140 MAINE AGRICULTURAL EXPERIMENT STATION. I904. 



able. It is a part of good farming to make this plant food 

 available and in no way can this be as effectively brought about 

 as by thorough preparation of the soil before planting and, in 

 the case of hoed crops, by thorough cultivation during the 

 growing season. The plant food in soil is, in general, available 

 to growing plants in proportion to the smallness of the particles 

 of soil. Too strong emphasis cannot be put upon the 

 proper plowing, harrowing and other mechanical preparations 

 of the soil and in the case of hoed crops, constant thorough cul- 

 tivation during the growing season. 



While recognizing the danger that may come from a blind fol- 

 lowing of definite directions for general practice, the following 

 quite specific suggestions are made for a few general crops. It 

 is to be borne in mind in using these formulas that they are only 

 suggestive and that different conditions of soil make such differ- 

 ent treatment essential that a formula which may prove success- 

 ful on one farm may not be equally so on another. 



In the suggested formulas the composition as given in the 

 table on page 135 is assumed for the chemicals. The analysis 

 of the Portland Rendering Companies screened tankage as found 

 in 1904 and given in the table is used for the composition of 

 tankage. 



FORMULAS EOR POTATOES. 



In 1904 there were licensed in Maine rather more than 40 

 brands of fertilizers in which the word potato entered into the 

 name. It is very doubtful if in more than one-third of these 

 brands there was any reason, other than the attraction of the 

 name, to call them potato fertilizers. More than half of them 

 have the composition of general purpose goods with about 3 per 

 cent nitrogen, 8 per cent available phosphoric acid, and 3 per 

 cent potash. Those that would be taken seriously as intended 

 for potatoes carry less phosphoric acid and relatively more 

 nitrogen and considerably more potash. Nearly all of the com- 

 panies put out a brand with the word potato in its name that 

 carries about 3.5 per cent nitrogen, 6 per cent available phos- 

 phoric acid and 8 or 10 per cent potash. 



A crop of 300 bushels of potatoes will remove from the soil 

 about 55 pounds of nitrogen, 25 pounds phosphoric acid and 85 

 pounds of potash. It is quite a common practice in Aroostook 



