IMPORTANCE "OF ARTIFICIAL MANURES.

Nelson Evening Mail, Volume XLII, Issue XLII, 15 April 1907, Page 1

IMPORTANCE "OF ARTIFICIAL MANURES.

IMrORTANCE OF ARTIFICIAL MANURES. .(By "MERLIN" in the London •' Field.") Thera are prola'bly very few persons engaged in the agricultural Industry or who are interested in t1.3 production of crops who are not aware of the influence of clovxrr. root upon succeeding wheat crop. Many persons have boen mystified by the really remarkable fact that a field m a y l>e much richer in n'itroßen after the removal of a heavy crop'of clover with the larffer, quantity of nitrogen it contains than it was before the crop wus Rrown. But the fact remains that sufficient nitrogen is left in the roots after the removal of a heavy cut to feed th'i succeeding* plant of wheat, and to feed it well. In days gone by this fact was recognised by the farmers of the time as ono which was the result of experimental knowledge, oven thoug<h the reasons could not be explained. A good clover plant was obtained by high farming, or, in other, words by what niay be termed the high' feeding of soil, by the aid of farmyard manure of high quality. That system of fcedinff, however is no longer essential to perfect success. A clover plant can be abtpained: and a heavy crop harvested by tho aid of artificials, and, al'thougih the soil may Ix-. almost destitute of nitrogen, the element in wihich clover is essentially rich, it te not npecessary to provide nitrogfen through the medium of manure; for as science has shown us, through thp medium of practicep durinp tho "flast twenty yearß, clover is ablo to obtain its own nitrogen through the inexhaustible supplies in the atmosphere, so long as it is provided with 'a sufficiency of tho other! food of which it almost invariably stands in need, and without which it is impossible for it to grow. We are often told by tihe chemist that all agricultural soil contain sufficidfe quantities of the various constituents of plants, with tha ex-i ception of nitrogen, phosphoric aoid, potash jvnd limep. In most soils.i and especially in soils adapt-* ed to the clover plant, potash i 6 present in fairly liberal quantities, although the same cannot bo Batfd either of phosphoric acid or lime. Many such soils are poor in lime, while it has become a truism that the one plant constituent of which the average agricultural soil is in need rln syhoric aoid, and thereforo lt is whero this is supplied to the clover plant through artificial means that the plant is enabled to draw upon Nature for its supply of nitrogen, nnd not only to feed R.elf generously, but to provide for thu equally generous production of the crop which is to follow it. Agricull in isis are aware that phos- 1 ohates are now obtainod in two oheaP nnd popular forms one in an acid form—superphosphate—adapterl to soils ioirly_rich in lime the other ln which tho base is lime, thereforo adnpUd to soils wihich stand in need ol lime, and known as basic slag. The whi-at plant is the first oousiil to the grasses; it belongs to tho same natural order, and what is adapted to promote the growUi of one is equally adapted to promoto the growth of tho other. Thus, wo ■ have seen that l\v tlie aid of arti- , ficial manure rich in phosphoric j acid, the clover plant ia enablod to . grow, to secrete nitropon in tho soil, ond to feed the succeeding crop Of wheat. Similarly, where phosphatic manures aro distributed ovor meadows, the clover present in the herbage nre encouraged to grow with greater freedom, with the result that in their turn tho grasses aro encouraged, and thus two birds, as it twero, are killed with' a single stone. Phosphates feed the clovers directly and the grasses indirectly. Farmers, however, who farm high, are not in a position to depend upon tho help of clover root. Tor cereal crops are grown under various rotations, and, ns a consequence, thoy employ phosphates and nitrogen in combination, the ond as. |.uperphosphate which is most commonly employed as a cereal fertiliser of this class, and tho .other in the form of nitrate of soda or sulphate of ammonia. Andi so it is with the herbage of the pasture or tho meadow. A dressing of superphosphate at the rate of 3cwt per aero on tho one hand, or of slagi at the rato of from scwt to 7cwt pro acre on the other, given in tho late autumn, followed by lewt of nitrate of soda in early spring, is practically certain to incrcaso the crop of the succeeding summer to such an extent tHat/, unless tho weather be extremely unfavourable, a handsome profit remains after the manures have been pai>d for. This practice is no longer to tho experimental stage, although thero >are no doubt many jinbel'i«vers, ] and who regard the employment of manures of this character and for i this purpose as laltogether risky. I Tlhere is, however, [another phaeo of the question which is worthy of notice. If.oTmel splendid results have been achieved in tho flooding ! of shoep upon poor Igrass land, j which has been improved by the aid of phosphates. Artificial fcrti. lisers of this character possess I therefore a double advantage in that they not only provide soma herbage for grazing or the scythe but herbage of a richer character. At ono time the majority of agri- j culturists believed that the feeding valuo of a particular grass wpag not improvable: in a word, that it was at all times similarly composed, but there is no tangible reason for such a belief. It is well known that tho mangel varies enormously in its richness in sugar i while the beat has within the past I fifty years, by the careful selection of seed, been ''enabled to produce j double the quantity of sugar in a , given weight. Thk remark aqually applies to the potato and to cereal crops, and possibly to every agricultural crop that is grown. It may. however, be sufficient to add that in tho feheep-fooding experiments better results wero obtained whero tho animals were fed upon the poor grass. which had been manured with nrl ificials, pthan upon the grass in the same field where , the sheep werr> supplied in addition with line".- . I <-ake. A fact of this kind is in-.nnri.ntly contary to the

experience of. both thc shepherd and the flock master; but there is no gainsaying results, an-d thoso results have added to the importance of phijsphorio acid when employed in thc form of 'ehc-iiic-al or artificial manure. Th-e day has gone ■by wlton the farmer, when urged to uso artificials, replies to tbe effect that they rob the land. Obviously when nitrate ef soda is employed on land poor in phosphates, it scourges it, for it enables the crop to oxtract* wHit phosphates remain, leaving nothing behind for a succeeding crop. Nitrate of soda, however, is not a whip to the soil, in thc sense which so many have remarked. The nitrogen it contains is identical with that which is provided, by the best farmyard manure, if, indeed, it is conveyed to the soil in a different form. Thero is nothing -more instructive than a simple farm experiment with each of these manures. Whether the crop bo corn or grass, a few carefuulypreparcd tests will tell their taleSupposing tho soil be in need of manure, a dressing of nitrate will probably be found to- deepen the colour and increase* tho height of the straw or of the grass, as thc caso may tie; but under such conditions both would be weedy in appearamoe, whi:lo the cereal crop would not obtain any assistance, or, if any, but little in the _ increased quantity of grain. Similar plants manured with phosphates would tell n different tale, for were thero no increase in the weight of the straw, there would usually be an increase in tho weight of the grain, whilo the gra»s crop would be improved by the additional weight of leguminous herbage th*j clovers and trefoils springing, as it were, into life in response to the special food provided for Ul-ir delectation. If, however, wo add a dressing of -hosphate. we find all the -diftorence, assuming that the soil is in need of both nitrogen and phosphoric acid. The increase in the breadth of the blade and -the height of tho straw of tho grain, crop would.be accompanied Iby an increase in the number of bushels of corn H.rvested' while the depth of colour of the grass crop, and its increased height and 'breadth of foliage, would _>e accompaiv.odi bv a thicker bottom a_d abundance of clover and cognate herbage. The combination would thus heavily increase the weight grown per acre and the feeding properties per cent^ I might mention an instance oi an entire estate purchased a few years ago by a purely business man, who carefully studied this question, and who distributed phosphates on tho whoio of the grass annually, with the result that in a few years its value was increased from £8 per acre-thc sum he paid for lt-to more than three times the amount. .An adjoining owner, following has example on still poorer clay, has obtaine- heavy crops of . RTaS^ three years in succession, although ' such crops had been practically unknown on the rotate. The judicious uso of phosphates, in the judgment of thc writer, who can porsonaMy speak of similar success, is more to bT commended than the one-timo practice of improving pastures by by the feeding of sheep on cotton cake, and yet, U wo may judge > by the number of saimples submitted for analysis throughout England, tiue nunuber of farmers who use artificial manures* is much amaller | than it should 'be. As a nation, we employ phosphates to a much smaller extent than any of the oither agricultural countries on thc Coai'tincnt, -including Belgium and ! Holland.