TWENTY-SIXTH CHAPTER 



MANURES FOR FARM AND MARKET 

 GARDENS. 



TN THE heavy dressings of compost which the 

 professional market gardeners and truckers give 

 to their lands year after year, and for an indefinite 

 period, immense quantities of the mineral plant 

 foods are put into the soil, most of which are left to 

 accumulate to an extent that few people would 

 imagine. 



If the average yearly application amounts to fifty 



tons per acre (an estimate that can hardly be con- 



mdered too high, as many gardeners use much more 



on their highly cropped lands) each 



Accumulation acre receives in the 1,000 tons put on 



of Mineral -, • ^ , • j ^ i 



Plant Foods. during a twenty year period not less 



than from 8,000 to 10,000 pounds of 

 potash, and from 4,000 to 5,000 pounds of phos- 

 phoric acid. Only a small part of these minerals is 

 removed again in the crops, even where large yields 

 are obtained. Twenty onion crops of 600 bushels 

 each, or their equivalent in other succulent market 

 and farm garden crops, consume less than 1,000 



