2 BULLETIN 1126, U. S. DEPARTMENT OF AGRICULTURE. 
carried on with potatoes, a decreased yield resulted in some cases 
where the potash was applied in quantities which would give 7.5 
pounds of borax per acre, while in other experiments as much as 18 
pounds was required to show injury. In some of the experiments 
with cotton a reduction in yield resulted where as little as 4 pounds 
of borax per acre were used, while on other soils no decreased yield 
resulted with the use of less than 12 pounds. 
That the injury caused by the Searles Lake potash was due to the 
borax it contained has been further demonstrated by experiments 
made in 1920. In these tests the effect of Searles Lake potash free 
from borax gave good results and compared very favorably with 
potash materials from other sources. : 
Owing to the great interest taken in the subject and its bearing on 
crop production it was felt essential to conduct further field studies 
in order to obtain detailed evidence on the effect of borax upon 
different crops with respect to growth as well as yield. 
This bulletin embodies the results of these field studies conducted 
cooperatively in the States of Maine, New Jersey, Virginia, and 
abana on several important types of soil. 
REVIEW OF THE LITERATURE. 
The injurious effects of borax in corn fertilizers were noted in 
Indiana in 1917 by Conner, which seem to be the first recorded field 
observations on the effect of borax and its occurrence in fertilizer 
practice. Conner (3) reached the conclusion from his experiments 
in pots that 100 pounds per acre of a fertilizer containing 2 per cent 
of borax when applied in the furrow caused injury to the corn plant. 
Work previous to this by Lipman (8) was confined to pot tests, and 
the work of Cook (5, 6, 7) was chiefly concerned with the action of 
borax in manure and is not directly applicable to present-day com- 
mercial-fertilizer practice; neither are the experiments of a number 
of European workers which are reviewed in Cook’s paper. 
Conner’s more recent report (4), giving the results of his work with 
borax on corn in two field experiments, confirms the data obtained 
from the pot tests. He found that borax caused the greatest injury 
when the fertilizer in which it was contained was applied in the row. 
From 0.5 of a pound up to 4 pounds of anhydrous borax per acre 
produced injury when drilled in the row, and 16 to 18 pounds were 
required to produce injury when the fertilizer was sown broadcast 
and worked into the surface soil. Conner also found that borax 
injury varies with the method of application, type of soil, seasonal 
conditions, and the crop grown. 
In field experiments reported by Blackwell and Collings (1), desig- 
nated a progress report, applications of a potash salt containing 17.75 
_ per cent borax (Na,B,O,), used in quantities varying from 25 to 1, 000 
pounds per acre, did not prevent germination of cotton and corn seed 
under the conditions of the experiment or hinder the normal growth of 
the young plants. Their experiments were discontinued when the 
young plants were 18 inches in height. Nor did applications of com- 
mercial borax ranging from 54 to 400 pounds per acre prevent germi- 
nation and normal growth of either cotton or corn. The planting was 
followed immediately by heavy rains, which it is stated may account 
in a large measure for the failure of these quantities of borax to show 
