ADVANTAGES OF DRAINING

Waipa Post, Volume XXIV, Issue 1689, 21 November 1925, Page 7

ADVANTAGES OF DRAINING

REMOVE WATER—A D3IIT SUNLIGHT. MYRIADS OP BACTERIA. Experiments have proved that there is a difference of as much as lOdeg. in the temperature of a drained and an undrained field side by side. Ten degrees of temperature represents about 2000 ft. altitude, so that the comparison between the two fields may be read as the drained field representing sea level, while the other is 2000 feet up. The reason for tne difference in temperature is that it takes more heat to raise the temperature of water than it does of soil. Then, with the land in a waterlogged condition, there is no hope of the sunlight and air penetrating to warm the soil. When there is no outlet for this water below ground, or at least a very inadequate means of escape, it has to be taken away by evaporation, and this is the coldest method of all. These are some of the most obvious reasons for the variations in temperature.

Another effect of drainage is to more thoroughly aerate the soil. With the removal of the moisture there is an immediate ingress of air and sunlight, two factors absolutely necessary o promote life, either animal of plant. It is true that there must be a certain amount of air in the water in the soil, but, with the stagnant conditions which obtain, there is too great a proportion of acid.ty, and this greatly restricts the forms of life which can endure under these conditions. By removing the water the sunlight is let in, and as a result all life in the soil is stimulated.

The soil teems with its myriads of bacteria, without which there would be no fertility in the soil. When the land is wet and cold and sour, the bacterial life is at a low ebb, for how could even the unseen bacteria operate to advantage? Again, only those acid-loving species can endure and their work is harmful rather than helpful. There are the species which operate on the humus in the soil and break it down into plant food; there are those nitrogen-collecting bacteria which operate through the medium of legume plants, plants which cannot live under acid conditions. All these and many others are stirred into activity with the removal of the stagnant surplus of water, with its consequent raising of the soil temperature and its better aeration. These are some of the effects of land drainage and though only a few in comparison to the total effects, they should suffice to show wherein lies the improvement resulting from this operation.