42 EXPERIMENT STATION. [Jan. 



We should realize that it is not the nitrogen alone that gives peat 

 or any other organic manurial substance its superior value as a 

 fertilizer. We depend upon these substances to furnish valuable 

 organic matter and humus, without which it is impossible to 

 successfully grow a crop, even with the most concentrated 

 mineral fertilizers. We dej^end upon these substances further 

 to imj)rove the mechanical condition of soils, to make the heavy 

 compact clay soils more open and porous, and to make the light 

 sandy soils more retentive of moisture, and to furnish condi- 

 tions whereby the soluble plant food may be retained near the 

 surface of the ground, within easy reach of the rootlets of grow- 

 ing vegetation. We acknowledge the value of barnyard manure 

 as a fertilizer, and vet a glance at its chemical analvsis reveals 

 only a small amount of nitrogen, potash and phosphoric acid. 

 The average of 38 analyses of barnyard manure made at the 

 Massachusetts experiment station shows only .42 per cent, of 

 nitrogen, .53 per cent, of potash and .31 per cent of phosphoric 

 acid. The calculated commercial value of the plant food con- 

 tained in 1 ton of the a^'erage barnyard manure would be about 

 $2. The agriculturist recognizes the value of the organic mat- 

 ter furnishing humus, and expects and is willing to allow a 

 reasonable amount for the same. It is well known that peat 

 carries a relatively high percentage of humus, and this fact, in 

 no small degree, enhances the value of this material as a fer- 

 tilizer. Aside from the consideration of the humus in peat it 

 is of interest to study the value of peat as based upon its con- 

 tent of nitrogen and the availability of this most expensive 

 clement of plant food. 



But little work has been done by the scientific agriculturist 

 to establish the relative value of peat as a fertilizer. A few 

 analyses have been made in various experiment stations, by the 

 alkaline and neutral permanganate methods, which show the 

 better grades of peat to have a nitrogen availability of 21.4 per 

 cent, as compared with blood and fish having a nitrogen availa- 

 bility of 65 per cent, or over, but this is only comparative. 

 These figures do not actually show the true amount of nitrogen 

 which is available ; this can only be accomplished by vegetation 

 experiments. The ]\rassachusetts experiment station has for 

 several years been carrying on such experiments by growing 



