Hiiimis in Forest Soils 135 



other nioss)" plants; it is more fibrous in nature, very acid in reaction 

 ( pH 3.5-4.5 ) , low in ash and nitrogen ( less than 1 per cent ) . After 

 proper drainage, the lowmoor peat, as well as a third type of jocat, 

 known as sedimentary, forms good agricultural soil. Lowmoor peat 

 is also harN'ested and marketed for making lawns. Highmoor or 

 sphagnum peat is used as litter in stables and for horticultural pur- 

 poses. A number of other peats, intermediary in nature, are formed 

 from different types of vegetation and under different environmental 

 conditions. 



Most peats are \aluable as sources of humus, but they are poor as 

 plant nutrients, and even the nitrogen in the peats is not so readily 

 available for plant growth as is that in animal manures and green 

 manures. Peat cannot, therefore, take the place of fertilizers for 

 plant nutrition; it serves primarily to improve the physical condition 

 of the soil. Peat is frequently mixed or composted with soil, before 

 its application to the soil, in order to prevent the formation of layers 

 and to improve the uniform structure of the soil. 



The chemical composition of a group of peats is given in Table 28. 



Table 28. Proximate Chemical Composition of Some Typical Peats 

 On basis of dry material (from Waksman). 



The marked variation in reaction, total organic matter content, and 

 chemical nature of the organic matter is due to differences in the 

 vegetation from which peat has been formed, the nature of the 

 waters finding their way into the peat bogs, the topography of the 

 region, and the climate. 



Humus in Forest Soils 



Forest humus varies with the nature of the vegetation and the 

 soil. The forest floor usually consists of several distinct layers of 



