THE GROWTH OF FOOD FOR STOCK.

Otago Witness, Issue 1970, 22 August 1889, Page 6

THE GROWTH OF FOOD FOR STOCK.

In, an essay "On the growth of mangels, cabbages, kale, kohl-rabi, and silage green crops as substitutes for turnips, and of catch crops to precede roots," published in the Journal of the Royal Agricultural Society, the author supplies a table compiled from the agricultural returns showing the acreages of the different varieties of root and green crops for the whole of England in the years 1870, 1878, 1884, and 1888. The figures show that last year the acreage under turnips* compared with that of 1870, was less by 250,259 acres, but that this decrease in turnips was counterbalanced by increases in other roots and green crops. The increase in mangels amounted to 52,130 acres ; in vetches, lucerne, and other green crops, 74,177 ; and in cabbages, kale, kohlrabi, and rape to 10,987 acres. The object the writer has in view is to point out the perilous difficulties frequently experisnced in obtaining satisfactory crops of turnips, and that therefore farmers should crop at least a portion of their land with root and green crops on which they can rely with certainty. Mangels are gaining rapidly in favour in England, but the objection to the crop is that a little more expenditure in manorial outlay is required than for turnips. The objeotion, however, does not apply to thousand-headed kale or kohl-rabi, which may be grown at as little cost and with more certainty than swedes. The strong point urged, however, is that farmers who find it difficult to rely on turnip crops can also fall back on vetches, trifolium, rye, and winter oats, which, when autumn sown, occupy the land at a- period when it would probably otherwise be either fallow or growing weeds. It is explained that the tillage expenses of the farm would be but slightly increased, and on tolerably clean land there would be many less weeds by two croppings instead of one, for Mm nearly all cases where land intended for turnips is- kept idle throughout winter and spring, three, and sometimes four, ploughings are given, the amount of additional cleaning being very great indeed." The writer proceeds to notice " the assertion often made that catch crops can only! be advantageously grown when the land is perfectly clean, as well as in a good state of fertility," but in the course of correspondence with practical farmers on the subject of the paper he was informed by a gentleman of great 6kill and excellent judgment that "there can be no more economical or remunerative course on all heavy and medium soils than to sow vefcches^in the autumn if the stubbles are foul, to ensile the orop in June and give the land fallow for six weeks, then to take a crop of mustard; to be sown about the last week in August, for sheep feeding or for a second \ crop, as may be most convenient." Many 1 cases" are mentioned of the success of the I catchcrop system on all kinds of soils.! "At West Shefford, the farm occupied by Mr John Brown is a very heavy wet soU on chalk ; still he grew no less than 72 acres to catch crops last year, 50 of which were afterwards g^wn to swedes and other turnips."' His method of cultivation is, after surface cleaning in autumn, to plough once for the catch crop, and in; spring the cultivator instead of the plough will suffi-

ciently prepare the. land for turnips. In the ' heavy Weald Clay districts of East Sussex many similar examples of success are adduced. In the Wold districts and on light soils generally equally satisfactory results have been attained. One example, however, will suffice. Mr T. B. Hulbert, of North Cerny, near Cirencester, occupies a large Wold farm containing 790 acres of arable land. Of this he devoted 45 acres to catch crops, 35 of which were consumed green and 10 acres converted to silage. The success was unquestionable. Another light land farmer writes —"I require a large quantity of rye, vetches, &c., for my ram lambs in the summer, and get what roots I can after them. I have planted more rye than usual this season, with the intention of converting a large portion of it into silage." On this farm out of 153 acres that came into course last year (1888), the system was carried out on 127, leaving only 26 acres not precededby a winter crop. "Surely," the author of the paper says, " the example of ; growing two crops instead of one in the root ' year might be more generally followed." A singular course is noticed in growing successional silage crops one year after another — a mixture of -spring vetches, oata, and peas being employed to carry out the object. The plan is adopted by Mr O. G. Johnson, The Oroft, Darlington. "For three years past ho has grown the same green fodder of this variety and will sow the fourth crop tor it bbis spring. Heavy weights of produce are raised, and the continuous green cropping keeps the land perfectly clean without there as yet any sign of the slightest /falling off." Mr Johnson, however, manures the land every year with 10 tons per acre of nightsoil. The scientific aspect of the question of autumn sowings has been dealt with by Mr Bernard Dyer, B.Sc, to whose paper on the subject the writer of the essay under notice refers. Mr Dyer's views are as follow : — " The greater part of a green crop — say from 80 to 80 per cent, of its weight when cvt — consists of water. The remaining dry matter consists mainly of carbonaceous material derived from the air. Of this carbonaceous matter some is removed when the crop is cut, and some — a heavy weight per acre — remains in the soil to decay in the form of roots and root fibres, adding to the vegetable mould present in the soil. But the dry matter in a crop is by no means merely carbonaceous ; all vegetable matter contains nitrogen ; and in an autumn green crop there is carried away such and sucha number of pounds of nitrogen per acre — as well as a not insignificant weight of mineral plant food. . . . Is not, then, the following root crop robbed by the autumn catch crop, which h surely appropriating the good things in advance ? No, for in autumn the root crop is not sown, nor will it be sown for many months. It is not there to get for itself the good things then in the soil ; but the catch crop is there, and gets them. But would not the good things of the soil remain there intact but for the catch crop, and be in due season appropriated by the main crop? No, for the chief of the good things is nitric acid, in combination with lime, in which form it is one of the most soluble materials that exist, so that it is readily washed down into the subsoil and into the drains by the rains ef winter; a portion only of the autumn store being left till the following summer for the use of the roots. . . . The idea that autumn cropping impoverishes the land is based upon a misconception of the chemical economy of the soil, and so far from temporarily exhausting or lessening its fertility by catch-cropping, we rather retard the exhaustion of that fertility, and so in effect increase it."