324 ELEMENTS OF FARM PRACTICE 



quickly that few weeds have a chance to ripen seed. This 

 crop is usually fed to stock on the farm, and a large part of 

 the fertility removed by the crop is returned in the form 

 of manure. 



Cultivated Crops. — Under cultivated crops we can place 

 corn, potatoes and root crops; as mangels, beets, etc., or 

 any crop planted in rows and cultivated while growing. 

 The cultivation destroys many weeds, conserves moisture 

 and causes the liberation of plant food; in fact, on very rich 

 soil much more plant food is liberated than is used by the 

 crop, and much is washed out. On this account cultivated 

 crops are much more exhaustive of soil fertility than the 

 other classes of crops. The corn and root crops are usually 

 largely fed on the farm; hence most of the fertility removed 

 by them is returned in the manure produced. 



A Good Rotation will usually include one or more crops 

 from each of these three classes. A rotation of wheat, 

 barley and clover, is not a very good rotation, because it 

 includes no cultivated crop to clear the land of weeds and 

 to conserve moisture. A three-year rotation of corn, oats 

 and clover, has one crop from each class and is a very good 

 rotation for many farms. 



A rotation is usually called a three, four, five, six or 

 seven-year rotation, according to the number of crops in- 

 cluded in it. 



The kind of rotation suited to any farm must be worked 

 out to provide the grain, feed and pasturage needed on the 

 farm. It is possible to plan a good rotation for any farm, 

 but it requires considerable knowledge and ability to select 

 the very best one. To properly manage a farm requires 

 as much knowledge, ability and judgment as to properly 

 conduct any other business. 

 Questions: 



1. What is gained by classifying field crops? 



2. What do you understand by grain crops, and what effect 

 do they have on the soil? 



3. What do you understand by grass crops, and what effect do 

 they have on the soil? 



4. What do you understand by cultivated crops, and what 

 effect do they have on the soil? 



Arithmet'.c: 



i. If a bushel of wheat removes 27c. worth of fertility from the 



