VERMONT AGRICULTURAL REPORT. 59 



1. The mechanical condition of the soil may be affected by liming in 

 two ways: 



(a) It flocculates soils of a clayey nature. 



(b) It binds soils of a sandy nature. 



(a) When lime is freely applied to soils of a clayey type it tends to 

 open them up, to lighten them, to render them more porous, more 

 crumbly and more friable. This peculiar action is called "flocculation," 

 the gathering together of minutely fine particles into floccules or flakes. 

 Too much lime may be used and the soil injured, but such a result is not 

 common. 



(b) When lime is used on sandy soils it tends to make them more 

 compact and retentive. The effect is not as pronounced as that ex- 

 erted on the clays and, it is to be observed, is in quite an opposite direc- 

 tion. 



2. The chemical comnosition of a soil may be modified by liming, 

 more particularly in two ways: 



(a) It frees certain forms of plant food from soil combinations, 



rendering them available to plant uses. 



(b) It counteracts the influence of certain more or less harmful 



ingredients naturally present or artificially formed. 



(a) Most of the plant food in soils is locked up quite securely in 

 soil combinations. Lime is one of the best keys with which to open some 

 of these locks. It frees considerable quantities of potash and phosphoric 

 acid and thus furnishes needed plant food from the soil rather than by 

 means of an added fertilizer. It is easy to see that such an action may 

 go too far, that lime may be used for a series of years and lead to soil 

 exhaustion. 



(b) There are several occasional soil constituents which may be 

 harmful to plant growth. Thus poisonous ferrous (iron) salts form in 

 some swamp soils and subsoils, which may be combatted with lime. 

 Soil acidity, too, may be thus neutralized. This acidity may be due to 

 any one of several causes, but is most commonly due to an accumula- 

 tion of plant acids arising from humus formation and change. Then, 

 too, upland soils of a granitic type are apt to lose lime by leaching and 

 by gravitation, and thus to become acid. Liming naturally tends to 

 counteract these conditions, and to neutralize the acidity. Inasmuch 

 as an acid soil is not a favorable one for the production of many of the 

 better forms of plant growth, it follows that liming is often found to be 

 a happy remedy for a desperate condition. 



3. The biological (or life) conditions of a soil may be changed 

 through liming in four ways: 



(a) It favors bacterial growth. 



(b) It helps to "bring in" clover and to improve the character of 



the vegetation. 



(c) It helps to decompose humus, etc. 



(d) It affects insects and fungus growths. 



