1901.] PUBLIC DOCUMENT — No. 33. 97 



have with very few exceptions done much the best on the 

 sulfate of potash; while the yield of corn, grasses, oats, 

 barley, vetches and sugar beets has been equally good on 

 the muriate. The quality of the crops of potatoes and sugar 

 beets produced by the sulfate of potash plots has been dis- 

 tinctly better than that of the crops produced on muriate of 

 potash. Taking all the crops except the clovers into con- 

 sideration, if we represent the efficiency of the high-grade 

 sulfate of potash by the number 100, that of the muriate 

 of potash is 98.1. Taking into account only those crops 

 showing the preference for the sulfate of potash, and repre- 

 senting the efficiency of that salt by the num])er 100, the 

 efficiency of the muriate of potash is 88.6. The present 

 difference in price between the two salts is only about $5 

 per ton. The conclusion, therefore, appears to be warranted, 

 that, under conditions similar to those prevailing in this ex- 

 periment, the selection of the sulfate rather than the muriate 

 is wise. 



Further, in estimating the significance of our results, it 

 should be kept in mind that the continued use of muriate of 

 potash causes the loss with drainage waters of large amounts 

 of lime. In the experiments on which the conclusions above 

 stated are based we have yearly supplied a large amount of 

 lime in the bone meal used, and accordingly the productive- 

 ness of the field even where the muriate of potash has been 

 used has been fairly well maintained. Results on other fields 

 on our farm indicate that when not used in connection with 

 lime the muriate of potash stands much lower than the sulfate 

 within comparatively few years. Whoever under ordinary 

 conditions uses muriate of potash continuously, must sooner 

 or later lime his land ; and this is equally true, whether the 

 farmer purchases muriate of potash and applies it by itself 

 or in a home-made mixture, or if it is the source of the pot- 

 ash in a mixed fertilizer which he purchases. In deciding 

 upon the purchase of any of the ordinary fertilizers upon 

 the market, it is important to inquire whether the potash 

 found in the fertilizer is present in the form of muriate or 

 in the form of sulfate ; and, other things being equal, the 

 fertilizer containing its potash in the form of sulfate should 

 be selected, unless the soil on which the material is to be 



