The Correct Place for the Ley in the Rotation
In this and the immediately succeeding chapters, we shall discuss in detail the six courses open to us for dealing with permanent grass, and we shall largely confine ourselves to a consideration of the methods that should be adopted in the conduct of the cultivational and other operations entailed.
A Sequence of Crops Ending with the Ley
Contrary to strongly held views, we are of the definite opinion that in this country there is no permanent grass too good to be ploughed up. There are often good reasons for not ploughing up particular fields -- the difficulties due to steepness, liability to excessive flooding, an over-waterlogged condition, or presence of boulders, may be insuperable, but super-excellence of sward is never, as such, an all-sufficient justification for withholding the plough. It is not a sufficient justification for two chief reasons. Provided that the system of cropping will have been sensible, it is to-day possible to put the very best sward back to grass of a quality at least equal to that which was broken. To do so, it is only necessary to ensure that the lime and phosphate status of the soil shall always be brought up to a standard no lower than when the turf was originally broken, and in any case, sufficiently high to favour the development of a good sward; to employ a seeds mixture consisting largely of persistent strains of grasses and of white clover suitable to the locality and to the conditions and to ensure that when the seeds mixture is sown, the soil is still sufficiently rich in humus and organic matter. The early management too must be such as is favourable to immediate sward development; the newly sown fields should be grazed and not used as meadows for a period of at least two years.
Our best grasslands constitute our richest reserve of fertility, while few indeed of them are producing even animal products up to their full possibilities. They are capable of producing an immense tonnage of crops like wheat, beans, sugar-beet, potatoes, as also of grass (as leys) and kale, and this over a number of years without any extravagant assistance from artificial manures. In the present emergency, therefore, it is to our richest grasslands that we should chiefly look for enormously increased crop production. We can do so with a light heart not only because it is a fallacy to suppose that we should be destroying something that we cannot replace, but for the much better reason that we could create enough excellent leys elsewhere and on land of not nearly such high crop-producing potentialities to more than compensate in grass nutrients for what we should have temporarily lost.
We should be fearlessly breaking up the very best ryegrass pastures in Leicestershire and Northamptonshire and in districts like that of Alnwick and Stamfordham in Northumberland. The same should apply to the better of the ryegrass-agrostis pastures and to those richer agrostis pastures which frequently contain large quantities of meadow foxtail, It is grasslands such as these which, if put into a sensible rotation, could carry a run of crops with perfect safety and then be put back to grass as good as or better than before. There are other and poorer types of grassland which could also stand a run of crops and which could finally be put back to grass of a character altogether better than the original swards. The best example of such a type is the torgrass-fescue pastures of the heavy clays of the Midlands -- they could hardly go back to grass worse than that!
On all the types of grassland we are discussing, it is not essential that the longer ley should intervene at an early stage in the rotation -- it can be safely deferred. We are not advocating a long and continuous run of white straw crops: the bean (with all the advantages of a leguminous crop) should intervene; as should roots or kale (and the dung cart) and as an aid to maintaining stock and creating dung, the one-year ley should also intervene. But from our best grasslands and those on soils suitable to beans as well as to wheat over a six-year period we could safely look for at least three cereal crops and one crop of beans, and this, as we say, without any very extravagant use of artificial manures.
Much is made, and not without reason, of the risks of lodging of cereals and of the ravages of wireworm, but neither risk must be allowed to be made the excuse for regarding our best grasslands as inviolate, or for regarding the clays as too difficult. Both are risks that, to a very real extent, can be countered. In the first place, it is not necessary to start the rotation with a cereal -- admirable first crops on such grassland are beans, kale, roots and potatoes.
The dangers from wireworm can be decreased by appropriate cultivations, while wheat and winter oats, both sown in good time, are not so prone to devastating wireworm damage as spring-sown cereals. Further, we must always remember that on rich land and on land suitable to wheat or to winter oats, the crop will have a much better chance of growing away from wireworm than on poor or thin land or on land generally not so well suited to these crops.
Consolidation undoubtedly acts as a countermeasure to both lodging and wireworm. Heavy disks must be regarded as admirable consolidating implements, and thus function in strong support of the roller: there is, however, no better consolidator than the sheep, and there is, therefore, much to be said for judicious grazing of winter wheat and winter oats, a procedure which also tends to lessen the dangers of winter killing due to adverse weather.
Wireworm can be decreased by the efficient precultivation of sward prior to sowing a winter cereal. The torgrass-fescue swards, as well as many other types, are of so little grazing value that not much is lost if cultivations are started as early as May -- while on even the richest grasslands there is much to be said for taking an early hay cut, or a silage cut, or grazing particularly heavily in the earlier part of the season, and starting cultivations in June or early July. There are many methods of dealing with turf prior to sowing a winter cereal, but mention may be made of a plan we have successfully adopted at the Grassland Improvement Station. We refer to heavily disking (four to five diskings) the turf and then ploughing in the disked surface. Birds of all kinds are greatly attracted to a disked surface. Sod that has been disked into fragments rots down much better when buried than sod in great slices, it also packs better and thus good consolidation is easier to achieve. On two fields we carried the disking far enough (seven to nine diskings) to drill wheat on the surface thus prepared without any ploughing at all.
Apart from methods of cultivation and management aimed at consolidation, the farmer can safeguard lodging to a quite remarkable extent by the choice of good standing and stiff-strawed varieties, such as Holdfast wheat and Aberystwyth S 172 white winter oats; more than this, he can prevent a too-heavy crop by rather long-continued grazing; by even taking a light silage cut, or by rolling when the crop is nearly fifteen inches high.
The grass-clover sward is not only a humus-maker, it is also a humus-demander, and therefore we must have ready a proper humus-containing soil for the reception of a seeds mixture designed to develop into a first-rate long-duration sward when the broken turf comes for regrassing. If rather many crops have been taken, it is consequently wisest to start with a two-year ley and to use this as a builder of fertility. In many instances it would be sown without a cereal covering crop and would best follow a root crop that has received ample dung, and it should be used as a grazing-only ley. The long-duration ley should then follow on the broken surface of the preparatory two-year ley, and it, too, where possible, would be sown without a cereal covering crop and at least during the earlier years would be used for grazing only. If cropping has not been too long continued and if the one-year ley and a properly dunged root crop have contributed to the rotation, then a preparatory two-year grazing-ley would not be necessary, and it would be perfectly safe to go straight into the long-duration ley -- remembering that lime (if necessary) must have been applied prior to sowing-out and that the developing ley should have had the support of an adequate dressing of phosphates. In our view, it is most undesirable, in the interests of high farming and the health of our livestock, that even the areas broken from the best permanent grass should be resown to permanent grass. They should be retained in ley farming, but a considerable proportion of the leys would be of quite long duration -- perhaps in some cases running on for ten or even fifteen years. In the affairs of agriculture, the peace will be lost unless the war experience has taught us to be done once and for ever with the permanent grass complex: we must talk, think and plan in terms of leys -- long-duration leys if we like, in their proper sphere -- but never again in terms of permanent pasture.
Seeding Out with the First or Second Corn Crop
There are literally millions of acres of poor permanent grass -- pastures of the agrostis, agrostis-fescue and semi-uncultivated types -- which are themselves so poor and which occupy land in such a low state of fertility that when ploughed they are incapable of carrying a long run of cereal crops. Their inability to do so would be further accentuated by poor cultivations and by insufficient help from artificial manures. It is true that when the cultivations will have been excellent and the ploughing started early enough and when artificials are freely applied a run of cereal crops -- three, or even four crops in succession -- can be successfully taken from some types of very poor permanent grass. This has been true of certain stretches of Downland, for example, but such successes do not constitute a good argument for a general attempt to over-crop land newly broken from the poorer types of grass on soils which lack body. It must be remembered that such grass, as feed for animals, has negligible value, and therefore it is important to plough up as much as possible, as soon as possible, and to be creating new and better grass at an early stage in the rotation. That is the grass argument. The cereal argument is no less pressing. With the fertilizers available and on the classes of land we are considering, a greater gross yield of cereals would be produced by continually moving the plough on and taking a larger acreage of each year's cereal quota from newly broken turf, than by a more continual cropping of areas previously broken.
Where there is the poorest permanent grass, it is usually present to great excess. On many all-grass holdings, every single field consists of the poorest possible permanent grass, while there are thousands of grass-arable farms where the permanent grass is so poor that every field in grass should be broken. In such cases, cereal production and grass production are both most expeditiously and most sumptuously to be increased by hastening the plough around the farm.
The plan is to sow a ley mixture with the first cereal crop on the newly broken sod, or in any event (and on some of the 'better' fields) with a second cereal crop. Where the lime requirement needs to be satisfied, lime should be applied in every case before the seeds are sown. No fields with high lime requirements should be permitted to struggle through a too long rotation and eventually be sown down to a ley without any lime having been applied.
To sow a ley with a first corn crop is economic, in two directions where economy is most urgent: in tractor hours and phosphates. From one ploughing will be achieved a corn crop, back-end (and in some districts winter) and spring grazing, followed by a hay crop and after-grass; or a corn crop and valuable grazing and all within a period of eighteen months. Further grazing and hay (if so arranged for) will be forthcoming if the ley is left down for two or three years.
As we have said, cereals grown on the poorest sods definitely require phosphates to ensure good yields, and on this account there is much to be said for sowing a seeds mixture with the first corn crop on newly broken swards of inferior quality and where fertility is exhausted. To defer phosphates and seeds mixture to a second corn crop would be to invite a partial failure of the first corn crop, while to defer the seeds mixture to the second corn crop without additional phosphates would be to jeopardize the establishment of a fully productive ley. Where there is permanent grass ad lib. and where such grass is completely run out, there is, therefore, everything to be said for sowing the ley mixture under the first corn crop and proceeding around the farm on that basis, with only the exception of a few of the 'better' fields, until all the poor permanent grass is broken. The 'better' fields can go into a more normal rotation, largely with a view to increasing the root breadth in closer harmony with the increased straw production.
On fields which will take two corn crops in succession, and will be sown to a ley with the second cereal crop, it is very important to have done everything possible to have helped the old turf to have rotted down so that there will be none left to be brought to the surface with the second ploughing and to interfere with the preparation of a tilth for the seeds mixture. With a view to this end, predisking the original sward before the first ploughing and then ploughing in the disked-up turf is to be strongly recommended. An additional help, if spring corn will follow winter corn, is to have sown a little Italian ryegrass and broad red clover with the first corn crop; this should provide useful stubble grazing, with consequent urination and dunging before the stubble normally comes for ploughing -- and this will further help to rot down the old turf.
Where the field is medium-poor and where there is no exaggerated mat, it is often best to sow to a one-year ley. We have in mind a particular field at Aberystwyth. We broke it from sod and sowed it to oats and a one-year ley in the spring of 1939. We had a heavy yield of oats, excellent back-end and winter grazing, good early spring grazing, a heavy yield of hay and subsequent grazing. We reploughed in the autumn (1940) and sowed winter wheat, and at the time of writing (June 1941) the wheat is looking full of promise. Where the field is definitely poor and the sod matted, it is best to sow to a two- or three-year ley and give ample time for the old turf to rot down and for the accumulation of fertility (via the residues of the grazing animal) before reploughing and replanting to a cereal or other crop.
The method of sowing a two- or three-year ley direct with the first cereal on newly broken sod is peculiarly applicable to wet and wettish land on banky fields. The plough furrows (drawn with the slope) undoubtedly help to carry away water both from the cereal crop and from the subsequent ley, and on such fields oats: ley: ley: oats: ley: ley would be a very sensible six-year rotation. In proportion as the land is poor, all-grazing rather than hay leys should be employed, and nitrogen should be judiciously used to encourage growth at appropriate periods throughout the life of the ley.
It is a very usual practice to sow the ley mixture on the brairded corn -- this must necessarily be done in the spring on autumn-sown oats or wheat -- and under these conditions the corn should be sufficiently well harrowed to ensure a good tilth for the seeds. When a seeds mixture is sown with spring corn, it is, however, probably wisest to sow at the final harrowing-down operations after drilling the corn. This will permit of early spring sowing, and if drought intervenes, the grass and clover seeds will be at no early disadvantage compared with the cereals -- fully brairded corn makes heavy demands on soil moisture. In dry districts it is probably safest to drill the grass and clover seeds into the soil and in the spring it would seem to be safe to sow these small seeds to a depth even slightly exceeding an inch. Seeds require a sufficiently deep and a firm tilth. To. sow on the rolled surface of a tilth prepared by harrowing and then to harrow the seeds in is usually a satisfactory method of procedure in the West and North.
The methods we have advocated in this chapter are particularly appropriate to dairy farmers operating on poor permanent grass, because grass must always be regarded as the chief crop of the milk producer, while under present conditions, oats and good oat straw are valuable assets on a dairy farm. Moreover, the dairy farmer, more than any other user of grass, needs to set off fields ploughed for crops for direct human consumption by increasing his yield of grass nutrients, and this he can best do by the rigid substitution of good leys for poor permanent grass on fields not actually in crop.
Similarly, the sheep man and the cattle rearer, who normally operate on the poorest of permanent grass, need rapidly to regain in bulk of grass nutrients what they may have momentarily lost in ploughing for cereal production, but these men, as far as their soils permit, must also continue in cereal production. Thus, equally on account of farm practices, commodity production and of sward and soil conditions, there are huge acreages in the following regions that should be sown to the ley with a first or second cereal crop.
The Downs, and over large areas of the Cotswolds, the Oxfordshire hills and the higher lands of Northamptonshire. Much the same may be said of the light sands of Norfolk and Suffolk, as well as parts of Lincolnshire and the Yorkshire Wolds.
The all-grass dairy farms in the Dales of Yorkshire and Derbyshire, Stafford, Cheshire and Lancashire. The same applies to other areas lying in close proximity to the large industrial areas.
Large areas consisting of the poorer lowland pastures of the whole of Wales and a very large acreage indeed between the 600-ft. and 1,000-ft. contours of the uplands of Wales and in counties like Lancashire, Westmorland, Cumberland, Cheshire, Durham, Northumberland, Derbyshire and Stafford.
Large acreages on all-grass and grass-arable farms in North Devon and West Somerset at the relatively higher elevations, and also in many parts of Shropshire, Hereford, Gloucester (the Forest of Dean area) to mention but the more obvious examples.
In addition, there are small districts within nearly every characteristic region where reseeding with the first cereal crop is the most generally appropriate procedure, just as there are individual fields on thousands of farms consisting predominantly of highly fertile grassland which demand the same treatment.
Taking England and Wales as a whole, and thinking in terms of the nine million odd acres that are ploughable and ought-to-be-ploughed, we would argue that something like fifteen out of every hundred acres broken ought to be regrassed with the first corn crop and perhaps 25 per cent with the second.