
FIELD EXPERIMENTS WITH. FERTILIZERS. 173 
Explanation of tables.—Two tables, containing the data of 
the experiments, are given in the discussion of the results for 
each crop. ‘The first table in each case shows the total weight 
of the crop taken from each section, the crops being weighed 
either at the time of harvesting or after drying in the field. 
In the experiments with corn and soy beans the total grain or 
seed from each plot was taken to the barn and allowed to dry 
before it was weighed. The corn stover was weighed after it 
had dried in the field. ‘The cow pea fodder was weighed green 
as soon as possible after it was cut. The table shows also the 
estimated yields per acre for each crop as calculated from the 
size of the section and the weight of the crop taken from 
it, as well as the increase in the weight of the crop from the 
plots with the different fertilizers over the weight of the crop 
from the plots with no fertilizer. The costs of the fertilizers 
given in one column of the table are based upon the system of 
valuation adopted each year by the New England Experiment 
Stations, which varies slightly from year to year. For the years 
in which experiments reported in this article were made the 
valuations per pound of the different ingredients of fertilizers 
were as follows: 
Assumed costs per pound. 


1896. 1897. 1898. 1899. 





Cents. Cents. Cents. Cents. 
Nitrogen (as nitrate of soda), Z - | 13% 14 14 12% 
Nitrogen (as sulphate of ammonia), Dee ark3 i 14 15 
Phosphoric acid (soluble*), - 2 : 5% | 5% 4% 4% 
Potash (as muriate), - - : mahirerrd Se SWRPA te 4% 4% 

The second table in each case shows.the estimated total yields 
of the crop per acre, the percentage of water-free substance or 
dry matter in the crop when weighed, the percentage of protein 
(N. X 6.25) in the dry matter, and the calculated yields of dry 
matter and of protein. ‘The total yield of dry matter per acre 
is found by multiplying the total weight of the crop by the 
percentage of dry matter in it; and the total yield of protein 
per acre is found by multiplying the yield of dry matter per 
* A small proportion of the phosphoric acid was probably present in the form 
known as ‘‘ reverted,”’ but the valuation for this is only one-half cent less per pound 
than for the soluble. 

