74 AMERICAN AGRICULTURE. 



water which falls into the drain ; while the increased depth 

 at which the drainage takes place, draws the water from a 

 much greater distance. With the depth indicated, it has 

 been found that the drains instead of being required once in 

 16 to 25 feet, may be placed at intervals of 40 to 50, and 

 accomplish the object with equal success, and in less time. 

 The expense of the former plan was from $20 to $30 per 

 acre, while the last is only from $12 to $18. 



The advantages of under draining are numerous and 

 important. They take away all the surplus water which 

 exists in heavy or tenacious soils, which in wet seasons are a 

 serious impediment to the successful growth and perfection 

 of vegetation ; thus always ensuring a full crop when fre- 

 quently not one -fourth of a crop is matured on similar 

 undrained soils. They allow of early cultivation in spring 

 and late in autumn, by furnishing a dry, warm soil, which 

 would not admit of cultivation except in the warm part of 

 the season ; thus enabling the farmer to grow a greater vari- 

 ety of products where only a few were adapted to the soil 

 before, and to these it gave several weeks' additional growth. 

 It saves all the trouble and waste of surface drains and open 

 furrows, which' require that much of the land be left almost 

 in an unproductive state, to serve as conductors of the sur- 

 plus water. The rains falling on the convex surfaces of 

 the lands, run off rapidly into the furrows, and not only 

 prevent the benefit to the soil which would result from its 

 absorption, but they carry with them much of the fine soil, 

 which is thus allowed to waste. 



Rainwater is charged with some of the most important 

 elements of nutrition to plants, and especially contains con- 

 siderable proportions of carbonic acid and ammonia. If 

 these be permitted to percolate through the soil, the roots of 

 the plants, or in their absence, the elements of the soil itself 

 absorb and form permanent combinations with them. Air 

 also holds vegetable food and it is necessary that this should 

 penetrate through every portion of the soil where the fibres 

 of the roots exist. Soils which are saturated with water do 

 not admit of any air, unless the small proportion combined 

 with the water ; and from all such this vital adjunct of vege- 

 tation is excluded. The porosity of the land thus secured, 

 facilitates the admission and escape of heat, which last con- 

 dition is of the utmost consequence in promoting the deposi- 

 tion of dews. 



