EFFECT OF FEEDING KOOTS OX TIIK LAM) jo; 



the yield of l)arley is increased l)y as imic-li as ."):} per fciii. 

 through tlie return of the root crop to tlie land. The residues 

 have, however, but a small effect two years later on the wheat 

 crop which follows the bare fallow, for where the roots were 

 fed the wheat crop is only 1:3 per cent, larger than where 

 the roots were carted off. The residual effect has practieallv 

 <lisappeared by the fourth year, and when the roots (to w hieli 

 a fresh application of manure is applied) come round again 

 they are httle the better for any accumulated residues in the 

 soil, even though the treatment of returning or removing tlie 

 roots is repeated through thirteen rotations, or a period of 

 tifty-two years. 



The next Table (LXXII.) shows the parallel experiment, 

 in which clover or beans are grown in the third year of the 

 course instead of taking a bare fallow. 



Table LXXII. 



In this case the effect of feeding the roots on the land is 

 plainly visible in the following crop, though the increase is not 

 so gi'eat (being 28 per cent, instead of 53 per cent.) as when the 

 rotation includes a bare fallow. 



The second crop, clover or beans, is also benefited to some 

 extent, for the residue of the roots produces a mean increase of 

 9 per cent. Now, however, the new .stores of nitrogen intro- 

 duced by the clover crop practically obliterate all further eflect 

 of the residues, and the wheat crop is to only a trifling extent 

 the better for the return of the Swetles to the land three years 

 previously. 



