lk, but the definite number
of pounds of nitrogen and other constituents of plant-food contained in
it, and the calculations in home-mixing become simple.

Materials that should not be Combined.--The advocate of factory-mixed
goods warns the farmer against the danger of making combinations of
materials that will cause loss by chemical action. The danger is wholly
imaginary if no form of lime, wood-ashes, or basic slag is used in the
home-mixtures. As has been said, some materials will harden, if
permitted to absorb moisture, and if the mixture must stand, a few
hundred pounds of muck or dry road dust should be added to each ton as
a drier, and a correspondingly larger amount per acre should be
applied.

Making a Good Mixture.--The process of mixing is simple, and careful
station tests have shown that it is fully as effective as
factory-mixing. The unmixed materials should be kept in a dry place
until the mixing is done. If there are any coarse lumps, a wooden
tamper can crush them on the barn floor, and the material should be
passed through a sand-screen. The material of largest bulk should be
spread on the floor, and the other materials should be put on in
layers. Three careful turnings with a shovel will secure good mixing.
Scales should be used to secure accuracy in desired amounts of the
materials.

Buying Unmixed Materials.--Acid phosphate, animal bone, and tankage can
be bought of any fertilizer agent, but when one pays cash, he does well
to get quotations from various leading manufacturers. The names of
dealers in nitrate of soda can be secured from the New York agency
which keeps its address before the public in agricultural papers. This
is likewise true in the case of the syndicate controlling all the
potash. When the addresses of leading distributors of all needed
materials have been secured, quotations should be obtained on a cash
basis. The best terms are obtained by groups of men combining their
orders.

CHAPTER XX

MIXTURES FOR CROPS

Composition of Plant not a Guide.--It has been pointed out that a
chemical analysis of a soil is not a dependable guide in the selection
of a fertilizer. Years ago the theory was advanced that the analysis of
the crops desired should be a guide, but it has proved nearly
worthless. This theory does not take into account the soil's supply of
plant-food. Moreover, a certain crop may demand a large supply of an
element at a time of the year when the soil's supply