The Bulletin 51 



the yield, but when used with the two together this does not seem to be 

 true, although on an average there is practically but little increase in 

 the yields of the two crops. The decided benefit of applications of 

 nitrogen to this soil certainly justifies the conclusion that in order to 

 produce large crops pemianently on this type of soil that nitrogen in 

 some available form must be added. Such a conclusion is borne out by 

 the chemical analysis of this soil which shows that it is high in phos- 

 phoric acid but very low in content of nitrogen. Although the amount 

 of potash present is fairly high yet the results indicate that next to 

 nitrogen Avith corn and cotton this is the plant food constituent stand- 

 ing next to nitrogen as a limiting factor in crop yields for the soil in its 

 present condition. The surface 6% inches of this soil contains enough 

 phosphoric acid for about 135 one hundred bushel corn crops; potash for 

 90 crops; and only enough nitrogen for less than 8 crops of corn of this 

 size. 



TREATMENT AND RESULTS ON MONROE FIELD. 



The soil of this field is typical Alamance silt loam which has been 

 derived from shales. The field was established in 1911, but the first 

 crop which was corn was lost. The plats are of the same size and 

 dimensions as Charlotte Pield No. 2. The rotation that has been used 

 on the field is as follows : 



First Year — Corn. 



Second Year — Oats and vetch, with cowpeas. 



Third Year — Cotton, with crimson clover. 



As the cowpeas and crimson clover of the rotation have been grown 

 for soil improvement they have in all cases been plowed into the soil. 

 The cowpeas, sown broadcast in the summer of 1913 over the plats 

 after the oats and vetch were removed for hay, made a fairly satisfac- 

 tory growth, the best growth having been produced on plat 10. On this 

 plat the vines were on September 9 of a very dark green color and were 

 on an average about thirty inches high. On the other plat (No. 1) 

 receiving lime, the Adnes were about twenty inches high and on all the 

 other plats, except for those receiving no fertilizers, the vines were of a 

 yellowish color and varied in height from twelve to fourteen inches. 

 The plat treatment with results of yields of corn, cotton, and oat-and- 

 vetch hay are recorded in the following table: 



