37 



high-grade sulfate of potash at the rate of about 125 to 150 pounds, 

 will give results highly satisfactory both in the product of corn and 

 in the product of hay rich in clover on seeding. 



That corn can be profitably produced on fertilizers alone is fortu- 

 nately thoroughly established by experiments in progress in the experi- 

 ment station. A field containing an acre of land was laid out for an 

 experiment in raising corn on fertilizers in 1891. Since that date ten 

 corn crops have been produced on one half of the field and eight upon 

 the other. The land has been seeded three times, and each time has 

 remained in mixed grass and clover two years. Two combinations of 

 fertilizers have been under comparison: one of these has given an 

 average yield of 56 bushels of shelled grain and 4,484 pounds of stover 

 per acre; the other, 52^ bushels of shelled grain and 4,615 pounds of 

 stover per acre. The hay crops have averaged on the first system of 

 manuring 3,557 pounds per acre for the first crop and 993 pounds for 

 the second. Under the other system of manuring, the average yields 

 have been 3,696 pounds for the first crop and 1,152 for the second crop. 

 It will be seen, therefore, that the fertilizer combination which gave the 

 larger corn crop proved inferior to the other for the production of hay. 

 The principal differences between the two systems are as follows: the 

 first combination of fertilizer materials furnished materially less potash 

 and more phosphoric acid and slightly less nitrogen than the second. 

 The second combination was made very rich in potash and light in 

 phosphoric acid. The superiority of the combination richer in potash 

 for the hay crop is without doubt connected with the fact that the 

 supply of potash was so much more liberal. The writer believes, in 

 the light of his extensive experience, that the amount of phosphoric 

 acid in the second combination might with distinct advantage have 

 been increased. It has been noticed especially that the corn crop 

 starts very slowly on the combination of fertilizers containing so small 

 an amoimt of phosphoric acid. It is now very generally understood 

 that a rather free use of highly available phosphates goes a long way 

 in insuring the rapid progress of the crop. It is the writer's belief that 

 the proportion of phosphoric acid usually found in special corn fer- 

 tilizers is needlessly high, and that the proportion of potash in such 

 fertilizers is often much too low. He is equally convinced that some- 

 what more phosphoric acid than he formerly loelieved to be essential 

 will prove useful. In the comparisons in question, phosphoric acid is 

 contained in the fertilizers used under the first system at the rate of 

 180 pounds per acre, actual potash at the rate of 77 pounds; in the 

 second combination (richer in potash), phosphoric acid was applied 

 at the rate of only 50 pounds per acre, actual potash at the rate of 125 

 pounds. The writer is now inclined to believe that an increase in the 

 amount of phosphoric acid to a total of about 100 pounds per acre 

 would prove useful. This he believes may wisely be supplied in the 

 form of basic slag meal. The best source of potash, in the writer's opin- 

 ion, is the high-grade or low-grade sulfate. It is true the muriate might 

 give an equally good crop of corn, but on many soils and in many 

 seasons at least, the clover in the succeeding hay crop will make a less 

 satisfactory showdng than where one of the sulfates is used. He is 

 inclined to recommend, therefore, a fertilizer application for corn at 

 the following rates per acre : — 



Pounds. 

 Nitrate of soda, ......... 100 



Sulfate of ammonia, . 

 Tankage, or dry ground fish, 

 Basic slag meal, 

 High-grade sulfate of potash, 



100 



200 



500 



200 to 250 



