GOOD AND BAD TILTH 



91 



On the other hand, the small particles may adhere 

 to the large ones, or a number of small particles may 

 adhere together as a group, or granule. When a number 

 of united particles function together as a single larger 

 particle or granule, the structure is termed granular. 



Fig. 28. Ideal tilth of a soil 



This arrangement is also termed the crumb structure. 

 According as these groups are prominent or incon- 

 spicuous, the soil is said to be well or poorly granulated. 

 But when the granules reach large size, so that they 

 interfere with the best functioning of the soil, they are 

 termed clods. That is, a clod is an unsizable granule. 



