Reconsideration 
the Fertilizer Problem 
Part I. 
E FFECT OF LOW PRICES.—The slump in the 
price of farm products has a tremendous 
effect on the business of the country. Low prices 
have affected the farmer directly, of course, but the 
indirect effect is one that will last for a long time, 
and will be felt in nearly every other industry. The 
farmer must follow the same process as any other 
manufacturer who is confronted with a period of 
deflation. As he studies the items that go to make 
up the cost of production the Eastern farmer in 
particular finds that the cost of commercial fertilizer 
is highly important. This situation is made more 
imperative by the increase in freight rates, amount¬ 
ing to 40 per cent in many sections and, further¬ 
more, the cost of mixed fertilizer has diminished very 
little as compared with war-time quotations. All 
these conditions, then, lead to a reconsideration of 
fertilizers and their usefulness in profitable crop 
production. 
ELEMENTS 
OF PLANT GROWTH.—We under¬ 
in the form best adapted for the particular crop. 
DETERMINING SOIL NEEDS.—There are var¬ 
ious methods suggested for determining the kind 
and quantity of fertilizer to be used in particular 
cases. Many well-known chemists have advocated 
the fertilization of soils on the basis of the quantities 
of nitrogen, phosphorus and potash which a good 
crop would remove from the soil. For example, the 
chemical analysis of wheat and straw shows that a 
crop of 30 bushels to the acre will remove approxi¬ 
mately 42 lbs. of nitrogen, 15 lbs. of phosphoric acid 
and 14 lbs. of potash. Therefore, say these chemists, 
we need to apply such amounts of chemical fertilizer 
as will supply these proportions of plant food. 
CHEMICAL ANALYSIS.—On the other hand, there 
are many farmers who believe that an analysis of 
soil is the best method of determining the kind of 
fertilizer to apply. They believe that if they could 
afford to have their soil analyzed chemically the 
answer would be indicated very plainly as to its 
shown that one type of soil, light sand, yields one- 
fifth of one per cent total potash, while another of 
clayey nature yields 2*4 per cent potash. If we 
consider that the surface soil extends to a depth of 
S inches, a crop would weigh about two and a half 
million pounds. This means that the first type soil 
contains 2 i /> tons of potash to the acre and the 
second more than 28 tons. While we may know 
nothing regarding the availability of the potash in 
either one of these types, it is logical to assume that 
the first type containing only one-fifth of one per 
cent of potash would need re-enforcement with 
potash salts long before the type which contains 2% 
per cent. The same thing may be said of the other 
fertilizing elements—nitrogen and phosphoric acid. 
M e may. therefore, assume that the user of com¬ 
mercial fertilizer should bear in mind both the par¬ 
ticular food requirements of the crop in question 
and the probable ability of the soil to supply this 
food, supplementing the suspected shortage of any 
A Small Portion of the 1020 Corn Crop. Fig. V t 
Stand that the chemical elements of which plants 
us** most, and which are usually deficient in soils, 
are nitrogen, phosphorus, potassium and calcium 
(lime). Chemical analysis of thousands of soil 
samples shows that the other essential elements in 
plant growth are present in sufficient quantities to 
supply crop needs for generations to come. Lime 
has other uses than as a direct plant food, and hence 
we are concerned principally with the supply of 
nitrogen, phosphorus and potassium. It is the quan¬ 
tity of these materials contained in a ton of fer¬ 
tilizer that gives it value. Therefore* we should recall 
that it is of greatest importance that fertilizer should 
be purchased on the basis of plant food supplied per 
dollar rather than simply by the price per ton. As 
crops are removed from the farm year in and year 
out the soil becomes depleted in available supplies 
of one or more of these elements, and'tlie successful 
farmer is the man who can most accurately sense 
the elements that are lacking and are limiting fac¬ 
tors in his crop, and who can supply this deficiency 
need for certain elements. Neither of these hypo¬ 
theses is correct when considered alone. For ex¬ 
ample, a crop may remove from tin; soil large quan¬ 
tities of a certain element, and yet the application 
or a small quantity of another form of plant food 
would materially increase the crop, since that might 
be the limiting factor. Soil analysis as a guide is 
not satisfactory, partly because of the difficulty of 
securing a sample which is representative of an en¬ 
tire field, and partly because it is impossible for the 
chemist to tell when the supply of plant food which 
he finds will become available to (lie plant roots. 
VARIATIONS IN PLANT FOOD.—It is not un¬ 
usual to find soils that contain sufficient phosphorus 
to feed crops with the element for a hundred years 
to come, and yet the application of a few hundred 
pounds of available phosphoric acid will profitably 
increase the crop. Soil analysis, as well as crop 
analysis, does, however, give some indication regard¬ 
ing the lacking element. Soil analyses made by- tin* 
New Jersey Experiment Station, for instance, have 
element with commercial fertilizer in the most avail¬ 
able form. 
'ALT E OF LIME.—One of the most important 
phases of soil analysis is the determination of the 
degree of acidity or alkalinity. Lime is a vital fac¬ 
tor in-making plant food available. In the chemical 
changes constantly occurring in the soil calcium or 
lime combines with nitrogen, phosphorus or potash 
compounds and makes these elements soluble or 
available to plant roots. One exception to this may 
be noted, namely, that an excess of lime coming in 
contact with available phosphoric acid may cause 
the latter to revert to an insoluble state. Under 
ordinary conditions, however, this is not likely to 
happen, and we may take it as a general rule that 
lime, in addition to its other valuable uses, is a most 
important chemical factor in making available the 
great insoluble supplies of plant food. In fact, this 
principle may be carried to excess and such quan¬ 
tities of lime added without the application of other 
fertilizers that the natural sources are seriously 
