384 PRINCIPLES OF AGRICULTURAL CHEMISTRY 



plants, such as cowpeas, are difficult to cure on account of the 

 large succulent vines, which remain moist after the leaves have 

 become dry and so brittle that they break off. For a similar rea- 

 son alfalfa also is difficult to cure . Often alfalfa hay consists 

 entirely of stems. 



The Arkansas Experiment Station found that young or vigor- 

 ously growing vines of cowpeas very difficult to cure even 

 under favorable weather conditions, while mature vines cured 

 with little difficulty in favorable weather, and usually made good 

 hay even after an exposure to rain and cloudiness from two to 

 four* days. 



In hay making the plants are usually cut and allowed to lie ex- 

 posed to the sun all day; then raked or piled into heaps more or 

 less loose, for further curing, and finally piled into larger heaps, 

 or taken to the barn. If the large heaps are formed while the 

 material is too moist, excessive fermentation will take place, 

 which in some cases has gone so far as set fire to the stack. In 

 Wisconsin, Short found that by leaving hay out four days after 

 cutting, during which time there was a rain, there was a loss of 

 over 4^2 per cent, dry matter and 3^2 per cent, protein. Six 

 weeks later nearly one-fourth of the dry matter and protein dis- 

 appeared. 



Emmerling left grass exposed for 18 days, during nine of which 

 rain fell, with the results given in the following table : 



PERCENTAGE Loss OF INGREDIENTS OF HAY IN EXPOSURE TO RAIN. 



Even without rain, when the process of drying is slow, a loss 

 takes place due to the respiration of the living tissues, by which 

 protein is decomposed or non-proteins oxidized. The loss has 

 been as much as 12 per cent, dry matter in 10 days with young 



