ECONOMIC PLANTS 237 



Root crops in general require a rich, mellow loam, well 

 supplied with potash, lime, and nitrogen. This initial 

 fertility must be supplemented by good drainage and 

 thorough cultivation, or a poor growth will result. 



The root crops are biennials ; that is, the plants store 

 up a rich stock of food in the root the first year, which 

 is used the following year in developing seed stalk 

 and seed. Gathered the first year, the roots form a 

 palatable food both for man and beast. 



The common white, or English, turnip is so rapid a 

 grower that it is often planted following early potatoes 

 or peas, but it does not keep well. It is valuable as a 

 forage crop for sheep. Rutabagas are larger and hardier 

 than the common turnip. They are also used for feed- 

 ing stock. 



Carrots are grown more extensively as a food for 

 horses than as a vegetable for table use, but still few 

 farm gardens are thought complete without at least 

 a row of these roots. The plants are tiny at first and 

 very slow growers, hence their productive cost is com- 

 paratively large. To raise good carrots a light, mellow, 

 deep soil is required, thoroughly free from weeds. 



Parsnips thrive in the same kind of soil that carrots 

 do. Having a deep rootage system, the plant is a deep 

 feeder and is proportionately hard to harvest. This 

 probably prevents its wide use as a stock food, although 

 it has been found to be especially good for milch cows, 

 increasing both the quantity and the quality of the 

 milk. 



The sweet potato requires a long, hot season and a thin, 

 loamy soil, not very rich. The sweet potatoes are laid 

 close together in a bed in early spring, where sprouts 

 and roots soon form. When the former are a few 



