CLOVER AND FERTILITY.

New Zealand Mail, Issue 1247, 23 January 1896, Page 5

CLOVER AND FERTILITY.

From time immemorial, writes “ Thistledown ” in the Australasian, it has been well understood that clover adds fertility to the soil. It is only in recent years, however, that the method by which this is accomplished, or, as our scientific friends would say, the modus operandi , lias been understood even by the scientists themselves. Clover cannot add anything to the potash or phosphoric acid of the land, for the reason that it can obtain no supply of it except what is within reach of its roots. It may, however, have a greater capacity than other plants for utilising that supply, and, when once it is utilised for its more available shape for the use of other plants than it was before. The clover obtains its fertility—the fertility which it gives to the land—solel}'' in the form of nitrogen ; and this, as we have explained over and over again, it obtains from the atmosphere. Just how this is done the scientists have not been able to tell us. They have, however, succeeded in demonstrating that it is closely associated with the little wart like protuberances on the root of the plant, which, for the want of a better name, they have called tubercles, from their simiUity to peculiar deposits on the lungs of the consumptive man or cow. They have, however, no connection with disease. These tubercles are filled with germs, not death dealing, but life-giving germs, which in a way not yet understood are able to utilise the free nitrogen of the atmosphere, amounting to about four-fifths of the total, for the purpose of meeting the enormous demand of the clover plant for this expensive kind of fertility. Of all the great elements of fertility nitrogen is the most easily exhausted. Potash and phosphoric acid do not escape from the soil to any great extent. Nitrogen does very rapidly, especially in wet climates and wet seasons. The

analysis of drain water from Sir John B. Lawe’s experimental plots fertilised with nitrogen proves this beyond question. It follows, of course, that when soil becomes exhausted, the farmer sows clover to restore it, as at once the easiest and cheapest possible method. This power of obtaining a supply adequate to its wants from the free nitrogen of the atmosphere is shared by all the legumes or plants that have a pealike blossom, such as peas, beans, and various kinds of weeds, but it is not shared with any of the true grasses, strictly speaking, nor by any of the grains in common use. This explains

is easy to see the great importance of clover in any rotation of crops.. It is, so to speak, the Alpha and Omega, tho beginning and the end, of every properly arranged rotation of crops-