THE FERTILISER QUESTION.

New Zealand Herald, Volume LII, Issue 15821, 19 January 1915, Page 10

THE FERTILISER QUESTION.

NITROGENOUS MANURES. BY I. I- «TREVEVS. M. JN'ST., r.T. Tin'. New Zealand farming community must realise the value of nitrogen to the j .soil, and the large proportional increase | yielded in their crops when this element j is introduced in some form or other. It | >an not be too strongly emphasised that : ..itrogen is a ncessary constituent for the • growth of all life, and the fertility of j . ultivated land is dependent most upon | the amount of nitrogen added, as fertiliser! --derived indirectly from the atmosphere. As nitrogen is the most expensive body to apply, the development of agriculture ! v largely dependent on the cheap product- j iion of available nitrogen. j 'the remarkable power of assimilating j i ltrogen from the atmosphere, possessed ' 1 y leguminous plants, .".fiords one of the i • lieapest and easiest methods of introduc- ( ing nitrosren to the soil, ami should be ' developed by tlie New Zealand farming j community to the utmost, in view of the : fact that artificial nitrogenous manures are [ -ipensive. and a certain loss from them! by oxidisation and drainage always takes i plate. ! By growing legumes alternately with ! i"Ot crops or cereals, their power to i absorb nitrogen from the atmosphere, is ! turned to full account. The utmost use of j natural sources of fertility can be made I by allowing the land to remain more than | '■no year in grass and clover, or one green I irop may ho followed by another, or a J perennial legume may be grown for several J years, thus keeping the land tender condi- j tions favourable to nitrogen accumulation in the soil and products of humus. \ Sources of Nitrogen. The free nitrogen of the atmosphere is j apparently made available, to legumious crops through their root tubercles, and is ! ;>Jso assimilated by certain nitrogen-fixing bacteria and organisms in the. soil. Small a rat variable quantities of ammonia and nitric and nitrous acids which are found in the atmosphere from time to time are absorbed by plants to some extent, either directly or through the rainfall which bring these bodies in solution to the earth. Most of the nitrogen necessary for plant growth is obtained by the application to the soil of the so-called nitrogenous manures, which include all the natural products such as dungs and guanos, the refuse material from slaughterhouses, nitrates and ammonia salts, and the re- < em. artificial compounds containing nitrogen produced directly from the atmosphere. ■ - Other* natural nitrogenous products in use to some extent are seaweed, fish manure, powered horn, woollen refuse, and oil-cakes, whilst soot and powdered leather are valuable for their nitrogen contents. In recant years the question of obtaining nitrogenous compounds by utilising t he nitrogen of the atmosphere has become of paramount importance, and already large industries depending on cheap electric power are developing in Norway, the United States of America, and Germany. Nitrogen from the Air. New Zealand's possibilities in this direction are worth serious consideration in > iew of the latent forces available through her natural water-power sources, especially where these are in the neighbourhood of limestone deposits. Thti-p. are four methods of utilising at- \ mospheric nitrogen, viz.. oxidation to nitric. acid, combination with hydrogen to I form ammonia, the formation of nitrides j and cyanamides. As these can onlv be produced by electric methods the situation of factories to manufacture, these nitrogenous products must be near a water power where current can be cheaply generated, as in Norway and near Niagara. < alciirai cyanamide (nitrolirn) is perhaps ihe best-known fertiliser obtained from the air, and is manufactured in most i<n:ro,ries other than the British Empire. It also serves'as the raw material for the production of .ammonia and its salts. The (iermans have recently successfully manufactured ammonia from the nitrogen ■•i the atmosphere, thereby monopolising another branch of chemical industry, and the fixation of nitrogeii with 'subsequent; production of ammonia by heating alumina and carbon with it. is an accomplice*! fact. Mtfioi'gh electro-chemical industries are only in their infancy, there is ample ... ope; for wide developments along these lines. • Dealing now with the production of ammonia salts from <■■;<], shale, peat, and ■tiler nitrogenous fuels generally, there ..in hopes that with the cheaper production .it sulphuri' acid in the Dominion, it may be possible to manufacture sulphate '.f ammonia commercially from the gas bepior now exported to Australia, or run I ■ I .« n the drains as » waste product bv ■ tonic gas companies. It may also he de- i lived from the shale deposits and from peat. The question of Chili saltpetre pup j p;ios. and too controversy which has; .aged so long as to the po.-.'-ible exhaustion ! of this material, should not affeitthe Dominion, which imports evry little. Nitrogen from Meat Works. ', Tie: output of byproducts (ontaining llitroneli from the incut v. oiks could he materially mci eased bv utilising horn local, flesh meal, and' dried tankage. Flesh meal .- made from wast.- . aliases in ■! Mesi unfit for human .•>!,. sumption, after being first thoroughly .stcrili.-ed, and a similar luanui'e ■a i be I'b'.ainnrl from the residue of lie. m.'iuul'.o tare '.:' meat .-'..ti ai t-. Ti.-h meal is made from small fish unfit for sale or unsuitable fur edible purposes siler first ivii!u\\;i- fat, glue, and water. An average rhh gu mo contains 7 (■■ ') per ' ei:t. of nitrogen an i 12 to 1 1 per c, [lt ].hosphoii< a. ill. .'... a Dominion fi,liing industry is ; , likely possibility in the mar future", then: should be scope for a subsidiary fishc'.iano works. Leather meal, containing 6 to 11 per cut. nitrogen, is produced from scrap leather, and there are local possibilities in this direction In view of the wide Australasian n arket for nitrogenous manures, the problem of Miecessfullv manufacturing these fertilisers in the Dominion becomes worthy of serious consideration. ('liven cheap power, and taking advantage of those modern devices capable of reducing power tostwhatever the source of fuel—to a minimum, the labour question— such an obstacle to starting industries here— loses much of its significance.