Pastures In N. Guinea’S
pp. 79-81 · Read in the full issue
Central Highlands
What Are The Value of The Indigenous Grasses?
IN the highlands of Central New Guinea there are thousands of square miles of cool, pleasant, fertile grasslands, which may yet be regarded as suitable for the raising of stock, especially cattle.
Many people now are seeking informa tion about the pastoral possibilities of these great valley systems. A question frequently asked is: “Is it possible to raise cattle on the indigenous grasses of the New Guinea Highlands? Or must these areas be planted with introduced grasses before suitable pastures for stock can be provided?”
There is some answer to these questions in an address given at a conference in India last year by Mr. W. Granger, B.VJSc., chief of the Animal Industry Division of the Papua-New Guinea Department of Agriculture. The following are extracts: — The extensive grasslands of the Terri tory apparently are artificial products of the native method of hunting, which in volves burning whenever there is a dry season.
In lowland areas, and on the lower slopes, the dominant association of these grasslands is a mixture containing Im perata cylindrica (the grass known in Malaya as “Lalang,” in the Philippines as “Cogon,” and in New Guinea as “Kunai” or “Kurra-Kurra”), Coelorrachis rotboel lioides) and Saccharum spontaneum —the dominance of any one of the three vary ing with local environment variations.
Though palatable immediately after cutting and burning, this type of sward is a very fibrous and poor feed. On light sandy soils and well-drained slope areas, Themeda australis dominates, and pro vides open-range type grazing; but such a sward has a low carrying capacity and poor resistance to intensive use.
On level land at 5,000 feet altitude, and above, Themeda gigantea dominates. This is fibrous and of poor value. With judiciously controlled burning and some preliminary weeding, a palatable and nutritious sward of native fine grasses, principally Poa spp., Sorghum nitidum, and Apluda mutica can be induced. These grasses are very sparse in the original sward.
In country with rainfall above 100 inches, and a ooorly marked dry season, clearing gives a sward of soft grasses in which Paspalum spp. (particularly P. conjugatum) predominate. Although this sward gives a fine bulk of palatable green feed, it is nutritionally inadequate without a legume or cereal supplement.
A number of useful legumes which have been introduced as plantation cover crops are available to introduce to this type of sward, notably Pueraria spp., and Centro sema spp. Valuable introduced grasses thrive under these conditions—for ex ample, Para grass (Brachiarya mutica), which is outstanding, Paspalum scrobi culatum, Axonopus compressus, and Digi taria spp. .Among cultivated fodders for these con ditions Pigeon Pea or Dahl (Cajanus indicus) grain and Sweet Sorghums, Sugar Cane, Cowpea (Vigna catjang), and Peanuts (Arachis hypogea) are outstand ing. Maize tends to be subject to excessive insect damage.
Supplementary feeding and foraging root and vine crops such as Sweet Potato (Ipofoea batatas), Tapioca (Manihot esculenta) , pumpkins and melons (Cucur
bitaceae), Mauritius bean (Stizolobium spp.), and Kengu (Ipomoea aquatica) is readily available.
In areas with a marked dry season, Guinea grass (Panicum maximum), Ele phant or Napier grass (Pennisetum pupureum) and Stylosanthes spp., are most useful introduced fodders. Certain potential fodders such as Leucaenia glauca, the rain tree (Pithecolobium saman) and Algoroba (Prosopis juli flora) can be readily grown. There is a need for storable cereals and pulses in such areas; and Maize, Grain Sorghum, Peanuts and Pigeon Pea are of im portance.
At higher altitudes, certain temperate and sub-tropical grasses and pasture legumes can be established. Notable among these are:— Grasses: Perennial Rye (Lolium perenne), Phalaris tuberosa, Paspalum dilatatum and Rhodes 'Grass (Chlorin gayana) ; with Kikuya (Pennisetum clan destinum) giving good grazing cover on hungrier soils.
Legumes: White Dutch (Trifolium re pens), Alsyke (T. hydridum) and Red (T. paratense) clovers; Lotus spp., which seems to be better adapted to the rather generally acid soil conditions; and
Lucerne (Medicago sativa), which is limited rather strictly by soil pH.
An important recent introduction which shows promise under a wide range of ecological conditions is Berseem or Egyptian clover (Trifolium alexandrinum).
Generally, we must develop pasture types and grazing and feeding patterns follow ing more closely those of tropical countries than those of Australia.
That is the end of the extracts from Mr. Granger’s paper. Experiments are under way in different parts of the High lands. The indications are that a good proportion of the indigenous grasses in the Highlands, when specially treated, can be used as pasture; but, generally, its nutritional value is not high, and it should be steadily reinforced by the introduction of specially-selected grasses and legumes.