62 NEW YORK STATE MUSEUM 



Many upland soils are improved ^ hj the application of a dress- 

 ing of peat or a compost of peat and stable manure, and the 

 benefits derived come from two causes (1) its action in improving 

 the texture and other physical qualities of the soil and (2) its 

 direct fertilizing value. 



The value of peat in improving the texture of the soil depends 

 on (1) its powers of absorbing and retaining water; (2) its 

 power of absorbing ammonia; (3) its effect in dissolving mineral 

 matters; and (4) its effect on the temperature of the soil. Its 

 value as direct fertilizer depends on some of the organic matter 

 present, particularly ammonia and the small amount of potash, 

 phosphoric acid and lime present. As these direct fertilizing in- 

 gredients rarely form 2^ of the entire mass when free from water, 

 it will readily be seen that the material as taken from the swamp 

 need not be looked on as a source of supply for mineral fertilizers. 

 In fact, where swamp soils give the best results, large amounts 

 of commercial fertilizers are added, so that the value of peat as 

 a direct fertilizer is almost nothing. The action of the organic 

 acids present in peat is unknoAvn; and it may be that some of 

 these have a decided fertilizing effect, but the probability is that 

 they have no fertilizing value, for ordinary crops can not be 

 raised till these acids have been rendered insoluble. 



The principal benefits arising from the application of peat to 

 soils come from its mechanical effect, which makes light soils 

 more retentive of moisture and ammonia and lightens clay soils. 



Associated products 



Marl. In many swamps, just beneath the peat, is a deposit 

 of shell marl. This material, which is nearly pure carbonate of 

 lime, is used extensively in the manufacture of Portland cement 

 and lime. It is used instead of marble dust as a source of car- 

 bonic acid for use in charging soda water and other carbonated 

 waters. Frequently the marl and peat are interstratified, in 



Johnson, S. W. Essays on Peat, Muck and Commercial Manures. 



