The natural Poorness of an hot Gravel may be compensated by Dung, more Heat, and the Benefit of the Hoe.
The natural Richness of the other sorts of Land being increased by hoeing and cleansing it from Grass, Luserne will thrive therein with the less Heat; for what the Soil wants of one of these Two Qualities, must be made up with the other; and it has grown high in hoed rich Ground at Christmas, when that in Land of an hotter Nature, but poorer, has not been able to peep out, for want of more Nourishment: So, if rich Land be clayey, very wet and cold, tho’ very rich, it requires much Heat, for as high a Growth of Luserne at Midsummer.
The best Season of planting it in England is in April, after the Danger of Frost is over; for a small Frost will destroy the whole Crop, when the Plants first appear; and too much Wet, with cold Weather, will rot the Seeds in the Ground; so that about the Middle of April may be generally esteemed as the best Season for sowing this Seed.
The hoed Plants of Luserne having larger Roots, and yielding more Crops than those of St. Foin, Reason seems to require, that the Number of the former be less.
But, on the other hand, if we consider, that as the Luserne-roots exceed the St. Foin in Bigness, so they also do in Length, by as great a Proportion; being generally less taper, and as they go deeper, they have more Earth to nourish them; they also require a better Soil, and more frequent Aids from the Hoe; and, by their extraordinary quick Growth, receive a speedier Relief from it, than the Roots of St. Foin do.
Thus, if by reaching deeper in a better Soil, and being more hoed, Luserne receives, from a square Perch of Ground, Nourishment in a proportion double to that whereby its Roots exceed those of St. Foin in Bigness, then I do not see why we should not leave the Number of Luserne-plants double to the Number of those we leave in St. Foin.
But if the Excess of Nourishment were no more than the Excess of Bigness of Roots, I think an equal Number of Plants should be left in Luserne, and in St. Foin: Yet since the hot or cold Constitution of a Plant, and also the Quantity it can produce, ought to be considered, as well as its Bulk, in relation to the Nourishment it requires, more Trials are necessary for determining the exact Number of Luserne-plants proper to be placed on a square Perch, than have been hitherto made.
Perhaps it will be thought heterodox to maintain by any Arguments, that to err in falling somewhat short of the just Number, is not of worse Consequence, than exceeding it.
Where they stand at Four or Five Inches asunder in the Rows, ’tis observed, that tho’ the Intervals betwixt the Rows be wide, yet the Plants are much the larger, and produce more that stand in the outside Rows (the Ground without being clean); and especially those at each End of the outside Rows, that is, the Corner-plants, are largest of all. I need not say, that had all the other Plants as much Room and Tillage as the Corner ones have, they would be as large, and produce each as much Hay; for those which stand perfectly single in Places by themselves, are seen to be larger, and produce more, than those Corner ones; and of the larger and longer Roots our Stock does consist, the more Nourishment they are capable of taking, as has been shewn. Where some Plants of the Luserne have been planted Two Feet asunder, in poor dry Land, which was kept clean from Weeds, and frequently digged, each Plant has sent forth upward of Three Hundred Stalks, and these have been Six or Seven Inches high by the Middle of March.
And it must be likewise observ’d, that the Crop will be produc’d in Proportion to the Nourishment it receives; for if the most gigantic Luserne plant, which, when pamper’d by the Hoe, has made a Produce more like a Tree than an Herb, remains a few Years without that or some equivalent Culture, it will by little and little cease to produce more than a few poor sickly Stalks, just to shew its Species; and then, if this Culture be repeated, will recover its pristine Strength, and yield as great a Crop as ever; but, if that be longer omitted, will die: The Vastness of its Root avails nothing, unless it has Food in proportion to it.