1903.] PUBLIC DOCUMENT — No. 33. 117 



The total yield on the two plots is nearly the same. The 

 crop on the sulfate of potash averaged of larger size than 

 that on the muriate, but there was most decay on the sulfate. 

 Whether this fact has any special significance it is impossible 

 to say, without repeating the experiment. 



4. Onions (^Sulfate v. Muriate of Potash) . 

 The onions grown in this experiment occupied two plots, 

 19 and 20. The crop of last year on these plots was cab- 

 bages, with winter rye as a cover crop, sown before the 

 cabbages were harvested. The variety of onions was Dan- 

 vers Yellow Globe. The seed was obtained from Gregory 

 & Son, Marblehead, 1901 ; it was therefore one year old. 

 It was sown in the thoroughly prepared soil in rows 14 

 inches apart on April 24. Growth throughout the earlier 

 part of the season was very slow, and the final crop Avas 

 poor. The fertilizers usually emploj^ed on this series of 

 plots were supplemented by the application of a combined 

 form of quick-lime and nitrate of soda, known as " niter- 

 lime," ^ at the rate of 175 pounds per acre. This was 

 applied on July 12 and cultivated in. Soon after its appli- 

 cation growth became much more rapid ; but whether this 

 was due chiefly to the somewhat more seasonable weather 

 which then prevailed, or to the application of niterlime, we 

 cannot feel certain. The onions were pulled on September 

 23, those on the sulfate of potash being more nearly mature 

 than those on the other plot. The yield per acre, in bushels 

 of sound onions and pounds of scaliions, is shown in the 

 table : — 



Muriate v. High-grade Srdfate of Potash. — Onions, Yield per 



Acre. 



Muriate of 

 Potiish. 



High-grade 



Sulfate 

 of Potash. 



OnioDs (bushels), . 

 Scaliions (pounds), 



no 



10,811 



8,828 



» Niterlime contains: nitrogen, about 10.5 per cent.; and lime, about 20 per cent. 



