246 MASS. EXPERIMENT STATION BULLETIN 194. 



Summary. 



A fertilizer experiment with asparagus was conducted for a period of 

 nine years in the town of Concord on coarse, sandy loam, which was 

 typical of the soils used for asparagus culture. Seven crops of young 

 stalks were produced during the experiment, and the jaeld steadily in- 

 creased each year until the sixth, which was the crop of maximum size 

 on nearly every plot. 



Of the chemical fertilizers used, a mixture of 466 pounds nitrate of 

 soda, 300 pounds acid phosphate, and 260 pounds muriate of potash per 

 acre produced the best yields. 



Manure at the rate of 10 tons per acre produced nearly as good results 

 as the chemicals, while combinations of manure with chemicals and with ni- 

 trate of soda were no better than manure or chemicals used separately. 



There was no apparent cumulative effect produced by the annual 

 use of manure, and the asparagus tops harrowed into the soil each year 

 seemed to supply sufficient organic matter for the efficient use of chemicals. 



When nitrate of soda was added to manure it was most efficient when 

 applied in two portions, one in the spring and one in the summer. Nitrate 

 of soda applied with acid phosphate and muriate of potash was slightly 

 more effective when applied in summer in four years out of seven. 



Muriate of potash was, on the whole, the most satisfactory potash 

 compound used. 



Following the second crop an attack of rust from an adjacent field 

 swept over about half of the plots. The plots nearest the source of the 

 attack were reduced in yield the next season nearly 20 per cent, and were 

 permanently injured. The remainder of the plots apparently recovered 

 before the maximum yield of the sixth crop. 



The sixth or maximum crop averaged about 80 per cent greater than 

 the second crop, which was the first full cutting. The seventh crop was 

 less than 10 per cent smaller than the maximum sixth crop. 



