1288 FORAGE CROPS, MEADOWS AND PASTURES 



Therefore, when the grain begins to leave the milky stage there is not 

 only a great disproportion between the relative weights of ears on the one 

 hand, and cnlms and flag on the other, but relatively to the period of full 

 bloom, a loss of weight in the latter, which although at first compensated for 

 by a corresponding increase in the weight of the ears, becomes in the 

 end an actual loss of what might have been good feeding material had 

 the crop been cut earlier. In other words, hay cut after the milky stage of 

 the grain tends more and more to become ill balanced hay, in which the 

 culms and flag rapidly lose their feeding value; whilst if the hay is not cut 

 at least a fortnight earlier than the ripening of the grain there arises to the 

 grower an actual loss of hay. 



In the matter of chemical composition the chief differences between 

 hay cut at full bloom, and later cuts are as follows : — i) Progressive 

 decrease in the percentage of mineral matter and corresponding increase 

 in that of organic matter characterises the gradual ripening off of the crop. 



2) The percentage of proteins shows a tendency to rise during the first 

 three weeks ; thereafter it steadily declines to the ripeness of the grain. 



3) The percentage of fat appears to remain more or less stationary through- 

 out the whole period. 4) The percentage of carbohydrates rises regularly 

 and steadily in the ears thoughout the six weeks. It is balanced by a cor- 

 responding regular decrease in culms and flag. 5) Conversely, whilst the 

 percentage of fibre steadily rises in culms and flag, it equally steadily de- 

 clines in the ears. 



A heavy loss of dry matter was noted in the last two or three weeks of 

 the development of the wheat crop, a loss which attained to 22.9 per cent 

 of the maximum cut in 191 1, and 6.41 per cent, of the maximum cut in 

 1912. This loss, no doubt, must be attributed chiefly to the fall of the 

 exhausted flag, and to a less degree to occasional shaking out of grain and 

 other accidental causes ; to the weakening or suspension of the assimilation 

 function ; and to the occasional leaching action of rain on a dry, porous 

 tissue. In each year, however, we found that the proportional loss of 

 mineral matter was considerably greater than that of organic matter, and 

 we infer therefrom that as maturity advances there must be some sort of 

 migration of the mineral matter towards the root system. 



The loss of weight on drying of a wheat hay crop becomes gradually 

 less and less as the ripening of the grain is approached. It is represented 

 by close on three-quarters of the green weight of the crop in the full bloom 

 stage, and by less than one-quarter of the green weight when the grain is 

 ripe. 



The percentage of moisture retained by wheat hay varies slightly 

 with the conditions under which the hay was dried. Generally speaking, 

 however, early-cut hay retains slightly more moisture than late-cut hay. 

 In round figures, 10 per cent, represents the average moisture content of 

 South Australian wheaten hay. 



When a crop of hay is left to dry in a field, the loss of weight observed 

 is not exclusively the result of the evaporation of water. Intimate chemical 



