120 MASS. EXPERIMENT STATION BULLETIN 161. 



poor, and each spring additional seed was sown on the surface, but grasses 

 crowded into the bare spaces. In August, 1909, one-half of the field was 

 limed at the rate of 3,000 pounds per acre ^vith slaked lime, the application 

 being made crosswise of the plots, so that every plot was half limed and 

 half unhmed. Alsike clover was again sown, but as in preceding years the 

 crop of 1910 consisted of more grass than clover. 



In 1911 and 1912 corn was grown with good yields on all plots, and in 

 the former year the product of the plots receiving no nitrogen, plot 4 

 and plot 7, was practically equal to that from plots 1 and 2, which received 

 nitrate of soda. Attempts to get a stand of alsike clover were made in 

 both years by sowing the seed in the standing corn late in Jul^^ Germina- 

 tion was good, but the clover was badly winterkilled both years. 



The liming of one-half of the area in 1909 showed no appreciable re- 

 sults on either corn or clover. Therefore in 1913, when it was apparent 

 that the land must again be plowed, another dressing of hydrated lime 

 was applied at the rate of 4,000 pounds per acre. 



Japanese millet was grown in 1913 with fair yields, but the crop was 

 cut short by drought. The growth did not appear to be much influenced 

 by the lime. In the spring of 1914 the plots were seeded with red clover, 

 together with oats as a nurse crop. The oats were removed in July, and 

 there were pronounced effects of the liming observable on all the plots, 

 least on the plots receiving nitrate of soda. 



After the oats were removed the clover on the limed halves of plots 4 

 and 7, receiving no nitrogen, was first to appear above the stubble. The 

 clover on the whole area of plots 1 and 2, receiving nitrate of soda, and 

 on the hmed halves of plots 5, 6 'and 8, receiving sulfate of ammonia, 

 followed about one week later. 



As the season progressed the clover on the limed areas receiving no 

 nitrogen continued to lead all the other plots in size and vigor of growth, 

 and began to bloom several da3's ahead of them. The whole area receiving 

 nitrate of soda looked uniform to the eye, but a little behind the limed 

 area without any nitrogen. The limed areas receiving sulfate of ammonia 

 were hke the areas receiving nitrate of soda. The unlimed areas without 

 nitrogen produced a slow-growing crop which looked scanty in com- 

 parison with the growth on the limed portions of the same plots, but an 

 examination of the ground showed the plants to be as numerous on one 

 area as on the other. The clover on the unhmed areas receiving sulfate 

 of ammonia looked noticeabl^y inferior to all other plots without hme, 

 and the division between the limed and unlimed halves of the plots was 

 clearly marked by vigorous, thrifty plants on the limed areas and small 

 stunted ones on the unhmed. A similar hne of demarkation existed on the 

 plots receiving no nitrogen, but was barely, if at all, noticeable on the 

 plots receiving nitrate of soda. 



The pronounced effect of liming the soil on the growth of clover made 

 it seem possible that a chemical investigation would show some specific 

 effect of the lime on the composition of the plants. Accordingly, samples 



