Land Drainage and Soil Efficiency 182 i 



some types of wet land * 



Flat clay land generally needs systematic drainage. Such land occurs 

 in large areas in the central part of the State along Lake Erie and 

 Lake Ontario, in the Saint Lawrence valley, the Champlain valley, and 

 the upper part of the Hudson valley as far south as Newburgh. Drainage 

 of such soil is needed because its fine texture causes water to circulate 

 very slowly. Moisture is likely to be retained so long that the productive 

 capacity of the soil is reduced. 



In the same regions where the clay soils occur, there are many other 

 conditions that may prodtice wet soils. There are terraces of gravelly 

 and sandy loam that are often wet along the base due to the water that has 

 percolated down from the topsoil and that has been brought to the sur- 

 face by some impervious substratiun. There may be the outcrop of 

 some porous strata through which the water moves freely, and on the hill- 

 sides this produces a seepage line or zone of wet soil. There are large 

 rounded hills of stony loam soil that often contain wet areas. Their 

 structiu-e consists of glacial till interstratified with layers and pockets 

 of gravel and sand in which water acctunulates. The dnmilin-shaped 

 hills typically developed in Wayne County are of this sort. Springs 

 and wet areas are of frequent occurrence. 



Some of the most misleading soil in reference to wetness is found in 

 the hill lands of southern New York. Much of this land has a good 

 slope and sometimes it is almost precipitous. The slope wordd seem to 

 insure good drainage, but the structure of the soil is such that good drain- 

 age does not exist. Much of the land has a moderately porous soil under- 

 lain by an impervious or hardpan subsoil. The rainfall is absorbed into 

 this loose topsoil and trapped by the subsoil, so that it is removed only 

 by slow percolation and by evaporation. In addition, springs are of 

 common occurrence and spread down the slope in the form of a fan of 

 wet soil. 



Many other special types of wet soil occur, but the kinds mentioned 

 above are those that are most frequently met. Indications of wet soil 

 are, heaving in winter, failure of seed to germinate, bare patches 

 or missing, trees, pale green leaves, slow and stunted growth of crops, 

 and either a black or a pale and washed-out, mottled color of the soil. 

 The tendency of the soil to puddle and to become lumpy under tillage 

 is further evidence of wetness. 



EFFECTS OF DRAINAGE 



The reasons for the importance of thorough drainage will be better 

 understood after a consideration of the far-reaching effects of drainage 

 on nearly all the factors of soil fertility. 



