The first, and certainly a very important advantage, resulting from ploughing old grass land, is, that a full supply of the necessaries of life would be obtained by the public, in consequence of that measure. It is com puted, by those versant in such inquiries, that good pasture land does not furnish above 1:3 stones (161h. avoirdupois each) of beef or mutton per acre per 0:muni, above the weight of the animal or animals when laid upon the grass; which, upon the supposition that a healthy person requires one and a half pound per clay to support him, would be consumed exactly in one hun dred and twenty-eiteht days. If this land, however, is converted into tillage, more than triple the number may be led upon its produce, as will appear from the tollowing- calculations. Suppose the crop to be only six quarters pt r acre, which is a low estimate upolu the hums under consiueration, and that four bushels are re quired for seed, and six bushels to the horses employ ed, there remains a disposable quantity of !Our quarters, six bushels, which, at the UN ersge tght ol lour hun dred pounds per quarter, gives nineteen hundred pounds weight 01 bread corn for the use of the people. ft we shall estimate that one-lburth of that weigill goes for pollard, seeds, or waste in the manulacturing, which is a great allowance, the remainder amounts to liairteen hundred and twenty-live pounds weight ol meal or flour to be used for bread and other purposes, which, at three pounds weight per head, per day, will supple the con sumption ol 475 people fur one clay, instead of 128, who procured food for the same time, from the beef or mut ton produced upon an acre of grass land. The compa rison would still be Inure striking, were it extended to potatoes and other esculents, which, of course, would form a part of every rotation, were convertible hus bandry introduced.
But it may be alleged, that a general introduction ol the alternate husbandry would occasion a scarcity or butcher meat, and that an exchange ol dillieulties would be the consequence of adopting the system recommend ed. To this it may be answered, that, if alternate hus bandry were practised, the quantity of butcher meat would be immediately increased, to the great advantage both of the public and individuals. After what has al ready been repeatedly urged in this article, it need hardly he stated, that a considerable quantity of land in England is oppressed by the plough, and that a very great improvement would be accomplished, were it rested and invigorated under pasture, after being com pletely summer fallowed, and laid down with suitable grass seeds. If the like quantity of this old tillage land was annually sown with grass seeds, as was broken up front old pasture, perhaps one fourth more cattle and sheep might be fed for the butcher than is practicable under the present system. None but those who have tried it, can be sensible of the vast improvement made by grazing old ploughed land. If one million of acres of old tillage land were sown down in a gradual man ner, and the like extent of old pasture broken up, it is probable that an additional annual supply, not less than two million of stones of beef and mutton, and three mil lions of quarters of grain, would be thrown into the public market. In short, were alternate husbandry ge nerally exercised in Britain, we are satisfied, that dou ble the extent of its present population might, with ease, be maintained ; and this might be proved in the most satisfactory manner, by an appeal to the quantity of grain and butcher meat produced upon these farms, where that system has been adopted and followed.
Another advantage of great magnitude would neces sarily be obtained, were the old pasture lands con verted to tillage, vie. the immense quantity of manures which would thereby be furnished for enriching the poorer soils, and ameliorating the old tillage fields. be fore they were laid down with grass seeds. Every three acres of old grass land broken up. would, with ease, furnish clung for one acre ; consequently the ploughing of one million of acres would return dung for three hundred and thirty-three thousand acres of barren or unproductive land, per annum, for three or four years afterwards. An additional increase of one quarter and a half of produce might reasonably be ex expected to lullow front the manure thus afforded to the unproductive lands, while the original stock of manure, like money vt sled at componnd interest, would accumu late and increase from year to year, till the country was improved to the greatest degree which physical circum stances permitted.
We have been more particular upon this branch of our subject, than at first sight may seem to be neces sary ; but an attentive examination 01 the rural cconomy of the sister kingdom convinced us, that the exclusive system generally followed, was attended with effects pernicious and destructive to the public interest. At the same time, as the great body of farmers in every district are more defective in the management of land newly broken up from grass, than in any other branch of practice, it occurred, that too much, if it was right. said, could not be urged in elucidation of the several processes which ought to be executed, when converti ble husbandry is introduced.
We cannot close this branch of our subject, urging the utility and advantage of conjoining live stock and corn together, and of making the management of the one subservient to the growth of the other. How ever much the general system of agriculture may have been amended of late years, there are comparatively few arable lands vv here double the quantity of live stock might not be kept, without lessening the annual pro duce of grain. By a proper combination of green crops, such as tares and clover for summer, turnips for win ter, and potatoes and luta baga for spring, the tillage farmer may fatten a quantity of stock equal to the gra zie•. No doubt a considerable capital is required to set such a s\ stem on foot, besides a good deal of trou ble in its execution; but these are indispensable requi sites in every improved system. What we chiefly con tend for is, that alternate husbandry is most beneficial to cultivators, and to the public ; that a farm managed according to its rules will yield a greater quantity of produce than if any other system is adopted ; that if one half of the Erin is kept under artificial grasses, and other green crops, as much live stock may be support ed and fattened upon their produce as if the whole farm was kept in old pasture ; and that the other half, from the large quantity of dung produced from the consump tion of green crops, will furnish as much disposable produce for supplying the market, as if the whole farm had been kept in a regular sequence of corn crops. All these advantages may be gained from a conjunction of ptock and corn husbandry ; and it is from this conjunc tion that the superiority of British over Continental hus bandry, already illustrated in another Chapter, chiefly proceeds.