1911 Encyclopædia Britannica/Grass and Grassland
GRASS AND GRASSLAND, in agriculture. The natural vegetable covering of the soil in most countries is “grass” (for derivation see Grasses) of various kinds. Even where dense forest or other growth exists, if a little daylight penetrates to the ground grass of some sort or another will grow. On ordinary farms, or wherever farming of any kind is carried out, the proportion of the land not actually cultivated will either be in grass or will revert naturally to grass in time if left alone, after having been cultivated.
Pasture land has always been an important part of the farm, but since the “era of cheap corn” set in its importance has been increased, and much more attention has been given to the study of the different species of grass, their characteristics, the improvement of a pasture generally, and the “laying down” of arable land into grass where tillage farming has not paid. Most farmers desire a proportion of grass-land on their farms—from a third to a half of the area—and even on wholly arable farms there are usually certain courses in the rotation of crops devoted to grass (or clover). Thus the Norfolk 4-course rotation is corn, roots, corn, clover; the Berwick 5-course is corn, roots, corn, grass, grass; the Ulster 8-course, corn, flax, roots, corn, flax, grass, grass, grass; and so on, to the point where the grass remains down for 5 years, or is left indefinitely.
Permanent grass may be grazed by live-stock and classed as pasture pure and simple, or it may be cut for hay. In the latter case it is usually classed as “meadow” land, and often forms an alluvial tract alongside a stream, but as grass is often grazed and hayed in alternate years, the distinction is not a hard and fast one.
There are two classes of pasturage, temporary and permanent. The latter again consists of two kinds, the permanent grass natural to land that has never been cultivated, and the pasture that has been laid down artificially on land previously arable and allowed to remain and improve itself in the course of time. The existence of ridge and furrow on many old pastures in Great Britain shows that they were cultivated at one time, though perhaps more than a century ago. Often a newly laid down pasture will decline markedly in thickness and quality about the fifth and sixth year, and then begin to thicken and improve year by year afterwards. This is usually attributed to the fact that the unsuitable varieties die out, and the “naturally” suitable varieties only come in gradually. This trouble can be largely prevented, however, by a judicious selection of seed, and by subsequently manuring with phosphatic manures, with farmyard or other bulky “topdressings,” or by feeding sheep with cake and corn over the field.
All the grasses proper belong to the natural order Gramineae (see Grasses), to which order also belong all the “corn” plants cultivated throughout the world, also many others, such as bamboo, sugar-cane, millet, rice, &c. &c., which yield food for mankind. Of the grasses which constitute pastures and hay-fields over a hundred species are classified by botanists in Great Britain, with many varieties in addition, but the majority of these, though often forming a part of natural pastures, are worthless or inferior for farming purposes. The grasses of good quality which should form a “sole” in an old pasture and provide the bulk of the forage on a newly laid down piece of grass are only about a dozen in number (see below), and of these there are only some six species of the very first importance and indispensable in a “prescription” of grass seeds intended for laying away land in temporary or permanent pasture. Dr W. Fream caused a botanical examination to be made of several of the most celebrated pastures of England, and, contrary to expectation, found that their chief constituents were ordinary perennial ryegrass and white clover. Many other grasses and legumes were present, but these two formed an overwhelming proportion of the plants.
In ordinary usage the term grass, pasturage, hay, &c., includes many varieties of clover and other members of the natural order Leguminosae as well as other “herbs of the field,” which, though not strictly “grasses,” are always found in a grass field, and are included in mixtures of seeds for pasture and meadows. The following is a list of the most desirable or valuable agricultural grasses and clovers, which are either actually sown or, in the case of old pastures, encouraged to grow by draining, liming, manuring, and so on:—
|Alopecurus pratensis||Meadow foxtail.|
|Anthoxanthum odoratum||Sweet vernal grass.|
|Avena elatior||Tall oat-grass.|
|Avena flavescens||Golden oat-grass.|
|Cynosurus cristatus||Crested dogstail.|
|Festuca duriuscula||Hard fescue.|
|Festuca elatior||Tall fescue.|
|Festuca ovina||Sheep’s fescue.|
|Festuca pratensis||Meadow fescue.|
|Lolium italicum||Italian ryegrass.|
|Phleum pratense||Timothy or catstail.|
|Poa nemoralis||Wood meadow-grass.|
|Poa pratensis||Smooth meadow-grass.|
|Poa trivialis||Rough meadow-grass.|
|Medicago lupulina||Trefoil or “Nonsuch.”|
|Medicago sativa||Lucerne (Alfalfa).|
|Trifolium hybridum||Alsike clover.|
|Trifolium pratense||Broad red clover.|
|Trifolium pratense||Perennial clover.|
|Trifolium incarnatum||Crimson clover or “Trifolium.”|
|Trifolium procumbens||Yellow Hop-trefoil.|
|Trifolium repens||White or Dutch clover.|
|Achillea Millefolium||Yarrow or Milfoil.|
|Lotus major||Greater Birdsfoot Trefoil.|
|Lotus corniculatus||Lesser Birdsfoot Trefoil.|
|Carum petroselinum||Field parsley.|
The predominance of any particular species is largely determined by climatic circumstances, the nature of the soil and the treatment it receives. In limestone regions sheep’s fescue has been found to predominate; on wet clay soil the dog’s bent (Agrostis canina) is common; continuous manuring with nitrogenous manures kills out the leguminous plants and stimulates such grasses as cocksfoot; manuring with phosphates stimulates the clovers and other legumes; and so on. Manuring with basic slag at the rate of from 5 to 10 cwt. per acre has been found to give excellent results on poor clays and peaty soils. Basic slag is a by-product of the Bessemer steel process, and is rich in a soluble form of phosphate of lime (tetra-phosphate) which specially stimulates the growth of clovers and other legumes, and has renovated many inferior pastures.
In the Rothamsted experiments continuous manuring with “mineral manures” (no nitrogen) on an old meadow has reduced the grasses from 71 to 64% of the whole, while at the same time it has increased the Leguminosae from 7% to 24%. On the other hand, continuous use of nitrogenous manure in addition to “minerals” has raised the grasses to 94% of the total and reduced the legumes to less than 1%.
As to the best kinds of grasses, &c., to sow in making a pasture out of arable land, experiments at Cambridge, England, have demonstrated that of the many varieties offered by seedsmen only a very few are of any permanent value. A complex mixture of tested seeds was sown, and after five years an examination of the pasture showed that only a few varieties survived and made the “sole” for either grazing or forage. These varieties in the order of their importance were:—
|Perennial rye grass||16|
The figures represent approximate percentages.
Before laying down grass it is well to examine the species already growing round the hedges and adjacent fields. An inspection of this sort will show that the Cambridge experiments are very conclusive, and that the above species are the only ones to be depended on. Occasionally some other variety will be prominent, but if so there will be a special local reason for this.
On the other hand, many farmers when sowing down to grass like to have a good bulk of forage for the first year or two, and therefore include several of the clovers, lucerne, Italian ryegrass, evergreen ryegrass, &c., knowing that these will die out in the course of years and leave the ground to the more permanent species.
There are also several mixtures of “seeds” (the technical name given on the farm to grass-seeds) which have been adopted with success in laying down permanent pasture in some localities.
|Young.||De Laune.||Leicester.||Elliot.|| Cambridge |
|Tall oat grass||..||..||1||3||..||..|
|Smooth meadow grass||..||..||..||1||..||..|
|Rough meadow grass||..||1||..||1||..||..|
|Golden oat grass||..||..||1||1||..||..|
|Broad red clover||..||1||..||..||..||2|
|Perennial red clover||..||1||..||11||..||2|
|Total ℔ per acre||30||40||17||40||30||40|
chalky hillsides; Mr Faunce de Laune (Sussex) in our days was the first to study grasses and advocated leaving out ryegrass of all kinds; Lord Leicester adopted a cheap mixture suitable for poor land with success; Mr Elliot (Kelso) has introduced many deep-rooted “herbs” in his mixture with good results. Typical examples of such mixtures are given on preceding page.
Temporary pastures are commonly resorted to for rotation purposes, and in these the bulky fast-growing and short-lived grasses and clovers are given the preference. Three examples of temporary mixtures are given below.
or four years.
|Broad red clover||8||5||3|
|Perennial ryegrass||. .||5||10|
|Meadow fescue||. .||2||2|
|Perennial red clover||. .||2||2|
|White clover||. .||1||2|
|Meadow foxtail||. .||1||2|
|Total ℔ per acre||30||36||40|
Where only a one-year hay is required, broad red clover is often grown, either alone or mixed with a little Italian ryegrass, while other forage crops, like trefoil and trifolium, are often grown alone.
In Great Britain a heavy clay soil is usually preferred for pasture, both because it takes most kindly to grass and because the expense of cultivating it makes it unprofitable as arable land when the price of corn is low. On light soil the plant frequently suffers from drought in summer, the want of moisture preventing it from obtaining proper root-hold. On such soil the use of a heavy roller is advantageous, and indeed on any soil excepting heavy clay frequent rolling is beneficial to the grass, as it promotes the capillary action of the soil-particles and the consequent ascension of ground-water.
In addition, the grass on the surface helps to keep the moisture from being wasted by the sun’s heat.
The graminaceous crops of western Europe generally are similar to those enumerated. Elsewhere in Europe are found certain grasses, such as Hungarian brome, which are suitable for introduction into the British Isles. The grasses of the American prairies also include many plants not met with in Great Britain. Some half-dozen species are common to both countries: Kentucky “blue-grass” is the British Poa pratensis; couch grass (Triticum repens) grows plentifully without its underground runners; bent (Agrostis vulgaris) forms the famous “red-top,” and so on. But the American buffalo-grass, the Canadian buffalo-grass, the “bunch” grasses, “squirrel-tail” and many others which have no equivalents in the British Islands, form a large part of the prairie pasturage. There is not a single species of true clover found on the prairies, though cultivated varieties can be introduced. (P. McC.)