Vermont Agricultural Report. 79 



tion of Connecticut, between the years 1890 and 1900. As the 

 writer had a part in conducting these experiments he is famiUar 

 with the work and feels free to make use of the results. In a 

 series of experiments on an old grass field the crop on plots 

 where no nitrogen was used, but mineral fertilizers were freely 

 used, the nitrogen in the grasses (free from clover) was 7.2% 

 in the dry matter, where 25 lbs. of nitrogen per acre was used 

 there was 7.75% of protein in the dry matter, where 50 lbs. of 

 nitrogen was used the protein was increased to 8.5% and where 

 75 lbs. of nitrogen was used the protein equaled 9.4%. It will 

 be understood that all of the fertilized plots were supplied with 

 mineral fertilizers (phosphoric acid and nitrogen) so that the 

 varying factor was the nitrogen. 



Similar experiments were made on pure species of grasses 

 but on much smaller plots. These experiments were carried 

 through quite a period of years. Five different grasses were 

 studied and the percentages of protein in the dry food substance 

 of the plants, from plots where mineral fertilizer only was used 

 ranged between 6.69 percent of nitrogen and 8.16 percent; 

 while where the largest quantities of nitrogen (75 lbs. per acre) 

 were used the protein ranged from 9.07 percent to 12.63 percent. 

 On the average, the five distinct kinds of grasses from the min- 

 eral plots (without nitrogen) gave 7.55 percent of nitrogen in 

 the dry matter of the crop, while the same five gave an average 

 of 1 1. 1 2 percent of protein in the dry matter of the crop, taken 

 from plots where 75 lbs. per acre of nitrogen was used as fer- 

 tilizer. 



The experiments indicate the possibility of increasing the 

 quantities of protein produced upon the farm. When the feed- 

 ing stuffs are high in price, it becomes important that the farmer 

 should adopt every means to increase the supply grown. The 

 supply of carbohydrates produced on the farm is usually suffi- 

 cient for the needs of the herd, but the supply of protein is gen- 

 erally deficient. We can increase the protein by growing more 

 of the clovers and other legumes, and we can also increase the 

 quantity produced by the judicious lise of manures and nitro- 

 genous fertilizers on the grass crop. 



What has been said about the use of nitrogenous fertilizers 

 on grasses does not apply to their use on clovers and other 

 legumes. Many experiments on this class of crops indicate that 

 the percentages of protein in the plants are very little influenced 

 by the use of nitrogen in the fertilizer. 



SUMMARY. 



In summarizing, we would call attention especially to the 

 following points: 



