Seed and soil inoculation for leguminous crops / by W.B. Bottomley.

  • Bottomley, William Beecroft, 1863-1922.
Date:
1907
Catalogue details

Licence: In copyright

Credit: Seed and soil inoculation for leguminous crops / by W.B. Bottomley. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    There is little cause for alarm of famine as regards phosphates and potash, for th^re are practically unlimited and cheap sources of supjily of these elements to draw upon for restoring the loss due tO’ Ciiopping. With nitrogen, however, it is quite different. The nitrogen naturally present in the soil is chiefly in the form of organic compounds. This organic nitrogen is converted by the nitrifying bacteria into nitrate nitrogen before being available for plant food, and is then removed from the soil by the crops grown thereon, or washed out and lost in the drainage waters. Unfortunately, the suj)ply of combined nitrogen in the universe is limited, and the two richest sources—guano and nitrate beds— are being rapidly exhausted. The guano deposits have already almost given out, and it is estimated that, at the present rate of con- sumption, the nitrate beds will not last for more than 40 years,^ Hence it may be truly said that the nitrogen iJroblem is one of the gravest importance. Recently, much has been heard concerning the manufacture of lime-nitrogen, as it is called, by means of electricity. This source, whilst allaying all fears of a nitrogen famine, is too expensive at ])resent for general farming. What is wanted is a cheap supply, and modern scietice has revealed this by showing the ability of leguminous plants, when in association with certain bacteria, to utili.se the inexhaustible store of atmos])heric nitrogen, and add large quantities of combined nitrogen to the soil. It has been calculated that there are about 75,000,000 pounds of atmospheric nitrogen above every acre of land of the earth’s surface. Taking the value of nitrate of soda, containing 16 per cent, of nitro- gen, at eight shillings per 100 pounds, the commercial value of one pound of nitrogen would be sixjience. At this valuation there is nearly £2,(K)O.Oi(>0 worth of nitrogen above every acre of land, free and waiting to be utilised ! How' can it be done ? Well, Nature has rev'ealed to us the way,, and shows how by means of those wonder working agents of heis— bacteria—it is possible to obtain practically unhmited quantities of nitrogen from the air for the use of farm crops, at a v^ery small cost. These bacteria live in the nodules or tubercles which are found upon the roots of all leguminous plants (peas, beans, clover, lucerne, &c.). There they multiply and absorb the free nitrogen from the air, and cause it to unite with other elements to form compounds which are suitable for plant food. From the earliest days of Agriculture it has been recognised that the growing of leguminous crops had a beneficial effect upon the soil. Pliny wrote ; “ The bean ranks first among the legumes. It