Grass and Grassland. Ian Moore

Lemon grass or Indian grass (Cymbopogon citratus), which grows wild in India, is also cultivated both there and in Ceylon and is used for infusing a tea which is reputed to have medicinal properties. Andropogon nardus is cultivated in Ceylon and Singapore for the production of citronella oil which is used extensively in the manufacture of soaps and perfumes as well as for the treatment of rheumatism in India. Finally, still other grasses provide the turf we use for sport and recreation.

      CHAPTER 2 THE ORIGIN AND DEVELOPMENT OF GRASSLAND

      For many generations the term “grasses” as used by farmers had an all-embracing significance and included companion plants like clovers, yarrow, dandelion, ribgrass, and so on, the blending of which made up the turf or sward of a pasture or a meadow which was eaten by horses, sheep and cattle. The term “pasture” usually refers to grassland grazed by animals, while “meadows” are mown for hay. These terms are often used loosely and frequently synonymously, for grassland may be grazed and mown in the same year. Moreover, grazing land is commonly referred to as “meadow” when it borders a stream or river, and in all probability in days gone by it was our poets who contributed to this confusion of terminology. Only in recent years have farmers consciously distinguished between the various plant species composing a particular type of grassland and realised the significance of the grazing animal or the mowing machine in determining the botanical composition of a particular sward or piece of turf. The groundsman, unlike the farmer, abhors all plants other than the special grasses required to produce a hard-wearing turf. Thus the clovers and other miscellaneous plants commonly seen in farm swards and indeed encouraged to flourish there, are eliminated as speedily as possible by both mechanical and chemical agencies when found in the domestic lawn, the cricket field or the golf green.

      The history of our grasses from the Ice Age can be traced through the pollen grains which have remained preserved for thousands of years in peat bogs. The pollen of many plants, including the bulk of our forest trees, is liberated in vast showers of golden dust, and is wind-borne for considerable distances. Even the centres of large cities receive their quota as the sufferers from hay fever know to their cost. Each pollen grain is protected by a thin skin which is highly resistant to decay; consequently when down the ages millions upon millions of these grains have settled on the land and been covered by further deposits they have not disintegrated. It is possible in the laboratory to separate the pollen grains from soil particles obtained by the simple process of boring into ancient lake beds and peat bogs. These can be identified and in this way precise records of the local vegetation can be secured from the glacial period onwards. Such information can then be cross-checked with any geological and archaeological data available enabling a complete picture to be built up.

      With the improvement in climate after the final retreat of the ice, the country was covered with vast woods of pine and birch, the only grassland being in parts of the forest cleared by early man. Then elm, oak, and hazel scrub gradually became established as conditions improved.

      What of the livestock whose development is intimately interwoven with that of the grasses? Animals clearly related to our present-day grazing animals appear in the fossil records early in the Eocene period, some seventy million years ago. Judging by the structure and arrangement of their teeth, these early ungulates were, however, mainly browsing animals, feeding by cropping the leaves of forest trees. This seems to have been true throughout the Eocene and the succeeding Oligocene period, but at the opening of the Miocene, some forty million years later, there appears to have been a decrease in rainfall and a consequent diminution of forest cover, leaving grasses and other low-growing plants in possession of the plains, both in the Old and the New World. True grazing animals, closely related to modern types, then developed. Antelopes and sheep are recognisable from the Upper Miocene, and oxen, goats, and horses from the following Pliocene period.

      The pastures which supplied the needs of the stock of primitive man were as can be imagined but a pale shadow of the excellent swards of to-day. It is unlikely that they did more than keep mature cattle alive, although for a short period during the summer months the best milk cows might have produced a few pints of milk per day, compared to the four, five or six gallons expected now. Nor was the farmer of those times conversant with the needs of the soil, and the constant leaching of nutrients by rain water and the removal of minerals by the stock themselves in the herbage consumed meant that phosphate, lime and potash deficiencies were common. As the fertility of the cultivated ground fell to the point where the yield of grain no longer rewarded the efforts of cultivation, this ground was abandoned. The former arable was then allowed to revert to some form of grass again. Such conditions favour the growth of mat grass (Nardus stricta), purple moor grass (Molinia caerulea) sheep’s fescue (Festuca ovina), bent (Agrostis spp.), bromes (Bromus spp.) and the oat grasses (Arrhena-therum, Trisetum and Helictotrichon), grasses of poor feeding value. These are in marked contrast to the broad-leaved succulent grasses of high feeding value which comprise a good pasture. Farm stock in those early times was small and stunted as shown by the skeletons which have been found and this was only to be expected under such conditions.

      The conversion from forest to pasture can be seen in minature on the broad verge of many a farm road crossing or common. Nearest the road, the constant trampling back and forth of cattle, sheep, and horses promotes the growth of the best pasture grasses, such as the ryegrasses (Lolium spp.) and the meadow grasses (Poa spp.) with wild white clover (Trifolium repens) and probably bird’s foot trefoil (Lotus corniculatus). As the trampling and grazing become less intensive further from the road-side so the bents (Agrostis spp.) the fescues (Festuca spp.) and Yorkshire fog (Holcus lanatus) become more dominant and these in turn are replaced by coarser grasses, the tall fescues, tussock grass (Deschampsia caespitosa) and oat grasses until bramble, hazel, blackthorn, wild rose, and hawthorn dominate the scene. It is then only a short step to true forest. This gradual progression from good grass to forest follows any change which results in less intensive grazing or neglect. Should a field be ranched, allowing only a few head of stock on a large acreage of grassland, as opposed to close grazing where many stock are concentrated in a field, or more especially if grassland is allowed to become derelict, young saplings of forest trees spring up and the once valuable turf soon becomes colonised by coarse grasses and scrubby growths reverting back in time to the original forest from which the pasture had been won by the efforts of man.

      Not until about 50 B.C. was the liming and marling of fields practised by the Belgae as a means of replenishing the fertility of the soil, and it was very much later that the droppings of animals were collected to be spread as farmyard manure. We owe much to the Belgae; with the eight-ox plough which they introduced, cultivation on a much bigger scale became possible and, moreover, they affected considerable forest clearance with their implements. So successful were their efforts, indeed, that corn and cattle were exported to the Continent, and when Caesar invaded Britain he was able to supply the food needs of his troops from the soil of Kent.

      The Romans did little for the grassland of Britain, but after they had withdrawn, the Anglo-Saxon invaders, with great vigour, began clearing more forest land and converting lowland soils into meadows and cornfields. Many more were enclosed for better cropping and compact villages were created. These were usually surrounded by large open fields in which each settler had a number of scattered strips, some for cultivation and others to be mown for hay, the underlying principle being to divide up as evenly as possible the different types of soil with their varying levels of fertility. After harvest the arable and the meadow land were opened for common grazing, the stock feeding on the straw which was left on the arable ground, together with any growth of grass which had been made since the hay was carted. The Anglo-Saxons were really the first farmers to appreciate the need for adequate pasture during the grazing season and the necessity of safeguarding their stock in winter time with a good supply of hay. By so doing, the former practice of slaughtering in the autumn all the stock which could not fend for itself during the winter was avoided. Each occupier of thirty acres was given at the beginning of his tenancy a cow, two oxen, and six sheep by the