630 SOILS: PROPEMTIES AND MANAGEMENT 



century. John Johnston/ a Scotchman Hving near 

 Geneva, New York, carried out the most extensive of 

 these pioneer enterprises, beginning about 1835. A very 

 thorough system of tile drains, aggregating about sixty 

 miles in length, was installed on his farm of three hundred 

 acres, and these drains are still in operation and are pro- 

 ducing excellent results. 



533. Effects of land drainage on the soil. — The need 

 and value of thorough drainage of the soil can often be 

 better appreciated after a careful summary of its effects 

 on the properties that determine crop growth. From a 

 study of these it may be seen that for the production of 

 the ordinary upland crops a reasonable amount of soil 

 drainage is the first requisite. It may well be termed 

 the foundation of good soil management. The more 

 noticeable effects are as follows : — 



1. Drainage permits the development of the granular 

 structure in soils, especially in those containing much 

 clay, and thereby permits the creation of a much better 

 tilth. This tilth is brought about by the frequent changes 

 in moisture content of the soil made possible by drainage, 

 coupled with other natural and artificial agencies, as has 

 already been explained. As a result the soil maintains 

 the open and friable condition favorable for the absorp- 

 tion of rain water, and the circulation of the water in 

 the spaces in the soil without interference with the crop 

 roots. The tendency of the soil to puddle and form 

 large, hard lumps is reduced. 



2, The withdrawal of the excess water from the larger 

 spaces in the soil permits the admission of air into those 



^Mellen, C. R. History and Results of Drainage on the 

 John Johnston Farm. Proc. New York Stajie Drainage Assoc, 

 pp. 27-32. 1912-1913. 



