298 Repoet of Farmers' Institutes 



ROTATION OF CROPS 

 D. P. Witter 



Plants do their feeding out of sight, and the process of jDlant 

 growth is always surrounded with mystery ; yet, the persons who 

 observe closely may, by their study, learn much of the laws and 

 needs of plants. 



They will find some plants which have roots that feed near 

 the surface, while others like alfalfa, or even corn and red clover, 

 send their roots down deep in the earth, if they find a congenial 

 feeding ground. They will find other plants Avhich require large 

 amounts of nitrogen, such as corn, and still others which require 

 much smaller amounts, like potatoes. What is true of the nitro- 

 gen requirement of plants is also true of potash and other 

 minerals. 



Some plants have the ability to feed and prosper on plant food 

 which would be locked up and unavailable to other plants. Some 

 plants have .small seeds and, to start growth well, require con- 

 siderable j^lant food already available ; while other plants may 

 live for some time on the nourishment found in the seed, and do 

 well when only a small amount of plant food is ready for assimi- 

 lation. Some plants feed largely from the air, wdiile others de- 

 pend to a greater extent upon the soil for their nourishment. 

 Some plants, such as rye, wheat, oats, and barley, germinate at a 

 low temperature, and so do best in cool weather ; while such 

 plants as com and cucumbers will not germinate except when the 

 weather is moderately warm. Some plants will stand severe 

 freezing, live all winter and start to grow early in the spring; 

 while others must be matured before frost comes or they will be 

 destroyed. 



Some plants make a happy feeding ground for certain insects, 

 or fungi ; while on other plants the same enemies would die for 

 want of food and congenial conditions. Weeds will flourish well 

 Math some plants, while with others they would scarcely survive. 

 Thus by a proper rotation of crops, the elements of plant food are 

 kept in a more even balance, the fertility of the land is more 



