EXPERIMENT STATION BULLETINS. 



673 



TABLE 92 —EFFECT OF DECOMPOSITION OF MANURE ON TEMPERATURE OF SOIL. AVERAGES FOR THE 



WHOLE PERIOD. 



The above tables contain the temperature in F. degrees for the days 

 the records were made, the difference for the corresponding days be- 

 i ween the 0.0 manure with any of the other amounts of manure, and the 

 average temperature for the whole period or at the expiration of the ex- 

 periment, for all the various amounts and different kinds of manure. 

 The data show that in the first day of the experiment the temperature 

 of the soil with the 5, 10, and 20 tons of manure of all three kinds, was 

 lower than that of the soil with 40 tons and 100% of manure. At the 

 end of the first day, or at the beginning of the second day, the tempera- 

 ture of all the soils containing the different manures in the various quan- 

 tities was appreciably higher than that of the check and increased regu- 

 larly and gradually with the increase in the amount of manure. The 

 rise in all cases tended to increase till the maximum was reached and 

 then showed a tendency to decrease but remained quite constant for a 

 long period and varied with the air temperature. On account of the 

 variation in air temperature it is somewhat difficult to state definitely 

 when the maximum temperature was attained by all the different ma- 

 nures. The results seem to show, however, that this was attained at 

 different days by the different kinds as well as by the different amounts 

 of manure but practically on the third, fourth and fifth day. The larger 

 quantities of every kind of manure attained the maximum temperature 

 earlier than the smaller quantities. The horse manure attained the high- 

 est temperature first, followed by cow and sheep one day later. The 

 magnitude of rise of temperature was also in the same order. The maxi- 

 mum temperature given by the 40 tons of the horse manure was 2,18° C, 

 of the cow 1,27°, and of the sheep 1,28° and by the 10 tons of the horse 

 manure ,5696°, cow ,7847°, and sheep ,4312°, While the highest tem- 

 perature reached by 100% horse manure was 23.27° C, and by the same 

 percent of cow manure 3.67° C, The check or the unmanured soil was 

 taken as a unit in every case. 



After the highest point was reached the temperature began to de- 

 crease slowly but on the whole it remained quite constant almost to 

 the end of January. During this time it varied from day to day with the 

 air temperature, Bj^ the middle of February it began to become some- 

 what imperceptible among the different kinds of manure as well as 

 among the different amounts within the same kind of manure. In fact 

 85 



