IMPROVING GRASS LANDS

Otago Witness, Issue 3489, 25 January 1921, Page 9

IMPROVING GRASS LANDS

IMPORTANT MANUEIAL TESTS. VALUE OF BASIC SLAG. At a recent meeting of the Farmers’ Club in London some important information was given by professor D. A. Gilchrist on the question of improving grass land. The value of grass depends as much on its treatment as the value of any other type of crop, and Professor Gilchrist’s wide experience enables him to speak with special authority on the subject. EXTENDED TESTS. The principal tests described recent work at the Nortnumberland Agricultural Station Cockle Parle, where the pasture results on silo different fields were as follows: —The Tree field extends to about 34 acres. The soil is of a -poor, stiff character, lyingon boulder clay. The plots, each auout three acres in area, were fenced/ eff in 1897 ; sheep have 'been fed regularly each summer on the different plots, and their live weight increases ascertained. Deducting coat of the dressings the average annual gains per acre for tile six • years 1912-1017 were : From feeding decorticated cotton cake to the sheep, an .annual loss of 11s 9d; from one dressing of lOcUrt an acre of high-grade basic slag, applied for the first of six years, an annual gain of 2.7 s sd; and from two dressings of scwt slag, an annual gam of 245. When, however, Icwt muriate _ of potash wa-s added to each of the two slag dressings, the gain was reduced to 17s; when one ton of lime was added to each, the gain was reduced to lbs 6d, and when icwt of nitrate of soda was added the gain was reduced to 13s 4d. APPLICATION - OF BASIC SLAG. When dissolved bones were used in two dressings, containing the came amount of phosphates as in trie slag, and about the same- amount of nitrogen as in the nitrate of soda, the annual gam was reduced to 8s lid. In the first mao years of treatment four tons of lime, applied in 1897, resulted in an annual less of about ICs an acre. 'The lime did not' develop clover, nor materially improve the herbage fer nine years after its application. These are striking results in favour of the continuous application of basic slag, and they show that neither a. potash mixture nor a nitrogenous manure ncr lime helped the slag to improve the pasture, but the reverse. It should be clearly understood that the soil of this field has a low content of lime (.69 per cent.). The Hanging Leaves pasture fields extend to 57 acres. These were originally poor pasture like that of Tree Field. Four plots each about 10 acres in area, were fenced off in 1802. These have each beentreated continuously in the same way since 1903, and grazed with a mixed stock of cattle and sheep, instead of sheep alone, as in Tree Field. On Field .1, where basic slag, 10cwt an acre, was applied for 1903. and scwt of the game for 1906, and every third year thereafter, the average annual gain for the three years 1815-17 was 49s an acre. On Field 2 the same basic slag has been applied as for Field 1, and, in addition, 3c wt, an acre of rough cotton cake has been fed annually to the grazing stock. Here the gains were reduced from 49s to 18s 3d an acre in the same three years. In Field 3 basic slag, 10ewt an acre, was applied for 1903; thereafter no further slag was used, but cake was fed annually as on Field 2. In this case, in the same three years, there was an annual loss of 2s scl an acre. STRIKING OB JECT-LE S SON. A walk over these fields during the grazing- season provides most striking objectlessons. The pasture is undoubtedly of the best quality, and contains most clover herbage where basic slag has been applied and cake has not been fed. Where cake alone has been used since 1903 the pasture is of a poor and benty character, and is rapidly deteriorating m value. When the fields were fenced off in 1902 the whin or furze bushes, which were present all over, were cut down. On Field 3, where basic slag has not been applied since 1903, but cake fed since that time, the furze bushes have rer,sserted_ themselves, but they have not done jso where basic slag continues to be applied. It is probable that the slag has made the young growth of the furze more nutritious and succulent, and as a, consequence it has been closely grazed by the grazing stock. On Palace Leas meadow field, old land hay has been continuously grown since 1897. Sixteen plots, each hall-acre in area, are regularly manured in various ways. On the untreated plot the average crop for 22 years is 19iewt of hay per acre, where Icwt an acre of sulphate of ammonia has been applied annnaiiv the hay has been reduced in value from 80s to 72s a ton, and there is a net annual loss of 15s 8d an acre. The average crop of hay where 3001 b of high-grade basic slag alone has been applied is 26jcwt, Its value has been increased to 93s a ton, and the average annual gain is 33s 7d. The addition of 1501 b an acre of sulphate of ammonia to basic slag and a potash manure on plot 13 has increased the hay by only 4-icwt, but decreased its value from 102 s to 39a a ton, and the net gain from 33s to 15a per acre. The results on that field show that dung and complete artificials, as well as nitrogenous manures, considerably reduce the quality of the hay ; that dung along rather improves the quality; and that phosphates

greatly improve the quality, especially when a potash manure is added. When an old pasture becomes dead on the surface and the herbage is not eaten by stock, this organic matter gradually accumulates and kills out the more nutritious grasses and clovers, the final result being a matty pasture of low feeding value, or, in the case of old land hay, a dead and matted turf on the surface, which effectually prevents the growth of nutritious hay crops. Old leys, with such an accumulation, should be ploughed out. In dry seasons it is striking how this dead matter prevents the passage of rain water to the soil,' and how dry the soil is of an old pasture in a dry summer when covered with suc-h a mat. This. is especially the case when the land is lying in old ridges, as the rain water is shed to the furrows. At Cockle Park most satisfactory results in the manuring of old land hay have been given bv applying about 6cwt an acre of high-grade basic slag every third year, with the addition of about 12 tons of clung an acre, also every third year. The crops of hay produced by this treatment are of a most satisfactory character, both as to quantity and quality. Native clover plants are abundantly developed by the basic slag, while the dung docs much to maintain the bulk of the hay. GRAZING SEASON PROLONGED. By the judicious use of basic slag at Cockle Park, tire grazing season has been greatly prolonged, the grass land lias been more than quadrupled in value, the bulk of the oid land hay has been increased, and the quality improved by over 20 per cent. The effective way to enrich the soil of a pasture in nitrogen is to encourage leguminous plants by the judicious use of phosphatio manures. In Tree Field phosphatic manures have increased the soil nitrogen by the equivalent of about SOcwt nitrate of soda an acre. When nitrogenous manures are added to the same the increase in soil nitrogen is reduced to what is contained in about llcwt nitrate of soda an acre. It is probable that few old pastures require potash manures. There is no loss of potash from a pasture field, as grazing stock retain practically no potash in their bodies, and water passing through the soil does not remove potash. When laying down new pasture on light soils deficient in potash, a potash manure is found to be helpful. At Cockle Park dressings of basic slag are regularly applied to the seed hay for one anti three years. On both light and heavy soils, dressings of lime have been applied in addition, but in no case lias lime been beneficial within the following three years. Heavy dressings of lime on poor clay pasture In Tree Field gave little result for nine years thereafter, even though this soil is comparatively poor in lime. The advantages of early mowing are : The hay is much superior in feeding value and very little less in bulk; the aftermath. is greatly increased in bulk and in feeding value, whether used for grazing or mowing; the hay and aftermaths of the following years are greatly improved in bulk and in quality, because the plants have not been allowed to exhaust themselves by becoming mature and producing ripe seed ; the weeds are effectually checked for reasons already stated as to thistles and yellow rattle, and because weeds are checked when their seeds are not allowed to mature. SHEEP, CATTLE, AND HORSES. When a pasture is grazed with sheep alone rough and benty herbage is developed, owing to the sheep grazing only the fine bottom and rejecting that of a benty character, and what they do eat they bite very closely. Cattle cannot select the finer herbage and leave that of a benty character, and they do not graze so closely. They are, therefore, more even mowers, and not so close mowers as sheep, and their heavier treading is also a great advantage for the pasture. At Cockle Park similar pastures, treated exactly alike, produce double the live-weight gains from a mixed stock of cattle and sheep than from sheep alone. Horses form large areas of “middens” in pasture fields to which they confine their droppings. They do not graze these areas, but only the remainder of the pasture, anrl this latter is grazed very closely by them. A horse pasture soon, therefore, becomes unsightly, and coarse in parts and very bare in the parts where they graze. Horses should never be the only grazing stock on a pasture, and should not be grazed in the same fields year after year, but should have a rotation of fields for different years. While in some cases too heavy grazing of a pasture may be practised, harm is much more frequently done by not grazing the pasture as closely as it should be. The ideal pasture has a sweet bottom of grass. and clover herbage like the pile of a Turkish carpet. Whenever pasture is allowed to develop too much herbage it becomes coarse, because the fine grazing herbage is choked out.