65G Field Experiments on the Fixation of Free Nitrogen. 
nitrogen in the soil itself resulting from the leguminous growth. 
I had then to consider what nitrogen-consuming crop I would 
make use of, that should be capable of utilising the accumulated 
stock of nitrogen then in the soil. I should have preferred a 
cereal, either barley or oats, but I had been so much pestered 
with wireworms, mice, and small birds, that I determined in 
spite of the natural heaviness of the soil to make use of the 
potato plant. The soil had, however, been made very friable 
by exposure during a hard winter. On March 15, 1892, Mag- 
num Bonum tubers were planted in rows ; they appeared above 
ground on April 10, and were duly hoed, and finally moulded 
up. The haulm was very healthy, dark in colour, but not 
remarkably luxuriant. I did not anticipate a very good crop ; 
nevertheless, on October 10, they were raised and weighed. 
The plot. No. 23, yielded at the rate of 7 tons 11 cwt. per acre ; 
and the plot. No. 24, at the rate of 8 tons 7 cwt. per acre. 
The average, as nearly as possible, is 8 tons per aci’e. This is 
about 2 tons above the average of the kingdom, and, for the soil, 
I considered it good. 
The cropping of plots 23 and 24 is here shown at one view : — 
Plot 
1888 
1889 
1890-91 
1892 
1893 
23 
1 Barley 
Beans 
Clovers 
Potatoes 
■Wheat 
24 
j Oats 
Beans 
Clovers 
Potatoes 
Wheat 
To resume and sum up the results. On a soil shown to be 
very low in “ condition,” so far as regards the production of 
cereals and other gramineous plants (consumers of nitric nitro- 
gen), and the proportion of ash constituents in the soil being 
unknown, after a very liberal manuring with phosphoric acid, 
lime, and magnesia, and taking it for granted that under the 
circumstances there would be an abundant supply of potash and 
other plant food resulting from disintegration, also with a com- 
jslete winter tillage of the best kind, we have grown a strong 
crop of beans, followed by a fair crop of clover hay, and this 
without the application of any nitrogenous or organic manure. 
The quantity of nitrogen collected in the bean crop may 
have been about 152 lb. per acre. In the two clover crops the 
quantity of nitrogen may have been 224 lb. joer acre. The 
quantity remaining in the soil, in the form of roots, and accu- 
mulated in the soil itself as the result of the leguminous growth, 
would be an essentially important item from a manurial point 
of view. The nitrogen from these two sources would necessarily 
be almost the only nitrogen that could be supplied to the 
nitrogen-consuming potato crop. As was ascertained at the 
