330 TALKS ON MANURES. 



depth of 6 inches. But jdu had not only 0.1 per cent, but some- 

 thing like H per cent and upwards in many soils. It is quite true 

 there were many soils from which you could not continuously 

 take crops witliout restoring the potash." 



" In all of which," said the Doctor, " there is nothing new. It 

 does not help us to determine whether potash is or isnot deficient 

 in our soil." 



" That," said I, " can be ascertained only by actual experiment. 

 Put a little hen-manure on a row of com, and on another row a 

 little hen-manure and ashes, and on another row, ashes alone, and 

 leave one row without anyth.ng. On my farm I am satisfied that 

 we need not buy potasli-salts for manure. I do not say they would 

 do no good, for they may do good on land not deficient in availa- 

 ble potash, just as lime will do good on land containing large 

 quantities of lime. But potash is not what my land needs to make 

 it produce maximum crops. It needs available nitrogen, and 

 possibly soluble phosphoric acid." 



The system of farming adopted in this section, is much more 

 likely to impoverish the soil of nitrogen and phosphoric acid than 

 of potash. 



If a soil is deficient in potash, the crop which will first indicate 

 the deficiency, will probably be clover, or beans. Farmers who can 

 grow large crops of red-clover, need not buy potash for manure. 



On farms where grain is largely raised and sold, and where the 

 straw, and corn-stalks, and hay, and the hay fiom clover-seed are 

 retained on the farm, and this strawy manure returned to the land, 

 the soil will become poor from the lack of nitrogen and phos- 

 phoric acid long before there would be any need of an artificial 

 supply of potash. 



On the other hand, if farmers should use fish, or guano, or 

 superphosphate, or nitrate of soda, and sell all the hay, and straw, 

 and potatoes, and root-crops, they could raise, many of our sandy 

 soils would soon become poor in available potash. But even in 

 this case the clover and beans would show the deficiency sooner 

 than wheat or even potatoes. 



" And yet we are told," said the Deacon," that potatoes contain 

 no end of potash." 



"And the same is true," said I, "of root-crops, such as mangel- 

 wurzel, turnips, etc., but the fact has no other significance than 

 this: If you grow potatoes for many years on the same land and 

 manure them with nitrogenous manures, the soil is likely to be 

 speedily impoverished of potash." 



" But suppose," said the Deacon, " that you grow potatoes on the 



