No. 4.] FIELD CROPS. 323 



which the soil can be depended upon to hold, so that the 

 productive capacity of the land in future years may be in- 

 creased. It will be noticed that the surplus was supplied in 

 cheap raw materials, such as manure, South Carolina rock 

 and muriate of potash. - 



For the silage corn there was also an excess of nitrogen ; 

 but this was in the form of the slow-acting organic constitu- 

 ents of manure ; and, as the land was to be seeded in the 

 corn, I considered it desirable to have a considerable surplus 

 of nitrogen for the grass. 



I believe that some have thought that, while the corn crop 

 in my experiments has almost invariably been largely in- 

 creased by the use of muriate of potash at first, such effect 

 would not long be found to follow its use. I have myself 

 been surprised at the extent of its influence, even after six 

 years' continuous cropping. 



In soil test experiments in Amherst in the sixth year 

 upon the same ground the average increase per acre in 

 shelled corn due to the use of potash was 29 bushels ; there 

 was no average increase due to nitrogen, and less than 2 

 bushels due to phosphoric acid. 



In similar experiments in Hadley in the sixth year the 

 increases were : for potash, 23 bushels ; for nitrogen, 9 

 bushels ; for phosphoric acid there was no increase. 



In Concord in similar work in the sixth year upon the 

 same ground the increases were : for potash, 22 bushels ; 

 for nitrogen, 3 bushels ; for phosphoric acid, 2 bushels. 



In view of these results, as well as the fine crops secured 

 upon the college farm, by liberal potash manuring, it docs 

 not seem possible to doubt that there should be less phos- 

 phate and more potash in fertilizers for this crop. 



Planting and Culture. 

 Experiments for comparison of hill and drill planting in 

 Amherst have been generally favorable to the drill system; 

 in other places the results have been various. For the silo, 

 corn should undoubtedly be planted in drills ; where grain 

 is the object, there does not appear to be much choice. 

 The labor is rather less under the hill system. Whether 



