80 SOILS AND FERTILIZERS 



It frequently happens, therefore, that plants suffer much 

 from lack of moisture on a soil that has been saturated with 

 water during the early part of the growing season. 



99. Length of growing season. — Drainage increases 

 the length of the growing season in two ways : (1) The soil 

 can be worked much earlier than on poorly drained land. 

 (2) The soil becomes warm earlier, because it is easier to heat 

 soil particles than it is to heat water. Then too the evaporat- 

 ing moisture causes a lowering of the soil temperature. 

 Seeds germinate more quickly and uniformly and plants 

 make a more rapid growth on account of the warmer soil. 



100. Other results of drainage. — All of these improved 

 conditions unite to produce larger yields of crops and more 

 uniform growth. Drainage eliminates the continually 

 wet or swampy portions of fields that interfere with tillage 

 operations and necessitate working the field in sections. 

 There is, accordingly, an economy in operation. In meadows 

 and pastures the kinds of forage plants that grow on a well- 

 drained soil make better feed than those kinds that grow 

 on wet land. 



101. Open ditches. — Excess water is sometimes removed 

 by means of open ditches of size and depth necessary to 

 drain water from the land and carry it to some waterway. 

 Such ditches sometimes merely follow a depression or swale 

 in the land and thus carry off the worst of the excess water, 

 especially that which comes from higher land, or they are 

 sometimes laid out in a more systematic way. 



Level fields may be plowed in lands with dead furrows 

 every twelve to twenty feet apart, and with a larger ditch 

 run through lower ground for the dead furrows to empty 

 into. This affords only surface drainage, but is better 

 than nothing. Larger ditches should have grass planted 

 along the sides for several feet from the ditch. Weeds must 

 be mowed and trash, dirt and stones removed at intervals. 



