Elements of agricultural chemistry, in a course of lectures for the Board of Agriculture / By Sir Humphry Davy.

  • Davy, Humphry, Sir, 1778-1829.
Date:
1813
Catalogue details

Licence: Public Domain Mark

Credit: Elements of agricultural chemistry, in a course of lectures for the Board of Agriculture / By Sir Humphry Davy. Source: Wellcome Collection.

    395/428 (page 39)
    The proportional value of the grass, like that of the T. pratense, is as 11 to 10. The produce of each of the above mentioned species, was taken from a similar soil, and in the same situation the conclusions must therefore be con- sidered positive, with respect to such soils only. It is evident that more than twice the quantity of nutritive matter is afforded by the produce of one acre of the T. macrorhizum, than from the produce of an equal space covered by the T. pratense. Its short duration in the soil (for if sown early in the autumn, on a rich light soil, it is only an annual plant) renders it fit only for green-food or hay; this in some measure lessens its value, when compared with the T. pratense. It possesses the essential property of affording abun- dance of good seed ; and if the ground be kept clear of weeds, it sows itself, vegetates, and grows rapidly, without covering-in, or any operation what- ever. For four years it has propagated itself in this manner, on the space of ground which it now occupies, and from which this statement of its compa- rative value is made. The produce of lucern in grass, comes nearer to this species in quantity, but is greatly deficient in nutritive matter, as much as 13 to 33. The long continuance of lucern in the soil is therefore the' only merit which it possesses above the two last mentioned species ; and when that is the object of the cultivator, it will of necessity have the preference. The value of the grass of saintfoin is equal to that of the T. pratense; and proportionally less than that of the Trifolium macrorhizum, as 10 to 11. The quantity of grass is very small, and on soils of the nature above described, it is doubtless inferior. However, from the superior value of the grass, on dry hilly situations or chalky soils, it may in such situations possibly be their superior in every respect. L1V. Medicago Sativa. Wither. B. 3, P. 643. Lucern. Nat. of Britain. At the time the seed is ripe, the produce from a rich clayey loam, is oz. or lbs. per acre Grass, 104 oz. The produce per acre - 1132560 0 =70785 0 0 80 dr. of grass weigh when dry. 32 dr. “1 The produce of the space, ditto 665.2f j ^3024 The weight lost by the produce of one acre in drying 64 dr. of grass afford of nutritive matter 1.2 dr.q The produce of the space, ditto 39 dr. f ^6544 or 0 =28314 0 0 - 42471 0 0