28 GARDEN FARMING 



the soil is practiced but once each year. In truck-crop work, how- 

 ever, it becomes necessary to stir the soil deeply several times. 

 With light sandy soils this deep stirring can be done very early in 

 the season, and little heed need be given to its moisture content ; 

 but with heavy, retentive soils it is of the utmost importance that 

 deep cultivation be done only when the soil is in good mechanical 

 condition. A soil is in good mechanical condition if, after being 

 gently compacted between the fingers and the palm of the hand, 

 it gradually falls apart when the pressure is released. If it is 

 moist enough so that it retains its form and the soil particles 

 seem to be broken down, it is too wet to work ; and if worked 

 in this condition, it will require several years of the most care- 

 ful management to restore it to its proper physical texture. 

 Upon clay soils or heavy clay loams it is, therefore, of the 

 utmost importance that the work of plowing and harrowing be 

 done when the soil is in proper mechanical condition. Not only 

 is the physical structure of the soil destroyed, but bad treat- 

 ment tends to lock up the available plant food and render the 

 soil unproductive. 



For truck farming and market gardening, deep plowing should 

 be practiced. If new land is to be brought under cultivation for 

 market-garden purposes, it should be broken up to the depth of 

 about 8 inches and a heavy coating of manure incorporated 

 with the surface layer of the soil. After the soil has been in cul- 

 tivation for one or two years, the process of deepening the seed 

 bed should then begin. This operation should not be a radical 

 one, but the seed bed should be deepened slightly each year ; that 

 is, by plowing 9 inches deep the second year, 10 inches deep the 

 third year, and so on, until 12 or 14 inches of the surface soil 

 have been brought under cultivation and reduced to the proper 

 state of a seed bed. This will necessitate the use not only of the 

 turning plow but of a subsoil plow as well. It does not neces- 

 sarily follow that the whole 1 2 or 14 inches of soil which is used 

 as a seed bed should be brought to the surface. It is sufficient 

 if the first 8 or 10 inches of the soil be turned over. This depth 

 will insure covering all organic matter sufficiently and will admit 

 the air to the lower layers, if they are broken up by the use of 



