“ May we not at least question whether the immediate 
effect of these special fertilizers has not been, in many 
cases, to aid the plant to use the more available stores of 
food in the soil, until these latter have become so far ex¬ 
hausted as no longer to respond to the stimulating action 
of the special manures ?—If the above supposition be 
correct, it is clear that what such exhausted soils need, is 
something to supply, not only the nitrogen and phos¬ 
phoric acid of the guano, or fish, or bone, or superphos¬ 
phates, or other special fertilizers, but also the potash 
and other materials that these latter do not furnish.— 
Ashes are, for many soils, a standard fertilizer. Places 
where a tree or a brush-heap has been burned, often show 
the effects of the manuring for years. It is an old saying, 
that ‘ The land never forgets ashes.’ Ashes supply di¬ 
rectly all the soil ingredients of plant-food except ni¬ 
trogen. Their indirect action is also, very likely, not un¬ 
important in rendering other materials in the soil avail¬ 
able. Instead of wearing out soils, they strengthen 
them. May not this difference be due, in part at least, to 
the fact that they furnish the other ingredients of plant- 
food which tlie guano and fish lack?—Stable manure 
furnishes all the ingredients of plant-food. It is a com¬ 
plete fertilizer. Farmers do not complain that it helps 
to exhaust their land.” 
In brief, these special fertilizers are useful in 
proportion as they supply the materials which the 
crops need and the soils lack in the special cases 
where they are used. Otherwise they cannot be 
profitable. And, as I have repeatedly urged, the 
question whether a guano, or phosphate, or bone 
manure, wiLl be profitable on a given soil is best 
settled by experience and experiment. 
Wesleyan University, Middletown , Conn. 
■ -—>»-•--■»»——- 
A New Wagon Brake. 
An automatic wagon brake that will act of itself, 
when needed, without the help of 
the driver, is a very desirable 
thing. In drawing heavy loads 
upon hilly roads, such a brake may 
prevent serious disaster, or loss 
of life. A brake of this kind is il¬ 
lustrated on the next page, where 
figure 1 shows the whole arrange¬ 
ment. The iron rods, A, A, fast¬ 
ened to the end of the tongue 
braces, are connected by screws 
Fig. 2.— slot- and nuts, C, C, to cross levers, 
ted shoes. b, B, upon which the slotted 
shoes, shown at figure 2, are huDg. The 
