THE SHRINKAGE OF MARKET HAY. 21 



LIMITATIONS OF RULES FOR MEASURING SHRINKAGE. 



If a definite rule for measuring shrinkage could be laid down, it 

 could be used to advantage in all of the hay-growing sections. That 

 there is a need for such a rule is shown by the number of inquiries 

 received by the Department of Agriculture. Such a rule could be 

 used to determine the yield of experimental plots, but its greatest use 

 would be to the hay grower who hauls his hay on wagons to the barn 

 and has easy access to wagon scales, for it would enable him to com- 

 pute, to the ton, just how much hay he would have for sale after 

 deducting the amount needed on the farm. Again, if he grows hay 

 for the winter feeding of stock, he could easily determine, by using a 

 rule for shrinkage, how much live stock he could keep during the 

 winter. Merely weighing the hay as it comes from the field, on its 

 way to the barn, does not give a significant figure to the average hay 

 grower, since he does not know whether the shrinkage will be 10, 20, 

 or 30 per cent; indeed is not sure that there may not be a gain a few 

 months later. 



The Rhode Island station used a rule allowing a 20 per cent re- 

 duction in the weight of field cured hay to represent barn-cured hay. 

 This rule was based on the usually accepted idea of practical farmers 

 in that State. In 1902 the actual weights of field-cured and barn- 

 cured hay were taken to check the accuracy of the 20 per cent rule. 

 With one plot there was an error of about 6 per cent, in another about 

 5 per cent, and in another about 0.5 per cent in total shrinkage. 

 In each instance it was found that a 20 per cent allowance for shrink- 

 age was too great. 27 



The Kansas station says, in regard to the average amount of 

 shrinkage : 



Men experienced in handling hay usually figure on about 20 per cent loss in the 

 weight of the hay after it is put into the mow. The statement is also made that each 

 bale (size and weight not given) will shrink from 2 to 5 per cent in weight. 



It appears that the amount of moisture retained in cured hay when stacked varies 

 with different kinds of hay and with different conditions of curing. Ordinarily the 

 loss in the weight of hay stacked when well cured and protected from loss other than 

 that which may occur by natural shrinkage should not be greater than 10 to 15 per 

 cent. 28 



According to this investigator, hay in the mow loses considerably 

 more by shrinkage than hay in the stack, provided the stack is pro- 

 tected from loss other than that which may occur by natural shrink- 

 age; that is, loss from bleaching and rotting due to exposure to the 

 weather. To prevent such loss it would be necessary to protect the 

 top and sides of the stack, which is exactly what the barn does, and 

 the amount of shrinkage would of necessity be the same in the bam 



2' Rhode Island Agricultural Experiment Station Bull. 82, 1902, p. 130-131. 

 28 Kansas Agricultural Experiment Station Bull. 175, 1911, p. 331. 



