It has been made a question, which is the better 
mode, if both are not alike, of making the soil 
fertile ?—the advocates of subsoil-ploughing al- 
leging that it is better to ameliorate the subsoil 
while under the soil by the admission to it of 
air and moisture; while those of the trench- 
plough answer, that if the object of both opera- 
tions is to ameliorate the subsoil, it will become 
sooner so by being brought to the surface, in con- 
tact with atmospheric air and moisture. But, 
say the promoters of subsoil-ploughing, there are 
subsoils of so pernicious a nature, having the 
salts of iron and of magnesia in them, that the 
upper soil would be much injured by its admix- 
ture with such substances. No doubt, answer 
the trench-ploughers, if the subsoil that con- 
tained these noxious ingredients in a large pro- 
portion were brought up in quantity, when com- 
pared with the bulk of the upper soil, injury 
would be done to it for a time, but they say it is 
not the abuse but the proper use of trench- 
ploughing which they advocate; and of such a 
subsoil, they would use the discretion to bring 
up only a little at a time, which they have it in 
their power to do, until they accomplish their 
end, namely, that of ameliorating the whole 
depth of subsoil. But they maintain, that by 
far the greatest proportion of subsoils do not 
contain those noxious ingredients; and, besides, 
the very best and quickest way of getting rid of 
even these is to bring them at once to the sur- 
face, for any of the acids, or the salts of iron, are 
easily neutralised by the action of lime, which is 
always applied to the surface; and those of mag- 
nesia are most easily reduced on free exposure 
to the air. And, moreover, they ask, If subsoils 
shall be ameliorated by air and moisture when 
stirred by a subsoil, why should they not also be 
ameliorated when stirred by a trench- plough ? 
And they urge further, that trenching may be 
practised more safely without previous thorough- 
draining, than subsoil-ploughing. I have no 
hesitation in expressing my preference of trench 
to subsoil-ploughing ; and I cannot see a single in- 
stance, with the sole exception of turning up a very 
bad subsoil in large quantity, there is any advan- 
tage attending subsoil, that cannot be enjoyed by 
trench-ploughing; and for this single drawback 
of a very bad subsoil, trenching has the advan- 
tage of being performed in perfect safety, where 
subsoil-ploughing could not be, without previous 
draining. Mr. Melvin, Ratho Mains, mentions an 
instance of a field containing both damp and dry 
ground; the dry was trench-ploughed in the 
autumn of 1836, an inch or two of the sandy 
gravel being brought up, and ‘ was decidedly in- 
creased in fertility,’ both in the turnip and bar- 
ley crops which followed. I trench-ploughed a 
field of 25 acres of deep black mould which had 
been worn out, with a 4-horse plough, taking 
and clearing a furrow from 14 to 16 inches deep 
in the solid land, and bringing up almost in 
every part a portion of the tilly subsoil, which. 
SUBSOIL-PLOUGHING. 
was only drained to the extent of a few roods 
put in the face of a slope exhibiting spouts of 
water. The turnips that followed were .excel- 
lent; the barley yielded upwards of 50 bushels 
per acre imperial, and the year after a part was 
measured off and fenced, containing 6 acres, to 
stand for hay, which yielded of good hay 1,999 
stones of 22 lb. Another field. the year after, 
that was not drained, suffered injury after trench 
ploughing; but that was in consequence of hav- 
ing been caught with a premature fall of rain in 
the autumn before the trenched land could be 
ridged up, and it lay in the trenched furrow 
all winter. It is stated that Mr. Scott, Craig- 
lockhart, Mid-Lothian, ‘ trench-ploughed, in the 
winter of 1833-4, with one common plough fol- 
lowing another, a field of 20 acres, every two 
alternate ridges, and he has never observed on 
any of the crops the slightest difference.’ This 
is, as I conceive, an unsatisfactory mode of test- 
ing the value of any sort of ploughed land, as it 
is possible that the untrenched ridges derived a 
certain, and it might be a sufficient, advantage, 
in regard to drying, from the adjoining trenched 
ridges.—But whilst giving a preference to trench- 
ploughing over subsoil, Iam of opinion that it 
should not be generally attempted under any 
circumstances, however favourable, without pre- 
vious thorough-draining, any more than subsoil- 
ploughing; but when so drained there is no 
mode of management, in my opinion, that will 
render land so soon amenable to the means of 
putting it in a high degree of fertility as trench- 
ploughing. Mr. Smith himself acknowledges the 
necessity of trench-ploughing land in a rotation 
or so after the subsoil has been subsoil-ploughed, 
in order to insure to it the greatest degree of 
fertility. The experience in trench-ploughing 
after thorough-draining of the Marquis of Tweed- 
dale at Yester, Hast Lothian, may with great 
confidence be adduced in favour of the system. 
I have seen a field on Yester farm under the 
operation of draining which did not carry a single 
useful pasture plant, but which afterwards admit- 
ted of the turnips being drilled across the face of 
inclining ground, and of presenting to sheep in 
winter as dry a bed as they could desire; and 
no farther gone than the spring of 1841, after 
the Swedish turnip seed had been sown, a field 
was trench-ploughed with 3 powerful horses in 
each plough, bringing up white and yellow tilly 
subsoil, as unpromising in ‘appearance as possi- 
ble. The weather being very dry, this till be- 
came so hard, that part of the field had to be 
rolled four times, before they were reduced to 
powder, and after all the operations there was 
apparently no sap left in the ground. White 
turnips were sown, came away, one half being 
eaten off by sheep; and when the land was 
ploughed up in spring 1842, it turned up to 
appearance a fine rich dark mould, rising in fri- 
able clods, and not a particle of till to be seen. 
No one need be afraid to bring up subsoil of any 
