i6 



FUNDAMENTALS OF AGRICULTURE. 



Puddling of Soil and Its Cause. When soils are in 

 a very moist condition their particles are free to move 

 over each other quite readily, and if they are worked 

 when in that condition the soil grains do move about 

 until they are packed as closely as possible, the soil 

 clusters being broken up. The soil is then said to be 

 puddled. If the soil is allowed to dry after being 

 worked when wet in this way, it contracts into a dense 

 mass which, in the case of clay, will be very hard. 

 This process when carried to the extreme is that used 



INJURIOUS RESULTS FROM CULTIVATION GIVEN AFTER GROUND HAD 

 BECOME TOO DRY. 



in brick making. It is extremely important, there- 

 fore, for the farmer to be careful when working with 

 clay soils that they are not worked when so wet as to 

 cause any of this puddling, because the dense chunks 

 resulting will frequently leave the soil in poor tilth for 

 several years afterward. On the other hand, if the 

 soil is allowed to dry somewhat before being worked 

 the clusters fall apart readily and good tilth can be 

 developed. 



Tilth of Soil. As previously mentioned, humus also 

 influences the mechanical condition of the soil in that 

 it tends to cement the grains of sand more closely than 

 would the films of water around such coarse grains, 



