30 FERTILIZERS. 



rarely found in the market for sale. The ashes analyze, 

 on an average, 19.5 potash, and 9.2 phosphoric acid ; nearly 

 all of each in a soluble condition. They are usually sold at 

 twelve dollars per ton, while the potash alone makes them 

 worth nearly twice as much. The strong potash attracts 

 moisture, of which there is usually 15 per cent present. 



THE NEED AND USES OF POTASH IN AGRICULTURE. 



Potash, as we have already stated, is one of the three 

 essentials for plant-growth. By this I do not mean to 

 advise that it should always be applied to every crop ; for 

 there are soils already so over-rich in potash and soda, that, 

 except the wild sage and a few other shrubs, nothing will 

 grow on them. This is the characteristic of what was 

 known in our geographies as "the great American 

 desert." The trouble was, it was over-rich in soda ; but* 

 when the Mormons at Utah diluted these with water from 

 the mountains, the " desert " disappeared, and in its place 

 stands a fertile land. Some of the soils of New Eng- 

 land, even, will bear cropping for a few years without any 

 application of potash : they may have good natural stores 

 of it in plant-food form, or the potash may have accumu- 

 lated in the soil through years of heavy manuring. The 

 natural growth on any soil is a good indication as to 

 whether or not our farms are rich in potash. If they yield 

 a thrifty growth of potash-bearing trees or plants, such as 

 beech, maple, oak, walnut, or elm among trees, or tansy or 

 purslane among plants, it is a fair inference that it is nat- 

 urally rich in potash in food condition. Soils that have 

 been manured for years with either barn manures or sea 

 manures, have large stores of accumulated potash ; and, 

 when using commercial fertilizers on such soils, this fact 

 might economically be borne in mind. As has been shown 

 before, about all soils derived from granitic rock are enor- 



