Production of Winter Green Feed Cereals and Renovation of Dairy Pastures in Canterbury by Autumn Overdrilling

New Zealand Journal of Agriculture, Volume 101, Issue 1, 15 July 1960, Page 21

Production of Winter Green Feed Cereals and Renovation of Dairy Pastures in Canterbury by Autumn Overdrilling

By

D. J. G. DAVIES,

Fields Instructor, Department of Agriculture, Christchurch

OVERDRILLING of pastures as a means of cereal green feed production without resort to the plough has been under trial on a number of town milk supply farms cooperating within the Department's farm improvement scheme. This article describes the recommended methods where overdrilling of pastures with cereals and/or grasses is contemplated.

THE provision of winter and early spring green feed is an important aspect of livestock husbandry under most farming systems, especially where whole milk production during winter is involved. This feed is conventionally provided by autumn-saved grass and/or the growing of green feed cereals, brassicas, or root crops on cultivated areas.

A system of combining the use o f nitrogenous fertilisers directly with sod-seeded cereals was investigated at the McGarvie Smith Animal Husbandry Farm, Badgery’s Creek, New South Wales, Australia, as early as 1956 with the primary concern of providing, out-of-season green feed for dairy farms engaged in the production of whole milk for the Sydney metropolitan area. The liberal use of nitrogenous fertilisers, a winter growing cereal, and, when occasion demanded, of sprinkler irriga-

tion was stated to be essential to success. When visiting Australia in 1958 the writer was so impressed with the possibilities of this method for application o n clover - dominant, high - fertility dairy farm pastures in New Zealand that local investigations were begun in Canterbury that year. These and subsequent field trials have confirmed earlier impressions and demonstrated the suitability of the method for town milk supply dairy farms. Local trial work began and still

continues on the property of Mr R. P. McCarthy, Tai Tapu, Canterbury, where for many years autumn-sown green feed had been grown by conventional methods to supplement autumn-saved pasture. Unfortunately, complete utilisation of this feed was often not possible because wet ground resulted in high wastage through excessive trampling by stock. Hand cutting and carting of the green material had often to be restorted to. The idea of growing green feed without cultivation naturally had much to commend it to this farmer, who had already established to his own satisfaction that cereals would grow without cultivation. A further stimulus for this work was provided by the severe drought of 1957-58 when an enterprising sheep farmer in the Amberley district successfully overdrilled with cereals two-thirds of his 250-acre farm. Since no prior ground preparation is involved, overdrilling can be conveniently undertaken as soon as adequate moisture is available, and the method has wide application as an emergency measure after drought and the depredations of insects and various farm pests. Suitable Cereal Varieties On the basis of trials to date the following varieties can be recommended as suitable for overdrilling according to recommendations: C.R.D. Ryecorn C.R.D. ryecorn, Crop Research Division, D.5.1.R., selection has proved to be among the most productive of our winter cereals. It has the capacity to remain winter green and is highly resistant to frosts, but because of its prostrate growth it tends to lodge. Therefore grazing should be carried out at frequent intervals until spring. Best results are obtained by grazing when growth is at 4 to 6 in. C.R.D. ryecorn will withstand severe trampling by stock, is most resistant to cereal yellow dwarf virus, and should be grown in preference to other varieties where this disease is severe. Wong Barley Wong barley has given consistently good results in trials on the more fertile soils of Canterbury and has for some years been grown to a limited extent in the Marlborough district. It is a good winter and spring producer and like ryecorn recovers well after grazing. Its erect growth enables it to compete vigorously with grass, but, once established, is likely to become dominant in the sward. Under continuous grazing it is subject to a dormant period during mid winter. Wong barley is susceptible to both rust and cereal yellow dwarf virus.

Arawa Wheat , Arawa wheat, one of the two new high-yielding varieties bred and recently released by Crop Research Division, D.5.1.R., Lincoln, is a most promising green feed for high-fertility conditions and compares most favourably with Dreadnought, which it was developed to replace. It gives best results when sown at a higher seeding rate than other cereals. However, it does not appear to withstand vigorous grass competition and is susceptible to cereal yellow dwarf virus. Cape Barley Cape barley is a most useful producer of a large bulk of late-autumn and early-winter green feed and is one of our oldest and more reliable feed barleys. It is essentially a producer of a large bulk of green material for a short period and cannot be relied on to produce through until the spring. Cape barley -is also susceptible to rust and cereal yellow dwarf virus infections. Winter Grey Oats Winter Grey oats have given consistently good results in field trials and are most suitable for low-fertility soils. Like most oat varieties the recovery growth is only fair, and the variety is susceptible to cereal yellow dwarf virus. Onward or Russet Oats Onward or Russet oats are the best cereals to grow, particularly where a fast-maturing bulk of feed is required. With their erect growth there is less tendency to lodge than with other varieties. Little recovery growth can be expected and both are susceptible to cereal yellow dwarf virus and rust.

A number of other cereal varieties are being tested for overdrilling and greenfeed, but those mentioned have been satisfactory when used as recommended. Pasture Renovation The inclusion of from J to 1 bushel of Italian or short-rotation ryegrass seed per acre with the cereal at sowing is strongly recommended, as it will substantially improve the grass/clover ratio and general quality of pasture by spring. Trials have shown that little winter production can be expected from any grass sown with cereals in autumn, but that such grass is well established by the end of winter. As the cereal production declines the grass contribution of the sward improves. This provides additional spring and summer grazing, and the combination of cereal and grass may be shut up for an aboveaverage yield of hay if desired. A hay crop on Mr McCarthy’s farm yielded 3.6 tons per acre after being shut up at the beginning of October. Early haying is desirable, especially where irrigation equipment is available to stimulate further growth of pasture for summer grazing. Experience has shown that the weed problem on overdrilled pastures compared with that on cultivated pastures is negligible and if it does occur, it can be effectively controlled by winter grazing. The light-suppressing effect of a dense bulk of cereal also hinders weed development and ultimately aids eradication. Seeding and Fertiliser Rates While further experimental work still remains to be done on optimum

levels of fertiliser and seed usage of cereals, sufficient is known to indicate that comparatively low seeding rates will give satisfactory results. However, the evidence also suggests that higher rates will give correspondingly higher production initially mgner production initially. required "Teedffil levels of un to 4 bushels and not less than 2 bushels 4 bushels and not less than z bushels per acre will give satisfactory results. In general, the lower the fertility is the more seed will be required, and, conversely where fertility is higher lower rates may be used safely. The above remarks apply only to closely grazed, bare, open swards and if cereal seeding is attempted under any other pasture condition, seeding rates should be stepped up accordingly to combat vigorous grass competition. The most satisfactory results to date have been achieved on basically clover-dominant swards where another cereal/grass crop is superimposed on established legumes. Fertiliser Because of variability in fertility from farm to farm and even paddock to paddock the exact quantities of fertiliser to use must be determined largely by the farmer’s knowledge of the productive qualities of the pastures to be treated. However, in general, the lower the level of fertility the

more nitrogenous and phosphatic fertilisers must be used. The following min imum rates are recommended as a guide and are based on the results o trials on a variety of di f pastures in which the dairy raim pastures in wnicn tne nitrogenous fertiliser used was of the ammonium nitrate ' lime mixture type: L High fertilit y ; 1 cwt of nitrogenfertiliser and 1 cwt of superphos- ' , „„„ „„„„ ' 2 - Medium fertility: 2 cwt of nitrogenous fertiliser and 1 cwt of superphosphate per acre. fertiliser X? ac S ®e and cwt or superphosphate p ’ f ~ ■ The liberal use of nitrogenous fertihsers during February and March will ensure the maximum production of f re f n ’ succulent leafage for winter feeding and will markedly improve pasture vigour by spring. High rates of nitrogen should not be drilled with seed if the soil is dry, as injury to young seedlings is likely to occur. As nitrogenous fertilisers will cause corrosion if they are m contact with . metals too long, the manure box should be thoroughly cleaned out as soon as drilling is completed. The use of fertiliser when overdrilling obviates the need for autumn topdressing the treated pastures. Where it is intended to concentrate on winter green feed production in the same

Daddoc k each vear adequate rates of P a<a eacn year aaequaie rares oi er t lbser particularly nitrogen, should be used . This will allow the intro . duced crop to get away to a good start with a minimum of interference from established plants. ~. , , The use of potash is recommended in addition to nitrogen and phosphate in those districts known to be deficient in potash. S ° win 9 Time Overdrilling may begin any time after mid January, but late Februaryearl March is normally the best time, provided soil condit ions are suitable, It is essential to delay drilling until there is a reasonable supp i y o f soil m oisture to ensure adequate and even penetration of the drill points or discs and to facilitate q Uc; uniform germinatiOn of seed. If overdrilling of several small pad . docks is contemplated during February and March, sowings at fortnightly intervals are recommended to provide continuous feeding. Drilling Equipment For relatively even and level ground on dairy and sheep farms both ordinary coulter and disc types of drills have been found suitable.

Disc Drills With the revolving cutting section of disc drills, penetration is easily achieved, except on hard, dry soils, which should not be drilled unless sprinkler irrigation is carried out either before or immediately after drilling. Hardened, steel-pointed groovers will assist the following discs to cut into the loosened soil and ensure uniform spread and coverage of the seed. They also prevent imprisonment of the seed under the cut furrow lip, which is a common fault of discs, especially in heavy soils. Where suitable grooving attachments are not available, the angle of tilt may be increased in some types of drills to cut a more open groove, thereby lessening the risk of smothering germinating seeds. Disc drills are also ideal for overdrilling, stubble paddocks provided threshed straw has been baled or evenly spread after heading. Conventional Rigid Coulter Drills Some excellent results have been obtained with conventional rigid coulter drills fitted with sharpened steel points and/or special grassland tips and used under ideal soil moisture conditions. Pastures must be bare and clean of all trash at drilling; otherwise frequent blocking will occur. Concentrated pre-grazing with .stock or close trimming of paddocks with a flail-type forage harvester will assist in the preparation of the pasture for overdrilling. A certain amount of spring tension is necessary on each coulter to aid

penetration and coverage of the seed. Individual coulters should be weighted on drills where spring, tension is not possible. However, such modification to conventional drills is only makeshift and these machines should not be used for drilling large areas unless they are specially strengthened. If these precautions are not taken, twisting of coulters out of alignment and/or bending of the drawbar frame is likely to occur.

Standard Sod Seeders Various types of sod seeders are available commercially for overdrilling and are particularly suited for rough, uneven flats and hill country.

Such drills are ruggedly constructed for work under adverse conditions. Most makes differ from ordinary drills in that maximum penetration is obtained by a combination of spring tension and screw pressure, the latter similar to that used on spring-type cultivators. As these machines were originally developed for sowing grasses and clovers, they are not entirely suitable for seeding cereals, because, without a grain box, seed must be sown mixed with fertiliser through the manure box. This results in erratic sowing of grain with a consequent irregular strike. They are also inclined to leave the soil in a semi-grubbed condition, allowing birds easy access to the cereal. No doubt, with modifications, these limitations could be overcome. Whether follow-up chain harrowing or rolling is carried out or not is largely determined by circumstances after drilling and obviously is warranted only if seed is not completely covered by soil or if the surface is left very rough. Chain harrowing is especially necessary after overdrilling into semi-moist to dry soil. Rolling will be beneficial in reducing a cloddy soil to a loose crumb structure. Management of Treated Pastures As the prime purpose of introducing cereals and grass into established pastures is two-fold, namely, the supply of valuable winter fodder and a renovated pasture by spring, the following management points should be strictly adhered to: 1. Do not allow established grasses and clovers to smother young cereal and grass seedlings. Graze lightly and often during first month after treatment. This aspect is particularly important where swards are dense, as such grazing treatment will suppress competition and result in the development of a strong root system and maximum absorption of light. 2. Once satisfactory establishment of cereals is achieved pasture may be shut up for first feeding. With declining soil temperatures grass and clover growth is not quite so rapid at this stage and cereal growth already accentuated by readily available nitrogen should dominate by the time of the first feeding, usually within six to eight weeks from sowing. 3. Strip grazing or break feeding with an electric fence will ensure a minimum of wastage. 4. To ensure a maximum bulk of green feed for the critical winter months of June and July early grazing should be lenient during MarchApril. The more feed is taken then, the less will be available when it is most needed. 5. It is recommended that several paddocks be treated in a similar

manner, at fortnightly intervals during February and March, to obtain an extended feeding period. Judicious grazing management should make possible a continuous supply of green feed throughout winter, with a consequent saving of valuable hay. 6. Cereals like C.R.D. ryecorn and Wong barley will recover for further feeding during August and September and grass will also be making a useful contribution of green feed at this period. After this final cereal feeding, which should coincide with the availability of alternative feeding, farmers would be wise to consider a further application of a nitrogenous fertiliser of up to 2 cwt per acre as an added stimulus to young grass growth that will lead to an above-average hay or grass seed crop. 7. If alternative grazing is clover dominant, grazing of overdrilled pasture should continue until bloat danger is past. Conclusions Possibly the chief advantage of this practice is the minimum time lag between sowing and utilisation; there is no lengthy period of cultivation to cause loss of production from a pasture. In addition, particularly in a dry season, good soaking rains can be

immediately capitalised on to obtain a certain “strike” of seeds. An attractive aspect and one of most importance to farmers is the . ease with which feed can be fed off directly to stock without trampling or fouling of pasture even in very wet weather. Yields of green fodder are comparable to those achieved by cultivation and therefore it is considered to be a more palatable and balanced ration for stock. In trials, recovery of pasture growth by spring has been remarkably quick. Depending on the fertility of the area, the cost of manures, seeds, and cultivation ranges from £4 to £9 per acre. Much work remains to be done on the economic implications of this system for both dairy and sheep farms, but for town milk supply farmers the economic advantages are clear. Other avenues remain to be explored, particularly the prospects of combining the method with chemical ploughing, the use of which has already been justified under certain conditions. There is no doubt that the equivalent production of feed and the attainment of a pasture performance which normally takes two seasons by conventional means can be achieved in a single season with one simple farm operation; and a more flexible patterr of pasture management, more adaptable to climatic vagaries, is introduced.

Objectives The main objectives are: 1. Provision of out-of-season green feed during autumn, winter, and spring, when both feed requirements and milk payments are at a premium. 2. More efficient utilisation of herbage grown as wastage is reduced through consolidated ground conditions. 3. Subsequent renovation of grass-deficient pastures by introduction of new grass. 4. The development of an effective means of reducing pasture renewal costs. 5. Stimulation of pasture production by the balanced use of nitrogenous and phosphatic fertilisers. Secondary objectives include: 1. A possible reduction of the bloat problem in the spring through the suppression of clover growth by introduced cereals and grasses. 2. The provision of a heavy summer hay crop after winter grazing. 3. Suppression of weeds. 4. The provision of more palatable and nutritive herbage. 5. More efficient management of pastures for winter feeding.

Recommendations 1. If grass grub or porina is present or suspected, DDT-superphosphate should be broadcast at I cwt per acre. 2. All cereals should be treated with one of the approved mercurial seed dusts to aid germination, establishment, and control of fungous diseases. 3. Use of sprinkler irrigation equipment will not only ensure ease of drilling and a good strike, but continued use will hasten development of a high yielding green feed crop. 4. Overdrilling without the aid of a nitrogenous fertiliser is uneconomic. 5. The following cereal varieties will give the best results for feeding to dairy cows. Long-term production: C.R.D. ryecorn, Wong barley, and Arawa wheat. Short-term production: Cape barley, Winter Grey oats, Russet oats, and Onward oats. 6. Always include from | to I bushel of Italian or short-rotation ryegrass at sowing.