TALKS ON MANURES A SERIES OF FAMILIAR AND PRACTICAL TALKS BETWEEN THE AUTHOR AND THE DEACON, THE DOCTOR, AND OTHER NEIGHBORS, ON THE WHOLE SUBJECT TEXT

when they yielded in 100 parts: Composition Of Clover-Roots, No. 1, (From Brow Of Hill). Moisture 4.34 Organic matter* 26.53 Mineral matter 69.13 ------- 100.00 ======= * Containing nitrogen .816 Equal to ammonia .991 “According to these data, an acre of land will yield three tons 12 cwts. of nearly dry clover-roots, and in this quantity there will be about 66 lbs. of nitrogen. The whole of the soil from which the roots have been picked out, was passed through a half-inch sieve. The stones left in the sieve weighed 141 lbs.; the soil which passed through weighing 218 lbs. “The soil was next dried by artificial heat, when the 218 lbs. became reduced to 185.487 lbs. “In this partially dried state it contained: Moisture 4.21 Organic matter* 9.78 Mineral matter† 86.01 ------- 100.00 ======= * Containing nitrogen .391 Equal to ammonia .475 † Including phosphoric acid .264 “I also determined the phosphoric acid in the ash of the clover-roots. Calculated for the roots in a nearly dry state, the phosphoric acid amounts to .287 per cent. “An acre of soil, according to the data, furnished by the six inches on the spot where the clover was thin, produced the following quantity of nitrogen: Ton. Cwts. Lbs. In the fine soil 1 11 33 In the clover-roots 0 0 66 -- -- -- Total quantity of nitrogen per acre 1 11 99 == == == “The organic matter in an acre of this soil, which can not be picked out by hand, it will be seen, contains an enormous quantity of nitrogen; and although, probably, the greater part of the roots and other remains from the clover-crop may not be decomposed so thoroughly as to yield nitrogenous food to the succeeding wheat-crop, it can scarcely be doubted that a considerable quantity of nitrogen will become available by the time the wheat is sown, and that one of the chief reasons why clover benefits the succeeding wheat-crop, is to be found in the abundant supply of available nitrogenous food furnished by the decaying clover-roots and leaves. CLOVER-SOIL NO. 2, FROM THE BOTTOM OF THE HILL. (GOOD CLOVER.) “A square yard of the soil from the bottom of the hill, where the clover was stronger than on the brow of the hill, produced 2 lbs. 8 oz. of fresh clover-roots; or 1 lb. 11 oz. 47 grains of partially dried roots; 61 lbs. 9 oz. of limestones, and 239.96 lbs. of nearly dry soil. “The partially dried roots contained: Moisture 5.06 Organic matter* 31.94 Mineral matter 63.00 ------- 100.00 ======= * Containing nitrogen .804 “An acre of this soil, six inches deep, produced 3 tons, 7 cwts. 65 lbs. of clover-roots, containing 61 lbs. of nitrogen; that is, there was very nearly the same quantity of roots and nitrogen in them, as that furnished in the soil from the brow of the hill. “The roots, moreover, yielded .365 per cent of phosphoric acid; or, calculated per acre, 27 lbs. “In the partially dried soil, I found: Moisture 4.70 Organic matter* 10.87 Mineral matter† 84.43 ------- 100.00 ======= * Containing nitrogen .405 Equal to ammonia .491 † Including phosphoric acid .321 “According to these determinations, an acre of soil from the bottom of the hill, contains: Tons Cwts. Lbs. Nitrogen in the organic matter of the soil 2 2 0 Nitrogen in clover-roots of the soil 0 0 61 --- --- --- Total amount of nitrogen per acre 2 2 61 === === === “Compared with the amount of nitrogen in the soil from the brow of the hill, about 11 cwt. more nitrogen was obtained in the soil and roots from the bottom of the hill, where the clover was more luxuriant. “The increased amount of nitrogen occurred in fine root-fibres and other organic matters of the soil, and not in the coarser bits of roots which were picked out by the hand. It may be assumed that the finer particles of organic matter are more readily decomposed than the coarser roots; and as there was a larger amount of nitrogen in this than in the preceding soil, it may be expected that the land at the bottom of the hill, after removal of the clover, was in a better agricultural condition for wheat, than that on the brow of the hill.” CHAPTER XXVI. EXPERIMENTS ON CLOVER-SOILS FROM BURCOTT LODGE FARM, LEIGHTON BUZZARD. “The soils for the next experiments, were kindly supplied to me, in 1866, by Robert Valentine, of Burcott Lodge, who also sent me some notes respecting the growth and yield of clover-hay and seed on this soil. “Foreign seed, at the rate of 12 lbs. per acre, was sown with a crop of wheat, which yielded five quarters per acre the previous year. “The first crop of clover was cut down on the 25th of June, 1866, and carried on June 30th. The weather was very warm, from the time of cutting until the clover was carted, the thermometer standing at 80 Fahr. every day. The clover was turned in the swath, on the second day after it was cut; on the fourth day, it was turned over and put into small heaps of about 10 lbs. each; and on the fifth day, these were collected into larger cocks, and then stacked. “The best part of an 11-acre field, produced nearly three tons of clover-hay, sun-dried, per acre; the whole field yielding on an average, 2½ tons per acre. This result was obtained by weighing the stack three months after the clover was carted. The second crop was cut on the 21st of August, and carried on the 27th, the weight being nearly 30 cwt. of hay per acre. Thus the two cuttings produced just about four tons of clover-hay per acre. “The 11 acres were divided into two parts. About one-half was mown for hay a second time, and the other part left for seed. The produce of the second half of the 11-acre field, was cut on the 8th of October, and carried on the 10th. It yielded in round numbers, 3 cwt. of clover-seed per acre, the season being very unfavorable for clover-seed. The second crop of clover, mown for hay, was rather too ripe, and just beginning to show seed. “A square foot of soil, 18 inches deep, was dug from the second portion of the land which produced the clover-hay and clover-seed. SOIL FROM PART OF 11-ACRE FIELD TWICE MOWN FOR HAY. “The upper six inches of soil, one foot square, contained all the main roots of 18 strong plants; the next six inches, only small root fibres, and in the third section, a six-inch slice cut down at a depth of 12 inches from the surface, no distinct fibres could be found. The soil was almost completely saturated with rain when it was dug up on the 13th of September, 1866: Lbs. The upper six inches of soil, one foot square, weighed 60 The second ” ” ” 61 The third ” ” ” 63 “These three portions of one foot of soil, 18 inches deep, were dried nearly completely, and weighed again; when the first six inches weighed 51¼ lbs.; the second six inches, 51 lbs. 5 oz.; and the third section, 54 lbs. 2 oz. “The first six inches contained 3 lbs. of silicious stones, (flints), which were rejected in preparing a sample for analysis; in the two remaining sections there were no large sized stones. The soils were pounded down, and passed through a wire sieve. “The three layers of soil, dried and reduced to powder, were mixed together, and a prepared average sample, when submitted to analysis, yielded the following results: Composition of Clover-Soil, 18 Inches Deep, From Part of 11-Acre Field, Twice Mown for Hay. {Organic matter 5.86 {Oxides of iron 6.83 {Alumina 7.12 {Carbonate of lime 2.13 Soluble in {Magnesia 2.01 hydrochloric acid. {Potash .67 {Soda .08 {Chloride of sodium .02 {Phosphoric acid .18 {Sulphuric acid .17 {Insoluble silicious matter, 74.61. { Consisting of: {Alumina 4.37 {Lime, (in a state of silicate) 4.07 Insoluble in acid {Magnesia .46 {Potash .19 {Soda .23 {Silica 65.29 ----- 99.68 ===== “This soil, it will be seen, contained, in appreciable quantities, not only potash and phosphoric acid, but all the elements of fertility which enter into the composition of good arable land. It may be briefly described as a stiff clay soil, containing a sufficiency of lime, potash, and phosphoric acid, to meet all the requirements of the clover-crop. Originally, rather unproductive, it has been much, improved by deep culture; by being smashed up into rough clods, early in autumn, and by being exposed in this state to the crumbling effects of the air, it now yields good corn and forage crops. “In separate portions of the three layers of soil, the proportions of nitrogen and phosphoric acid contained in each layer of six inches, were determined and found to be as follows: Soil dried at 212 deg. Fahr. 1st six 2d six 3d six inches. inches. inches. Percentage of phosphoric acid .249 .134 .172 Nitrogen 1.62 .092 .064 Equal to ammonia .198 .112 .078 “In the upper six inches, as will be seen, the percentage of both phosphoric acid and nitrogen, was larger than in the two following layers, while the proportion of nitrogen in the six inches of surface soil, was much larger than in the next six inches; and in the third section, containing no visible particles of root-fibres, only very little nitrogen occurred. “In their natural state, the three layers of soil contained: 1st six 2d six 3d six inches. inches. inches. Moisture 17.16 18.24 16.62 Phosphoric acid .198 .109 .143 Nitrogen .134 .075 .053 Equal to ammonia .162 .091 .064 Lbs. Lbs. Lbs. Weight of one foot square of soil 60 61 63 “Calculated per acre, the absolute weight of one acre of this land, six inches deep, weighs: Lbs. 1st six inches 2,613,600 2d six inches 2,657,160 3d six inches 2,746,280 ========= “No great error, therefore, will be made, if we assume in the subsequent calculations, that six inches of this soil weighs two and one-half millions of pounds per acre. “An acre of land, according to the preceding determinations, contains: 1st six 2d six 3d six inches, inches, inches, Lbs. Lbs. Lbs. Phosphoric acid 4,950 2,725 3,575 Nitrogen 3,350 1,875 1,325 Equal to ammonia 4,050 2,275 1,600 ===== ===== ===== “The proportion of phosphoric acid in six inches of surface soil, it will be seen, amounted to about two-tenths per cent; a proportion of the whole soil, so small that it may appear insufficient for the production of a good corn-crop. However, when calculated to the acre, we find that six inches of surface soil in an acre of land, actually contain over two tons of phosphoric acid. An average crop of wheat, assumed to be 25 bushels of grain, at 60 lbs. per bushel, and 3,000 lbs. of straw, removes from the land on which it is grown, 20 lbs. of phosphoric acid. The clover-soil analyzed by me, consequently contains an amount of phosphoric acid in a depth of only six inches, which is equal to that present in 247½ average crops of wheat; or supposing that, by good cultivation and in favorable seasons, the average yield of wheat could be doubled, and 50 bushels of grain, at 60 lbs. a bushel, and 6,000 lbs. of straw could be raised, 124 of such heavy wheat-crops would contain no more phosphoric acid than actually occurred in six inches of this clover-soil per acre. “The mere presence of such an amount of phosphoric acid in a soil, however, by no means proves its sufficiency for the production of so many crops of wheat; for, in the first place, it can not be shown that the whole of the phosphoric acid found by analysis, occurs in the soil in a readily available combination; and, in the second place, it is quite certain that the root-fibres of the wheat-plant can not reach and pick up, so to speak, every particle of phosphoric acid, even supposing it to occur in the soil in a form most conducive to ‘ready assimilation by the plant.’ “The calculation is not given in proof of a conclusion which would be manifestly absurd, but simply as an illustration of the enormous quantity in an acre of soil six inches deep, of a constituent forming the smaller proportions of the whole weight of an acre of soil of that limited depth. It shows the existence of a practically unlimited amount of the most important mineral constituents of plants, and clearly points out the propriety of rendering available to plants, the natural resources of the soil in plant-food; to draw, in fact, up the mineral wealth of the soil, by thoroughly working the land, and not leaving it unutilized as so much dead capital.” “Good,” said the Deacon, “that is the right doctrine.” “The roots,” continues Dr. Vœlcker, “from one square foot of soil were cleaned as much as possible, dried completely at 212°, and in that state weighed 240 grains. An acre consequently contained 1,493½ lbs. of dried clover-roots. “The clover-roots contained, dried at 212° Fahr., Organic matter* 81.33 Mineral matter,† (ash) 18.67 ------ 100.00 ====== * Yielding nitrogen 1.635 Equal to ammonia 1.985 † Including insoluble silicious matter, (clay and sand) 11.67 “Accordingly the clover-roots in an acre of land furnished 24½ lbs. of nitrogen. We have thus: Lbs. of nitrogen In the six inches of surface soil 3,350 In large clover-roots 24½ In second six inches of soil 1,875 --------- Total amount of nitrogen in one acre of soil 12 inches deep 5,249½ Equal to ammonia 6,374½ ========= Or in round numbers, two tons six cwt. of nitrogen per acre; an enormous quantity, which must have a powerful influence in encouraging the luxuriant development of the succeeding wheat-crop, although only a fraction of the total amount of nitrogen in the clover remains may become sufficiently decomposed in time to be available to the young wheat-plants. CLOVER-SOIL FROM PART OF 11-ACRE FIELD OF BURCOTT LODGE FARM, LEIGHTON BUZZARD, ONCE MOWN FOR HAY, AND LEFT AFTERWARDS FOR SEED. “Produce 2½ tons of clover-hay, and 3 cwt. of seed per acre. “This soil was obtained within a distance of five yards from the part of the field where the soil was dug up after the two cuttings of hay. After the seed there was some difficulty in finding a square foot containing the same number of large clover-roots, as that on the field twice mown; however, at last, in the beginning of November, a square foot containing exactly 18 strong roots, was found and dug up to a depth of 18 inches. The soil dug after the seed was much drier than that dug after the two cuttings of hay: The upper six inches deep, one foot square, weighed 56 lbs. The next ” ” ” 58 ” The third ” ” ” 60 ” ======= “After drying by exposure to hot air, the three layers of soil weighed: The upper six inches, one foot square 49¾ lbs. The next ” ” 50½ ” The third ” ” 51¼ ” =========== “Equal portions of the dried soil from each six-inch section were mixed together and reduced to a fine powder. An average sample thus prepared, on analysis, was found to have the following composition: Composition of Clover-Soil Once Mown for Hay, and Afterwards Left for Seed. Dried at 212° Fahr. { Organic matter 5.34 { Oxides of iron 6.07 { Alumina 4.51 { Carbonate of lime 7.51 Soluble in { Magnesia 1.27 hydrochloric Acid { Potash .52 { Soda .16 { Chloride of sodium .03 { Phosphoric acid .15 { Sulphuric acid .19 { Insoluble silicious matter, { 73.84. Consisting of: { Alumina 4.14 { Lime (in a state of silicate) 2.69 Insoluble in acid { Magnesia .68 { Potash .24 { Soda .21 { Silica 65.88