THE CHIEF FUNCTION OF LIME. 
Acidified Soils and “Acid Phosphate.” 
In your issue of August 26, I read an interesting 
article by Mr. J. C. M. Johnston entitled: “The Story 
of Lime.” In it he decries the use of caustic lime 
because it “stimulates the soil” so that excellent crops 
are obtained by the father, but leave it depleted for 
the son. Can we “have our cake and eat it, too”? 
Can we grow excellent crops without removing fer¬ 
tility? The point is to grow the crops, to double the 
yield which we are now obtaining from the same area, 
and at the same time to keep up the physical and 
chemical properties of the soil, which we know can 
be do)ie by modern, economic methods. 
Mr. Johnston argues that because caustic lime 
burns and cracks the hands when applying, it must 
eat up the humus in the soil in much the same way 
that it eats the skin off the hands. But supposing 
the hands were covered with a layer of earth, would 
it then eat the skin? It is a pretty well-known fact 
that when caustic lime enters the soil it unites with 
the free organic acids and is no longer caustic, but 
as. Mr. Johnston expresses it, non-caustic. In other 
words, it has been neutralized, and in turn has neu¬ 
tralized the acids in the soil, sweetened the soil, so 
that the beneficial bacteria of the soil can multiply 
and grow—the bacteria which convert organic mat¬ 
ter, humus, etc., into available plant food, also other 
forms of bacteria which gather nitrogen from the 
atmosphere, and which will not survive and thrive 
in an acid soil. It is a question whether lime di¬ 
rectly acts upon the humus of the soil to any con¬ 
siderable extent and breaks it down. Its action is 
secondary. It renders the soil neutral or alkaline, in 
which condition bacteria thrive and perform their 
appointed work; but lime alone will not bring about 
this condition. There must be the right 
amount of moisture and warmth, all in¬ 
fluenced by proper drainage and cultiva¬ 
tion. It is no doubt true that non-caustic 
lime, such as marl and even finely ground 
limestone, will sweeten soils, but it takes 
a larger quantity and a much longer time 
to accomplish the results than with caustic 
lime. 
ACIDIFIED SOILS.—But the point to 
which I want particularly to call attention, 
is the statement that acid phosphate renders 
soils sour. What is there about acid phos¬ 
phate that is absolutely known to produce 
this result? Is it not an assumption rather 
than a known fact? It is assumed that it 
is the sulphuric acid used in dissolving the 
phosphates which renders soils sour. But 
if acid phosphate is properly made, there 
is no free mineral acid; if there were, it 
would immediately destroy the bags. The 
sulphuric acid unites with the lime in the 
phosphates and forms sulphate of lime. 
Now, is sulphuric acid combined with lime 
any more likely to acidify soils than it is 
when it is combined with potash, as sul¬ 
phate of potash, or with ammonia, as sul¬ 
phate of ammonia? So combined, is sul¬ 
phuric acid more harmful than that de¬ 
posited in the soil in the rains and dews? 
It is reported at the Rothamsted Experi 
coal is consumed, rich in sulphur. However, is it 
not more likely that any free mineral acid, whatever 
its source, is soon neutralized in the soil, in the 
same zvay that caustic lime becomes non-caustic when 
it is mingled with the soil? It is well known that 
A SUTTON APPLE TREE. Fig. 435. 
SUTTON APPLE AS GROWN AT HOPE FARM. Fig. 
ment Station in England that over 17 pounds of 
sulphuric acid is deposited to the acre by the rains 
and dews during the year. If this is likewise true 
in this country, and sulphuric acid renders soils 
sour, then we must stop the rains and dews from 
falling on our soils, especially in regions where soft 
there are millions of acres of extremely acid soil 
on which no acid phosphate was ever used. They 
had acid soils before acid phosphate was discovered. 
The Romans used lime as a corrective, before the 
Christian era. 
In the writer’s opinion, the term “acid phosphate” 
is unfortunate. It gives the impression, at least to 
the layman, that it is a mixture of acid and rock 
phosphate, whereas it is a complete chemical union, 
the sulphuric acid taking up two parts of lime (form¬ 
ing sulphate of lime), leaving the phosphoric acid 
combined with one part of lime, which is soluble in 
water and thus immediately available for plant nutri¬ 
tion. The name invented by Liebig, “superphosphate 
of lime,” is much better, or better still, the abbrevia¬ 
tion “superphosphate,” which is used to some extent 
in this country. 
It is believed that acid phosphate (superphosphate), 
in addition to supplying available phosphoric acid, 
available sulphuric acid, and available lime for crop 
requirements, also exercises a stimulating or cata¬ 
lytic influence is the giant or in the soil, and also 
encourages the growth of beneficial bacteria; hence 
the necessity for, and value of an excess in mixed 
fertilizers. The fact is, we do not know much about 
the complete function of phosphorus and sulphur in 
crop production, but we do know that for more than 
70 years the great discovery of Liebig, namely, super- 
pnosphate of lime, has helped to make crops grow, 
and has now become the predominating constituent 
in all successful, complete fertilizers, w. H. bowker. 
R. N.-Y.—Probably Mr. Bowker does not wish 
to be understood that all the acid phosphate used in 
fertilizer is “properly made.” We have seen it where 
the bags were “eaten” nearly away and where it 
stung the hands on using. It is also generally un¬ 
derstood that sulphate of ammonia does act to sour 
the land. _ . 
HOW OLD A TREE? 
The buying of a tree is a problem that few people are 
prepared to solve for themselves at the time they are 
to do the actual buying. The average buyer as a rule 
puts the whole matter of size, age and va¬ 
riety up to the nurseryman from whom he 
intends to buy his trees, but puts it up to 
the nurseryman in such a way there is no 
doubt in the nurseryman’s mind that no 
matter what advice he gives, it will be 
treated with suspicion that lie is trying to 
work off grades and varieties he has a 
surplus of. The nurseryman, being human, 
oftentimes gives the right kind of advice, 
but in such a way as to encourage the 
suspicion in the mind of the buyer, who 
will be sure to go contrary to the advice 
given and take grades and varieties the 
nurseryman is glad to get rid of, and a£ 
the same time give his customer his own 
choice. 
I have a case in mind. A customer 
wanted to buy asparagus roots, and he 
wanted strong two-year roots. It so hap¬ 
pened there was a scarcity of -that grade 
on the market, with a heavy demand from 
retailers to supply their customers who 
buy in small quantities and pay big prices 
for all stock that shows up big from the 
beginning. This customer wanted 10,000 
roots, and he was advised by the nursery¬ 
man to plant one-year roots, the price being 
one-half that of the two-year, and the ad¬ 
vantage of a young root was two to one in 
starting growth at once after the transplant¬ 
ing and the future growth of the plant. No amount of 
reasoning would convince this man that the one-year 
plant was the best for him; he bought the large roots 
and paid double the price for them. At the same time 
one of his neighbors bought the one-year roots, 
planted them at the same time, and hardly had a lost. 
436. 
NEW YORK, NOVEMBER II, 1911. 
WEEKLY, $1.00 PER YEAR 
Vol. LXX. No. 4124. 
