RENOVATING FARM PASTURES

New Zealand Journal of Agriculture, Volume 63, Issue 3, 15 September 1941, Page 213

RENOVATING FARM PASTURES

Sooner or later the poorer pastures on the farm must be renovated. What is the best way to go II about it? This article discusses the various methods available, and particularly deals with the

question of ploughing and cultivation versus surface sowing. It is emphasised, however, that no matter which method is adopted, the ultimate result will depend largely on the topdressing practice and subsequent management.

By

P. S. SYME,

Instructor in Agriculture, Warkworth.

T“' , VERY farmer is at some time conEVERY farmer is at some time conI 4 fronted with the problem of how best he can renovate his poorer pastures. Almost inevitably the time must arrive when he is called on to decide whether to make a clean sweep and a fresh start with the plough, whether to rely on a programme of surface sowing combined with, topdressing, or whether the object might possibly be economically achieved by generous topdressing alone. Although, in the extreme case of a pasture which is very poor or one which is moderately good, the answer

is obvious, the problem is frequently very complex, and only too often the correct answer is found , too late at the price of costly experience.

Importance Of Clovers

Considering the last-mentioned method first, experience goes to show that it is indeed difficult to over-esti-mate the cumulative' effect of a sustained programme of efficient topdressing.. While this is undoubtedly true, it must also be admitted that heavy topdressing is expensive, and that if insufficient of the better clovers are already present in the sward, the cost may well be altogether disproportionate to the results obtained. Wherever really spectacular results have followed topdressing, a detailed study would almost invariably have shown that, although very minute and inconspicuous, nucleii of clover plants already existed in the sward before the topdressing. Even though only

one starving, pin-head-sized white clover plant per square yard can ■ be found after diligent search, this, considering the rapid spreading powers of its runners and seeds, can, under conditions of improved fertility, quickly produce a complete ground cover.

Clovers Not Always Present

It may be argued that nowadays such nuclei! will invariably be found in any pasture, no matter how poor. It should be pointed out, however, that clover is not always present. In poor

danthonia country which has been repeatedly burned over it is frequently conspicuous only by its absence, and on such land much water will have run under the bridge before an appreciable return is obtained from topdressing. Moreover, the clover present may well be of a very inferior and low producing strain, having little value compared with modern clover standards. While it is sometimes extremely difficult to decide whether topdressing alone will prove a practicable and effective method of renovation, a close examination of the proportion of the more valuable species of grasses and clovers will at any rate provide some indication, and this, in conjunction with any previous experience obtained by topdressing somewhat similar adjacent pastures, may enable the farmer to arrive at a reasonably safe decision.

Ploughing and Resowing

Where the land is easily ploughable and the area not too extensive, and where the existing pasture is particularly poor, ploughing and resowing is likely to prove the best method of

renovation. If, in addition, the farmer can perform the whole of the work with his own labour, this may very confidently be recommended as , the most satisfactory method. Whether or not the opportunity should be taken to crop the land before the final grassing must depend largely on circumstances. It should be borne in mind, however, that while cropping may reduce the overhead cost of grassing, the difference in value between a poor pasture and a really good pasture is so great that future prospects should not lightly be jeopardised merely for expediency dr for present gain. The speedy establishment of the more valuable pasture' species is very largely dependent on the soil fertility, and where this is even a matter of doubt, every effort should be made to conserve the food reserves for the crop which matters mostthe permanent pasture—rather than to dissipate this fertility on a crop which, after all, may be of only secondary importance. Under modern conditions, with the seeds and fertilisers now available, really excellent pastures can be com-

paratively easily established even on land which a generation ago was regarded as almost worthless. By ploughing, the inferior grasses and weeds are at once eliminated instead of having to be completely displaced over a period of years by the spreading of a relatively small proportion of the desirable grasses and clovers, encouraged by suitable topdressing. The ploughing and cultivating raises the level of fertility, and at the same time permits of a full sowing of selected strains of the best species of grasses and clovers. Sown on a clean, well-prepared seed bed with no weed competition, these germinate quickly and speedily establish a high producing pasture. Although the cost may appear fairly high, the returns in proportion are still higher. There is no long interim period of waiting for results; with proper management, high production may be expected within a matter of months.

Surface Sowing

Where, for various reasons, ploughing is either impracticable or inadvisable, the surface sowing of selected

pasture seeds may provide a satisfactory alternative. While spectacular results have been achieved by this method, much depends on the soil and on the sward. In general, success is more slowly achieved than by ploughing, and it may be necessary to continue the sowings over a? number of years. Although costs are low, the loss in production during the building-up period as compared with the almost immediate increase obtained by ploughing must be taken into account when making a comparison. This particu-

larly applies where the existing pastures are very poor. Surface sowing does, however, permit the introduction' of the best species and strains of seeds, and in this respect it may ‘have a decided advantage over topdressing alone as a means of pasture renovation.

Select Species By Fertility

Although the practice of sowing a general mixture of both grasses and clovers is fairly common, it is apt to be wasteful. ' If the clover is seriously deficient and the fertility low, the sowing of high fertility grasses, such as perennial ryegrass, at this stage is likely to prove a mere waste of money. Under, these conditions, an effort should first be made to build up tire fertility by means of clovers before sowing the better grasses. If, however,- the clovers are already fairly abundant, ryegrass may be sown with fair prospects of success. In selecting the gasses and clovers to be sown, preference should be given to the most valuable and productive species, having regard to the existing standard of fertility and the projected

topdressing programme. Although the choice of the grasses may cover a fairly wide range according to the varying soil conditions, in general practice perennial ryegrass and crested dogstail are probably those most commonly included. 5

The clovers are even more important than the grasses, and should receive special consideration. Where conditions are likely to favour its growth, a good strain of white clover should certainly receive first preference. Where conditions are somewhat too hard for

white clover, subterranean clover may offer better prospects of success. Although subterranean clover is inferior to white clover on good land, its ability to thrive on land which is too dry for white clover, its , earliness?, of growth, its persistence, and. its high efficiency as a nitrogen-producer, combine to make it worthy of consideration under a wide range of farming conditions. When used, this clover should be sown when conditions are favourable in the autumn. , . Lotus major is well worthy of inclusion where the soil is moist, and is a useful ally in the combating of rushes. Red clover is sometimes included because of its bulk of feed, but unless conditions are particularly favourable for its establishment, it is probable that it is much inferior to the long-lived and rapid-multiplying white clover for this purpose.

Time of Sowing

Just when the sowing should be performed must depend largely on circumstances and on the locality. Usually, however, autumn is the time most favoured, and, as the success of the sowing largely depends on the top-

dressing, it is common to apply the seeds with the , fertiliser during the normal autumn topdressing. When superphosphate is used, the seed should be mixed and sown on the same day to avoid risk of germination injury. Before sowing, the pasture should be fairly well grazed to ensure that the seeds will ■ actually come in contact with the ground. While good results are sometimes attained without harrowing, much depends on the type of the sward. Where the turf is close and matted, or where moss is prevalent, a good penetrating harrow can frequently be employed to considerable advantage to open up the turf and prepare a bed for the seeds. The use of a roller or the running of sheep over the area after sowing will greatly improve the prospects of a successful strike.

Rates of Sowing

Sowings may range from a few ounces of subterranean clover per acre repeated over a number of years up to 10 lb. of mixed clovers per acre in one year. While the mixture to be used must depend on circumstances, it should be remembered that with a

poor seed bed and severe competition from already established plants, mortality must inevitably be high. For this reason the heavier sowings are not ' to be recommended unless conditions appear to be reasonably favourable. ' The following sowings might be considered as fairly representative, but the species and quantities may be materially altered according to requirements:— Good Quality Land where Clovers are Deficient. to 3 lb red clover; 1 to 2 lb. white clover. Where both Grasses and Clovers are Poor on Land of Fair Quality. 6 lb. perennial ryegrass; 1 to 2 lb. white clover; 1 lb subterranean clover. Second-class , Land Deficient in Clovers. —2 lb. subterranean clover; 1 lb. white clover; | lb. lotus major. When the Clovers are Established. 6 lb. perennial ryegrass; 1 lb. crested dogs tail. ...

Seeding From Hay

This modified method of surface sowing as a means of improving the poorer areas of the farm by. a systematic programme of feeding out hay is

well known to every farmer, and has proved particularly successful in the establishing of ryegrass and paspalum. Quite apart from the seed which may be shed, the manurial return from the hay has a very potent effect in raising the fertility, and this in turn tends to encourage the spread and development of the better species of pasture plants. So far as the seeding aspect is concerned, however, it should be noted that the germination percentage of useful seed in hay cut at the proper time must be extremely low. When, owing to circumstances, the hay has been cut too late, the germination of the seed may be proportionately higher and may provide a very appreciable sowing. The trampling effect of the stock combined with the rise in the soil’s fertility greatly assists in improving the strike, and tends to promote rapid development of the young plants. While the practice of delaying the cutting of the hay for the sake of the

''iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiii' seed cannot altogether be recommended, some farmers with ryegrasspaspalum swards have made it a practice to allow the ryegrass to ripen before cutting. By this time the young paspalum is making vigorous growth, and it is contended that the inclusion of this more than compensates for any deterioration of the ryegrass element, so that such hay not only possesses a high feeding value, but is also extremely useful for renovating the poorer areas. Whether or not this practice is desirable must obviously depend largely on the relative > proportion of the ryegrass and the paspalum in the hay.

Leaving the Sowing To Nature

Under certain conditions a surface sowing can be efficiently applied by leaving, the work to Nature alone. Where the sward is rather thin and the ground reasonably clean in a young pasture, excellent results are often obtained by lenient grazing, which permits the plants to produce considerable quantities of seed. This seed is

eventually shed, and readily germinates when conditions are suitable in the autumn, the shelter afforded by the rough growth of stems helping to prevent drying out and promoting speedy establishment. This method is only to be recommended where conditions are favourable, however, and good results cannot be expected where the bulk of the seed falling is from weeds or the soil conditions are unsuited for the development of the young seeds. Needless to say, the subsequent management should be designed to encourage and establish the regeneration.

Choice of Methods -'l';* Just which of the above methods will prove most profitable must necessarily depend on the farm and on the farmer. On many farms, particularly if the area is large and the majority of the pastures poor, all these methods may usefully be employed. It must be emphasised, however, that no matter which method is adopted, the ultimate result will be largely decided by the topdressing practice and the subsequent management of the pasture.

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