MANUKES FOK SPECIAL CROPS. 293 



yard-manure, consists principally in this : The rich manure con- 

 tains more nitrogen and phosphoric acid than the ordinary stable- 

 manure and it is in a more available condition. 



To convert common manure into rich manure, therefore, we must 

 add nitrogen and phosphoric acid. In other words, we must use 

 Peruvian guano, or nitrate of soda and superphosphate, or bone- 

 dust, or same other substance that will furnish available nitrogen 

 and phosphoric acid. 



Or it may well be, where stable-manure can be bought for $1.00 

 per two-horse load, that it will be cheaper to use it in larger quan- 

 tity rather than to try to make it rich. In this case, however, we 

 must endeavor to follow the cabbage by some crop that has the 

 power of taking up the large quantity of nitrogen and other plant- 

 food that will be left in the soil. 



The cabbage needs a large supply of nitrogen in the soil, but re- 

 moves comparatively little of it. We see that when 75 tons of 

 manure is used, a crop of 50 tons of cabbage takes out of the soil 

 less than 30 per cent of the nitrogen. And yet, if you plant cab- 

 bage on this land, the next year, without manure, you would get 

 a small crop. 



" It cannot be for want of nitrogen," said the Deacon. 



" Yes it can," said I. " The cabbage, especially the early kinds, 

 must have in the soil a much larger quantity of available nitrogen 

 than the plants can use." 



I do not mean by this that a large crop of cabbage could be 

 raised, year after year, if furnished only with a large supply of avail- 

 able nitrogen. In such a case, the soil would soon lack the necessary 

 inorganic ingredients. But, what I mean, is this : \Hiere land has 

 been heavily manured for some years, we could often raise a good 

 crop of cabbage by a liberal dressing of available nitrogen, and still 

 more frequently, if nitrogen and phosphoric acid were both used. 



You may use what would be considered an excessive quantity 

 of ordinary stable-manure, and grow a large crop of cabbage ; but 

 still, if you plant cabbage the next year, without manure of any 

 kind, you will get a small crop ; but dress it with a manure con- 

 taining the necessary amount of nitrogen, and you will, so far as 

 the supply of plant-food is concerned, be likely to get a good crop. 



In such circumstances, I think an application of 800 Ibs. of ni- 

 trate of soda per acre, costing, say $32, would be likely to afford a 

 very handsome profit. 



For lettuce, in addition to well prepared rich land, I should sow 

 3 Ibs. of superphosphate to each square rod, scattered in the rows 



