8 
At Arlington also most of the field tests have been conducted on 
twentieth-acre plats (16J feet by 132 feet). During the earlier years 
of the work tenth-acre plats (33 feet by 132 feet), and also a few 
fortieth-acre plats (8J feet by 132 feet), were used. These plats also 
lie in series running north and south, with 18-inch alleys between the 
plats within the series. The series are separated by roadways 19f 
feet in width. 
TREATMENT AND CROPPING OF PLATS. 
The cereal experiments at Arlington Farm have been conducted 
on land that is undergoing a system of soil renovation by the use of 
green-manure crops, stable manure, commercial fertilizers, and lime. 
Sufficient acreage has been available to allow the alternation of the 
cereals with other crops. By this method the mixing of varieties 
from volunteer plants is avoided, and there is opportunity to carry 
cut the general scheme of soil improvement. In general, the cereals 
have followed crops of cowpeas or soy beans plowed under in late 
August or early September. This is usually the third green-manure 
crop to be plowed under during the 15 months that elapse between 
the two grain crops, as the latter are always immediately followed as 
well as preceded by cowpeas or soy beans with a crop of winter rye 
between the two legume crops. 
In addition, a top-dressing of about 10 tons of stable manure per 
acre is applied to the rye during the winter. At seeding time 200 
pounds of acid phosphate, containing about 14 per cent of phos- 
phoric acid, are applied. 
Immediately after plowing the plats are worked down with the 
disk and acme harrows and allowed to remain until seeding time, 
when a good seed bed is usually obtained by double disking and 
harrowing. 
The seeding is done with an 8-foot single-disk drill. The disks 
are 8 inches apart, with no chains or other leveling or compacting 
device attached. After seeding, the plats receive no further treat- 
ment, except that just prior to harvesting they are rogued in order 
to keep the varieties as free as possible from mixtures. The har- 
vesting is done with an ordinary grain binder. The bundles are 
shocked, placing from 12 to 14 in a shock, and are allowed to stand 
in the field until stored or thrashed. The grain in the shock usually 
is protected from birds and the weather by canvas shock covers. 
The small-grain crops at College Park are included in a more or 
less definite rotation, in which no hay or grass crop is used. The 
scheme has been to grow corn two years, followed by wheat or other 
small grains two years, with supplementary crops of crimson clover 
and cowpeas for green-manuring purposes. 
Manure and commercial fertilizers also are used to maintain the 
soil fertility. The former is used on the corn crop, while the latter 
