152 STATE BOARD OF AGRICULTURE. 



SOIL xAIOISTURE, ITS IMPORTANCE AND MANAGEMENT. 



JOS. A. JEFFEBY, PBOFF.SSOB OF AGRONOMY AND SOIL PHYSICS. 



Bulletin No. 219. 

 COMPOSITION OF SOILS. 



Soils are composed principally of two materials, mineral matter and organic 

 matter. 



The mineral matter consists of fragments of rocks, sand and clay. All these 

 have come from the breaking down of larger masses of rock. 



The organic matter consists of decomposing leaves, stems and roots of plants, 

 and of the remains of the bodies of animals. When these materials are so far 

 decomposed as to lose their form the resulting organic mass is called humus. 



In addition to these materials there are found in soils varying quantities of 

 salts of potash, lime, etc., which, dissolved in water, are taken up by plants 

 through their roots, usually as food. 



While not forming a part of the soil, strictly speaking, there are in it great 

 numbers of very small plants, especially in the upper six or eight inches. They 

 are spoken of as bacteria, molds, and algae. Many of them are very important 

 because, by their action, some of the plant foods and perhaps most, if not all of 

 them, are prepared for the use of our higher plants. So important are they that 

 the wise farmer handles his soils with a view to keeping their numbers as great 

 as possible. 



The mineral matter and organic matter in our soils are found in varying quan- 

 tities. In our cultivated upland soils the organic matter will amount to from 

 3% to 6% of the total dry weight of the soil. In our muck soils the amount of 

 organic matter is much greater, some times reaching 97% or 98%. Such a soil is 

 worthless for cropping purposes. 



All soils contain moisture in s-ome condition. 



THE WATER OF THE SOHj. 



A soil may have in it too much water, or it may have too little water, or it 

 may have just the right amount of water for the best germination of seeds and 

 the best growth of plants. 



To discuss the management of soils so that they shall hold the most nearly 

 proper amounts of moisture for crop production and at the same time retain 

 these amounts as far as possible from unnecessary losses is the object of this 

 bulletin. 



When water stands upon the surface for any considerable time at any season 

 or within three feet of the surface during the growing season, the land should 

 be drained — preferably tile drained. When soils take on the appearance and feel 

 of dryness, although they may still contain a measurable amount of moisture, they 

 have reached a point where they will no longer yield moisture to the growing crop. 



' CAPHJ^ABY MOISTURE. 



Capillary moisture is the visible moisture which clings to the walls of the soil 

 grains or remains suspended in the smaller openings between the grains. Capil- 

 lary moisture does not occupy all the pore space of a normal soil and therefore 

 leaves room for the entrance of air into the soil. But there may be too much 

 capillary moisture in a soil or too little for the best growing of crops. 



