72 
THE CULTIVATOR. 
that are argillaceous, they may still be improved; especially by giving to 
them the power of retaining water for a longer time, that they may thus be 
better able to supply the wants of plants: for this purpose, it is sufficient 
to add to them some fat marl, or for want of that, calcined clay. These 
soils, being naturally warm, require not the fresh dung of neat cattle; the 
unctuous manures are best adapted to them. 
Sand incorporated with finely divided calcareous earth, forms an excel¬ 
lent means of amendment, especially if it be combined with clay or fat 
marl. I have likewise seen the rich mud drawn from rivers, used with 
great success in improving calcareous soils. 
There is a great resemblance in many respects between sandy and cal¬ 
careous soils: both are formed, generally, by the alluvion of rivers; both of 
them are nearly barren when they contain no other principles; and both 
of them form the base of very good soils, if they are suitably amended. 
ALLUVIAL SOILS, HOW PRESERVED AND ENRICHED. 
When these soils are formed by the inundations of rivers, or by streams 
that have taken new channels, they are for some time destitute of fertili¬ 
ty; but the successive swellings of the rivers deposite a rich mud, which 
becomes at length incorporated with the first layer; and when the whole 
is well united, an excellent soil is formed. This mud is very fertilizing, 
from its containing the remains of all those animal and vegetable substan¬ 
ces, which muddy waters carry with them in their overflowings. VV hen 
these soils are left to themselves, we se plants springing upon them 
spontaneously, from the seeds deposited by the waters which conveyed 
them there. 
Soils of this kind rarely require manuring: successive inundations con¬ 
stantly renew their fertility: their level is raised by the accumulation of 
deposites, till at length they are not subject to being overflowed, except¬ 
ing when the rivers rise unusually high; and in those cases the large peb- 
ples, which never float upon the surface of water, cannot be deposited 
upon them. These lands, so valuable for agriculture, do not offer much 
resistance to the rapid current of great inundations, which often carry 
them off; nor to the masses of ice, which at the breaking up of the frosts 
gully and furrow them. I believe I ought here to devote a few lines to 
pointing out some methods for preserving these valuable lands from such 
accidents; it is of more consequence to preserve property than to improve 
it. 
In order to prevent the evils of which I have just spoken, it is custom¬ 
ary to surround lands of this kind with plantations of trees; but trees of a 
large size cannot take root firmly in a sandy and easily disturbed soil. The 
winds are generally very violent in those valleys through which large ri¬ 
vers flow; and these, by the violent motion which they give to the branch¬ 
es, twisting them in every direction, loosen the roots; and the earth being 
continually disturbed, the water penetrates in, and softens it so that when 
an overflow of the river happens, the breaches thus made in the soil les¬ 
sen its powers of resistance to the flood. 
If we observe carefully the action of currents upon the great trees sur¬ 
rounding lands situated upon the banks of a stream or river, or upon an 
island lying in the course of one, we shall be convinced, that, so far from 
preserving, they facilitate the destruction of property; for as the trunks 
oppose an invincible resistance to the force of the current, it is divided, 
and, encircling them, it meets again, having formed a complete trench in 
the soil. Thus though large trees may be useful for turning aside masses 
of ice, and preventing the land from being much injured by them; yet in¬ 
stead of preserving it from the ravages of a rapid current, they become 
powerful auxiliaries to its destructive action. 
Flexible shrubs are undoubtedly preferable to large trees; their roots 
bind the soil; their branches lie upon the surface of the earth, and pre¬ 
serve it from injury during flood®; but these shrubs do not present any re¬ 
sistance to the ice when the livers are breaking up; they cannot turn 
aside the masses of it, and force them to remain in the bed of the river, 
that they may not furrow the meadow or field It is necessary then to 
unite the resistance offered by trees with that of flexible shrubs: in order 
to do this, it is necessary to plant willows or poplars on the extremity of 
the banks, at the distance of seven or eight feet apart; the heads of these 
may be cut off some feet above the height to which the highest floods ever 
reach: the w’ater willows or osiers may be planted all along upon the shelf 
or slope of the land, and from twenty-five to thirty feet inward. In a few 
years there will be nothing to fear from floods or ice upon land defended 
tn this way; and a considerable revenue will arise from the pruning of the 
trees, and the clippings of the osiers. 
After having placed the land out of danger from inundations, the neigh¬ 
borhood of a river opens sources of profit that are very simple, and may be 
taken advantage of at a slight expense. I have heretofore remarked, that 
the mud of rivers is of great use as an amender of soils, and that when em¬ 
ployed upon alluvial lands it supersedes the necessity of applying to them 
other manures; it is then advisable, in overflowings, to retain that mud, 
and that only, which possesses the greatest power of fertilization. 
When the overflow of a stream commences by inundating that portion 
of land which lies highest up the current, it spreads with great rapidity 
over the whole extent of it, furrowing its surface, and carrying beyond it 
all the most finely divided mud with which it is loaded: often up-rooting 
crops and washing away the manures which have been deposited during 
former overflowings; and thus impoverishing instead of enriching the soil. 
But when the rise of water begins down the current, and the whole tract 
of land is slowly submerged, till, even to the head, it is under water, the 
soil receives and retains all the richest and most finely divided mud, as 
well as the remains of animal and vegetable substances which the stream 
has in its downward course washed off from other tracts of country, with¬ 
out any injury being sustained either by the harvest or the land In order 
to give the desired direction to the current, it is only necessary to raise 
the head of the land, or that part which lies up the stream, and to plant 
the bank with osiers. 
By these means, I have improved and tripled the value of certain islands 
belonging to me in the river Loire. These islands, which formerly pro¬ 
duced but little, and were constantly receiving injury from the swellings 
of the river, are now the most productive portions of my estate, for the 
cultivation of grains and beet roots. 
SILICEOUS, HOW IMPROVED. 
When sandy or siliceous soils are situated at a distance from a river, or 
are by the height of the banks placed beyond the reach of an overflow, it 
is necessary to ameliorate them by art; and this must be done by the addi¬ 
tion of fat marl, clay, dung, &c. The amendment must be varied accord¬ 
ing to the nature and fineness of the sand; calcareous sands retain mois¬ 
ture better than siliceous sands. 
I have seen some soils formed of beds of large pebbles, which-without 
the appeaiance of mould upon the surface, produced very good crops; the 
layer of pebbles, which was second from the surface, contained earth 
enough to enable the plants to take root and flourish. 
Soils of this kind furnish excellent pasture for sheep, as may be ob¬ 
served on the ancient and immense alluvions of the Durance and the 
Rhone. The herbage upon these is excellent, and suffers less from drought 
than elsewhere; being protected from the ill effects of the scorching rays 
of the sun by the pebbles lying above its roots. 
Rozier made the experiment of covering a part of the soil of his vine¬ 
yards with pebbles, and found it attended with good effects, especially as 
it regarded the quantity of wine obtained. One of my friends owned in 
Paris, near the barrier d’Enfer, an enclosure, of which the soil was so dry 
and poor, that notwithstanding all the pains he bestowed upon it, he could 
never make any fruit-trees thrive there; in order to amend the soil, he 
covered it with a layer of good earth, which he mixed with the dry sand of 
the spot; this give it some degree of fertility, but the heat dried his plan¬ 
tations so much, that he could only preserve them by frequent and very 
expensive waterings: he at length concluded to cover the surface of the 
ground with a layer of pebbles, and from that time the trees prospered. 
BURNING OF SOILS, WHEN BENEFICIAL, AND WHEN HURTFUL. 
In some countries, recourse is had to fire as an amender of the soil; this 
process, called burning, is strongly recommended by some practical farm¬ 
ers, and highly disapproved of by others: both sides rely on the test of 
their own experience; and both are so sincere in their opinions, that it 
would be useless to contest the truth of their observations. I can only 
agree with each of these contradictory opinions, and at the same time 
make known the cases to which burning is applicable, and those to which 
it is unsuited, in order to enlighten the agriculturist as to the effect of the 
operation: he can afterwards make for himself just and rational applications 
of the theory. 
In the process of burning, a layer of from two to four inches in thick¬ 
ness, is removed from the soil in clods: little heaps of combustibles are 
formed with the broom, thistles, fern, and shrubs that grow upon the spot: 
these are covered with the clods, and at the end of some days are set on 
fire; the combustion of them lasts a longer or shorter time. When the 
the whole has become cool, the heaps of ashes are spread over the surface, 
and thus mixed with the soil. 
By this operation the constituent parts of a soil are divided, and rendered 
les3 compact; the disposition which a clayey ground has to absorb a great 
quantity of water, is corrected, and this soil rendered less cohesive and 
pasty; the inactive vegetable matter contained in it, is converted into ma¬ 
nure: the oxidation of its iron is carried to its maximum; and insects and 
the seeds of injurious plants are destroyed. Hence we perceive that burn¬ 
ing belongs to moist, compact soils; it is attended with good effects when 
the bed of earth is too cohesive, or when it presents veins of blackish ox¬ 
ide of iron: it is suited to nearly all cold and compact lands. 
Burning, especially if it be judiciously conducted, completely changes 
the nature of a soil, and corrects the greater part of its imperfections. I 
have by this means given to agriculture 120 acres of land reputed sterile, 
formed almost entirely of a ferruginous and very compact clay: the burn¬ 
ing extended to the depth of four inches. For twelve years this land, 
though not very productive, has afforded me good returns. Its former 
sterility had procured it the name of the Jews’ heath. 
Burning is hurtful to calcareous and light lands; to soils of which the 
composition is perfect; and to fertile lands, rich in decomposed animal and 
vegetable substances. 
It is useless to soils purely siliceous, for these can receive no modifica¬ 
tion from fire. 
