VALUE OF ORGANIC MATTER IN SOILS 



Forest Hkxry 

 Farmers' Institute Lecturer 



In order that one may clearly understand the true value of 

 organic matter in soils he must first understand something of the 

 law governing the growth of plants. He must understand that all 

 the plant foods taken from the soil by the plants must be taken in 

 a soluble form. They must first be mixed with many times their 

 volume of water before the plant can make use of them, since a 

 plant drinks in its food ; therefore, it must be in a form of a thin 

 soup before the plant can make use of it. This means that the 

 soil moisture is just as important as plant food. Anything that 

 will tend to conserve soil moisture will therefore tend to improve 

 the growing crop when we have our periods of drought. In 

 fact there are few seasons in Xew York State when the later 

 maturing crops are not affected more or less during the growing 

 season by drought. 



Soil is composed of ground rock and decomposed organic matter, 

 and ground rock alone will not hold moisture. The more organic 

 matter it contains the more soil moisture it will hold in suspen- 

 sion. 



Organic matter, then, is very necessary in a soil to assist in 

 holding moisture near the surface where most of the feeding 

 roots of plants are located. We also need the organic matter to 

 assist in separating the particles of soil in a very wet season. 



One of the conditions necessary for plant growth is warmth. 

 When a soil becomes sodden as it will in a wet time, the air is shut 

 out and consequently it does not warm up as it should for the best 

 growth of vegetation ; hence a wet season usually means a cold 

 season. When we introduce organic matter in such a soil it sepa- 

 rates the soil particles, admits air and sunshine and the soil in 

 consequence becomes very much warmer. Vegetable matter in 

 soils, therefore, assists in equalizing the soil moisture, making the 

 soil more moist in a dry time and tending to warm it in a wet, 

 cold season. 



[1688] 



