IRISH POTATOES. 207 



grow potatoes continually upon the same land, using 

 the same measures namely : Three hundred pounds 

 of sulphate of potash, soda, magnesia, superphosphate, 

 with, in one case, 400 pounds of phosphate of ammonia, 

 and in another, 550 pounds of nitrate of soda. The 

 potash and phosphate are in excess of the require- 

 ments of the largest crop grown, so they are an accu- 

 mulation in the soil. The nitrogen is also largely in 

 excess of what the crop takes up, but this does not ac 

 cumulate. Eainfall in inches : 



May to October, five mo. 1881, 13i in., yield 482 bush, per acre. 

 1882, 12 " yield 397 " 

 1883,13 " yield 401 " 

 1884,9, " yield 222 " 



In 1881, the rainfall was better distributed over the 

 season than in 1883. Of course, I do not advocate 

 the use of irrigation unless for the purpose of experi- 

 ment, but merely wish to point out how important an 

 abundant supply of rain is. The rainfall last year was 

 fairly abundant for all other crops, but not for pota- 

 toes." 



In preparing the land, all debris and rubbish should 

 be removed. The plowing should be deep and thor- 

 ough, so there will be no difficulty for the plants to 

 find moisture. Thorough plowing will in a way com- 

 pensate for a lack of nitrogenous fertilizer. This point 

 is not usually accepted, but it seems to be established. 



If the field is to be irrigated (and this should be 

 done where it is possible), it may be thrown up in beds 

 wide enough to hold two rows. The trenches between 

 the rows are to guide the water. During a very wet 

 season, this trench of about nine inches in depth is 

 excellent for drainage, as it keeps the water from 

 standing on the land. By this method the plants are 

 fed from the bottom, and keep sending their roots 

 downward to the stratum of even moisture. 



