508 BOAED OF AGRICULTURE. [Jan. 



occupied by our experiment, for two years in succession, — 

 1883 and 1884, — for the production of fodder corn without 

 the use of any manurial matter. The degree of exhaustion 

 of the entire field w^s very marked and practically uniform. 

 During the spring of 1885, when all other plats were planted 

 with the same variety of corn, plat 6 was ploughed and 

 harrowed like the remainder, but not planted with corn ; it 

 was assigned to the task of ascertaining the effects of " black 

 fallow " on the soil under treatment. It seemed of interest, 

 in connection with our inquiry, to illustrate the influence of 

 mere atmospheric agencies on the future productiveness of 

 our field. For this purpose, during the years 1885, 1886 

 and 1887, the plat was ploughed, harrowed and treated with 

 the cultivator in the same manner and at the same time as 

 the remaining plats. During that entire period no manurial 

 matter of any description was applied. The appearance of 

 every description of vegetation was, as far as practicable, 

 prevented by a timely use of the cultivator. 



At the beginning of the past season, after having pro- 

 duced no crop for three succeeding years, it was prepared 

 in the same way and at the same time as the other plats for 

 the planting of one and the same variety of corn. No 

 manurial matter was on that occasion applied to plat 6. 

 The date of planting the corn, and the subsequent treatment 

 of the crop to the time of harvesting, was the same in all 

 cases. The yield of fodder corn upon plat 6 was the third 

 lowest in the scale including all plats; ^. e., 1,930 pounds 

 per acre. It was also the poorest-looking crop upon field 

 "A" during the larger portion of the season. The result 

 shows, in a very striking manner, that the growing of 

 plants does materially assist in rendering available the 

 inherent mineral plant food of the soil. The growth ot 

 three years, although in our case exceptionally small, was 

 lost to us. Our observation in this connection confirms the 

 results of more recent careful investigations into older 

 systems of agricultural practice. Black fallow, as a rule, 

 does not materially benefit the productiveness of an ex- 

 hausted soil, and ought to be discouraged, therefore, from a 

 mere financial point, at present rates of rent. 



The subsequent more detailed description of the field 



