PASTURE RESEARCH IN GREAT BRITAIN

New Zealand Journal of Agriculture, Volume 95, Issue 2, 15 August 1957, Page 133

PASTURE RESEARCH IN GREAT BRITAIN

/\F the many important differences between grassland farming in New Zealand and in Great Britain two deserve special mention: The first is the much greater severity and length of winters in Britain. In practically all districts > pasture growth ceases completely for several months in winter and makes slow recovery in spring. This spring growth is often acutely nitrogen deficient, mainly due to a deficiency of vigorous clover, which is not really productive and releasing nitrogen to associated grasses until summer. A second important difference is the high percentage of short-term pastures. Cropping both for cash- crops and for supplementary fodder crops is on a much more extensive scale than in New Zealand and pastures of I year to 4 years of age dominate the grassland of ploughable country. Large areas of fodder crops must be grown to supplement pasture production during long periods when pasture is dormant.

DESPITE these differences New Zealanders can learn much from British grassland workers. Such knowledge may have special application in some of the colder and more difficult-to-farm parts of New Zealand. Ryegrasses The winter of 1955-56 was exceptionally severe in Britain and there were widespread complaints of winter killing of New Zealand short-rotation ryegrass. This has caused considerable interest in the 522 strain of Italian ryegrass bred by the Welsh Plant Breeding Station, Aberystwyth. This strain has given good early spring production (“early bite”), especially when manured with nitrogenous fertilisers. Work with a range of special lateflowering ryegrass strains at the Grassland Research Institute, Hurley, was particularly interesting. Some of these strains have a longer productive grazing period and may be worth trying in districts such as Southland

where perennial ryegrass rushes to seed in November and the lamb-fat-tening capacity of such pastures is seriously reduced as a result. The English practice is to sow a range of strains, particularly of ryegrasses, in seed mixtures. One of the objects in so doing is to extend the length of the productive season. Another is to make more certain that one at least of the strains sown will fit in with the soil and management practices 'of the sward in . question. New Zealand practice, differs sharply from this, and seeds mixtures are, in general, much simpler than in Britain. A ryegrass-white clover seeds mixture for “long-duration grazing leys” as recommended by the British Ministry of Agriculture, Fisheries and Food is as follows:

Lb. per acre Perennial ryegrass: Certified 524 . . . . .. 8 Certified 523 . . . . . . 4 Certified SlOl . . . . . . 4 White clover, certified SlOO . . 1| Wild white clover, certified SlB4 | 18

The S strains identify lines bred by the Welsh Plant Breeding Station, Aberystwyth. 524 ryegrass was bred from English and Hawke’s Bay (New Zealand) seed and is, perhaps, most near in type to New Zealand pedigree strain. It is early in spring and about mid-season in flowering. It may be less persistent than some other strains under hard grazing. , . 523 ryegrass was developed primarily from some very old-grazed pastures in Wales, but other English types were included in its breeding. It is lateflowering, high-tillering, dense, and leafy, but is rather late in producing in spring. It is not as productive as some of the other strains. SlOl ryegrass on the other hand is not quite

as late flowering as 523, and the plants are bigger and leaf blades are larger and generally more of an erect hay type. Of the two white clover types in the mixture given, SlOO is large leaved and more like New Zealand pedigree strain. SlB4 is smaller .leaved, dense, and highly persistent under close grazing. Perhaps more work could be done in New Zealand in the sowing of mixtures of various strains of . pasture' species, though obviously this would be out of . the question in seed-produc-ing areas. Meadow Fescue There are many enthusiasts in England for meadow fescue. Two Aberystwyth strains are available: 553, which is primarily a pasture type and rather more dense than 5215, the “pasture hay” strain. Meadow fescue is commonly sown with timothy for 3- to 4-year leys. Most of the timothymeadow fescue pastures seen were vigorous in growth but lacked density. Some very high production figures have been secured from timothymeadow fescue pastures, though they are slow in establishing. They seem to be more suited to dairying and to cutting for silage or dried grass. Two virtues are continued palatability despite lax grazing and ability to withstand severe winter conditions. New Zealand experience with meadow fescue has not been very encouraging, as it is generally very slow to establish and suffers from weed competition in the early life of the sward. Generally meadow fescue does not produce as much as perennial ryegrass, except possibly in early summer, when ryegrass has seeded and meadow fescue is still making leafy. growth. Experimental work with this grass is continuing, however.

Meadow fescue has been used successfully as a companion grass with lucerne. It cannot be sown with perennial ryegrass, as it is unable to compete with that species in the sward. Tall Fescue To a New Zealander, accustomed to regard tall fescue as a dangerous weed, it comes somewhat as a surprise to find quite an interest in this grass for grazing. It has special merit for winter hardiness and productivity. Aberystwyth has developed a strain of tall fescue, Sl7O, which seems quite palatable to cattle and highly productive. No place visited reported any toxic effects on stock from grazing of tall fescue. Tall fescue in a pasture sward is, however, a very different proposition from the rank clumps of tall fescue infesting swamp lands in places such as the Manawatu. It is being tried with some success in low-rainfall areas in New Zealand, such as Central Otago, and may have a place on such country. Timothy Breeding work at Aberystwyth with timothy aims at securing winter hardiness, early spring growth, and rust resistance. A range of strains with different maturity dates has been developed with the aim of extending the productive season of timothy. Timothy is widely sown in general-purpose seed mixtures and also for special pastures, particularly in association with meadow fescue. It has been used sue-

cessfully for winter grazing and is productive and palatable over - winter. In Scotland some of the quicker maturing commercial . Swedish and Scottish strains of timothy are preferred to Aberystwyth strains, owing to their earliness and greater bulk of production in the first few years. In rigorous climates with a short growing season it seems more important to have a species capable of responding rapidly to good growing conditions than to aim for length of productive season. Aberystwyth strains of timothy have been tried in New Zealand, but show no special merit over New Zealandbred strains. As new strains are developed, however, they will require testing in various localities. Cocksfoot Cocksfoot is highly regarded in Great Britain for winter production and ability to withstand grazing throughout winter. For this purpose sowing in rows has been found to give less waste and higher carrying capacity than broadcast sowing.

The winter “foggage” typical of pastures saved for winter grazing is, however, much removed from the well-controlled, leafy, winter-saved pastures of New Zealand. It is more in the nature of a standing hay crop and cocksfoot is particularly suitable for use under these conditions. Some particularly winter-hardy strains were impressive and may be worth trying in some of the high country in New Zealand. Effect of Clovers on Grass Production In Britain there is widespread interest in, and research into, the nitrogen-supplying powers of clovers in a mixed sward. Most British research workers agree that vigorous clover growth will supply'the equivalent of Bcwt. to lOcwt. of sulphate of ammonia per acre a year, and the use of lower rates of fertiliser merely replaces some of the clover nitrogen with “artificial” nitrogen. (This does not apply to the use of nitrogenous fertiliser for out-of-season growth when clovers are not growing vigorously.) Extra pasture production can, however, be secured from the use of artificial nitrogen above lOcwt. per acre up to a maximum of about 1 ton per acre of sulphate of ammonia equivalent. Work at the Grasslands Division, Department of Scientific and Industrial Research, places the nitrogen-supply-ing power of clovers several times higher , than the British figure.* This clearly reflects the different length of

growing season of white clover in New Zealand and Britain. 4 Effects of Leys on Soil Fertility Practically every appropriate research station in Great Britain has a trial or trials with a complicated series of crop rotations. ,These experiments evaluate the effects of different types and lengths of leys (pasture in a cropping. rotation) on soil fertility, this being measured by the yields of crops in the rotation. Type of pasture and length of leys unquestionably have a marked effect on crop yields, much of which can be traced to the effect on the nitrogen status of the soil. Under typical farming systems on arable land in England about 50 per cent, of the farm area is under crop, and work on the effects of duration in pasture and of type of pasture on

subsequent crops is of considerable practical importance. In New Zealand, where intensity of cropping is usually much less, the type of pasture ploughed under is probably more important than the length of the ley. It was interesting to see work in England which confirmed the findings that good pastures were necessary for highproducing crops. Quality of Grassland It is easy to form a false impression of the standard of grassland farming in Great Britain. Pastures considered to be first class by New Zealand standards are by no means common and there appears to be less appreciation of the potentialities of good pasture. Pasture-management practices are very often of the type that leads to depletion of fertility and ■ a clover-deficient, nitrogen - starved sward. A common practice is to cut first-year pastures for hay to the detriment of the swards. Apart from nitrogenous fertilisers, which are used much more extensively and heavily than in New Zealand,

many pastures seem to receive inadequate fertiliser—a position that contrasts strongly with the liberal use of fertilisers on crops. But fertiliser use is governed by a short growing season (and consequently a need to produce far more hay and silage per unit area than in New Zealand), and a much greater intensity of cropping. Thus the number of stock-grazing days on each acre of grass is much below the average for New Zealand. This is reflected in a greater drain on soil fertility, a drain, particularly of nitrogen, which is not helped by a short productive season for clovers.. It is from the progress that has been made in overcoming these difficulties that New Zealand can draw useful ideas for application to some of its grassland problems.

Need for Caution

THE information in this article was gathered in 1956 in the course of a tour of agricultural research stations of the British Isles, from . visits to a number of farms, and from discussions at the summer meeting of the British Grassland Society at Hereford. It must be stressed that farmers in New Zealand would be wise to await the results of testing of the pasture species and the pasture-manage-ment techniques that are mentioned before applying them in this country.

*P. D. Sears and L. T. Evans: “New Zealand Journal of Science and Technology”, vol. 35A, supplement 1 (1953).