116 



THE IBEIGATION AGE. 



TO RECLAIM A SWAMP. 



Mud Lake, in Hamilton County, Iowa, one of the 

 greatest prairie swamps in the west, will be converted 

 into one of the largest farms in the State of Iowa by 

 plans carried out by Engineer D. A. Kent, of Hamilton 

 county. 



The land belongs to the Rand estate, of Burlington, 

 Iowa, and the engineer has started to work to build a 

 ditch seventy-five miles long, which will easily drain 

 180 square miles of land. Cairo Lake, as it is some- 

 times called, contains 1,600 acres of land, and is the 

 basin of about 43,000 acres of land. It lies near Jewell 

 Junction. 



The main ditch will have a bottom width varying 

 from thirty-two to nine feet. The estimated cost of 

 the ditch and the four lateral ditches is $57,000. If 

 the plan works as contemplated this land will then be 

 easily worth $100 per acre. 



BENEFITS FROM TILE DRAINAGE. 



There are a good many direct benefits which follow 

 the drainage in localities where drainage is necessary 

 or where it might be said to be desirable. Where it 

 is absolutely essential to drain a piece of land in order 

 "to make it useful, no argument is needed to convince the 

 farmer that it will pay to drain, but when draining is 

 apparently not needed in all seasons, the full benefit 

 from drainage is oftentimes not appreciated. Stating 

 a few of the benefits incident to drainage will therefore 

 be of interest to many. 



The roots of our ordinary farm crops extend from 

 two to four feet into the soil, and ideal mechanical con- 

 ditions is in a soil when they can do this readily. One 

 of the functions of the root is to supply the plant with 

 food and moisture, the more the roots can spread and 

 ramify the soil the more plant food and water they can 

 come in contact with and hence the more rapid will be 

 the growth. All roots, however, need air, because roots 

 breathe; in a water logged sail the air has been crowded 

 out by the water, and hence there is not enough oxygen 

 left for the breathing process to take place as it should, 

 and this is one reason why plants turn yellow when 

 grown on land that is not well drained. 



A well drained soil will also withstand drouths bet- 

 ter for the reason that in such soils the roots penetrate 

 deeper and hence during periods of scant rainfall are 

 less affected by drouth. 



Another important factor which comes from proper 

 drainage is increased warmth of the soil. .Wet soils are 

 cold for the reason that large quantities of water evapo- 

 rate from them. When water evaporates it is converted 

 into vapor and during this change it stores up large 

 quantities of heat which it takes from the surrounding 

 particles of soil. It is a well known fact that to convert 

 water into steam requires a large amount of heat; the 

 same amount of heat is needed to convert water into va- 

 por which occurs naturally when exposed to the air. 

 This is the reason why wet soils are always late and cold 

 soils. After drainage of such lands it becomes possible 

 to seed crops earlier in the spring and thus prolong the 

 season of growth. This difference in temperature of 

 drained and undrained soils is often underestimated; 

 Observations show that during early spring there is fre- 

 quently a difference of 12 F. in the temperature of 

 well drained and poorly drained soils. 



We have referred to the fact that air is needed by 

 the roots of growing plants for breathing purposes, and 

 that, a well drained soil has more room for air than has 

 one whose pores are filled with water, but this is not the 

 only use of the soil atmosphere by any means. There 

 are myriads of bacteria and other small plants con- 

 stantly at work in all soils changing insoluble soil par- 

 ticles into soluble substances. These vegetable organisms 

 also require air or oxygen, one of the constituents of air, 

 in order to live and multiply. If we wish to preserve 

 fruit, ensilage, meat or any other organic substances, we 

 keep the air from them for the reason 'that practically 

 all changes in such organic substances are brought about 

 by low organisms which can not live and develop in the 

 absence of air. The minute air is allowed to come in 

 contact with dead organic matter, provided the temper- 

 ature is also favorable, chemical changes at once take 

 place. The same thing happens to the organic matter 

 in the soil. If air is excluded from a soil organic mat- 

 ter or crop residues remain unchanged, or at least are 

 not sufficiently changed to become soluble plant food. 

 This is well illustrated in peat bogs, which always form 

 in low, wet places, and for no other reason than that the 

 organic matter present is not changed into soluble humus 

 compounds. 



Aside from this indirect effect, the oxygen of the air 

 also has a direct influence upon the soil constituents, 

 changing the mineral particles from insoluble to soluble 

 substances. This action may perhaps be illustrated by 

 the well known change that takes place when iron rusts 

 or when rocks decay and crumble from contact with 

 air. Such changes are purely chemical in their nature, 

 and do not depend upon the intervention of germs, 

 but arc a direct result of the action, of oxygen upon the 

 soil compounds. Such changes, of course, can not take 

 place unless air can circulate freely in the soil. 



Earth worms also work freely in soils that are weil 

 drained, and they are known to be soil builders of con- 

 siderable importance; their burrows and passageways 

 also act as channels for the free circulation of air. 



Much has been said of nitrification and dentrifi- 

 cation. The former is a process of oxidation brought 

 about by certain species of bacteria changing the nitrog- 

 enous organic compounds in soils of soluble substances 

 called nitrates. For example, clover or alfalfa roots 

 contain a large amount of nitrogen, but it exists prin- 

 cipally in the form of compounds called proteids and 

 amides. These substances can not be used by plants, 

 but they must first undergo certain changes which are 

 brought about by certain organisms that need free oxy- 

 gen in order to perform their work, which consists in 

 changing these substances into nitrates that are soluble 

 in water and can be directly appropriated by plant roots. 



When air fails to circulate freely in a soil, these 

 germs do not thrive, but certain other species,- which 

 can only live in the absence of air, begin to work on 

 these valuable nitrogenous compounds and change their 

 nitrogen into free nitrogen or into the same form in 

 which this element exists in the atmosphere. Thus it 

 will be seen that in poorly drained soils the proper 

 changes in the organic substances do not only fail to 

 take place, but that there is actually an absolute loss 

 of one of the most important and expensive soil con- 

 stituents. This fact naturally emphasizes the importance 

 of proper soil ventilation which in wet soils can only be 

 brought about by drainage. 



