256 
Journal of Agricultural Research 
Vol. XXVIII, No. 3 
EXPERIMENTAL WORK 
FIELD METHODS 
The Sudan grass, soybeans, and cowpeas were sown on* June 3, in separate 
plots of less than an acre, on land previously used for corn at the United States 
experiment farm at Beltsville, Md. The first two made good growth, but the 
stand of cowpeas was very thin and spindling. They were all harvested Sep¬ 
tember 2, when the Sudan grass was in the dough stage and the soybeans and 
cowpeas were well podded. All the Sudan grass and the part of the soybeans 
which was ensiled with it were hauled to the cutter fresh; but the remainder of 
the soybeans, which was ensiled alone, and all the cowpeas were allowed to 
wilt before being hauled from the field. 
The experimental silos used were wooden tubs 2 feet in diameter and 4 feet 
deep. They were provided with wooden followers fitting as closely as possible 
within the silo walls. Pressure of 100 pounds per square foot, to approximate 
the pressure within a large silo, was obtained by means of a lever and weight 
applied to the center of the follower. The silo was filled to within 16 inches of 
the top, and a piece of cheesecloth was then carefully spread over to make a 
complete separation between the portions of silage below and above. The 
portion below the cheesecloth was called the experimental portion. The re¬ 
mainder of the silo was then packed with the same kind of silage material, another 
piece of cheesecloth was spread on, and the follower, lever, and weight were 
adjusted in place. 
Five of these silos were used. They were filled as follows: (1) Sudan grass 
alone; (2)’Sudan grass and soybeans, half-and-half; (3) wilted soybeans alone; 
(4) wilted cowpeas alone; (5) Sudan grass and wilted cowpeas, half-and-half 
mixture. Samples were taken at the time of filling for laboratory analyses. 
Three months after ensiling, on December 3, all five silos were opened. The 
top portions down to the cheesecloth separators were weighed and discarded. 
The remainder, or experimental part, in each silo was weighed, thoroughly 
mixed, and a portion of the well-mixed lot taken as a sample for laboratory 
analysis. After the laboratory samples were taken, the remaining portions of 
the silages were used as material to conduct comparative palatability tests. * 6 
METHODS OF ANALYSIS 
A 1-kilogram subsample from a thoroughly mixed field sample of each kind of 
silage was dried in a steam-heated drying closet at about 55° C. to air-dry weight. 
These subsamples were then ground in an electric pulverizing mill so as to pass 
a 40-mesh sieve. Moisture, total protein, albuminoid protein, ash, crude fiber, 
and ether extract were determined on the finely ground sample according to 
methods outlined in “ Methods of Analysis” by the Association of Official Agri¬ 
cultural Chemists. 7 Moisture was found by adding the weight of moisture lost 
in obtaining the air-dry sample to that lost on drying the air-dry sample, and 
calculating as a percentage of the original moist material. 
• Acknowledgment is made to H. T. Converse for suggesting and conducting the palatability test 
and summarizing the results. 
7 Association of Official Agricultural Chemists, official and tentative methods of analysis. 
As compiled by the Committee on Revision of Methods. Revised to Nov. 1,1919. p. 71-99. 1920. 
