16 THE ROTHAMSTED EXPERIMENTS. 



statistics of the crops so variously grown, and the chemical 

 statistics of the soils of the plots upon which they have been 

 grown, must afford very important data for further study and 

 elucidation. 



An examination of Table I. will show that the individual 

 crops which have been grown separately year after year on the 

 same land include — wheat, barley, and oats, as members of the 

 order Graminese ; beans, clover, and other plants, of the order 

 Leguminosse ; turnips of the Cruciferse ; sugar-beet and mangel- 

 wurzel of the Chenopodiacese ; and potatoes of the Solaneae. 

 Then the experiments on rotation include those with members 

 of three of the above orders — turnips of the Cruciferae, barley 

 and wheat of the Graminese, and clover and beans of the Legu- 

 minosse. Lastly, there are the experiments on the mixed herbage 

 of permanent grass - land, which includes, besides gramineous 

 and leguminous plants, numerous species of other natural orders. 



The first experiments undertaken were those with root-crops, 

 which were commenced in June 1843, so that last year (1894) 

 was the fifty -second of their continuance. The second were 

 those on wheat, commenced in the autumn of 1843, so that the 

 crop of the last harvest was the fifty-first grown in succession 

 on the same land. The experiments with beans were com- 

 menced in 1847 ; but, for reasons which will be fully explained, 

 tbey have not been continued up to the present time. Those 

 with clover were commenced in 1848, and have been succeeded 

 on the same land by others with various leguminous plants, 

 which are still continued. Then of the other more important 

 series, those on barley were commenced in 1852, and are still in 

 progress, the crop of 1894 being, therefore, the forty-third in 

 succession. Experiments with oats were commenced in 1869, 

 and continued for ten years. Others, on the growth of wheat 

 alternated with fallow, but without manure, were commenced in 

 1851, and are still going on, 1894 being the forty-fourth year; 

 and those on potatoes were commenced in 1876, the crop of 

 1894 making, therefore, the nineteenth in succession. The ex- 

 periments on an actual course of rotation were commenced in 

 1848, and are still continued, so that the crop of wheat now 

 growing will complete the twelfth course of four years, and the 

 forty - eighth year of the experiments. Lastly, those on the 

 mixed herbage of permanent grass - land were commenced in 

 1856, so that 1894 completed the thirty- ninth year of their 

 continuance. 



It should be observed that the earlier field experiments were 

 commenced without any idea of long continuance, and it was 

 only as the results obtained indicated the importance of such 

 continuance that the plan eventually adopted was gradually 

 developed. It is, however, to long continuance that we owe 



