Ryegrass-dominant pasture was differentially grazed in May 1975, and recovery of heavily and laxly defoliated swards compared over a 6-week growth period
A study of the population density and the viability of buried seeds was determined in soil from six sheep pastures of varying ages; on two soil types, clay and sand, and at two depths (0 to 7.5 cm and 7.5 to 15 cm).
Experimental results on development of pakihi soils are presented. Coating of inoculated white clover seed had no effect on establishment or initial growth. Liming had no effect on establishment but increased initial growth. The improved lotus cultivar G4703 outyielded white clover at low rates of lime and phosphate but firstyear dry matter yields were very low. The use of less soluble forms of potassium and phosphate on the low retention pakihi soils had no effect on dry matter yield. There W’BS a useful pasture yieid response up to 75 kg P/ha but the response diminished from 30 to 75 kg P/ha. Pasture yield responses to potassium occurred up to 175 kg K,/ha using the mowing and clippings returned measurement technique but only up to 25 kg K/ha where the response was measured under grazing. Elemental sulphur at 60 kg,/ha significantly increased pasture yield and restored a deteriorated pasture in one trial. A simple technique based on aerial oversowing has evolved for establishing pastures on pakihi soils. Given proper management, the resulting pastures are high-producing. The conversion of grass to beef and sheep products has been demonstrated on the Pakihi Demonstration Farm near Westport and by the Department of Lands and Survey, but dairying is yet to be tested. The economy of the West Coast will be considerably enhanced by progressive development of the pakihi soils.
The performance of six grass and seven legume cultivars was evaluated over a two year period under dryland and irrigated conditions in North Otago.
The performance of ‘Grasslands Huia’ white clover, ‘Grasslands Turoa and Pawera’ red clovers, ‘Grasslands Maku’ lotus, alsike clover, Wairau lucerne and a mixture of Mt Barker and Tallarook subterranean clovers was evaluated over five seasons on sunny and shady faces at 1070m altitude in the MacKenzie basin, North Otago. Mean productions in tonnes/ha on sunny and shady sites respectively were: Huia 2.3 and 0.7, Turoa 3.0 and 1.2, Pawera 3.8 and 1.4, Maku 2.5 and 0, Alsike 2.6 and 1.4, Wairau 2.3 and 0.8, and the subterranean clovers nil. Their performance on these sites is discussed in relation to their possible use in mixtures for oversowing into tussock grasslands.
Samples of perennial ryegrass plants were taken from nine sites on one farm at Mangere. Single tillers were planted out as spaced plants in contiguous rows in a trial site on the same farm.
Results are given from two experiments comparing the establishment and production of ‘Grasslands Huia’ white clover (Trifolium repens) aid ‘Grasslands Maku’ lotus (Lofus pedunculatus) . ‘These were oversown alone or as a mixture on to a low-fertility, acid, tussock grassland soil (pH 4.6) near Berwick, Otago. Establishment of both species was slow and in the second year there were only small differences in yield between white clover and lotus. However, in the third year iotus markedly outyielded white clover in the presence and absence of lime; at four levels of P from 7.5 to 60 kg/ha; and at seeding rates from 2 to 10 kg/ha. Lotus also outyielded the lotus/white clover mixture at the .5 and 10 kg/ha seeding rate.
Controversy has surrounded the possible differences in pasture production which result from grazing by cattle or sheep. Experiments conducted over the 1972-76 period show that pasture production under grazing by sheep is greater than under grazing by cattle under similar intensive managements. A change from sheep grazing to cattle grazing can cause a rapid deterioration in pasture production, while the change in grazing from cattle to sheep brought a slo~ver improvement in pasture production. Cattle grazing restricted the production of the ryegrass component of the pastures in the five management systems considered.
THIS is a description of farming in the area of the Manawatu catchment upstream of the Manawatu gorge plus the catchments of the Akitio and Owahanga rivers. This area corresponds closely with the counties of Dannevirke (including Akitio), Woodville, Pahiatua and Eketahuna. The statistics given are for the total of these counties. Without attempting to study the financial implications, some effort is made to pinpoint weaknesses in present farming practices and possibilities for improvement. The main landscape units within this area are the Tararua and Ruahine ranges and foothills which form the western boundary, a central depression known by geologists as the “Dannevirke-Pahiatua Depression”, along which flow the Mangahao, Mangatainoka and upper reaches of the Manawatu, and the eastern hill country which stretches to the Pacific Ocean. The length from north-north-east to south-south-west along the central depression (corresponding to State Highway 2 and the Wairarapa- Hawke’s Bay railway line) is about 90 km, and distance along the eastern coast is about 50 km.
Annual pasture dry matter (DM) production from improved browntop- dominant hill pastures varied from 3.5 to 7.4 t DM/ha over three years. A south aspect produced on average 14% more dry matter than a north aspect; both had spring and autumn growth peaks, and a summer depression which was greater on the north aspect. A nucleus flock of hoggets was set-stocked on each aspect from October to June. and numbers of extra sheep were adjusted monthly if necessary to maintain similar quantities of available herbage on each aspect. Both nucleus flocks generally grew at similar rates so their seasonal growth patterns were similar. In the second and third year those on the south aspect grew 3 to 5% more wool. Net liveweight gain per hectare was greater on the south than the north aspect in the first year owing to a higher seasonal stocking rate on the south aspect, but in two subsequent years production was similar. The digestibility of pasture on offer to stock was 75 to 80% in spring and 45 to 50% in summer. It recovered to 50 to 55% in autumn then deteriorated to 40 to 45% in June. Small differences were measured between aspects.
The establishment of oversown lucerne and white clover, in relation to time of sowing, was examined over two seasons on seven unimproved sites in the North Otago tussock grasslands - sunny and shady faces with lucerne at 450m, with white clover at 880 and 1070 m, and a flat site at 1330 m. Seedling establishment showed an optimum at times associated with 3 to 7” C earth temperatures at 10 cm depth, with poorer results at both earlier and later times. Nodulation was high at times associated with temperatures up to 5 to 6’C, but fell with later sowings. Best plant establishment also occurred at times associated with 3 to 7” C. 10 cm earth temperatures. These results suggest that optimum sowing dates for the sites used would range from mid-August to October with earlier sowing dates on the sunny faces.
Errors in field subsampling of pasture plots for herbage dissection are presented from nine different sites. There were marked site differences in error level. Two different basic methods of sainpling were employed at the sites included in the survey. Subsamples were either taken from a mown herbage sample or were cut to ground level with a motorized shearing machine from the uncut plot areas following mower cuts. Standard error was compatible with an appfoximate parabolic relationship with percentage herbage dissection values and was symmetrical about 50%. Percentage errors associated with herbage components constituting up to 5% of the sample, were unacceptably large.
HERBACE DISSECTION is the process in which samples of herbage cut from trials are separated by hand into component species. Heavy reliance is placed on herbage dissection as an analytical tool ,in New Zealand, and in the four botanical analysis laboratories in the Research Division of the Ministry of Agriculture and Fisheries about 20 000 samples are analysed each year. In the laboratory a representative subsample is taken by a rigorous quartering procedure until approximately 400 pieces of herbage remain. Each leaf fragment is then identified to species level or groups of these as appropriate. The fractions are then dried and the composition calculated on a percentage dry weight basis. The accuracy of the analyses of these laboratories has been monitored by a system of interchanging herbage dissection samples between them. From this, the need to separate subsampling errors from problems of plant identification was, appreciated and some of this work is described here.
Results of trials evaluating the effectiveness of different inoculation and pelleting techniques on the establishment of clovers oversown in tussock grassland sites are discussed. These trials were carried out simulating as far as possible the practical applications. Response to inoculation and pelleting varied with environmental conditions (e.g., altitude, soil acidity and vegetative cover), time of sowing, and populations of rhizobia in the soil. On some soils, clover established reasonably Erom inoculated seed, while on some acid soils effective pelleting of inoculated seed was essential. Environmental conditions influenced the standards required for inoculants and pelleted seed. The importance of field testing in addition to laboratory testing is stressed.
ABOUT 1960, after a partnership with our father, my brother and I took over this part of the property as a partnership with a flat mortgage for 100% of land and buildings, plus a mortgage for the portion of the livestock which we did not already own. Five years ago my brother withdrew his interest and I now employ a married man.
The effects of summer spelling, frequency and severity of defoliation on improved pasture which had reverted to browntop dominance in spite of adequate topdressing were investigated on northwest and south-east aspects in North Wairarapa hill country pastures. Frequency and severity of defoliation affected both pasture production and botanical composition on the south-east aspect but had little significant effect on the north-west aspect. A pasture improvement programme based on the field trial results was devised and applied. The interim results of this programme are given.
Conditions that warrant the development of a new approach to hill country grazing management are outlined. The effect of three grazing systems on pasture growth and species composition is discussed. Livestock feed requirements are related to pasture production. An action calendar shows the modifications to the grazing system which allows better exploitation of the pasture and stock potential. Finally, results of the adoption of the recommended grazing systems are given.
CRAIGMORE, a family farming company, in late 1973 bought 256 ha of undeveloped light land, of predominantly Steward soils, 5 km north of the Waitaki River on the coast. The Papamoa farm is in the Morven-Clenavy irrigation area, the first scheme in New Zealand which planned to make maximum use of unlimited supplies of water on a whole area basis. The farm therefore had the water and no future limitation likely on its use. There was the promise of a lahour-light automatic flood irrigation system. It was felt that this irrigated permanent ryegrass and clover management system would soften the periodic summer drought problems of Craigmore itself, and provide diversification.
On eroded, acid subsoils above 1OOOm Lotus spp. were better adapted than clovers to low phosphorus and high exchangeable aluminium levels in the soil. Lotus grew better and fixed more nitrogen than white clover, and its uptake of aluminum was less than clover. With adequate supplies of fertilizer, lotus and clover fixed up to 140 kg N/ha/yr, most of which was incorporated in a surface turf. The proportion of lotus in the sward was reduced by the greater production of grass associated with increasing rates of superphosphate.
IN September 1956, Transport (Nelson) Holdings Ltd entered into an agreement to lease 910 ha at Redwoods Valley from the Crown for a 13-year term from fanuary 1, 1957. The Redwoods Valley area is 29 km from Nelson, with saleyards, fertilizer works and freezing works within a 16 km radius. The area leased was in an unimproved state with a cover of gorse, fern, heather, and pines. A condition of the lease was that the lessee develop 35 ha/yr and it was expected that 300 ha could be developed. In November 1963, Transport (Nelson) Holdings Ltd entered into an agreement with the Crown to purchase the freehold of the property by way of a deferred payment licence. To round off boundaries, two other properties of 40 and 15 ha were purchased in January 1957, and a further 75 ha in 1961, all in a reverted state.
Description of development method and problems experienced in farming pakihi in Golden Bay and present costs of development and maintenance of pasture are given. It is considered that with high fertilizer cost dairy farming is the most economic use of pakihi. Problems likely to occur in dairy farming on pakihi are discussed.
Nelson is a dificult farming district with only one-third farmable, inherently poor soils, and fragmented farming areas. Dairying predominates in the wetter northern and southern parts, with sheep and cattle on the hills, and wide enterprise diversity on the eastern coastal plains. There is scope to increase production from existing pastures, but little new land development is expected apart from Golden Ray pakihi. Expansion of production will not be rapid, influenced as it is by land use competition from forestry and by individual farm physical and financial limitations.
AMONG legumes used in pastures red clover has an important role in maintaining pasture production in late summer. whentemperature and soil moisture levels may limit the growth of white clover. Under these conditions red clover is capable of high levels of growth and is one of the most productive pasture species at that time.
Photographic, optical, electronic and digital methods are available for using Landsat data in applied problems of pasture surveys at a range of scales. The most versatile technique involves three stages of analysis: satellite data, aircraft photography, and field surveys
THIS PAPER was requested by the organizers of this Conference. The title was not defined, nor was the content, and the result is a pretty broad and general discussion of some aspects of pasture development and management in New Zealand.
Grazing experiments investigating some factors determining the dry matter production and oestrogenicity of Pawera red clover are described. The legume content of the summer dry matter yield was double that of Ruanui and Huia pasture following overdrilling of lightly paraquated pasture with 4 or 8 kg/ha of Pawera. Persistence of Pawera was demonstrated by its ability to survive in sufficient density under grazing to contribute 35% of total summer dry matter production in its fourth year after direct drilling into lightly paraquated pasture. A Pawera sward when overdrilled with Tama ryegrass or Rahu ryecorn produced the same annual yield as Ariki/ Huia pasture, but the seasonal distribution was markedly different, with production from the overdrilled Pawera being greater in winter and summer. Pure Pawera swards produced some 70% more dry matter during December-February than Ariki/Huia pasture. The significance of this is related to conservation practices in Southland. Oestrogenicity of pure swards of Pawera was determined by measuring the cervical mucus response in ovariectomized ewes. Responses to grazing were equivalent to a single injection of 9 to 31 ug of oestradiol-17B
Survival of Rhizobium trifolii on white clover seed before sowing is adversely affected by both drying and a water-soluble toxin which diffuses from the seed coat during the inoculation process. Survival of rhizobia is increased by removal of the toxin by seed washing or the suppression of its inhibitory effect by treatment of seed with phenolic adsorbents. Survival of rhizobia introduced into tbe soil on seed before the rhizosphere is capable of supporting growth and multiplication may be affected by the toxic diffusate and competition and/or antagonism from naturally occurring populations of soil micro-organisms, Selection of effective strains of rhizobia on criteria such as survival and competition abilities, as well as on the ability to nodulate and fix nitrogen, is considered to be extremely important.
Investigations into particular aspects of the biology, toxicity and eradication of three different growth forms (arborescent, suffrutescent and herbaceous) of Coriaria found in the South Island, New Zealand, are reported. Previous relevant studies are reviewed and some recommendations for future research given.
An established grass/clover pasture was subjected to two different grazing treatments in April-May 1976. The recovery of continuously and intermittently defoliated swards was compared over a 6-week recovery period.
Large differences in climatic, edaphic, and biotic variables were recorded among four aspects of a hill in the Southern Ruahine range over a twelve-month period. Productivity of the existing sward appeared to be strongly influenced by available soil nitrogen levels, and soil moisture status during the summer/autumn months. Pasture botanical composition was related to both these factors and also to soil available phosphate status. Some practical implications of the differences recorded are discussed with reference to farm subdivision, seeds mixtures and feriiiizer requirements.
Evidence is reviewed to show that, in most circumstances, legumes are of higher nutritive value than grasses. The reasons for such differences are explored using evidence from indoor feeding experiments. In particular, the superiority of legumes over perennial ryegrass appears to be due to a higher intake and a higher ratio of protein/energy absorbed. The mechanisms by which tannins in legumes such as Lotus and sainfoin can reduce bloat and improve nutritive value are also considered. Finally, the management of legumes in relation to their higher feeding value is discussed. It was considered that, because of agronomic factors, the superior nutritive value of legumes is not being exploited in agriculture.
The high phosphate requirements of grass/clover pastures are discussed in relation to the greater efficiency of grasses compared with clovers in extracting limited amounts of available soil P. Results of experiments are briefly described which show that variation in response to applied P exists within the white clover species. It is suggested that the emphasis of research effort should be shifted from its present preoccupation with the determination of P requirements of soils to that of selecting and breeding cultivars which have lower soil P requirements than do cultivars now available. This approach could provide a means of reducing dependence on heavy phosphate topdressing.
The relationships of growth and flowering to nonstructural carbohydrate reserve storage and the influence of the pastoral management practice of burning on these relationships were investigated in Chionochloa rigida and C. macra on the Old Man Range, Central Otago
Rhizobia may be classified as either fast or slow growers, or alternatively into different cross-inoculation groups depending on the host plants they can nodulate. The clover, lucerne, lotus-lupin. and sainfoin cross-inoculation groups are of importance in New Zealand grasslands. Within each group there are numerous strains which differ in many respects, in particular in their ability to fix nitrogen with different host species. The clover and slow-growing lotus rhizobia are now widespread in New Zealand pasture soils but the others are not.
THE Hill Farming Research Organisation (HFRO) was established in 1954 as an independent state-aided institute with a board of management appointed by the Secretary of State for Scotland. It is financed by the Department of Agriculture and Fisheries for Scotland and receives advice on scientific work and on staff management from the Agricultural Research Council in London.