284 SOILS: PBOPJERTIES AND MANAGEMENT 



compact to the very surface as a result of the winter 

 rain and snow, and are therefore in condition for the 

 most rapid loss of water. They should be plowed as 

 early as practicable without injury to their structure. 

 At the Wisconsin Experiment Station^ two adjacent 

 pieces of land very uniform in character were plowed 

 seven days apart. At the time when the second plot 

 was plowed, it was found to have lost 1.75 inches of 

 water from the surface four feet in the previous seven 

 days ; while the piece plowed earlier had actually gained, 

 doubtless by increased capillarity, a slight amount of water 

 over what it had contained when plowed. There was a 

 conservation of nearly two inches of water in the root zone 

 as a result of plowing one week earlier — enough to 

 produce 1500 pounds of dry matter in maize to the acre, 

 if properly utilized. 



202. RoUmg.-Very often m the spring, when the 

 seed bed is very loose, rolling is resorted to, in order to 

 bring about a compaction of the soil. At the same 

 time capillarity is established with the firmer earth 

 beneath, and as the moisture moves upward a rapid 

 germination of the seed is induced. Care must be taken 

 that this capillarity be checked once it has performed 

 this office, as great losses from evaporation may occur 

 at the surface and the crop be robbed of much available 

 water. It is an economic procedure in such cases to 

 follow the roller after a few days with a harrow, in order 

 that a mulch may be established and this loss checked. 



203. Shelters. — Shelters of any kind, whether natural 

 or artificial, tend to break the wind velocity and thereby 

 check losses by evaporation. Strips of timber are com^ 



1 Kiag, F. H., The Soil, p. 189. New York. 1906. 



