42^ MANURING BY THE ROOTS OF CLOVER, AND BY 



crop. If a ton and a half of he^ have been reaped — then about six 

 tons of dry vegetable matter remain in the soil in the form of roots. 



In the case of clover, at the end of the second year the quantity of 

 dry vegetable matter left in the form of roots is equal to upwards ot 

 one-half the weight of the whole hay which the clover has yielded. 

 Suppose there be three cuttings, yielding 4 tons of hay, then 2 tons 

 of dry vegetable matter are added to the soil in the form of roots, 

 when the clover stubble is ploughed up. 



But the quantity of roots, like that of green produce, is dependent 

 upon a variety of circumstances. It will sometimes, therefore, be 

 greater and sometimes less than is above stated. It may be received 

 as a rule — not without exceptions perhaps, yet still eis a general rule 

 — that whatever causes an increased produce above ground, will 

 cause a corresponding increase in the growth of roots. Thus nitrate 

 of soda, which gives us a larger yield of hay, makes the roots also 

 stronger and deeper, and the sward tougher and more difficult to 

 plough {Appendix^ No. III.) Hence it is that the farmer is anxious 

 that his clover crop should succeed, not merely for the increased 

 amount of green food or of hay it will give him, but because it wiU 

 secure him also a better after-crop of corn. 



This burying of recent vegetable matter in the soil, in the form of 

 living and dead roots of plants, is one of those important amehorating 

 operations of nature which is always to some extent going on, where- 

 ever vegetation proceeds. It is one by which the practical man is 

 often benefitted unawares, and of which — too often without under- 

 standing the source from whence the advantage comes — he syste- 

 matically a vails, himself in some of the most skilful steps he takes 

 vvith a view to the improvement of his land. 



§ 7. Improvement of the soil by laying down to grass. 



One of the most common of these methods of improvement is that 

 of laying down to grass. This may be done for two, three or four 

 years only, or for an indefinite period of time. In the latter case, the 

 land is said to be laid down permanently, or to permanent pasture. 



1°. Temporary pasture or meadow. — If the land be sown with 

 grass and clover-seeds, only as an alternate crop between two sow- 

 ings of corn, the effect is fully explained by what has been already 

 stated (§6.) The roots which are left in the soil enrich the surface 

 with both organic and inorganic matter, and thus fit it for bearing a 

 better after-crop of corn. 



If, again, it be left to grass for three or five years, the same effect is 

 produced more fully, and therefore this longer rest iVom corn is better 

 fitted for soils which are poor in vegetable matter. The quantity of 

 organic matter which has accumulated becomes greater every year, in 

 consequence of the annual death of stems and roots, and of the soil being 

 more closely covered, but this increase is probably never in any one 

 after-year equal to that which takes place durhig the first. The quan- 

 tity of roots which is produced during the first year of the young plants' 

 growth must, we may reasonably suppose, be greater than can ever 

 afterwards be necessary in an equal space of time. Hence, one good 

 year of grass or clover will enrich ihe soil more in proportion to the 



