138 AGRICULTURE OF MAINE. 



pound of nitrogen as any of the others. Potash can be secured 

 in the form of kainit. muriate and sulphate of potash — the 

 last two being the preferred as kainit is a low grade potash 

 fertilizer. Phosphoric acid comes in the form of acid phosphate, 

 phosphate rock, bone meal, basic slag and from other sources. 

 Raw rock should not be used except where there is plenty of 

 humus. The most common phosphate fertilizers used by gar- 

 deners are acid phosphate and steamed bone meal, because 

 they are more readily available than the others. These fertil- 

 izers can be bought ready mixed in any proportion desired, 

 but the plant food can be secured at less cost per pound by 

 buying the dififerent kinds separately and mixing them at 

 home. The dealers or mixers charge from five to eight dollars 

 per ton for mixing, and, besides, the farmers have to pay 

 freight on worthless filler. For most garden crops a high 

 grade fertilizer is used and some gardeners use practically the 

 same kind for all crops. This is not a good practice for differ- 

 ent classes of crops require different amounts and proportion of 

 plant food. For example, foliage crops like cabbage require 

 relatively larger quantities of nitrogen than root or seed crops. 

 Root crops such as potatoes, turnips, parsnips, beets, etc.. re- 

 quire more potash and seed crops relatively more phosphorous 

 than the other two classes. 



Many gardeners hesitate to mix their own fertilizer because 

 they think there are scientific mysteries involved. It is very 

 simple when once explained. Take a formula 8-4-8 and see 

 what it means. It means simply that each one hundred pounds 

 of the mixture contains eight pounds of phosphoric acid, four 

 pounds of nitrogen and eight pounds of potash. In a ton there 

 would be twenty times this much or one hundred and sixty 

 pounds of phosphoric acid, eighty pounds of nitrogen and one 

 hundred and sixty pounds of potash. To secure one hundred 

 and sixty pounds of phosphate from acid phosphate containing 

 sixteen per cent phosphorous, we would need one thousand 

 pounds. To find the amount needed, divide the amount of each 

 element requirefl by the per cent in the source usc<l, and multi- 

 ply by 100. To get eighty ]X)unds of nitrogen from nitrate of 

 soda which contains fifteen per cent nitrogen, divide eighty 

 pounds by fifteen and multiply by one hundred. This would 



