304 



Relative weight of roots and leaves. 



Vol. VII. 



Relative weight of roots and leaves. 



An interesting series of experiments on 

 the relative weights of the roots and of the 

 green leaves and stems of various grasses, 

 made by Hlubek, throws considerable light 

 upon their relative efficacy in enriching the 

 soil by the vegetable matter they diffuse 



through it, in the form of roots. The 

 grasses were grown in beds of equal size 

 (180 square feet,) in the agricultural garden 

 at Laybach, and mown on the fourth year 

 after sowing, just as they were coming into 

 flower. The roots were then carefully taken 

 up, washed and dried. The results were as 

 follow: — 



Kind of Grass. 



■ Tall 



¥ s i 



1. Festuca Elatior 



Fescue-grass 



2. Festuca Ovina — Sheep 



Fescue-grass 



3. Phleum Pratense— Ti- ) 



mothy-grass - - -.-A 



4. Dactylis Glomerata — \ 



Rough Cock's-foot £ 



5. Lolium Perenne — Pe- > 



rennial Rye-grass \ 



6. Alopecurus Pratensis — ) 



Meadow Fox-tail } 



7. Triticum Repens — ^ 



Creeping Couch or > 

 Quicken-grass ) 



8. Poa Annua — Annual ) 



Meadow-grass ) 



9. Bromus Mollis and Ra- i 



cemosus — Soft and > 

 smooth Brome-grass ) 



10. Anthoxanthum Odora- i 



turn — Sweet Scented > 

 Vernal-grass - - - j 



Produce in 

 Grass. Hay. 



lbs. 



124 



90 

 90 

 202 

 50 



106 



120 



lbs. 



36 

 30 

 25 

 67 



17 



35 



60 



Produce in Roots. 

 Fresh. Dry. 



lbs. 



56 



56 



lbs. 



22 

 80 

 17 

 22^ 

 50 

 24 



70 



Weight of dry 

 Roots to 100 

 lbs. of Hay. 



lbs. 

 61 



266 

 60 

 33 



300 

 70 



116 

 111 



105 



93 



A mixture of white clover, of ribwort, of 

 hoary plantain, and of couch-grass, in an old 

 pasture field, gave 400 lbs. of dry roots to 

 100 lbs. of hay — and in a clover field, at the 

 and of the second year, the fresh roots were 

 equal to one-third of the whole weight of 

 green clover obtained at three cuttings — one 

 in the first, and two in the second year — 

 while in the dry state, there were 56 lbs. of 

 dry roots to every 100 lbs. of clover hay 

 which had been carried oft*. 



The fourth column of the above table, 

 shows how large a quantity of vegetable 

 matter some of the grasses impart to the 

 soil, and yet how unlike the different grasses 

 are in this respect. The sheep' s-fescue and 

 the perennial rye-grass — besides the dead 

 roots, which detatch themselves from time 

 to time — leave, at the end of the fourth 

 year, a weight of living roots in the soil, 

 which is equal to three times the produce of 

 that year in hay. If we take the mean of 

 all the above grasses as an average of what 



we may fairly expect in a grass field — then 

 the amount of living roots left in the soil 

 when a four-year old grass field, is ploughed 

 up, will be equal to one-sixth more than the 

 weight of that year's crop. 



In an old pasture or meadow field again, 

 when ploughed up, the living roots left are 

 equal to four times the weight of that year's 

 hay crop. If a ton and a half of hay have 

 been reaped — then about six tons of dry ve- 

 getable 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 of one-half the weight of the whole 

 hay which the clover has yielded. Suppose 

 there be three cuttings, yielding four tons of 

 hay, then two 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 dependant upon a variety of cir- 



