Note 137 — CHAP. IX. Of Wheat.

They do reach through all the Mould (as shall be proved by-and-by); and yet may leave sufficient Pasture behind; because it is impossible for them to come into Contact with all the Mould in One Year; no more than when Ten Horses are put into an Hundred Acres of good Pasture, their Mouths come into Contact with all the Grass to eat it in one Summer, though they will go all over it, as the Vine-roots go all over the Soil of a Vineyard without exhausting it all; because those Roots feed only such a bare competent Quantity of Plants, which do not overstock their Pasture.

The Superficies of the fibrous Roots of a proper Number of Wheat-plants bear a very small Proportion to the Superficies of the fine Parts of the pulverized Earth they feed on in these Intervals; for one cubical Foot of this Earth may, as is shewn in p. 29. have many thousand Feet of internal Superficies: But this is in proportion to the Degree of its Pulveration: and that Degree may be such as is sufficient to maintain a competent Number of Wheat-plants, without over-exhausting the vegetable Pasture, but not sufficient to maintain those, and a great Stock of Weeds besides, without over-exhausting it. And this was plainly seen in a Field of Wheat drilled on Six-feet Ridges, when the South Ends of some of the Ridges, and the North Ends of others, had their Partitions Hand hoed, and cleansed of Weeds, early in the Spring, the opposite Ends remaining full of a small Species of Weeds, called Crow-needles, which so exhausted the whole Intervals of the weedy Part of the Ridges, that the next Year the whole Field being drilled again with Wheat exactly in the Middle of the last Intervals, the following Crop very plainly distinguished how far each Ridge had its Partitions made clean of those small Weeds in the Spring, from the other End where the Weeds remained till full-grown; the Crop of the former was twice as good as that of the latter, even where both were cleansed of Weeds the next Spring. This Crop standing only upon that Part of the Mould, which was farthest from the Rows of the precedent Crop, proves that the Roots, both of the Wheat and Weeds, did enter all the Earth of the former Intervals.

It was also observable, that where the Partitions of Two of the Six-feet Ridges had been in the precedent Year cleansed of Weeds, and those of the adjoining Ridges on each Side of them not cleansed, the Row that was the next Year planted exactly in the Middle of the Interval between those two Ridges, was perceivably better than either of the Two Rows planted in the Intervals on the other Side of each of them: The Reason of which Difference must be, that the Middle of the Interval, that was between the Two cleansed Ridges, was fed on by the Wheat only, and by no Weeds; but the other Two Intervals were fed on by the Wheat on one Side, and by both the Wheat and Weeds on the other Side of each.

There were, in the same Field, several Ridges together, that had the Ends of their Rows of Wheat plowed out by the Hoe-plough, and their other Ends cleansed of Weeds: This was done on purpose, to see what Effect a Fallow would have on the next Crop, which was indeed extraordinary; for these fallowed Ends of the Ridges, being Horse-hoed in the Summer, as the other Ends were, and the Intervals of them made into Ridges, the following Year produced the largest Crop of all; this Crop was received in 1734.

These several different Managements performed in this Field, shewed by the different Success of the Crops in each Sort, what ought to be done, and which is the best Sort of Management.

This Field indeed is some of my best Land; and by all the Experiments I have seen on it, I do not find but that, by the best Management, never omitted in any Year, it might produce good annual Crops of Wheat always, without Assistance of Dung or Fallow; but it would be very difficult for me to get Hands to do this to the greatest Perfection, unless I were able constantly to attend them.

The whole pulverized Earth of the Interval being pretty equally fed on by the former Crop, ’tis no great Matter in what Part of it the following Crop is drill’d: I never drill it but on the Middle of the last Year’s Interval, because there is the Trench whereon the next Year’s Ridge is made with the greatest Conveniency: But there may be some Reason to suspect, that the Plants of the Rows exhaust more Nourishment from that Earth of the Intervals which is farthest from their Bodies, than from that which is nearest to them: Since their fibrous Roots, at the greatest Distance from the Rows, are most numerous, &c. by these the Plants, when they are at their greatest Bulk, are chiefly maintained.

It must be noted, that the above Experiments would not have been a full Proof, if Weeds had been suffered to grow in the Partitions of the Ends of those Ridges, in the Year wherein the Difference appeared. It may also be noted, that a Mixture and Variety of bad Husbandry are useful for a Discovery of the Theory and Practice of good Husbandry.