|
 |
|
|
Chapter 10
PretreatmentBy pretreatment we would wish to imply the conduct of certain lesser operations in preparation for the more successful accomplishment of a major operation. Thus, to predisk before ploughing is to make it easier, and more successfully to rot down an old turf for the benefit of subsequent crops. Again, to pitchpole an old turf a few times some weeks before disking is an admirable pretreatment in preparation for the more thorough work of the disk. In brief, pretreatments are operations that need not necessarily be undertaken preparatory to the major operations, but which, if undertaken, will greatly facilitate the major operations themselves, and greatly help towards the end ultimately in view -- enhanced soil fertility and increased crop production.
In my (R.G.S.) earlier writings I have used the word pretreatment, like the word pioneer, in a restricted sense. I have written much and talked much about pretreating rough and matted permanent swards in preparation for subsequent ploughing, and it is to this all-important subject that we shall now address ourselves. In parenthesis, we may, however, add that the whole question of pretreatment in relation to ploughing and cultivations in general has become one of extreme importance just because of the unprecedented facilities that modern implements and tractors have put at the disposal of the farmer. Pretreatment, in both its narrower and wider implications, constitutes an issue of the first moment, and it is one that demands a great deal of research, and merits the most earnest consideration of the practical man. In effect, pretreatment conducted upon permanent grass is to make an efficient pioneer crop of the permanent grass itself.
With the best will in the world, we could not plough up the whole nine million odd acres (there are still 6 million acres of plougbable permanent grassland [Jan. 1948, W. D.]) of permanent grass that are due to be ploughed in one, or even in two years. We must, therefore, be doing all we can -- and at once -- to get the poorer acres ready for ploughing at a later date, and in the meantime to make them yield the maximum possible tonnage of grass nutrients. Pretreatment implies doing both of these things, and with the emphasis strongly laid on getting ready for the plough.
Pretreatment would naturally be applied to fields most out of heart and in the least ploughable condition. Generally speaking, then, to fields with a coarse and tufted vegetation and with a pronounced mat. The treatment must aim at eliminating roughage, and breaking down the mat. The first necessity is, therefore, to make such fields capable of holding stock in order that the mat may become impregnated with animal residues. Briefly, the procedure is to start with the mowing machine, to follow up with heavy and repeated pitchpoling (the pitchpole is an excellent remover of ant-hills), then to lime up to the lime requirement (preferably in terms of ground limestone) and by further heavy pitchpoling to incorporate the lime with the underlying sod: ideally, the next procedure is to slag heavily, accompanied by further attacks with the pitchpole, or perhaps by now the Aitkenhead grass ripper will meet the case. By now stocking will have begun, and because stock are the essential improvers, when roughage has been cleared and the liming completed, it will be necessary to start on a generous, judicious and oft-repeated use of nitrogen, either as nitro-chalk or ammonium sulphate -- the more keep, the more animal residues!
To use nitrogen unless the grass is converted as it offers itself is to invite the return of roughage, and to defeat our own ends, so that if the animals are unable to keep pace with the growth, the mowing machine must be brought to their aid.
The best months to conduct the necessary dragging operations are probably late September, October and November. On the most worthless swards, such operations can, however, be conducted practically all the year round, and only good can result. The acreage demanding pretreatment is enormous, and in our opinion, on many farms it is almost as important to give pretreatment quotas as it is to give plough-up quotas.
By far the larger acreage of poor permanent grass demanding pretreatment is on land both highly deficient in lime and strikingly deficient in phosphates. Experiments conducted in Wales show that on such land excellent results can be obtained by the use of lime, even if phosphates are not employed -- results will not, however, be so quickly obtained without the use of phosphates, and in all cases where reliance is placed only on lime, the dragging should be extra heavy and seeds of wild white clover should be thinly scattered over the ground. Where the acreage of poor permanent grass is very great indeed, the farmer should not hesitate to conduct pretreatment on the worst of such land even if he is unable to obtain or to spare phosphates, for by the use of lime alone, he should have brought even the roughest sward into a condition fit for the plough and reseeding or crop production in a period of no more than four or five years. On many farms it would take quite four years to get the plough round the whole of the poor permanent grass fields. Pretreatment should, however, not only be thought of in terms of farms, but equally in terms of districts. There are hundreds of thousands of acres of heathy and moorland vegetation towards the upper limits of the plough-line as well as at lower elevations in the Welsh counties and elsewhere where, under any ordered method of reclamation, pretreatment should be taking its place along with pioneer crops, reseeding and oat and potato production in a well-conceived plan of operations. This the more so because the most economical way to bring lime to the land is to organize liming on a grand scale district by district, and when a district is under treatment to lime every field and every area of agricultural potentiality demanding lime. Again, wherever there is rough grassland there is always scope for pretreatment as well as immediate ploughing up. Merely to slag or to lime even on the roughest swards constitute useful acts of pretreatment, but without resort to the mowing machine and heavy dragging, and unless supported by concentrated grazing, the benefits are too slow for the present emergency. We now more particularly need to be taking action that will bring even the most obdurate swards into a ploughworthy condition and hence the immense importance of the thoroughgoing pretreatments we have described. The aim is to encourage the most rapid spread of white clover and the immediate rotting-down of the mat -- to the latter end, lime, the spreading white clover, the animal residues and added soluble nitrogen are complementary to each other and all are equally essential. The magnitude of the results that can be effected primarily by white clover responding to generous. liming and supported by heavy grazing have been demonstrated over and over again when fields that have been heavily limed and well stocked have been subsequently ploughed and brought into a rotation. These effects are often very long-standing. In the case of land taken over by the Cahn Hill Improvement Scheme, near Knighton, which was in a vegetation of Nardus-fescue and bilberry, a certain area had received lime eighty years previous to our ploughing it up for reseeding. This prelimed portion ploughed more easily than the remainder, and also gave a much heavier crop of rape and an altogether better sward than the remainder that had received no lime. This is an exaggerated example, but one of great interest, but wherever we have conducted experiments on pretreatment there always the subsequent ploughing has been more easy and subsequent crop or grass production (from reseeding) has shown marked benefit.
Pretreatment is indicated on many types of matted grassland. It is peculiarly efficacious on Molinia and Nardus swards, it is very effective on swards full of tussock grass, although on such swards the heavy pitchpoling should be continued for two or three years. Marshy and semi-marshy land covered with rushes and with rushes and Molinia have been effectively treated at Aberystwyth, where surprisingly rapid results have followed the strenuous use of mowing machine and pitchpole, supported by lime and phosphates, accompanied by judicious dressings of nitrogen and heavy stocking. The areas so treated have been subsequently ploughed and reseeded, and now carry first-class swards, and this on quite wet land and without resort to extensive drainage operations. There can be little doubt that the torgrass-fescue pastures of the Midlands would respond well to pretreatment, and experiments have been conducted at the Grassland Improvement Station on some particularly stubborn and unsightly representatives of these useless swards.
It should be emphasized that pretreatments can be conducted under weather conditions when it is often impossible to plough or cultivate, and that they make for an immediate increase in the bulk of grass nutrients from worthless swards. Pretreatment should be regarded always as something extra to the year's ploughing quota, and never in any one year by one single acre as a substitute for ploughing. We must, as we have said, be ploughing representatives of our best, medium, poor and poorest grasslands every year, but so vast is the acreage of the poor and poorest that, as well as ploughing representative acreages each year, we must also be pretreating further acreages of the worst and most tufted of them.
On many of the poorer grasslands on retentive soils mole-draining should be regarded as an essential act of pretreatment, for to have mole-drained a year or two in advance of ploughing-up will have done much to help further to ameliorate the soil conditions and to accelerate the rotting-down of the mat. Subsoiling has also proved to be an efficacious aid, and is best undertaken as an act of pretreatment.
In our chapter on permanent grass (Chapter 11), other methods of improvement will be considered, and all of them can also be employed as pretreatment according as the circumstances dictate.
Next: 11. The Improvement of Permanent Pastures and Rough Grazings
Back to Contents
Back to Small Farms Library index
Community development | Rural development
City farms | Organic gardening | Composting | Small farms | Biofuel | Solar box cookers
Trees, soil and water | Seeds of the world | Appropriate technology | Project vehicles
Home | What people are saying about us | About Handmade Projects
Projects | Internet | Schools projects | Sitemap | Site Search | Donations | Contact us