1918.1 PUBLIC DOCUMENT — No. 31. 29o 



North Corn Acre. 



For twenty-seven years there have been under comparison on 

 this field two fertihzer mixtures. In one, the percentage of 

 potash is high and that of phosphoric acid low; in the other 

 (which represents about the average analysis of the commercial 

 corn fertilizers offered on our markets) the percentage of phos- 

 phoric acid is high and that of potash low. For twenty-one 

 years the rotation on this field has been two years grass and 

 two years corn. The seed (a mixture of timothy, red top and 

 clover) has usually been sown in the standing corn the latter 

 part of July. The soil has not had the benefit of a green 

 manure crop nor an application of manure during the twenty- 

 six years of the experiment. The turf and corn stubble which 

 have been plowed under have been the only source of humus. 



This year potash was omitted from the mixture containing 

 the lower amount and cut down in the mixture containing the 

 larger amount, so that plots 1 and 3 this year received no 

 potash, and plots 2 and 4 received potash at the rate of 160 

 pounds of muriate per acre instead of 250 pounds per acre as 

 in previous years. 



The crop this year was mixed grass and clover. The results 

 obtained are in accordance with those of previous years, viz., 

 the combination containing the larger per cent, of potash gives 

 the larger yield of hay. 



North Soil Test. 



This is the twenty-eighth year of this experiment, which has 

 for its object a study of the effect of the continued use of 

 fertilizers containing single plant-food elements and different 

 combinations of plant-food elements for different crops; also 

 the effect of lime added to each fertilizer under comparison. 



The west half of each plot received an application of hydrated 

 lime at the rate of 1 ton per acre in 1899 and again in 1904, and 

 at the rate of one-half ton per acre in 1907. In 1916, 2 tons 

 per acre of ground limestone were applied. 



The crop this year was cabbages. The following table gives 

 the yields per acre and the fertilizer schedule: — 



