1906.] PUBLIC DOCUMENT — No. 33. 23 



II. — The Relative Value of Muriate and High-grade 

 Sulfate of Potash. (Field B.) 



This experiment, which has been in progress since 1892, 

 was designed to test the relative vahie of muriate and high- 

 grade sulfate of potash used continuously upon the same 

 soil. These salts since 1900 have been annually applied at 

 the rate of 250 pounds each per acre. There are ten plots 

 in the field, each containing about Vr of a" acre. Five of 

 these receive muriate of potash, and these plots alternate 

 with the same number of plots which are yearly manured 

 with sulfate of potash. Each plot in the field is manured 

 annually with fine-ground bone at the rate of 600 pounds 

 per acre. The crops grown in this field this year have in- 

 cluded soy beans, celery, asparagus, rhubarb, raspberries, 

 blackberries and clovers. The yields of the three crops, 

 asparagus, raspberries and blackberries, have been small, 

 and the differences in the results on the diflerent potash 

 salts did not appear to be sufficient to be of much signifi- 

 cance. There was, however, a very marked difference in 

 the extent to which the blackberry bushes on the two potash 

 salts winter-killed. Those on the plot which has annually 

 received an application of sulfate of potash were killed back 

 much less seriously than the bushes on the muriate of potash 

 plot. There was a marked difterence in the growth of the 

 celery on the two potash salts, that on the muriate being 

 much better than that on the sulfate. This fact is reported 

 at this time without comment, as it seems to the writer 

 probable that some accidental cause, not connected directly 

 with the system of manuring, unfavorably influenced the 

 growth on the poorer plot. Six plots in the field have been 

 in clover during the past year. All of these plots were 

 sown to clover in the late summer of 1904, one pair of plots 

 each (muriate and sulfate) with Alsike, Medium and Mam- 

 moth clovers. The clover on all plots germinated well, but 

 early showed a very unhealthy condition on the plots occu- 

 pied both by the Medium and Mammoth red clovers. The 

 young plants early turned yellow and gi-adually disappeared. 

 So poor was the condition of ,these varieties of clover this 



