20 BULLETIN 353, U. S. DEPARTMENT OF AGRICULTURE. 
were split in the Hays samples, while in the Amarillo samples the 
stems were left entire. Splitting the stems when collecting sorghum 
samples greatly accelerates air drying and probably adds to the uni- 
formity of the dried samples. This practice is recommended in the 
preparation of sorghum samples for correcting yields. 
AMOUNT OF MOISTURE IN AIR-DRY SAMPLES. 
The amount of moisture in the air-dry material depends not only 
upon the humidity of the atmosphere but also on the nature of the 
matcrial in the sample. The sorghums, unless allowed to remain 
an extraordinary time under conditions suited for drying, retain a 
considerable percentage of moisture because of their large stems 
with the hard outer walls. Alfalfa, on the other hand, being quite 
succulent and leafy, loses its moisture rapidly and rather completely. 
Alfalfa at Chico had 9.7 per cent of moisture in the air-dried mate- 
rial, while at Arlington Farm, Va., there was 10.4 per cent. This 
difference probably represents the effect of the different degrees of 
humidity at the two places. 
Timothy at New London, Ohio, retained 14.7 per cent of moisture 
in the air-dried material, while the mixture of tall oat-grass and orchard 
grass at Arlington Farm, Va., retained 17.9 per cent. Sorghum at 
Amarillo, where the stems were not split in the samples, retained an 
average of 32.7 per cent. It is unfortunate that dry-matter deter- 
minations were not made on the samples collected at Hays, Kans., 
as this would have given an opportunity to compare with the Ama- 
rillo samples others in which the stems were split and the drying 
was much more complete. 
The above percentages no doubt represent fairly accurately the 
moisture percentages which may be expected in the air-dry samples 
of these different crops. 
EFFECTS OF DRYING SAMPLES IN THE SUN AND IN THE SHADE. 
To compare the relative moisture content of air-dry material 
allowed to cure in the shade with that cured in the direct sunshine, 
two sets of alfalfa samples were taken at Chico, Cal., and two sets 
of the mixture of tall oat-grass and orchard grass were prepared at 
Arlington Farm, Va., one set at each station being placed in the 
shade to cure, while the corresponding set was cured in the sun. 
The results, as given in Table V, show that while the total shrink- 
age was greater in the shade-cured samples at both places the mois- 
ture content of the air-dry material was a little less in the sun-cured 
samples at Chico and a little greater in those cured in the same way 
at Arlington Farm. 
