EXPERIMENTS WITH NITROGEN FERTILIZERS 13 



Hay 



Several crops of hay were produced in these experiments, but not in system- 

 atic rotation with other crops. Numerous efforts to secure a crop of clover are 

 mentioned in the records of the field but repeatedly the stand was so reduced by 

 winterkilling that the remaining plants were plowed under in the spring and an 

 annual crop was substituted. The first hay crop reported was in 1899. Red 

 clover had been sown after a crop of oats late in the previous August. The field 

 had been limed before the oats were sown and the catch of clover was successful. 

 The winter of 1898-99, however, injured it somewhat; April and May were un- 

 usually dry and the first crop was small. The season was favorable for the 

 second cutting, which was made August 21. Considerable grass had appeared 

 in all plots. Both crops are combined in the table. 



Although limed the previous year, the ammonia plots were inferior to the 

 other nitrogen plots. Manure produced the best crop. 



The years 1907, 1908, 1909, and 1910 were devoted to attempts to grow 

 clover. The field had been limed at the rate of one ton per acre in 1905. Peas 

 and oats in that j^ear and corn in 1906 had been the preceding crops. Alsike 

 clover was sown in the corn. In April, 1907, additional alsike clover seed was 

 sown. Two cuttings were made, July 17 and October 7, the second of which was 

 small. The field was carried over to the next season, when in May, 1908, the rec- 

 ords state that grasses were replacing clover and at the time of cutting, July 1, 

 the plots contained mostly timothy and very little clover. 



After the hay was removed, the field was plowed and harrowed. Alsike 

 clover was sown on August 20. Late in November, there was a fairly uniform 

 but thin stand of clover. 



The crop of 1909 consisted principally of alsike clover, except on Plots 5, 6, 

 and 8, where by actual weights the crops were half weeds, mainly sorrel. The 

 field was plowed after the removal of the hay and on August 7 alsike clover was 

 again sown. Previous to the seeding, an application of agricultural lime had been 

 made to the east half of the field at the rate of 2500 pounds per acre. 



In April, 1910, all plots had a good stand, but there was considerable grass 

 mixed with the clover. As the season advanced timothy overtopped the clover. 

 The hay was harvested on July 9. 



These four seasons were notable for severe droughts during the growing 

 season and a scanty rainfall for each year. The nitrate plots bore the heaviest 

 crops in 1907; organic nitrogen gave a little the best yields in 1908; the two kinds 

 were about equal in 1909; and in 1910, the ammonia plots responded to lime by 

 practically equaling the other nitrogen plots in yields. 



The crop of 1915 was seeded in the spring of 1914 with oats as a nurse crop. 

 A mixture of timothy, red top, and red clover was used. After the removal of 

 the oats, the clover predominated over the grasses, especially on the limed 

 halves of the plots. The crop was not cut in the fall but permitted to remain as 

 a protection to the roots. In the spring of 1915, the plots had passed the winter 

 in excellent condition. Clover predominated except on the unlimed halves of 

 ammonia Plots 5, 6, and 8, where red top constituted about half the crop. 



The first cutting was made June 18, and the second on August 20. The 

 season had been unusually dry in May, normal in June, and abundantly moist 

 in July and August. Organic nitrogen and ammonia plots averaged nearly alike 

 in productiveness and exceeded the average of the two nitrate plots. 



