REPOBT ON VARIOUS MANURES AT CHTSWICK. 
73 
meut) probably more under-ground growth than any other. 
Many of the parsnip-like roots, indeed, were from i to | inch or 
more in diameter at the top, tapering down a foot, or 15 inches, or 
more. Although, too, the actual amount of growth above ground 
was so small, there was a pretty regular gradation of increase 
under the influence of the different manures, from No. 2, with 
mineral manures alone, up to No. 6, with mineral manures and 
nitrate of soda ; and, a.gain, although the actual amount was not 
great, the lyrojportion of the manured to the unmanured produce 
was, as a rule, higher than with any other plant. The percentage 
of mineral matter also was throughout extraordinarily high, in- 
dicating the early stage of progress of the plants at the time of the 
completion of the first year's growth. All conditions, therefore, 
tended to show that, far from having attained the full growth 
which the soil-conditions supplied were adapted for, the plants 
had, at the time they were cut, much potential work before 
them, and in degree much in proportion to the provision of the 
constituents available for assimilation. 
To the above few comments on the amount of growth attained 
by the different species, under tlie difterent conditions of manu- 
ring, it may be interesting to add a few observations as to the 
relation of the amounts of constituents removed to the bulk of 
soil, and to the supply by manure. 
Table II. shows that the grasses removed from 0*5 to 1'23 oz., 
or an average of about 0-8 oz., of mineral matter from the un- 
manured soil ; whilst under the same conditions the Legumi- 
nosse removed from under 1 to over 2 oz. ; the Achillea 3|, and 
the Flanfago nearly 3| ozs. Some idea of the richness of the soil 
in available mineral matter which these amounts indicate will be 
acquired when it is stated that 1 oz. of mineral matter removed 
from one of the boxes by one of the grasses, would correspond 
to as much per acre as would be contained in about 5 tons of 
meadow hay, 1 oz. in one of the clovers to as much per acre as 
would be removed in about 4 tons of clover hay, and 3 to 3| 
ozs., as in the cases of the Achillea and Plantago, to a ton or 
more of mineral matter per acre. 
phosphoric acid, the grasses would, on the average, thus re- 
move from the unmanured soil about one-seventh as much as was 
supplied where the heavy mineral manure was employed ; and 
of potass from one-fourth to one-third as much as the mineral 
VOL. III. 
