PLANT FOOD. 3893 
be beneficial. The “gumbo” subsoil,to a greater extent than any other 
found in this state, prevents moisture from penetrating deeply into 
the soil, and as a consequence such lands are the first to suffer dur- 
ing adrouth. If the “gumbo” could be loosened, it would obviate 
this to a great extent. 
Understand the nature and condition of the subsoil on your farm 
before subsoiling. 
PLANT FOOD.—COMMERCIAL FERTILIZERS OR FARM 
MANURES. 
PROF. HARRY SNYDER, ST. ANTHONY PARK. 
The question of plant food, together with the most economical 
ways of feeding plants, is equally as important as the economical 
feeding of animals. In fact, it is more important because animals 
are dependent, directly or indirectly, upon plants for food. The 
feeding of plants has not required such close attention as the feed- 
ing of animals, because in a new soil plants are usually provided 
with an abundance of food, but when this necessary plant food is 
reduced to a narrow working limit, the question of food becomes a 
more serious problem. 
In some states and localities which have been settled for a much 
longer period than Minnesota, the cost of plant food in the form of 
commercial fertilizers has reached very large figures. In many 
states the sale of commercial fertilizers is regulated by law, so as to 
prevent the practice of gross frauds. New Jersey,in 1893, expended 
$1,650,000 in commercial fertilizers, and many other states propor- 
tionately as large, if not larger, sums. There is expended annually 
in the United States not less than $40,000,000 in commercial fertilizers. 
The extensive use of these commercial articles has created a great 
deal of interest in regard to their value. Under the horticultural 
and agricultural conditions of this state, but little, in fact, nothing 
is heard about commercial fertilizers. Inasmuch as they are so 
extensively used in other states, we are naturally much interested 
in regard to them, especially in relation to the following questions: 
1. Is the present use of commercial fertilizers necessary? 
2. Will they producecrops which have a greater food value? 
3.. Can their use be put off or possibly avoided? 
4. How do the commercial fertilizers compare in value with 
ordinary manures? 
5. What kind of fertilizers are best adapted for certain crops? 
These questions are easier to ask than they are to answer, and, be- 
fore taking up any of them, let me say that our exact knowledge in 
regard to many of the topics is not so complete as could be desired 
—in many cases it is quite fragmentary, but we must look theques- 
tion squarely in the face and discuss it as fully as our knowledge 
will allow. 
A commercial fertilizer is a mixture of various materials which 
are supposed to be rich in the elements of plant food. The elements 
which are the most necessary for plant growth are nitrogen, phos- 
phoric acid, potash and lime. In commercial fertilizers these ele- 
