18 INTENSIVE FARMING 



tatoes or early cabbage, the onions, radishes, 

 and lettuce going to market in a few weeks, 

 thus clearing the ground so as to give the po- 

 tatoes or cabbage the whole area. This is 

 followed by planting summer cabbage between 

 the potatoes before they are dug and sowing 

 fall beets, turnips, or beans between the early 

 cabbage before it is ready to harvest. By 

 double cropping and a succession of crops up- 

 on the same soil it is practicable to grow four 

 or more crops on the same area in a single 

 season. 



Following upon this intensive utilization of 

 the land during the open growing season comes 

 a system in which protective devices are used 

 to lengthen the season and to insure crops when 

 they could not be safely grown in the open. For 

 this purpose hot beds, cold frames, and 

 " muslins " or muslin covered frames are em- 

 ployed. Both double cropping and a succes- 

 sion of crops is resorted to in frame farming. 

 The next step in the scale brings the crop within 

 the artificially heated glass structure, where the 

 grower has practically all the factors of plant 

 growth, save that of sunlight, under his con- 

 trol. In the modern forcing house soil, heat, 

 and moisture are absolutely under the manage- 

 ment of the gardener, but he cannot make the 



