Untitled

Otago Witness, Issue 2299, 24 March 1898, Page 4

THE VALUE OF PLANT ROOTS AS TILLERS OF THE SOIL.

In reference to the comprehensive and lengthened series of investigations conducted at llothamsled, Sir John Lawes, in ona of the annual repo:t3, observed that "All our experiments tend to show that it 13 the physical condition of tho soil, its capacity for absorbing and retaining water, its permeability to roots, and its capacity fcr absorbing and radiating heat that is of more importance than its, strictly speaking, chemical composition." In fttiacle on " The Value oE Plant Roots as

Tillers of the Soil," in the Royal Society's Quarterly Journal, September 1897, Mr Robert H. Elliot, Kelso, Scotlaud, confirms the Rothani3fcead experiences that the permeability of the soil, ics maintenance in a thoroughly disintegrated, friable condition, while afc the same timo largely and economically improving the fertility of soils, are the elementary principles afc the basis of successful farming. Mr Eiliot explains that he succeeded to a property in Roxburghshire in 1873, and ever since has been engaged in farming on a very considerable scale, Gut "as a practical man who has had ongina'ly to earn his living ! by tilling the soil," his efforts were directed to remodelling the faruric g ajslem so as to make i'j pay in the face of th.H foreign competition ! which was sure to rise higher and nigheras time I advanced. He then proceeds to show how this may be done and how the cos 1 ; of production may be chapei^ed, while cumulative fertility may be assured. To clearly apprehfnd how , both these ob]erts may be carried out, Mr | Elliot first remarks on the causes of decline in j the fertility of most soils. The condition of a soil when taken in from, say, forest land, or from the original turf which has never been disturbed from time immemorial, partly frcm the laud not having been exposed to the element 5 , but mainly from ks being interspersed with the rootlets of jungle, nhzubg, and other vegetation, will be found in petieci physical condition. But as time advanc s the rootlets of course decay; the foil then loses its original condition, becomes consolidated, and a bad nidus for plants. When land is fir^t ploughed up from tho original t,urf, or, wjich is uear'y the same thin;?, turf of very Ion?; standing, it being deeply impenetrated with grass roots is in the same condition as new forett land, and no decline of fertility is apparent till *fter the lapse of a number ot yf aw. Then as the vegetable matter becoaies exhausted the soil Bolidifirs, and becomes not only tough bub shallow, as it is no longer at oucd de< per ed and disintegrated by rooty, a decline in fertility beinp the sure result ; and though tillage may lessen the evil for a time, the particles ot the soii ! being no longer kept apart by vegetable matt'T ! soon run together.andthustheland becomes a bad i nidus lor tho plant. The value ot roots in \ maintaining the physical condition of the foil once recognised, tho urxl cons deration is \h«. '' value of the rooti of certain classes of plants ' for bringing up nitrates and moietur<j from depths iar below the range or grass and corn roots, and so ought to bo looked upon be.iidr-s as feubsoil-ploughing agente. Gardenem who are practically acquainted with soil-tilling by the great agency of roots know that if they trench tand a foot deep and take from it a crop of parsnips they fli.d on liftiat* the crop thas ! the soil immediately below the part dag is in finer physical condition than the cultivated portion above, and this of course arises from the j roots penetrating and minutely subdividing tho ' hard subsoil Mr Eliios gives an illustration j frcm bis own txperieace of the value of plant- ' root tillage. Wi'h stm-? dtt&il tbe particulars ! are as follows. Towards the end of AprTl 1895, | & field of deep, strong soil on a low alluvial ! flat ou his property was sown wish a thin .seed- J ing of c&ts end the following mixture : 51b j each cf cock»foofc, mend-jiv foxtail, asid tall | fescue ; 7lb of m»sdow fescu*. 4-lb of timothy ; lib each of wo^d trievlow grass Mid roughstalked meadowgr.iPS ; 2, beach cf whice clover, aleike, perennial red clover, kidney vetch, aud j lucerne ; 31b of chicory, 81b of burner, l.b of sheep's parsley, and £lb of yarrow. Trie field, one of 15 acre?, was cu 1 ; for hay in 1896. and ( j the crop amounted to 36 tons 14-cwi-., whilst the ! I aftermath wss an excellent crop. Two trenches i were subsequently cul in the field to a depth of aboub 3ft, and oa Saptembjr 11, or about 17 months after the seed was sowr-, Mr Eiliot, accompanied by ~Dc Voelcker, proceeded to examine the depth fco which some of the roots had penetrated. Tile results were found to j be particularly interesting, especially as regards i chicory, which evidently had a profound contempt for the hard pan which was found about 14in below .the surface, and which was about a foot thick, and so hard that s. man with a sharp spade had to use great force to break it open when the descs-nt of the vaiioas roots was being traced. What was especially remarkible was that the chicory had passed straight downwards without aEy deflection whatever through the pan into a softer subsoil, snd to*a total depth of about 30in. The burnet and kidney vetch roots had gone down aboub 20ic, bub the lucerne roots only from Bin to lOin. Ib was particularly remarkable how the strong roots of the chicory had succeeded in disintegrating the pan with their lateral offshoots. Me Elliot and Dr Voelcker came fco the conclusion that the roots of these plants are c-vpable of doing all the work of a subsoiler in breaking up the pan, which is the most formidable ! object to be contended with in the cultivation j of o!d arable lands, and especially when laying j the land down to grass. Ib is interesting to mention tint it was found the clover had turned into plants more or less robust and large, according as their roots were furnished with a larger or smaller quantity of thosa nodules which, in the opinion of the bsst authorities, have been proved fco supply the plants with nitrogen derived trom atmospheric source 3. One SDlution of the serious agricultural difficulties experienced, Mr Elliot thinks, li^s mainly in the production of a good turf, and one largely composed of deep-rooting plants which will at once disintegrate the coil, till i& to the lowest depth possible, supply ib with vegetable matter through and through, and at the same birae steadily increase the fertility of the soil. He claims to have effected this on his property, and in showing how gives the history of a single field. The field in question is one of 25 acres. It lies on the slope of the Cheviots, close to the Northumberland border. The elevation of the field is aboub 200 ft above the sea level. The climate is dry, and the rainfall is so small that farmers consider they suffer from drought aboub one year out of three. The field was first enclosed from tha hills aboub 60 years ago, and is so distant from the steading that farmyard manure has never been applied to ib. Everything went down and nothing went up, except the ploughs and horses necessary to thoroughly exhaust the land and some artificials to start the turnip crop. The tenant, who had been in long occupation of the farm," said ifc was the worst field on it. When Mr Elliot took the farm in hand the field was in what was called grass — some ryegrass and clover so poor and thinly planted that the clover could be readily seen. There was, however, an abundant crop of thistles. Some lime was applied to the land, it was then ploughed and cropped with turnips, and in the year 1890 was laid down to grass with a thin seeding of oats, and some barley in one part of the field. The mixture consisted of 141b of the fioest cocksfoot, 51b of tall fescue, 31b of hard fescue, 2lb each of smooth stalked meadow grass and crested dogs^ail, lib of golden oat grass, 21b of alsike, 41b of white clover, lib ot yarrow, and £lb of bird's-foob trefoil. The very large proportion used of I cocksfoot and the large proportion of yarrow and tall fescue were calculated to store the Jj.ud with a. large amount of vegetable) matter,

and as regards this no disappointment was experienced, for when the field was again ploughed up in 1893 there was a turf which apparently contained more vegetable matter than tho ground did when it was enclosed from the hill some 60 years ago, aud of this turf cocksfoot and yanow roots were tho chief cocnpoaenlß. In 1694 a crop of turnipn was taken — a fair crop for euch land — • and in 1695 it was laid down again with half a seeding of oats aud a mixture containing 6lb of cocksfoot, b\b of meadow fescue, 41b of Italian ryegrass, 41b of tall fescue, 2lb each of hard fescue aDd smooihstalked nsendow grass, 3'b of tall oatlikc grass, 41b of golden oat grass acd rough-jfc'Uked meadow gras?, 21b each of al-ike, late-flowering red clover and white clover, 2£!b of kidney vetch, lib each of yarrow snd bheep's parsley, 21b of chicory, and 81b' of burnet. The oats with which these seeds were sown turned cut a very fair crop, and qaite a good one ia the hollowß. That such laad c.uld grow r>. crop of bay w.^rtb. having was thought to be beyond th-j range of possibility, aad without the application of any minure to tbe land except some artificials to bring awsy the turnips that preceded the oat crop. But the result was astonishing. In 1896 a crop of hay of two tons to the acre wag cut, leaving a splendid aftermato, acd in 1897 no pasture hi the country presented a finer appearance. As regards the light arable lands of tbe farm the system pursued by Mr Blliob is-; the land is left in grass for various periods from four to six years, sccordicg to the requirements of tho fdrra and the appear*ncs of the pasture. Then it is again brought under plough, when turn : »s are first taken, theu cut*, then turnips, and the land is l«id down to grass hgain with a thin Feeding of barley oc oat?, and the work of making a deep-rooting turf again commenced.