THE SHRINKAGE OF MARKET HAY. 13 



practical point of interest to the hay maker and shipper — that is, the 

 manner in which the bales were stored during the experiment. If they 

 were stored separately, cross piled, placed on the top or outside of a 

 pile, or in a small pile by themselves, then the small bales would 

 naturally be influenced by weather conditions to a greater extent 

 proportionally than would large bales. If baled hay is stored flat- 

 wise — that is, the bales resting on their sides and no air space allowed 

 between, then there should be practically no difference in the amount 

 of gain and loss due to changes in the weather, etc., between hay in 

 large bales and hay in small bales, provided the degree of compression 

 were the same. 



Reactions from changes in the weather do not affect the entire 

 mass of hay quickly unless the bulk is small. In large mows and 

 stacks the hay in the interior is more or less protected by the top 

 and side layers of hay ;. consequently it loses water slowly without 

 being affected by exterior changes in humidity. The center of the 

 stack often dries out much more slowly than the top and bottom. 

 The Colorado station 15 found a difference of 10.3 per cent in the 

 amount of water lost by different parts of stacked alfalfa hay. A 

 large stack of well-cured alfalfa was put up June 15, being divided into 

 four layers by slats. On February 12, eight months later, the loss 

 of the different layers was found to be as follows: Bottom layer 

 17.6 per cent, third layer 17 per cent, top layer 23.8 per cent, and 

 the second layer only 13.5 per cent. Experiments by Wale 16 also 

 show a greater loss by shrinkage in the top layers of stacked hay 

 than in the lower layers. 



These experiments explain why hay that is baled after having 

 passed through the sweat sometimes loses weight by shrinkage. 

 The loss of water occurs in the hay taken from the middle of the 

 stack, where it has been insulated by the hay on the outside. 



It is not definitely known to what extent the degree of atmos- 

 pheric humidity influences the water content in well-cured hay in the 

 barn or stack. The data indicate that, under average conditions, 

 the water content will vary with the weather from 2 to 4 per cent 

 below normal, to about the same amount above normal. There is 

 need for a number of carefully conducted experiments to determine 

 the extent of gain or loss of cured hay in storage. 



The loss by shrinkage of well-cured hay during dry weather is, in 

 time, offset by the gain in weight during wet weather, although, in 

 individual cases, shrinkage may cause a loss to the producer or 

 shipper. In various hay-growing sections the high price of hay during 

 the summer months (see p. 26) more than makes up for any loss 

 caused by low water content. 



is Colorado Agricultural Experiment Station, Bull. 57, 1900. p. 6-10. 



" Journal Southeastern Agricultural College, Wye, No. 18. 1909. p. 52-53. 



