The root-germ of the seed is developed sooner than the leaf-germ, and is, with some kinds of seed, as much as 2 to 3 inches long, while the leaf-germ is but a few lines in extent. The vigorous development of plants depends less on the size and weight of the seed than on the deep or shallow covering of the seed, and on the root finding at once abundant and vigorous nourishment in its first period of life. The shallower the covering is, the more vigorous will be the development both of the plant and root; both produce shoots, while the plant, sown at the same time several inches deep, employs its strength not only to lengthen the roots but also to develop near the surface the necessary crown-roots from the leaf-germs. The plant from a seed sown over inch deep in the ground never has sprouts, with equally close or wide position, as many stools, as the grain covered inch + or less. The stronger or weaker plants in summer-grains show at once whether the seed has been covered shallow or deep. Experiments with wheat-grains prove positively that their power of germination is increased and strengthened by complete ripeness of the seed. The wheat used for these experiments was taken at three different times before harvest: No. 1, the grain was in the milk state; No. 2, when the grain was in the pasty state; No. 3, when the contents of the grain was completely formed, and the germ far enough developed to loosen it with the fingernail. Fifty grains of each kind were sown at the usual time of sowing the winter grain; sown 1, 2, 3, &c., to 6 inches deep. The grains designated as No. 1, which were least ripe, sown 2 inches deep, one-half the number came up while the other half remained in the ground. Of No. 1, with a depth of 3 inches, but 2 to 3 grains germinated; one-third of No. 2 did not come up; all the grains of No. 3 germinated. At the depth of 4 inches none of No. 1 germinated, not quite a third from No. 2, while more than half of No. 3 came up. At the depth of 5 inches none of 1 and 2 germinated, and hardly one-third of No. 3; and even of the last No. but 2 to 3 grains at a depth of 6 inches. L Weight and Nitrogen of several plants with their entire roots. The results of investigation as to the weight and some chemical facts may be seen in the following summary: It is well known that in taking up plants-especially such as have no top or main-root, as clover, rape, lupine, etc. a considerable portion of the more delicate root-formations are torn away and remain in the ground. The figures above given give some hints as to the quantity of these remaining roots. The root-quantity amounted in per cent. of the whole dried mass of plants: By means of the ordinary shallow taking up plants, as done by a spade, but one-half of the actual quantity of roots in young plants and only one-fourth in older ones are obtained. The wheat plants examined show very plainly that the start obtained by early sowing over late sowing, for the growth developed from fall to the first of spring, gives the proportion between both of 386 to 88. The increased root-formation amounts with the early sown plants to 3 times as much as the late sown plants, and the increased herb-formation fully to 5 times as much. The peas show in a similar manner the advantage gained by shallow planting over deep sowing; for the ratio of the simultaneous growth of shallow and deep sowing is as 212 to 153; it has, consequently, been fully one-third quicker and stronger in the former case (shallow sowing). In what ratio are the roots of plants and their nitrogen distributed in the soil and sub soil? This important problem could not be solved with any of the dug and washed plants, but with such only as offered roots sufficient for investigation The soil proper has herein been fixed at a depth of 9 to 10 inches. The results of these investigations are in the following table: The proportion of roots which went into the indifferently loosened sub-soil are very considerable, and relatively larger with stalk-plants (27 to 28 per cent. of the root-quantity) than with rape and clover (but 15 to 24 per cent). It is, therefore, entirely erroneous to regard our grain plants as surface-rooted plants; they are such upon compulsion only, and against their nature if a shallow soil with solid or wet sub-soil is allotted to them; if the latter be opened by loosening and draining, they will at once take hold of it, to the advantage of the owner. The roots of the sub-soil are unexceptionally richer in nitrogen than those of the upper stratum of soil; which fact is another confirmation of the general law that the younger plants and parts of plants contain more nitrogen (and also more mineral elements) than the older ones. The yourger roots in the sub-soil have accordingly (for manuring), a higher manure value (with equal weight) than the older ones of the upper soil, as a comparison of the columns in the preceding table will show. The lowest and the highest parts of the plants contain most of nitrogen. With perennial plants, as for example, clover, the root-increase of the second year seems to be far greater than the one of the first year, for the root-weight of a one-year clover plant rises in the second year of growth from 166 milligr, to 719-fully to four-fold that of the first year. Should this fact be confirmed by further investigations, it might, with respect to the enriching of soil, be of more advantage to leave perennial forage plants and grasses on the same spot, at least for some years, than to change them every year. As to the total quantity of roots belonging to a certain number of plants, or to the mass of plants cultivated on a certain area, and remaining in the ground after mowing, is very different according to the species of plants, and considerably greater with clover, lupine, and generally with the so-called soil-enriching plants, than with the stalk-plants, peas, etc. Precise figures can be made only after the examinations of roots, continued till the period of full maturity, have been received. In order to be able to compare approximately the plants examined in this regard, we give a calculation of the root-quantities and of the quantity of nitrogen per acre contained in them, derived from figures resulting from weights and chemical examinations, and with the supposition that there was a produce on Should these suppositions appear too high or too low, the following value in figures can easily be corrected on the basis of more correct proportions. Root-quantity per acre, perfectly dry. Nitrogen in the rootquantity per acre. PLANTS. Lbs. Lbs. Winter wheat, sown early, from April 30 (in 1,000, 000 plants)... 190 The same, sown late, from April 26 (in 1,000,000 The same, from June 8 (in 1,000,000 plants). Winter rape, from June 7 (in 500,000 plants). The same, sown shallow, from May 5 (in 500,000 The same, from June 6 (in 500,000 plants). Clover, of two years, from Apr. 2 (in 1,500,000 plants) 1782 375 *[!08-qu ༈:3 ཧུ : : 118 51 430 468 280 748 6.5 5.4 119 2979 76 .... *tour ིི : :ཊཿ [1o9 -qns uI ིི::ཌ :; Total. Lbs. Lbs. Lbs. 6.9 2.1 1.1 3.2 572 10.8 3.7 14.5 22.7 4.2 26.9 19 III. On the presumptive advantages of deep plowing or loosening of the soil. The preceding investigations on depth, quantity and quality of the roots of our agricultural plants, and the probable dependence of the latter on the greater or less looseness of soil, induce us to sum up the advantages to be expected-according to the principles of natural science-from a deep loosening of soil, for the quality of soil and for the plants growing therein. These advantages may be classified as physical and chemical changes by means of loosening. The soil becomes, in consequence of the former, a better and more convenient dwelling place for the plants; and can, in consequence of the latter, offer to these healthier and more abundant nourishment. The advantages are, in detail, the following: |