254 



Bulletin 254. 



Such marked effects are supported by the observations of King, Parkes 

 and others. Parkes found in the peat bogs in Lancashire, England, that 

 at a depth of 7 inches the drained soil was 15° warmer than the undrained 

 soil and at a depth of 31 inches the drained soil was still 1.7° warmer. 

 John Johnston wrote in 1853: "Such fields (undrained) must generally 

 be left late in the spring — perhaps too late to work favorable — and in 

 the autumn the frost will inflict an injury." On the Yoemans farm it has 

 been observed many times that the oat crop may be planted in well 

 drained land before adjoining land of the same kind is in condition to 

 plow and in the spring it is commonly observed by farmers how the seed 

 in the wet spots is delayed in appearance above the surface. 



These latter observations emphasize one other very important effect 

 of drainage in this connection. It lengthens the growing season by per- 

 mitting the land to be cultivated and seeded earlier in the spring and by 

 keeping up the temperature in the fall sufficiently late to ward off early 

 frost. In the southern part of the State on the high hills where it is diffi- 

 cult to mature corn even in the favorable seasons it may be readily seen 

 .. -J^g^' how important to the farmer is this extension of the 

 growmg season. In many cases the difference is that 

 between a successful crop and a failure. 



(6) Drav'.agc increases the m'aiJahJe food supply in 

 the soil. This results from the effect of drainage on 

 the moisture retaining capacity, the temperature, the 



aeration and the growth 

 of soil bacteria. The ad- 

 mission of air acts directly 

 on the minerals as an oxi- 

 dizing agent, thereby ren- 

 dering some of them more 

 -'.^ soluble. The increased 

 /' temperature increases the 

 solution processes and both 

 the aeration and higher 

 temperature promote the 

 larger growth of soil bac- 

 teria, which are vitally re- 

 lated to the plant food 

 supply. It is through their 

 \0 action that the organic 



Fig. 195.— Drainage system adapted to small wet matter in the soil is decom- 

 areas of tine sandy loam soil. Wetness is in pro- nosed The arrnmnlatinn 

 portion to shading. Distances: o-c, 675 feet; o-f,>^^^^^^- ^"^ accumulation 

 558 feet. Sices of tile, to a and b, 4 inches, of peat and muck in boggy 

 Remainder of system, 3 mch. pl^^^g ^3 ^he result of the 



