The Hon. C.P. Holcomb, of Delaware, furnishes some interesting remarks on the wheat crop of the United States:—

A short wheat crop in England, Mr. Webster says, affects the exchanges of the civilized world. In the vast increase of population in the absence of long wars and famines, the importance of this staple is constantly increasing. Its cultivation is the most attractive and pleasant of all descriptions of husbandry; and its rewards are generally remunerating, when the soil and climate are favorable, and the markets are not too distant.

It is important to know what our relation is to this staple of the world, and what is, and what is likely to be, our contribution to the great aggregate of production. Beyond feeding our own great and rapidly increasing population, it probably will not soon, if ever, be very great. It is a mistake, I apprehend, to suppose our country is naturally a great wheat-producing country. The wheat district at present, in comparison to the whole extent of our territory, is limited. It is confined, so far as any appreciable amount is grown, to about ten degrees of latitude and twenty degrees of longitude, and embracing about one half the number of the States. The crop of 1848 is estimated by the Commissioner of Patents at one hundred and twenty-six millions, and our population at twenty-two millions. This gives a less number of bushels, per head, to our population than the consumption of Great Britain, which is generally set down at one hundred and sixty millions, or six bushels to each inhabitant. But with us Indian corn is a great substitute; so are potatoes and oats in Ireland and Scotland. Still our consumption of wheat, including the black population, is undoubtedly less, per head, than theirs. But in the absence of any certain data, to ascertain either the actual production, or our consumption, our only safe course is to take the actual excess, or the amount exported, after supplying our own wants. This, for the fiscal year 1848, being the crop of 1847, amounted, in flour and wheat, to twelve millions two hundred and ninety-four thousand one hundred and seventy-five bushels, although Mr. Burke's figures would show a surplus of some forty millions! That there was not, and never has been any such surplus in the country is very evident, for the foreign demand was all the time good, and drew away all we had to part with.

The crop of 1848 was, undoubtedly, one of the best and largest we have ever grown; yet I have ascertained, by application at the registrar's office, that the exports for the fiscal year 1842, amounted in wheat to but 1,527,534 bushels, and in flour to 2,108,013 barrels, or less by 226,676 bushels than the exports of 1848. Twelve millions is comparatively a small surplus in a favorable season, for a country with a population of twenty-two millions of inhabitants. The loss of a small per cent. in an unfavorable season would at once sink this excess.

Let us now notice more in detail the different sections of our country as adapted to the growth of wheat.

The New England States, some of them aided in their recent enterprises by bounties offered by the state governments, have failed to insure such success as is likely to encourage them to continue the culture of wheat; or, at all events, to induce them to aim at increasing their product to any considerable extent, since, as one of their own farmers candidly states, "the attempt to grow a crop of wheat is an experiment."

The States south of North Carolina, and inclusive of a part of Delaware, have never heretofore succeeded in growing wheat to any considerable extent, though there were periods in their history—before the general introduction of the culture of cotton—when, if it had been practicable to make the cereal one of their staples, they would certainly have done so. Besides the common dangers from rust and blight, the fly, and sometimes the frost—as the past season—they have a most formidable enemy in the weevil. In Upper Georgia, in the Cherokee country in particular, wheat will probably be cultivated to some extent, and a limited cultivation of it by the planters for their own use will probably continue in several of the southern states. But the cotton, rice, and sugar states, like the manufacturing states of New England, will not soon, if ever, add much to the supply of wheat; the rich staples of the former, and the varied husbandry and grazing of the latter, suited to supply the immediate wants of a manufacturing population, will be likely to receive their attention in preference.

Kentucky and Tennessee, though their agricultural history dates back beyond the settlement of the north-western states, have already been out-stripped by at least two of them. In neither of these states has the culture of wheat ever been put forward, and regarded as one of their best staples, or as very favorably adapted to their soil and climate. Still, notwithstanding the formidable danger from rust, the production of Tennessee is estimated to be equal to nine bushels to each person, and Kentucky about seven and a half bushels. Missouri may be classed with Kentucky and Tennessee, which she much resembles in soil, climate, and productions, except that she raises much less wheat than either, her crop being placed by the Commissioner of Patents at only two millions, or less than four bushels to each resident of the state. But, besides that the experience of the past discourages the idea that these fine states are likely to become great wheat-producing states, the fact that the staple of cotton may be cultivated over a considerable portion of one of them, and that hemp and tobacco are among the valuable products of the other two; that Tennessee is the very largest corn-producing state in the Union, showing her soil and climate are particularly adapted to this description of grain, and that Kentucky and Missouri are unsurpassed as grazing countries, and there is little ground to suppose that any change in their husbandry will very greatly or suddenly augment the production of wheat. Let us come now to the States of Indiana, Illinois, Wisconsin, and Iowa, and that fabulous wheat district or territory to the west of these again, from which, according to the vaticinations of some, may be drawn supplies of wheat to feed the population of both Europe and America, or fill warehouses that would sustain our people through a longer famine than that which afflicted the people of Egypt! I cannot help thinking that, to some extent, this generally fertile district of country has, so far as the production of wheat is concerned, been "shouted forth in acclamations hyperbolical." My own impression in regard to it is, including the states last named, derived in part from observation, from intercourse and correspondence with intelligent agriculturists of these states, and from a careful examination of a geological survey of two of them, that the soil and climate of this whole district of country are not particularly favorable to the production of wheat. The popular idea I know to be otherwise. I am not going to dwell upon it, or to examine the subject at any length. There is a single remark that may help to explain the reputation that has gone abroad in reference to the wheat-producing qualities of these lands. The prairie sod, when first broken up, generally produces wheat well, often most abundantly, provided it escapes the rust, insect, &c. But, when this ground has been much furrowed, becomes completely pulverized by exposure to the atmosphere, the light and friable mould, of which most of it is composed, drenched, as a good deal of it is, at times, with surface water, fails to hold or sustain the roots of the plant, it is thrown out, or winter-killed; and "winter-killed," "winter-killed," "winter-killed," we all know, is among the catalogue of disasters that almost annually reach us. Sometimes, when escaping the winter, the high winds of spring blow this light soil from the roots, exposing them to such an extent, that, in a dry time in particular, the wheat often perishes. When breaking up fresh prairies, there was much encouragement and promise of hope, but which, I believe, has not been, nor is likely to be, realized by their husbandmen, in the degree that early experiments induced them to look for.

As appears by the last report of the Commissioner of Patents, the crop of Illinois, in reference to population and production, is below that of Kentucky, and both Indiana and Illinois are below that of Tennessee. The crop of Indiana is set down at 8,300,000, her population at 1,000,000, or equal to 8½ bushels a-head. The production of Illinois is stated at 5,400,000, her population at 800,000, or less than seven bushels to each inhabitant—and both these "fair and fertile plains" are still farther behind the old "battered moors" of Maryland and Virginia.

Much of their wheat, too, is spring wheat, sown often on land where the fall crop had winter-killed, increasing the number of bushels much more than the value of the crop. I have heard it estimated that full one-third of all the wheat shipped from Chicago was of this description. Chicago is their great wheat depot. Several millions of bushels are shipped from this point, the contributions from parts of three States, Wisconsin, Indiana, and Illinois; and which concentration of their joint product at this new western city, or something else, seems to have imparted to each and all these states the reputation of great wheat-growing states, though they are, in fact, with the advantage of a virgin soil, behind several of the western states, and two at least of the eastern or Atlantic States. The geological explorations of the Hon. Robert Dale Owen, undertaken under the authority of Congress, throws much light on the character of the soil of Wisconsin and Iowa, and the description given undoubtedly characterizes much of that region of country. The specific gravity of the soil, Mr. Owen states to be remarkably light; but what he represents to be a "striking feature in the character of the Iowa and Wisconsin soils, is the entire absence, in the most of the specimens of clay, and in a large proportion of silex." Again, he speaks of their being particularly adapted to the growth of the sugar-beet, which he truly says, "flourishes best in a loose fertile mould." Again, he detected no phosphates; but they might be there, as the virgin soil produced good wheat. So does the virgin soil of most of the prairie land.—"The soil was rich in geine," &c. But I submit that this does not describe a wheat soil, hardly in any one particular. Liebig tells us, that "however great the proportion of humus in a soil, it does not necessarily follow it will produce wheat"—and cites the country of Brazil.