42 N. H. AGE. EXPERIMENT STATION. [Bulletin 142 



EXPERIMENTS OF 1907 AND 1908. 



In 1907 and 1908 further studies of the availability of the soil 

 potash were made in connection with some fertilizer experiments 

 on grass conducted by the Agronomy Department. These plot 

 experiments afforded opportunities for securing crops from soil 

 fertilized liberally with potash salts, and from soil with no fer- 

 tilizer ; also from soil to which had been added nitrogen and phos- 

 phoric acid without potash. The plats were so arranged that 

 every fertilized one had an unmanured plat immediately beside 

 it for comparison. The only treatment which noticeably af- 

 fected the yield was the application of nitrogen in the forms 

 of nitrate of soda and sulfate of ammonia. 



At the time of cutting, samples of the crop were gathered, 

 dried and subsequently analyzed. The yields of the different 

 plats were obtained from the Agronomy Department. 



In 1907 especial attention was paid only to the plats receiv- 

 ing potash alone, nitrogen alone, and the unfertilized plats ad- 

 joining them. Considerable alsike clover was mixed with the 

 grasses this year, but was not uniform over all the plats. Sep- 

 arate analyses were therefore made of the clover and grasses 

 from each plat, which required two samples of the crop from 

 every one of the plats studied. 



The application of potash had no perceptible effect on the 

 yield of crop nor on the percentage of potash in either grasses 

 or clover. Neither was the clover any more abundant in pro- 

 portion to grasses on the potash plats when compared with the 

 adjoining unfertilized plats. 



The application of nitrogen made a marked increase in yield, 

 and the stimulation was greater on the grasses than on the clover, 

 causing the latter to appear less prominent on the nitrogen plats 

 than elsewhere in the field. 



Although there was a notably increased demand for potash 

 on the nitrogen plats, due to the increased crop, there was no 

 marked falling off in the percentage of potash in either grasses 

 or clover, when compared with the corresponding unfertilized 

 crop. 



