笔下文学
会员中心 我的书架

Nitrification of the Soil, or, How Plants Grow

(快捷键←)[上一章]  [回目录]  [下一章](快捷键→)

by william dennison of fargo, north dakota.

we will venture the assertion that when the history of the past century is being written up, the chroniclers will discover that there has been as much, if not more progress and advancement made in the nineteenth century than in all of the eighteen centuries preceding it. the advancement in the past century was phenomenal in the marvelous achievements in inventions and in discoveries in every branch of industry, in the arts and sciences; and i am delighted to know that agriculture, horticulture and floriculture have also received some attention, although not so much as might have been. still, we are pleased that a beginning in those branches has been made, and we hope for much more rapid advancement within the next two decades.

that there has been a great awakening and a marked advancement in the material progress in the past century no one will seek to controvert the fact, but let us hope that while we have been making such rapid strides materially we have also, during the same period, made equally as much advancement spiritually, for to glorify god is (or ought to be) man’s chief aim in life. there has been a beginning in the advancement of scientific agriculture, and the agricultural world is indebted to no one so much as to john bennett lawes, of rothamsted, england, who devoted a lifetime of study and the lands of his large estate to experimental farming, the results of which he published from time to time in the gardener’s chronicle, and at his death left a fund sufficient in trust to carry on the great work he had begun and carried forward his celebrated tests of experimental farming, extending over fifty years, from 1844 to 1893. indeed, john bennett lawes may justly be called the father of the experimental stations in our country. in these earliest experiments the effects of various manures were carried out. it was in these trials that the excellent results obtained by manuring turnips with phosphate previously treated with sulphuric acid were first discovered, and his taking out a patent, in 1842, for treating mineral phosphate with sulphuric acid, which was the commencement of the present enormous manufacture of artificial manures. the above experiments were carried on in pots by mr. lawes, but, in 1843, he was joined by dr. gilbert, as eminent a chemist as was mr. lawes himself, and from 1844 began the field experiments, which have become world-wide for the great benefits they have resulted in to agriculturists everywhere.

the rothamsted estate was divided into small fields, and the effects of the various crops on the fields with and without manure were carefully noted. soils were analyzed before the crops were planted, and also after the crops were harvested, to determine the loss or gain of nitrogen.

the rotation of crops was studied thoroughly, and beans and peas were then made one in a four-course rotation. but even earlier than 1844 it had been observed that leguminous plants, of which there are thousands distributed over this sphere, had a beneficial effect on the land for the succeeding crop. at rothamsted the legumes, or such of them as beans, peas or red clover, were thoroughly tried, and it was invariably found as one in a rotation of four to produce the same results. in some way that they then could not explain, the land after a crop of legumes was very much richer in nitrogen, amounting in many instances to 300 pounds per acre. these worthy gentlemen kept on for years trying to account for the phenomenon and endeavored to discover the true source of nitrification. but to the french chemists schlosing and muntz belong the credit of establishing by experiment the true nature of nitrification. their first paper on the subject appeared early in 1877, or only twenty-nine years ago. they wished to ascertain if the presence of humic matter was essential to the purification of sewage by soil, and for this purpose they conducted an experiment, in which sewage was passed slowly through a column of sand and limestone. under these circumstances complete nitrification of the sewage took place. they then allowed a chloroform vapor to fall for some time on top of the column, the sewage passing as before. nitrification now entirely ceased and was not renewed for seven weeks, though the supply of chloroform was suspended. a small quantity of nitrifying soil was shaken with the water and the turbid extracts poured on the top of the column. nitrification at once recommenced, as strongly as before.

to appreciate the force of the experiment, muntz had previously shown that chloroform was a means of distinguishing between the action of a simple ferment as diastase, and a living organism, as yeast, the chloroform having no influence on the work of the unorganized ferment, which immediately stopped the activity of a living agent. the above discovery of schlosing and muntz of the true theory of nitrification of the soil was the greatest achievement to the agricultural world, inasmuch as it has been demonstrated by numerous eminent chemists and proved to be an ascertained fact; and this problem solved, which had occupied the ablest scientific minds for centuries. now we hope for some advancement with the farmers of the united states in the future. with the discovery of schlosing and muntz there is no necessity for such an idea as wornout land, as is prevalent in this great country, where the chief occupation of the agriculturist has been in exploiting his land, just in the same manner as everything else has been exploited. with an ever increasing population of this sphere, there is no need to fear the earth’s capacity in producing enough to supply all their wants. that is when our farmers realize the paramount importance of the above discovery, and begin to see how bountifully an all-wise creator has provided for us in placing these legumes on this earth for the benefit of mankind. they are a double blessing to us, for they not only abstract nitrogen from the atmosphere and deposit it in the ground for the succeeding crops, and restore the fertility of the land, but also, when they are made one in a four-course rotation, fill the soil with fibre or roots, which no soil can be in its highest productive condition without.

the great new south

in the past quarter of a century (1880–1905) from statistics gathered by richard h. edmonds, trotwood’s finds the south has doubled the value of her cotton crop, her exports and her assessed property; has trebled her manufacturing products, her railroad mileage and the value of her farm products. she has multiplied by five her lumber products, increased her manufacturing capital six-fold, her tons of pig iron produced eight-fold, her phosphate tons mined nine-fold, her cotton bales consumed ten-fold, her capital invested in cotton mills eleven-fold, her tons of coal mined twelve-fold, her number of spindles on cotton mills fourteen-fold, her tons of coke produced sixteen-fold, her number of cotton oil mills seventeen-fold, her capital invested in cotton oil mills eighteen-fold, and her barrels of petroleum two hundred and thirty-five-fold!

she raised three-fourths of the world’s cotton, and has one-half of the standing timber of the whole country. her own cotton mills consume 2,282,900 bales yearly, or nearly as much as new england and all the rest of the country combined, whereas in 1880 she consumed but one-sixth as much as new england. europe pays her a tribute of over one million dollars daily for cotton. thus marches on the great new south.

先看到这(加入书签) | 推荐本书 | 打开书架 | 返回首页 | 返回书页 | 错误报告 | 返回顶部