WEEKLY $1.00 PEE YEAR. 
THE CROPS 
Why the 
ACID SOILS, 
is Sour. 
Part I. 
For the past 20 yeais a good share of our farm- 
teaching efforts at the East has been devoted to try¬ 
ing to make misfit crops feel at home. In the north¬ 
eastern part of this country the soil is naturally 
acid, yet we have heeti working on the proposition 
that clover, Alfalfa aid similar crops, which belong 
[to an alkaline soil, sSould be made the foundation 
readily on, and thus there is a lack of available 
nitrogen. Professor Coville started out to find how 
the blueberry could find the food under such con¬ 
ditions. This led to a further study of acid soils and 
the reasons for their acidity. 
What makes land sour? One chief reason is the 
decay of vegetable matter, especially in soils which 
are naturally deficient in lime. Professor Coville 
found that blueberries grew successfully in very 
acid soils which were composed chiefly of rotted oak- 
leaves. The fresh oak leaf contains so much acid 
soil. What is the difference between the fresh oak- 
leaves and the decayed leaf mold? How can the 
blueberry plants extract plant food and grow well 
where Alfalfa starves? Most of us know that rye 
and Red-top will make a fair growth on soil which is 
so sour that wheat and Timothy will fail. Here we 
have been taught that bacteria are needed to break 
up organic matter and provide plant food. These 
bacteria need an alkaline soil to do their best work, 
and as acidity increases they stop working. Yet we 
find that blueberry plants make a good growth in 
VOL. LXXIII., No. 4236. 
NEW YORK, JANUARY 3. 1914. 
A PAIR OF OHIO FARM BEAUTIES AND THEIR REFLECTION IN THE POND. Fig. 1. 
ot our farming. This is responsible for the immense 
use of lime, \ihich is growing all over the Eastern 
States. Our soil is naturally acid, and unless it be 
artificially sweetened by the use of lime, such crops 
as clover, wieat, Alfalfa and Timothy will not 
thrive. Whew lime is cheap the practice is wise and 
economical. There are some localities where lime, 
laid down on the farm, is expensive, and in these 
cases it may be better economy to give up the effort 
to neutralize the soil with lime, and use crops which 
are naturally adapted to acid soils. Some of these 
crops are rye, vetch, cow peas, Red-top, and some 
varieties of Hint corn. 
Some of the most interesting experiments of recent 
years are those conducted by Prof. Frederick Y. 
Coville. A few years ago Professor Coville found 
that the blueberry would not thrive except in an acid 
soil. Most of our cultivated plants fail when the 
ground is sour, because nitrification does not go 
that it is by comparison one-third as sour as pure 
lemon juice. Of course we know that most of our 
ordinary farm crops—except perhaps cranberries 
and strawberries—could not grow in a soil as sour 
as this. Notice how the grass, especially Timothy 
or Blue grass, dries when fresh leaves fall from the 
trees and decay upon the lawn. Now since the blue¬ 
berry did so well in this partly decayed oak-leaf soil, 
Professor Coville assumed that the plant would do 
still better in leaf mold which had been fully de¬ 
cayed. So blueberry plants were started in oak-leaf 
mold which had been rotting for five years. But the 
plants failed to grow—were practically ruined, very 
inferior as compared with plants started in the sour 
oak-leaves. Yet with Alfalfa and rose cuttings there 
were exactly opposite results—these in the rotted 
leaf mold made luxuriant growth, while those in the 
fresh leaves showed that they were starving. Here 
we have the basis for a new scientific study of the 
soil even more sour than picnic lemonade! How do 
they do it? 
Here comes one of the strangest things connected 
with the study of soils. Fresh fallen leaves from our 
common trees are full of acid. The following table 
Table I.— Acidity of freshly fallen leaves, in terms of lime 
requirement per acre. 
Kind of leaves. 
1 
Acidity. 
Kind of leaves 
Acidity. 
White oak. 
Red oak .. 
Silver maple. 
Tons. 
25 
Hi 
go 
Sugar maple. 
Tulip tree. 
Virginia pine. 
Tons. 
22 
14 
22 
shows comparatively how sour they are. This table 
gives the number of tons of lime which would be 
needed to neutralize the acid in a layer of forest 
leaves covering one acre six inches deep. 
The oak leaves contain so much acid that they are 
