The yield and sugar content of alfalfa cut at various times of day and the sugar content of the hay after various methods of drying
1945
Dexter, S.T.
In an experiment designed to measure the yield of alfalfa hay when cut at various times of day, it was found that no marked increases occurred from morning until night, nor were large decreases found from evening until the next morning. At about one-half bloom, a growth of about 100 to 200 pounds dry matter per acre per day was found. The average fluctuation in yield of 10% between night and morning reported by Curtis was in no way approximated. In almost continuously sunny weather, there was a small but rather consistent increase in the percentage of sugars and starch in the hay as the day proceeded. The highest percentage of these carbohydrates was found on the brightest and hottest day. When samples of hay were dried in unheated circulated air, over a period of 3 days, there was a considerable loss of sugars as compared with rapidly dried samples. Whether this sugar was lost as carbon dioxide in respiration, or used in the synthesis of other materials, is not known. Certain data from Henson (3) suggest the former. When hay was dried much more slowly over a period of about 3 weeks in a "mow drier", the losses of sugar were still more pronounced. Ordinary field-cured hay was far higher in sugars than the hay dried slowly in the mow. Precisely how much difference in actual feeding value will result from such differences in sugar content remains to be determined. The feeding trials now in progress may give some idea of the influence of slow mow drying, in deep mows, upon the feeding value of the hay.
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