FARM CROPS II 



own which experience has shown to answer 

 best, but there is one named the Norfolk 

 or four-course rotation, of which all others may 

 be said to be variations. This rotation is as 

 follows : — First year — an autumn-sown corn 

 crop ; second year — a root crop ; third year — a 

 spring-sown corn crop ; fourth year — a forage 

 crop ; the rotation is of course repeated in 

 this order every four years. 



Next as to the reasons which have fixed 

 this rotation in the order it is. The wheat is 

 grown after the clover because it is a crop that 

 flourishes best when it has a plentiful supply of 

 a certain kind of plant-food, termed nitrates. 

 Now, the forage crop that usually precedes 

 wheat is clover, and clover belongs to an order 

 of plants botanists term the leguminosae — they 

 are plants which produce pods, and include 

 clover, lucerne, sainfoin, peas, beans, etc. These 

 crops have a characteristic possessed by no 

 other plants, it is the power to extract nitrogen 

 from the air and convert it to nitrates, and 

 after the crop has left the land their roots 

 leave the soil enriched with these nitrates ; 

 consequently, as wheat requires these nitrates 

 so much, it naturally follows clover. Roots are 



