2 BULLETIN 353, U. S. DEPARTMENT OF AGRICULTURE. 
but this variation is within rather narrow limits. The term ‘field 
cured”’ is more indefinite, denoting that condition of forage which 
obtains in general farm practice when the hay or fodder is consid- 
ered sufficiently well cured or dried so that it will not spoil when 
placed in bales, stacks, or in a haymow. In this stage the forage is 
very seldom completely air dry. 
Most publications on forage crops use the term “‘field cured”’ to 
denote the condition of the forage under consideration, but such a 
term does not imply a uniform percentage of moisture, and little or 
no care has ever been used to indicate even approximately the 
moisture content of the forage when the yields were determined. It 
is, therefore, impossible to mterpret correctly many data found in 
such publications. 
The variation in the moisture content of forage when yields are 
taken is often greater than the actual difference in yield that we may 
expect from improved varieties or improved ‘methods. There is 
little dependence therefore to be placed in experimental results along 
these lines until this factor of error is eliminated, or at least greatly 
reduced. The data presented in this bulletin are sufficient to sug- 
gest a remedy for this difficulty, and it is hoped that experimenters 
will consider carefully the method here indicated. 
Aside from the experimental value of this work, it has an economic 
significance, in that it points out the relative weight value of forages 
at different stages of maturity. However, the economic side of the 
question is not discussed in detail and is given only as it forms a part 
of the experimental data presented. 
GENERAL PLAN OF THE EXPERIMENTS. 
During 1914 a series of experiments was carried out to secure data 
on which to base a sampling system that would give greater accuracy 
to field tests in forage experiments. In connection with the efficiency 
of the sample method, investigations were also carried on to determine 
the amount of moisture in forage plants at different stages of devel- 
opment, the variation in moisture content due to locality and to 
cutting at different times of the day, and the differences in loss of 
weight when samples are dried in the sun as compared with those 
dried in the shade. Information was also secured on the rate of 
moisture loss in forage in the early stages of curing and the changes 
in moisture content of hay stored in bales and loose in a barn. 
In conducting the experiments at the various places the methods 
followed were the same or varied only in minor details. Half-bushel 
and bushel cotton bags were used to receive all samples except the 
largest, for which common burlap grain bags having a capacity of 2 
bushels were used. For inclosing the bales of hay a close-weave 
burlap was used. In taking samples of field-cured forage, care was 
