Establishing Permanent Pasture in Bay of Plenty

New Zealand Journal of Agriculture, Volume 84, Issue 1, 15 January 1952, Page 41

Establishing Permanent Pasture in Bay of Plenty

By

A. V. ALLO,

Instructor in Agriculture,

Department of Agriculture, Tauranga

THE suitability of the Bay of Plenty for • grassland farming is very apparent. Pastures yield very freely, and, from the relatively small amount of cropping done, it is clear that this fact is appreciated by farmers. THE climate generally is excellent for pasture production, although a dry autumn will adversely affect production on many farms. Apart from dry autumns, there is ample rainfall for pasture growth, and relative freedom from cold winds and heavy frosts (except in inland districts) assists prolific growth. The soil, which varies from medium to light pumice loams to peaty silts, responds readily to phosphatic fertilisers, and even the poorest soils give surprisingly good returns if adequately topdressed. Even so, there is room for improvement in the quality of many of the pastures. Six years of fertiliser rationing during the war were responsible for some deterioration in pastures, particularly on the higher country, but in many cases the reasons for low pasture production go deeper than this. Thin and weedy pastures lacking clovers and ryegrass and far inferior to those which the soil is capable of maintaining are seen frequently. Such conditions are often due to faulty methods of pasture establishment. This article deals with the putting down of new grass. Place in the Rotation In the Bay of Plenty the types of land sown down to permanent pasture may be considered under four headings: Sown down on virgin country. Sown down after an autumnharvested crop. Sown down after a winter-harvested crop. Sown down after grass. Virgin Country Virgin country in the Bay of Plenty is covered either with bush, manuka scrub, gorse, or fern or a mixture of two or more of these. In many cases, particularly on unploughable country, scrub may be cut and burnt and sown down in autumn with a mixture of swedes and turnips and permanent pasture. Though this practice has resulted in some fairly good pastures, it is essential that land so developed should be well stocked with sheep and cattle rather than dairy cows so that second growth can be controlled. Development of large tracts of country by this method followed by under stocking, usually with dairy cattle, has nearly always failed.

Good results have been obtained on fern country by burning followed by a heavy harrowing. The grass seed is sown on the harrowed surface, which is then given a stroke with the chain

harrows. For this method to be successful it is essential to get a clean burn; ' otherwise there will be too much surface litter and the harrows will not function properly. Subsequent stocking preferably should be with cattle to crush any fern which may reappear. ■ Virgin country capable of being cultivated is usually handled in this way, the common practice being to take a crop of swedes or turnips and follow this with either temporary or permanent pasture, according to circumstances. If the land is badly infested with gorse, it is cleared, burnt, and worked down, and sown either in swedes or temporary pasture. If the former, the swedes are followed with temporary pasture, which is, if possible, cut for hay during the first year to kill much of the spindly gorse that will appear. . Such temporary pasture is oversown with the permanent pasture species after, a year or —when the greater part of the land is free of gorse. In dealing with gorse country it is usually considered advisable to allow the young gorse seedlings to come away after the burn and then to plough the land as deeply as the depth of the topsoil will allow. Any subsequent ploughings are shallower so that fewer of the buried gorse seeds will be brought to the top again. In grassing down fern country one of the essentials is not to plough heavy fern growth under. This has been done on several farms, the result being a layer of undecomposed fern at the bottom of the furrow which will remain for several years. Any crop grown under these conditions has little chance of success, as the continuity of the topsoil and subsoil is broken and the land will dry out badly during summer. Fern country should always be burnt before being cultivated, unless it is intended to develop

a block of sown grassland that has reverted to fern, when excellent work can be done using cattle as the implements of pasture regeneration. During the past few years many farmers have developed areas of rather poor fern country by using lupins to build up soil fertility. The land is burnt and disced and sown with 2 bushels of blue lupins per acre in spring. These are ploughed under in sufficient time to allow them to rot before the land is sown to grass. This method is to be recommended where a farmer wishes to obtain a good pasture on the poorer pumice soils. Sowing after an Autumn-harvested Crop The most commonly grown autumnharvested crops are soft turnips and greenfeed maize. After these crops have been fed off the land is usually disced down and worked to a seed-bed for grass in March, good results being obtained if the working is sufficiently thorough and a consolidated seed-bed is obtained. Sowing after a Winter-harvested Crop Sowing down after a winterharvested cropthe most commonly grown are swedes and cob maizeis more difficult than after an autumnsown crop. For reasons that will be discussed later spring sowing is not normally recommended, so that the farmer has the alternative of summer fallowing his land or of growing a catch crop that will be out of the ground in time to allow the land to be worked up for grass the following autumn. Some farmers overcome the difficulty by sowing soft turnips or green maize, a practice which normally gives good results. A few have grown a green-manuring crop of lupins, a sound practice for anyone who can

afford it, particularly on maize ground. Another alternative is to grow a crop of oats and sweet blue lupins to be harvested in December for silage. The ground could then be ploughed and fallowed until sowing time in March. Possibly this last practice is as sound as any. The disadvantage of a full summer fallow is the danger of winds blowing loose soil; land that is being summer fallowed should not be worked down too finely. Sowing after Grass Many farmers have paddocks of runout pasture which they wish to resow in good Certified strains of seed. These paddocks are usually ploughed in December or January and resown in March, although sometimes they are ploughed in spring and sown with soft turnips for autumn feed, after which they are worked down and sown with grass seed in March. Any autumn supplementary fodder crop that is to be followed by grass must be out of the ground in time to allow the paddock to be worked down to a satisfactory seed-bed in autumn. If, as happens sometimes, autumn crops are not fed off before April, ground for grass has to be worked up in a very hurried manner, frequently with disastrous results to the young grass. Cultivation Thorough preparation of the seedbed is of paramount importance. No matter how much high-quality seed is sown or how much fertiliser is applied the successful establishment of a pasture is greatly jeopardised if the seed-bed is not satisfactory. This is not always fully appreciated, and it is not uncommon to see seed being sown on a loose, unconsolidated, hurriedly prepared seed-bed. Seed sown under such conditions has little chance of establishing satisfactorily, and many failures in pasture establishment can be attributed directly to this cause. Success depends on early and thorough working. Early ploughing to a depth of sin. is strongly recommended. A long mouldboard plough is preferable to the short mouldboard type, as it turns a better furrow on this type of country. After the land has been ploughed it should be rolled on the furrows to pack them down and then disced thoroughly to work up the ground to a fine tilth. If the surface of the ground is not very level, it can be smoothed out considerably by angle discing and by a few strokes of the clod crusher.

The final working should be done with harrows and roller, the aim being a seed-bed which is level, fine, firm, and moist, with no clods or lumps on the surface. All the operations mentioned are important in obtaining a good seed-bed, and ample time must be allowed to do the work properly. It is useless ploughing a piece of ground one week and then discing and sowing the seed within a few days. Early working permits the land to settle naturally, so that a mellow, weathered seed-bed is obtained.

In recent years there has been an increasing use of heavy discs in preference to ploughs. Sometimes, as on steep country, heavy discs can be used where the plough cannot, and the lower cost and higher speed of working with discs have helped to attract

some farmers away from the plough. Giant discing must be done sufficiently early for the ground to have ample time to consolidate before the seed is sown. • Many farmers think that a good rolling before sowing the seed is sufficient to give a good, firm seed-bed. However, such a rolling probably will pack the top 1-in. of soil, but unless every operation from ploughing onward is aimed at giving a firm seed-bed, it will be found that the soil under the rolled layer is loose and puffy. A Cambridge roller will not, in itself, give deep consolidation on loose ground, as many farmers have found to their cost. After autumn harvesting of a crop such as soft turnips the surface of the ground is frequently in such a condition that a light discing followed by a good harrowing and rolling . will give a satisfactory seed-bed. If this method of cultivation is adopted, it is easier to get a consolidated seed-bed. On the other hand, if the ground surface is rough or there is a large accumulation of weeds or surface litter, it is normally necessary to plough before working down the paddock for grass. If this is the case, it is essential that the crop be fed off in time for the land to be ploughed by the end of the first week in March at the latest, if best results are to be obtained. When land is ploughed out of grass in December or January for resowing into grass the normal routine of rolling on the furrow, discing, harrowing, and rolling should be followed. Time of Sowing The seed-bed should be ready for sowing between the middle of February and the middle of March, depending on the weather. Seed should not be sown during dry weather, but immediately after autumn rains. If sowing is delayed until late autumn

and early winter, an early frost may nip off many young clover plants, and young ryegrass is subject to frost lift in inland areas, particularly the valleys, during winter. Spring sowing is sometimes tried, with varying success. Often competition from annual weeds results in indifferent establishment, and weeds such as twin cress, which is commonly found in a spring-sown pasture, will give rise to strong feed flavours in cream if cows are grazed on the new pasture. A further point is that in recent years many spring-sown pastures have been severely checked during dry weather and in some cases pastures have had to be oversown. Normally, autumn sowing is strongly recommended. Seed should be sown on a rolled surface and lightly harrowed in, preferably with brush harrows, and the area rolled finally. Although autumn sowing is normally advocated, this recommendation could be modified by a farmer wishing to get paspalum established on a farm on which there is not very much of this invaluable summer- and autumn-pro-ducing grass. Paspalum germinates best in warm soil, and if it is sown in autumn, particularly late in March, germination is often poor and establishment slow. On the other hand, September sowing, with almost certain heavy weed competition, is also frequently unsuccessful. In several cases good results have been obtained by sowing paspalum alone or with red clover in November and oversowing the balance of the pasture mixture the following autumn. A modification of this method is the sowing of paspalum and red clover seed with a swede crop in November, which has given excellent results in some cases. Best results in pasture establishment are, however, obtained from autumn sowings.

On the light soils of the Bay of Plenty, as on all other types of soil, satisfactory clover establishment is essential to the success of the pasture. Some farmers who omit white clover from the seed mixture claim that it will eventually come into the sward of its own account. The entry of such volunteer clover is usually slow, and in the meantime the grasses will have suffered owing to the deficiency of nitrogen normally supplied by the clover. Volunteer white clover is nearly always of a poor, low-producing type, and Certified white clover should never be omitted from seed mixtures.

Perennial ryegrass is also essential, as it provides the bulk of the spring feed and useful autumn feed. The value of short-rotation ryegrass under Bay of Plenty conditions is still under examination, though unquestionably the species produces a greater bulk of feed in winter and spring than true perennial strains. A weakness is that it tends to disappear during a dry autumn, particularly on the lighter country. Further investigation is needed on the behaviour of short-rota-tion ryegrass under various soil and climatic conditions before any conclusions can be made.

However, it is suggested that some Certified short-rotation ryegrass should be included in the pasture mixture — 51b. of Certified short-rotation ryegrass and 151 b. of Certified perennial ryegrass per acre on the lighter soils and 101 b. and 151 b. respectively on the heavier swamp country. Paspalum Valuable Paspalum is a grass of great value in the Bay of Plenty. Some farmers fear its prolific growth in summer and autumn and its habit of dominating a sward, sometimes to the extent of subduing or choking out other species, when unchecked for some years. With correct pasture management, adequate topdressing, and topping of pastures, however, paspalum can be controlled as readily as other pasture plants. The wealth of feed it will produce

during summer and early autumn, when white clover and ryegrass are dormant, makes it a grass of great value in the Bay of Plenty and it should be used on every farm. Cocksfoot is also of value, particularly on dairy farms on the higher country, and is worth' including in the seed mixture. It will produce good summer feed and in a well-managed sward is a very valuable constituent of the pasture. Crested dogstail should also be sown, particularly on the higher country, its low, dense growth habit making it very useful for filling up thin places in a pasture. Timothy, which is very palatable to stock, should always be sown on the peaty silts, and

many experienced farmers include a little of it in seed mixtures for the higher country. Because timothy is eaten readily by stock, it does not always show up in pastures, but there is a surprisingly large amount of timothy in many of the late hay crops. It is impossible to give a grass seed mixture to suit all conditions in western Bay of Plenty, but the following are suggested as a basis on which to build up a mixture to suit local circumstances: —

SWAMP COUNTRY

lb. per acre Perennial ryegrass .. .. 15 Short-rotation ryegrass .. 10 White clover .. .. .. 2-3 Red clover (cowgrass) .. 3-4 Timothy . . . . . . 2-3 Cocksfoot . . . . . . 4-6 Paspalum (if required) .. 8

COASTAL AREAS AND HIGH COUNTRY

lb. per acre Perennial ryegrass .. . . 15 Short-rotation ryegrass .. 5 Cocksfoot . . .. . . 4-6 White clover . . .. 2-3 Red clover (cowgrass) . . 3-4 Crested dogstail . . . . 2 Timothy (if required) .. 2 Paspalum (if required) . . 5-10

It is essential that Certified seed be sown. Farmers have often sown so-called “cheap” seed which has proved anything but cheap. Farmers should examine the Purity and Germination Certificate issued with every line of Certified seed. There have been some instances of farmers having poor results from Certified seed, but investigation has shown that the seed used was of a

low germinating capacity. If a farmer buys such seed, he should increase the rate of seeding to compensate for low germinating capacity. Two years ago a farmer sowed down 281 b. to the acre of a grass seed mixture, details of which were:—

The' sowing of this seed at the rate of only 281 b. to the acre meant that the farmer applied about 111 b. of living seed per acre. The rate was far too low and the resultant strike was so thin that it was necessary to oversow the area with more grass and clover seed. This example shows how essential it is for farmers to ascertain the germination of the seed before sowing it. Rate of Seeding The rate of seeding used in the Bay of Plenty varies considerably. Some farmers sow at. the light rate of 201 b. per acre, claiming that by using more fertiliser and less seed they will ultimately obtain a better pasture for a certain expenditure. However, when a sowing is too light weeds usually develop in the bare places between useful plants and it may take up to 2 years for a pasture to thicken up properly. Heavy seedings, up to 601 b. per acre including sometimes over 301 b. of ryegrass, are also used. These give a very thick strike with too much competition between the individual plants, so that plants become “leggy” and spindly and stooling is very much retarded. The ideal rate of seeding should give an even strike sufficiently dense to cover the ground but not so heavy that plants are choked out. The rate varies according to the type of seeds in the mixture. Generally, a seeding of 35 to 401 b. per acre is satisfactory for a mixture based on those given in this article.

Manuring New Pasture

Phosphates are essential in the Bay of Plenty, and when a paddock is sown down to grass it should have a dressing of, 3 to 4cwt. of “super, compound” or serpentine superphosphate per acre. This should be followed by a further dressing > the following spring, after which. regular autumn topdressing should keep the pastures in good heart. Any farmer who can afford it will find that spring and autumn dressings of 2 to 2|cwt. of phosphate per acre will give excellent results. On the Waihi Plains and on parts of the hill country of Tauranga County improved results have been obtained by using potassic fertilisers in addition to phosphates, and on such potash-responsive soils i to lcwt. of muriate of potash per acre could be applied with advantage. The need for potash is becoming increasingly evident on many paddocks in the Bay of Plenty, and it will pay a farmer to ascertain whether or not there is need for potash on his farm.

On virgin land where humus and nitrogen are low good results have been obtained by manuring new grass with a mixture of 2cwt. of superphosphate and 2cwt. of blood and bone per acre, as the blood and bone helps the young grass to get away to a good start. The use of slow-acting (rock) phosphates is not recommended on new pastures in western Bay of Plenty. Management of New Grass The management of a paddock of young grass during the first few months of its life has a profound effect on its future productivity. Overgrazing of a new grass paddock is frequently responsible for poor production the following spring and undergrazing may result in suppression of white clover. The first grazing should be given, where possible, with sheep or light , stock rather than with mature cattle, and it is preferable to use large mobs for a short period than to have a handful of stock trying to trim down a large paddock of new grass over a long period. A paddock of new grass should never be grazed by heavy stock in wet weather. If the first grazing has to be

done by mature dairy cows, they should be turned on to the paddock when the soil is reasonably dry. Any system of management that permits even, light grazing will encourage the sward to thicken up and provide a dense cover over the ground. On no account should farmers succumb to temptation and take a cut of hay during the first . year of a new grass paddock. This will severely check the ryegrass and clover and will lead to serious weakening of the sward. The sowing down of new grass in the western Bay of Plenty offers no insuperable difficulties and success is bound up in the following of a few well-proven rules: 1. Thorough and early preparation of the seed-bed to permit of adequate consolidation. 2. The autumn sowing of a suitable mixture of Certified seeds of satisfactory germination. 3. The provision of an adequate amount of seed per acre to give a good coverage of pasture plants. 4. The use of adequate supplies of quick-acting phosphates (and potash where necessary) . 5. The correct management of the new grass. -☆ '

GermPurity ination per cent. Germination per cent. Perennial ryegrass 73 50 Cocksfoot . . 10.7 32 Red clover 5.4 0 Crested dogstail .. 5.3 16 White clover 4.5 42 Weeds 0.2 — Inert matter 0.3 —