Improving the Condition of the Soil 



Humus. 



Humus is animal or vegetable residue which is 

 found in the soil in various conditions, either not 

 yet decomposed, in process of decomposition, or 

 decomposed — soluble or insoluble. 



Theoretically it ought to be considered only as 

 humus. It ought not to include nitrogen, but as a 

 matter of fact it does. It is this material which 

 gives the soil its colour, and makes it earlier, because 

 bemg black it easily absorbs the heat of the sun. 



It has the property of retaining water in the soil ; 

 so that certain soils too rich in humus retain too 

 much water ; but, generally speaking, humus is 

 valuable, largely because it helps to retain the 

 fertilising matters, which otherwise would be too 

 easily lost m the subsoil. 



Humus possesses two opposite characteristics, 

 according to the soil in which it is found. It gives 

 more cohesion to sandy soils, rendering it more 

 compact and less permeable, and makes clayey soil 

 more friable, porous, and permeable. It promotes the 

 development of the bacteria of nitrification and of 

 favourable moulds. The bacteria of nitrification 

 travel little through the soil, and in sour sandy soil 

 they are very often non-existent, because of the 

 absence of lime. That is why when attempts were 

 formerly made to cultivate these soils, only very 

 poor results were obtained from green manures in 

 the first year. To introduce them, the agriculturist 

 had to turn to humiferous soil close by, where he 

 knew the bacteria were found, and spread one or 

 two cartloads of this soil on the surface of the 

 new plot. 



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