Bare summer fallowing has in part been superseded by the culture of green crops, but is still extensively practised by intelligent and successful farmers in the best farmed districts of country. On this subject, one of the most accomplished farmers and writers on agricultural matters has the following remarks: "Though it cannot be desirable to see the practice of bare fallows extended (for it exists too much already upon many soils where it might be with every advantage substituted by green crops), it must yet be borne in mind that it is not in the mechanical structure alone that heavy soils differ from light soils; their chemical difference - which is quite as great - lies in that essential particular that the clay soil is naturally richer in the mineral constituents required by your crops. Potash, soda, and phosphorus, which you must supply to a light soil before you bow it, you have only to develop in a clay soil by deep and frequent stirring, and submitting to the oxidation of the atmosphere. The green crop, with its carbon-obtaining leaves, will no doubt supply organic wealth to either; but inorganic food can come from the soil alone, and if the soil be able to supply it from its own resources, one-half the value of the green crop, as a fertilizer, is renounced.

Its remaining value as a collector of organic matter from the atmosphere, is the point upon which the question will be poised, of its adoption on a soil which, after effectual drainage, subpulverization, and liming, still retains the character of a 'clay.' Even upon such land (which is not so plentiful as some imagine), experience has yet to prove how far, by deep ploughing and subsoiling immediately after harvest, and making the most of suitable weather between that time and the following summer, the green crop may take its place in a six-course system as profitably as in the four-course system upon lighter soils. The bare fallow is too ancient, too prospectively laborious, and patient, not to have deep reason at the bottom of it. Chemistry has discovered the truth which practice has attested. The question may be not whether the fallow shall be abandoned, but whether its objects can be achieved at a less sacrifice of time".

We are told that fall ploughing of light soils is universally considered as positively injurious. The soil must be light, indeed, that is injured by fall ploughing. That there is no such universal opinion, is too well known to require comment; I would, however, in passing, ask " Cincinnatus" to inform us why it is injurious?

We are further informed, that clay lands ploughed in the fall are heavier In summer, and for once a reason: " Because the frost also decomposes the roots of weeds," etc. The farmer who grows weeds in sufficient quantity, that his future crop is mainly dependent upon their decaying roots for an existence, is a relic of something, whether of a "barbaric age of agriculture" or not, I will not determine; but I would consider him a fitting companion for Bo-Bo and his father, Ho-ti, as described in Elia's dissertation on " Roast Pig:" Bo-Bo accidentally Bet fire to his father's cottage, In which there was a fine litter of pigs. Both father and son were so pleased with the burnt remains, that " as often as the sow farrowed so sure was the house of Ho-ti to be in a blaze I"

When planting a tree, it is a matter of paramount importance to have the soil in so finely divided a state that every root will be enveloped, and the smallest crevioes and interstioes filled. It is then surely a question of moment to know how this friability is to be obtained. The cheapest and most effectual crusher is frost. Here is the process described, as I find it in a recent agricultural monthly periodical: " The freezing and thawing process is of vast benefit to soils. Investigations go to show that the fineness of a soil is among its best qualities. Some have gone so far as to say that it matters little what a soil consists of, if it is sufficiently fine; that the New England granite soils, if as fine as those of the Ohio valley, would be as good. This may seem extravagant, and probably is so, yet all will agree that fineness is a most important quality. Now, a December frost, stiffening the ground for eight, twelve, sixteen inches deep, is a silent, quiet operation, bat it is one in which an immense amount of mechanical power is exerted.

By reason of the expansion of water at the point of freezing, particle is made to impinge against particle by a slow but irresistible movement, both held as in a vice, and pressed against each other, till probably more particles in an acre of soil are broken up, and divided into two, five, or a dozen, than could be effected by the labor of a score of men in a whole summer. Clay soils are rendered less adhesive, and coarse soils (not made up too much of mere sand, that holds no water) are rendered finer by freezing. Throwing them into ridges in autumn, to give the frost greater access, is beneficial." One more extract on this subject: " That which, under the name of oxygen, we are accustomed to consider as a gas, forms, in fact, one-half of what geologists call the whole solid crust of the globe. In the subsoil, it exists in combination with metallic substances, which, when so combined, we call earths. Until they have been brought into free contact with the air, these earths are said, in the language of chemists, to be in the protoxide state - that is, in a state of early oxidation, containing free acids injurious to vegetation; by free and complete access to the air, the protoxide is converted into the peroxide, a state favorable to vegetation.

Now, farmer, the question for you is how, as speedily as possible, to convert the protoxide into the peroxide - an enemy into a friend. Paring and burning will do it immediately, but at a cost more (perhaps) than the worth of the land. Subsoil ploughing will do it - in eight or ten years, perhaps. A winter's frost, if your land is well drained, and well worked the following spring and summer, either as a fallow or manured green crop, will do it in one year." This is the language of a practical farmer, whose practical success has been often and justly extolled. I would not dwell so long upon this subject were I not convinced, after twenty years' practical experience, that it is of the utmost importance. It has long been my belief that there are few soils actually deficient in inorganic substances, if, by due exposure to the decomposing effects of the atmosphere, their latent principles of fertility were rendered available. This can only be secured by thorough granulation, and, until this is effected, manure applied is as much thrown away as food upon a disordered appetite, or words upon an unteachable mind.

Your correspondent cautions us not to plant a tree in soil " which frost will have a beneficial effect on in the way of rendering it friable." To this I will simply reply, that a soil which will not be rendered more friable from freezing and thawing, is incapable of supporting vegetation. His advice to gentlemen who wish to plant in clayey soils, "to go out with a wheelbarrow for decayed leaves and road sand," is so limited in its application that I fear the only gentlemen who will be likely to adopt it are those "Gemmen whose lands, Inclosed all In bow pots, their attics adorn, And whose share of the soil," &c.

The impropriety of planting, generally, in such mixtures, I may at some future time notice more in detail.

With regard to the " hard fisted" gardeners, and their astonishment at my advising the abolition of raking soil finely for ordinary seed crops, it occurs to me that they must have a " soft" spot somewhere. All good gardeners know that a finely divided surface will cake sooner than when it is rough, and daily act upon that principle.

I feel, Mr. Editor, that I have occupied too much space in replying to the lucubrations of an anonymous novice in horticulture; but since these animadversions are in a measure indorsed by their publication, I had no other alternative than to defend myself, and prove to your readers that my advice is neither hastily nor carelessly given. I now ask your correspondent to point out the errors in my advice to which he alludes in his concluding paragraph, as I am ready to correct any wrong impressions that I may have been the means of creating. So much do I feel interested in this subject, that I will, for the present, waive all the disadvantages I would be under in replying to the carpings of an anonymous writer; but, for the future, all such communications will be considered as unworthy of serious consideration.