Perhaps just as strange to many grassland farmers as a cow jumping over the moon, would be a farming enterprise in which a combine harvester covers every hectare of the farm in order to gather the income for the business. But this is the lot of the Mid-Canterbury seed producer. Seed production on a specialist Mid-Canterbury farm can be divided into three main operations: planning, growing the crop, then harvesting and handling.
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(21 KB)The objective is to optimise financial return to the seed grower by saving the maximum amount of seed at the highest possible quality standards. It is possible to always achieve the highest grades by dressing* a line very hard and discarding a large proportion of the sample, with a loss of potential value to the grower. It is also possible to take out too little of the empty seed and weeds, with a consequential loss of value to the grower which may equal that of the first instance. The trick is’to achieve a balance wherein all possible good seed is saved while the required standards for that type of seed are still met.
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(32 KB)At Lincoln University, a small (3.7 ha) beef unit operates annually with the objective of closely fitting seasonal pasture growth rate to cattle feed demand on Canterbury dryland pasture with no requirement for making or feeding conserved feed. Inputs to this dryland pasture beef production system are kept low. Cattle are not purchased in autumn until the results of a feed budget show that pasture mass plus expected winter pasture growth will meet target animal winter intake. In some years not all cattle are bought at the same time, but the unit is fully stocked (around 6 cattle/ha) by the end of July. Cattle are sold for slaughter progressively from December through February as pasture production ceases to meet animal demands. Grazing methods typically vary from autumn-winter rotations of up to 100 days with weekly block grazing, to 6-paddock rotations of 28-34 days in spring and 2-paddock, 30-day spelling intervals later in the grazing season. The unit-consistently produces each year a carcass weight gain of 500 kg/ha with gross margins of around $400-600/ha representing a utilisation of 100 GJ ME/ha. This performance is consistent with that of other intensive beef production systems. Keywords beef production, dryland, seasonal pasture production
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(569 KB)The intensive sheep farming systems in place in Southland and South Otago are not capturing the genetic potential of lamb growth rates. Growth rates of works lambs average 100-140 g/day post weaning - less than half their genetic potential. The major reason for low growth rates of lambs is the lack of adequate quality feed. Planting a range of herbage species, with the area in each pasture species balanced with its growth characteristics, can give a balanced supply of quantity and quality feed sufficient to meet the requirements of the animal system. This leads to more balanced matching of feed supply and demand, both within the four seasons of the year, and from year to year. Keywords lamb growth, alternative species, integrated herbage
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(589 KB)Experiments on the effects of Argentine stem weevil (Listronotus bonariensis (Kuschel)) predation on perennial ryegrass (Lolium perenne L.) were carried out at Palmerston North from 1978 to 1986. A tagged tiller technique was used to assess the probability that any tiller would be attacked by Argentine stem weevil larvae. After grazing by sheep, a single tiller was tagged with a plastic ring at 25 sites 15 cm apart along line transects through each plot, and examined twice weekly throughout the seasons during which Argentine stem weevil is active. Annual variation at Palmerston North was substantial, with the probability of a low endophyte ‘Grasslands Nui’ perennial ryegrass tiller being attacked ranging from 55% to 95%. ASW annual larvae production calculated from the probability of tiller site damage and the tiller site density varied from 800 to 3000/m’. Variations in the severity of attack of this magnitude are sufficient to explain the variability in the success of sowings of low endophyte grass. Variations in annual larvae production were not correlated with weather parameters, but may be related to natural cyclic disease infestations. Keywords Argentine stem weevil, ‘Grasslands Nui’ perennial ryegrass, endophyte
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(725 KB)‘Grasslands Pacific’ perennial ryegrass (Lolium perenne L.) was compared in the field with available cultivars in plot trials at 6 sites and as sown rows at 7 sites. Pacific showed consistently good performance, particularly in summer and winter when it was superior to other perennial ryegrass cultivars. Keywords perennial ryegrass, ‘Grasslands Pacific’, cultivars, ‘Grasslands Marsden‘
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(658 KB)Seed yields of ‘Grasslands Roa’ tall fescue (Festuca arundinacea Schreb.) have ranged from 200 to 1450 kg/ha, with some hand harvested research plots producing 3600 kg/ha. Better management has increased seed yields, i.e., growing seed crops on deep, moistureretentive soils, lenient autumn and winter grazing, closing by late winter (mid July), applying 120 kg N/ha and careful harvesting techniques. Time of sowing, undersowing with barley crops, weed control and plant growth regulators are also discussed. Keywords tall fescue, seed production, Festuca arundinacea, ‘Grasslands Roa’
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(630 KB)‘Necton’ sulla (Hedysarum coronarium L.) is a perennial forage legume with potential to provide high quality, non-bloating feed. This trial examined the effect of grazing intensity and frequency on sulla over one year. Annual dry matter yields ranged from 7.4 to 18.0 t/ha. There was no difference in the yield of hard and lax-grazed plots but grazing in late autumn significantly decreased plant density and yield. Keywords ‘Necton’, sulla, legume, grazing management
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(449 KB)The grass grub (Costelytra zealandica) is a major pest of Canterbury pastures. Grass grub numbers are low in young pastures and then commonly rise to a peak 4-6 years from sowing, before declining. Grass grub numbers in older pastures fluctuate but rarely reach the same levels as the early peak. Biological control agents such as bird and invertebrate predators, parasites and diseases cause mortality in grass grub populations; the effect of predators and parasites is limited. Pathogens are common in grass grub populations. Amber disease, caused by the bacteria Serratia spp., was the disease most frequently found in population surveys in Canterbury, while milky disease (Bacillus popilliae) and protozoan diseases were less common. The level of amber disease was reduced in pastures where insecticide had been applied. Inundative applications of entomophagous nematodes and the bacterium Serratia entomophila have been tested against grass grub. A bacterial productbased on S. entomophila is now being marketed for grass grub control. Keywords grass grub, biological control, pathogens
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(624 KB)A survey of ‘Grassland Egmont’ browntop (Agrostis capillaris syn. A. tenuis) seed yields (1987-1989 incl.) showed a range in production from 0 to over 400 kg/ha, with a relatively low average yield (107-147 kg/ha). In order to elucidate the problems associated with growing Egmont for seed, crops on 23 farms were monitored during the 1989/90 growing season. Trends on yield data were then analysed according to precipitation (rainfall or irrigation) and soil type. Precipitation was found to be the major factor in limiting seed yields. With this information, refinements were developed to present management systems including fertiliser application, weed control, irrigation and harvest and post-harvest management. Keywords: browntop, seed production, irrigation, ‘Grasslands Egmont’
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(505 KB)‘Grasslands Puna’ chicory (Cichorium intybus L.) has been harvested for seed in New Zealand since 1984. Seed yields have ranged from 0 to over 700 kg/ha with an average yield of around 200 kg/ha. Data from Manawatu and Canterbury trials were combined with information gained from monitoring 25 Puna seed crops in Canterbury. Results from work on establishment, time of closing, seed development, response to nitrogen, herbicide tolerance and methods of harvesting are reported, and differences between Manawatu and Canterbury in terms of management of Puna seed crops are highlighted. Keywords: chicory, seed production
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(518 KB)Different forms and rates of sulphur (S) fertiliser were examined for developing oversown tussock in sunny-lying South Island high country. Sulphur significantly increased dry matter (DM) production (p = 0.0001). Soluble forms of S were most effective in the first year, and lasted 15-18 months. Sulphur bentonite prills took 6 months to be effective, but over time the higher rate (56 kg S/ha) was one of the better treatments. Elemental S on its own was ineffective even after 3 years. The combination of soluble sulphate and finely divided elemental S (56 kg S/ha as sulphur super extra) was the most effective treatment. In the first 2 years alsike clover was the most dominant pasture species. Native grasses became dominant in the third year. After retopdressing at the beginning of year 4, pasture production again improved, particularly in those treatments containing only soluble forms of S. White clover was the dominant pasture species in the fourth year. Sulphur significantly increased soil-available nitrogen levels (p = 0.0001). Keywords development, sunny hill country, sulphate sulphur, elemental sulphur, sulphur super extra, sulphur bentonite prills, available nitrogen
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(588 KB)The effect of winter and spring feeding on milk production was investigated on a Mid-Canterbury dairy farm. High feeding of Friesian/Jersey cows to gain 64kg of liveweight during winter resulted in an extra 20kg of milkfat and 15 kg of milk protein production compared with feeding to maintain empty body liveweight. Extra feeding of cows during the first 8 weeks of lactation produced 7 kg of milkfat and 6 kg of milk protein over that period. The carry-over effect from this for the next 22 weeks of lactation of normal feeding was an extra 11 kg of milkfat and 5 kg of milk protein per cow. Simple financial analysis showed that off-farm wintering of cows to either maintain or gain liveweight and consequent high spring feeding were profitable options returning $40-42 per cow after extra grazing and topping costs. Keywords: winter, spring, feeding, milkfat,milk. protein, production
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(66 KB)The effect of a molluscicide or an insecticide on the establishment, by direct drilling of ‘Grasslands Roa’ tall fescue (Festuca arundinacea Schreb.) ‘Ellett’ perennial ryegrass (Lolium perenne L), and ‘Grasslands Maru’ phalaris (Phalaris aquatica L.) was measured in spring and autumn establishment over 2 years. In autumn after a wet summer the application of a molluscicide significantly increased seedling numbers and establishment yield for ryegrass and tall fescue. A molluscicide applied in autumn after a dry summer or in spring had no effect . Application of insecticide significantly improved the establishment of ryegrass and tall fescue in only one of the two springs and had no effect in autumn. Phalaris was the least responsive of the pasture species to either an insecticide or molluscicide. These differences observed at establishment resulting from the applications of a pesticide were not apparent in an assessment made 1 year later. For tall fescue the results recorded on seedling numbers and yield of sown species at establishment and 1 year would suggest that for this species establishment by direct drilling is not recommended. Keywords pasture establishment, ‘Grasslands Roa’ tall fescue, ‘Ellett’ ryegrass, ‘Grasslands Maru’ phalaris, direct drilling, molluscicide, insecticide
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(533 KB)A field experiment was structure and light intensity on seed production A field experiment conducted during the summer of 1989-90 to determine to what extentand under what growing conditions the seed yield of white clover flower heads is influenced by canopy density and overcast weather conditions in plants of ‘Grasslands Pitau’. Overcast weather was simulated by artificially shading the plants. The flower heads developed in a dense canopy produced 37% fewer seeds per head than those formed in an open canopy. Seed yield per flower head was also strongly affected by artificial shading. When plants were shaded only before pollination there was a 3 1% reduction in seed number per head; when shade was given only after pollination there was a reduction of 25%. It is argued that a major advantage of the practice of defoliation at the time of closing for seed production is enhancement of flower fertility; and that decreased seed set in duller, wetter summers is probably, at least in part; attributable to increased ovule sterility in the dense canopies formed under those conditions, Keywords: white clover, canopy, light intensity, seed yield
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(535 KB)A pasture containing Concord and Yatsyn ryegrass, ‘Grasslands Wana’ cocksfoot, ‘Grasslands Pawera’ red clover and ‘Grasslands Pitau’ white clover was established in autumn 1987. From spring 1987 this sward was grazed at 2-, 3- and 4-weekly intervals in spring, down to a mean height of 2-3 cm or 5-6 cm in one experiment, while in another trial it was grazed in summer at 3-, 4- and 5- to 7-weekly intervals to a mean residual height of 3-4 cm or 5-6 cm. The longest grazing interval applied in spring or summer increased spring and summer pasture yields for the 3-year period by 51 and 35% respectively, compared with the shortest grazing interval. Lenient grazing in spring or summer increased both spring and summer yields by an average of 16% over 3 years. Lenient spring grazing reduced summer pasture yields by 7% over 3 years, but much of this reduction was the result of a decreased proportion of summer-growing volunteer grasses. Yatsyn ryegrass established quickly and performed well, providing the major contribution to pasture production in these 3 years. Its content in the sward was depressed by frequent spring grazing and infrequent summer grazing, but it was not significantly affected by grazing intensity and it can be recommended as the basic ryegrass in a mixture. The contribution of Concord ryegrass was confined mainly to the first winter and spring. Wana cocksfoot was slow to establish and its content in the sward wax increased by frequent spring grazing and lenient spring and summer grazing. Its greater drought tolerance will make it a useful addition to a ryegrass pasture in areas of low summer rainfall. Pawera red clover made only a small contribution to the sward and this declined with time. The effects of summer grazing management differences were mainly confined to that season, but spring pasture management treatments also affected pasture yields and botanical composition in the following summer. Keywords seasonal pasture grazing management, pasture production, botanical composition, cattle grazing, grazing frequency, grazing intensity, ryegrass, cocksfoot
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(720 KB)A field trial was conducted on a yellow-grey earth in the Hawke’s Bay (mean annual rainfall 875 mm) over a period of 5 years to measure the effects of lime applications (0, 5, 10 t/ha) on soils high (50 kg P/ha applied annually) or low (5 kg P/ha applied annually) in phosphorus (P). The average annual pasture production on this dryland soil in the absence of applied lime or P was 5060 kg DM/ha (range 3861-6024). The botanical composition of the pasture was variable, average annual legume composition (4/o on DM basis) ranging from 3 to 42%. The predominant. legume was subterranean clover (Trifolium subterranean) with white clover (Trifolium repens) making a small contribution in some years. In the first two years after application responses to lime were large (lo-20%), due entirely to liming stimulating the grass component of the pasture, and consistent with liming enhancing the rate of net mineralisation of soil organic nitrogen (N). In years three and-four-the-dominant treatment effect was to P applications (130% increase in total pasture production), which stimulated legume growth initially, but subsequently increased grass growth. In the fifth year no significant responses to lime or P were observed. The seasonal pattern of pasture responses to either lime or P was related to pasture botanical composition. The size of the annual total DM pasture responses to P was positively related to the legume content of the pasture. Conversely the lime responses were negatively related to pasture legume content. These results suggest that pasture botanical composition could be used to improve the ability to predict lime and P responses based on soil nutrient levels. This may be important where pasture botanical composition is extremely variable over time. Keywords fertiliser, lime, pasture, pasture composition, phosphorus, soil acidity
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(653 KB)The seasonal production of autumn-sown Concord Italian ryegrass was compared with that of an existing perennial ryegrass pasture. Concord (10 kg/ha) was direct-drilled into large plots previously. sprayed with glyphosate or was undersown into the existing pasture. Nitrogen fertiliser (25 kg N/ha) was applied to half the area of each plot on 3 occasions during June and July. The major objective of the experiment was to examine the effects on pasture production in late winter-early spring (early lactation) when cows are often underfed. During late winter-early spring, direct-drilled and undersown plots accumulated 44 and 20% more dry matter (DM), respectively, than did the existing pasture (2.5 t DM/ha). Addition of N increased overall accumulation during early lactation by 18%. The direct influence of Concord on pasture accumulation was restricted to winter/spring, as was the pasture response to N. Argentine stem weevil populations were low and were not affected by winter applications of N. This work suggests Italian ryegrasses, like Concord, can be used to boost feed production during early lactation on dairy farms, and that winter N applications can be used to enhance their contributions. Further farmlet work is required to determine the milk production responses possible from the use of Italian ryegrasses. Keywords Lolium multifloru-m, ltalian ryegrass, direct drilling, seasonal herbage accumulation, early lactation period, pasture botanical composition, tiller density, major element composition, Argentine stem weevil populations
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(115 KB)The effects of sowing depth on the seedling growth of three dryland pasture grasses and five legumes from an on-farm trial in the Hakataramea ‘Valley, South Canterbury was examined. The drill was set to sow seed at depths of 10 mm, 20 mm, or 30 mm depending upon species, but in practice a wide range of drilling depths occurred. Seedling growth was highly correlated with sowing depth for the majority of species. The level of dependence of seedling growth upon sowing depth for the species examined was as follows: Tetra alsike >> Cascade birdsfoot trefoil = Kara cocksfoot > Hakari brome = Dryland birdsfoot trefoil = Redquin red clover > > WL 320 lucerne = Maru phalaris. In general, seedling growth was good from sowing depths of less than 12.5 mm and extremely poor from depths greater than 25 mm. A prediction of the relationship for these species on the basis of seed weight was not possible. Keywords sowing depth, pasture species, dryland species, seedling growth, hypocotyl length, epicotyl length
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(579 KB)Most field trials conducted in New Zealand for assessing pasture plant sulphur (S) requirements use the mowing and clipping return technique without the inclusion of grazing animals. A rotational grazing experiment and a field plot trial were conducted on a Templeton silt loam soil (Udic Ustochrept) in Canterbury using radioactive S35-labelled fertilisers to examine the effects of grazed sheep on the plant availability and cycling of applied S fertilisers. An additional plot trial was conducted to determine leaching losses of S35-labelled urine applied to pastures. The results obtained showed that maximum 3sS concentration in pastures treated with elemental S occurred 3 months earlier in the grazed trials compared with that of ungrazed plots. This increased herbage S was also reflected in the wool 35S of ewes which grazed the pastures. In addition, the amount of residual elemental S remaining in the soil after 3 months of its application was significantly lower in grazed than in ungrazed pastures. These results suggest that grazing animals enhanced the plant availability of elemental S probably because of the effects of animal trampling and the return of animal faeces. It was also found that about 36-44% of the applied 35S fertilisers and up to 68% of the applied urinary s35 were not recovered in the soil within one growing season in the field. __ Thus grazing animals enhanced not only the availability of elemental S, but were also responsible for substantial losses of S from pastures through animal excreta. The present data suggest that field trial results obtained from mowing plot trials without the inclusion of grazing animals are unlikely to assess adequately the plant availability of elemental S. Keywords sulphur, nutrient cycling, urine, sulphur leaching, recovery, fertiliser, elemental sulphur, oxidation, sheep grazing, mowing, grazing
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(589 KB)‘Grasslands Matua’ prairie grass was direct drilled into easy hill county at Whatawhata Research Centre. Establishment was excellent, but persistence was poor in most paddocks after 2 years. Site conditions associated with a range of Matua populations were surveyed. Matua population decline was greatest during spring. Spring soil nitrogen levels were associated with persistence, implying that nitrogen application in late winter may enhance persistence. In a trial to assess the effect of spring management on tillering patterns, seed production and seedling vigour, October closing resulted in the highest seed production, seed vigour and highest tiller density after herbage removal. It is proposed that a springsummer hay making policy will enhance the vigour of the existing population and provide adequate reseeding for new plant recruitment. Keywords Matua, persistence, soil survey, nitrogen, tiller density, closing date
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(709 KB)The Drought Pasture Demonstration Programme invloves 81 farms in the North Otago and South Canterbury areas, with an average 19.7 ha per farm, and total area of 1595 ha. The purpose is to demonstrate, in a practical and effective way, the benefits and establishment methods of drought tolerant pasture species. Ten different species of forage grasses, legumes and herbs were used, comprising 19 different cultivars. Half the area was sown in February and March 1989 with the remaining areas sown in spring 1989 and autumn 1990. Sowing was done by either full cultivation, minimum tillage or direct drilling. A 97% success rate was achieved in establishing these pastures, despite a dry and mild autumn, demonstrating to farmers that with correct technical advice the risks of poor establishment are low. The aspects most important for pasture establishment were paddock preparation, moisture at sowing, timing, sowing depth, insect control, soil fertility, initial grazing, and patience. A survey of farmers has shown that a large number of farmers in the region have already viewed the demonstration pastures, and subsequently sown their own. Keywords dryland, pasture establishment, drought, technology transfer
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(698 KB)The Taranaki Agricultural Research Station (TARS) has produced 52% more milkfat/ha than the average Hawera farm through the 1980s. Respective stocking rates (3.7 vs 2.8 cows/ha) are the major reason for this production difference. Very little improvement in relative performance has been made over the decade. Monitoring projects in South Taranaki during 1988-89 and 1989-90 have shown that adopting a monitoring programme can result in increased production. The quantitative information collected provides farmers with the information and confidence to make major changes in their farming system. Dairy farmers need to monitor their own farms themselves. The programme chosen should be simple so that it can become incorporated into the farming routine. A simple method of monitoring is described that is based on recording pre- and post-grazing level on 2-4 selected paddocks. Research and extension organisations need to adopt a number of recommendations if farm monitoring is to be taken up by the majority of dairy farmers: pasture assessment methods need to be standardised; production of a simple monitoring handbook for farmers; the publication of regular comaprative data from dairy companies and research organisations; and the commercial production of predictive computer-models. Keywords monitoring, stocking rates, decisions
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(60 KB)Over the last 10 years Canterbury farmers have started to diversify their pasture base in order to optimise their stock production. While ryegrass is still the base grass of our pastoral system, it is unsuited to many sites where pasture must generate high stock growth rates despite seasonally low rainfall, high soil temperatures and pasture pest challenge. On such sites, pastures based on cocksfoot, (Dactylis glomerata L.), phalaris (Phalaris aquatica L . ) and tall fescue (Festuca arundinacea Schreb.) or prairie grass (Bromus willdenowii Kunth, cv. ‘Grasslands Matua’) or lucerne (Medicago sativa) or chicory (Cichorium intybus L.) have lifted net farming returns. Keywords ryegrass, endophyte, tall fescue, phalaris, cocksfoot, prairie grass, chicory, pasture pests, rainfall, stock production, pasture persistence
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(815 KB)Condensed tannin concentrations (% of dryweight) were measured in leaves of 22 accessions of Lotus corniculatus, 10 accessions of L. pedunculatus, 2 accessions of L. tenuis, and 1 accession of L. subbiflorus from plants growing on limed (pH = 5.2) and unlimed (pH = 4.3) soils near Canberra, A.C.T. There was a non-significant decrease in the mean condensed tannin concentration due to liming. The differences between species and between accessions within species were significant. For the L. corniculatus entries the range of tannin concentrations over the limed and unlimed sites was 0.15-7.28%, with a mean of 2.09%. The highest concentration was found in the otherwise promising accession CPI 66414. L. pedunculatus accessions ranged from 2.53-10.72% in tannin content, with a mean of 5.99%. Two Portuguese accessions that have promising agronomic features for coastal east Australian pastures had unacceptably high tannin levels above 7.50%. Genotypic differences accounted for a large proportion of the total variability for tannin production, so there are good prospects for the improvement of these species by selection and breeding. Keywords: Lotus corniculatus, L. pedunculatus, L. tenuis, L. subbiflorus, condensed tannins
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(80 KB)As an essential ingredient in the development of the South Island’s dry hill country, shrubs have a vital role in the amelioration of extreme climatic effects, gully erosion control and in the provision of stock forage. Trials have been conducted in the South Island over the past 20 years, culminating in the establishment of farm scale plantings of Atriplex halimus (Mediterranean saltbush) on “Riverside” (Mike Brosnan), Hakataramea, in 1985. Some 20+ ha of saltbush “forage banks” now exist on this property. The selection of Atriplex species adapted to the dry, cold hill country in the South Island is briefly described together with establishment and grazing management techniques appropriate to farm scale plantings of forage banks. These have been developed on exposed, sunny faces which, in the past, were low priority areas for pastoral development. The climatic adaptability, the preferred soil types and nutrient status, the management and the conservation values of Atriplex halimus as a forage plant are discussed. This is directed at stimulating further integration of forage banks into farming systems appropriate to semi-arid conditions. Planting normally unproductive dryland site with forage shrubs, in combination with other drought tolerant pasture plants, is seen as an important step in the development of successful farming strategy suited to these environments. The positive and practical results realised to date at Riverside need to be developed on other South Island dryland properties as a means of expanding shrub forage bank plantings over a wider range of climate and soil types in New Zealand. Keywords Atriplex halimus, Mediterranean saltbush, forage banks, nutrition, grazing and economic analyses, semi-arid climate
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(789 KB)Two experiments were conducted to study the weekly and seasonal growth rates of lucerne in Canterbury (Winchmore) and the Rotorua- Taupo area (Wairakei). One of the, main objectives was to measure more accurately the weekly growth rates of lucerne, rather than the rates measured from final yields under a hay type regime, and relate them to weather factors over time. Weekly growth rates of lucerne were assessed from sequential cutting over S-week periods, followed by rapid grazing. After defoliation with sheep, the sequential cutting was repeated at a new site to avoid any interaction from repeat samplings of the previously measured areas. ‘Wairau’ lucerne was used but after the second year of the irrigated experiment at Winchmore ‘Saranac’ was used. Lucerne growth curves with and without irrigation in Canterbury and without irrigation in the Rotorua-Taupo area were constructed. During periods of rapid production lucerne growth rates were linear for up to 5 weeks. Daily growth rates of up to 185 kg DM/ha were recorded on both sites. These trials suggested that ceiling yields can reach 8500 kg DM/harvest. The main determinants of the amount of lucerne available at a particular time were the time of the year and length of regrowth period. Lucerne yields can be predicted from evaporation data and age of regrowth. Keywords: lucerne, growth curves, seasonal growth rates, weather, regressions
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(104 KB)Herbage seed lots of the same chronological age, certification class and germination values often differ in performance in the field, in storage, or both. These performance differences are ascribed to another seed quality factor, seed vigour. Vigour differences have been shown to occur in New Zealand seed lots of Trifolium repens, T. pratense, Medicago sativa, Bromus willdenowii, Cynosurus cristatus and Festuca spp., and are highly likely to occur in all other herbage species. This review of vigour in herbage seed lots discusses the concept, its possible causes, the implications for sowing, storage and export of seed, and how seed lot vigour information might be used by the farmer, seed store manager and seed marketer. Keywords seed vigour, field emergence, storage, export, herbage seed, germination
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(110 KB)Clover-based grasslands as used in New Zealand, while considered “clean” relative to grasslands farmed intensively with fertiliser nitrogen (N), are nevertheless polluting. Recent measurements of nitrate-N down the soil profile below heavily stocked (22.5 ee/ha) pastures grazed by sheep, have shown that leaching losses under set stocking are 2-3 times those from rotational grazing (37 vs 16 kg N/ha/yr). As the input of N, its storage, and outgoings in animal products are similar in both systems, this indicates that considerably more urinary N is being lost to the aerial environment from rotationally grazed pastures, with nitrate leaching being the main avenue of loss under set stocking. Differences in sward structure are suggested as the major factor. Lower nitrate leaching from cocksfoot vs ryegrass-based pastures are thought to be associated with lower herbage quality factors reducing urinary N formation. While grazing management will not greatly influence total N losses to the environrnent, it can mfluence the avenues by which N enters the wider environment. Aquatically sensitive catchments may be better protected from leaching of nitrate by modification of the grazing management approaches. Keywords pasture management, nitrate leaching, ammonia volatilisation, pasture structure, herbage quality, groundwater pollution
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(517 KB)Two field-plot trials were superimposed on irrigated, sheep-grazed pastures on Lismore stony silt loam in Canterbury to investigate residual effects of previous superphosphate applications on dry matter (DM) production and herbage composition. Residual effect of phosphorus (P) in superphosphate was shown to depend upon previous application rate and number of years of superphosphate application. In contrast, residual effect of sulphur (S) in superphosphate was independent of previous application rate if superphosphate had been applied for 25 years at rates at or above the S maintenance rate. Previous applications of superphosphate at the annual rate of 376 kg/ha for 6 years failed to safeguard pasture against yield reduction even in the first year after superphosphate was discontinued. This reduction was attributed equally to both P and S deficiencies. Residual values of both P and S were more substantial in areas where superphosphate had been-applied-at--the-higher rate of 564 kg/ha for 6 years. However, these residual values were also short-lived and DM production declined by 13% in the second year after the cessation of superphosphate application. Different patterns of residual values of superphosphate were recorded on areas where superphosphate had been applied over a longer term of 25 years. Where superphosphate had been applied annually at 188 kg/ha, DM production fell by 10% in the first year after topdressing ceased. This reduction was due entirely to P deficiency affecting clover growth, while S deficiency - in both grass and clover - was not observed until the third year after topdressing ceased. On areas where superphosphate had been applied at a higher rate of 376 kg/ha for a similar period of 25 years, DM production did not decline until the second year. This initial decline was attributed to S deficiency in clover while P deficiency in grass and clover was not apparent until the 4th year after the cessation of superphosphate application. The results were used in a simple model that uses previous topdressing history to predict yield reductions if topdressing is withheld. Keywords residual effects, phosphorus, sulphur, irrigated pasture
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(574 KB)Changes in soil phosphorus (P) associated with the establishment and maintenance of improved ryegrass-clover pasture under different superphosphate fertiliser treatments were examined over a 20-year period (1957-77). Results showed that soil organic P increased with increasing applications of P fertiliser. This represents a dynamic balance between rates of organic P addition and breakdown in the soil. This balance is reached slowly and may be significantly altered only by drastic changes in land use. In annually fertilised soils, amounts of inorganic P increased with time. However, the potential utilisation of this residual inorganic P is limited by its apparent stability in the soil. Keywords grazed pasture, irrigation, fertiliser P, soil inorganic P, soil organic P, soil P fractionation
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(414 KB)Our objectives as farmers are to sustain a pastoral farming system that converts the optimum amount of grass grown to milk solids. The key to achieving this is by adopting the correct stocking rate. On our property,production has increased from 330 kg milkfat/ha in the first year to 430kg milkfat/ha in the second year. Conservation is not the preferred option when dealing with surpluses. A combination of supplements, nitrogen and off-farm grazing is used to make up the deficits. The absence of a mid-season slump in grass growth results in a sustained production curve through the season. This is a feature of borderdyke dairy farming. The correct stocking rate will enable costly grass surpluses and deficits to be kept to a minimum. The distribution of grass growth on our farm is what is really important, not total dry matter. The availability of crop residues and off-farm grazing in this area can be used profitably to make up feed deficits. Production Increases in the short term will come through improvements in sward composition, fertility, cow quality and irrigation. Longer term, production increases can come only through growing more grass and finding the correct blend of calving date, stocking rate and drying-off date, to utilise that grass to the optimum. Keywords: dairy farming, stocking rate, borderdyke, pasture management
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(57 KB)Lambs were rotationally grazed with ewes in a ‘sheep only’ system and with low, medium, and high proportions,of wether goats from October to March on dryland perennial ryegrass-white clover pastures in Canterbury. Lambs grazed with ewes and goats until they were weaned; then they grazed ahead of other stock. Treatment ratios of adult stock on a per head basis were 3 ewes:1 goat (‘low goats’), 3 ewes:2 goats (‘medium goats’) and 3 ewes:3 goats (‘high goats’). The ewe:lamb ratio was 1:1.35 on all treatments. Lamb growth rates (g/day) were 152 for ‘sheep only’, and 169, 185 and 203 for low, medium and high goat treatments respectively. As each treatment lamb reached a target draft weight, it was replaced by a lighter lamb for finishing. In comparison with the ‘sheep only’ treatment, an extra 1.6 lambs/ha were drafted off the ‘medium goat’ and an additional 2.6-lambs/ha off the ‘high goat’ treatment by the end of January. Increasing the proportion of goats:ewes increased the supply of white clover in pastures especially after lambs were weaned. Examination of faecal plant material showed 30% clover in the diet of lambs in a ‘sheep only’ system, increasing as the goat:sheep ratio increased to 60% clover in the ‘high goat’ treatment. Keywords white clover, perennial ryegrass, goats, sheep,grazing management, diet, lamb
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(569 KB)A simple model was used to estimate losses of potassium (K) which occur from a Mid- Canterbury dairy farm. Analysis of the results shows the role of the dairy cow in causing losses of K from the farm. The results from this study could be used to refine the estimates of animalinduced losses of K in the model used by MAF Technology to predict fertiliser recommendations. Such refinements include the incorporation of information on the time that cows spend off the pasture (in the dairy shed, raceway and on feedpads) and the amount of K lost from urinations. The study suggests that savings in K fertiliser requirements through reduced losses from dairy farms are best achieved by minimising the time that dairy cows spend off the pasture and avoiding excessive K concentrations in herbage through heavy rates of K fertiliser. Keywords potassium, model, potassium cycling, potassium losses, dairy cattle
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(596 KB)The performance of dormant and winter-active lucerne (Medicago sativa L.) cultivars was compared under sheep grazing in 2 experiments during the cool season. The objectives were to define the cool season management required for winter active cultivars in sheep farming systems. The ‘winter-active cultivars Matador and Rere yielded 1760 and 1220 kg DM/ha compared with 890 and 760 kg from Wairau and Saranac respectively in mid-winter, while the reverse occurred in spring when dormant cultivars yielded 50% more than the winter active. This was related to differing levels of non-structural carbohydrates in roots, which had declined to insignificant levels in Rere and Matador by early spring. June grazing increased spring yields of Wairau by 35% due to control of overwintering aphids, but reduced yield of Rere by 25% due to effects on root reserves. Early September grazing greatly - reduced subsequent lucerne yields at late October and early December grazings, and increased the content of weeds. Our findings show that if farmers graze winter-active lucerne with sheep in winter the advantage in production disappears in spring. Cool-season management which combines the use of dormant and winter-active lucernes is discussed. Keywords winter-active lucerne, dormant lucerne, cool-season grazing, root reserves, lucerne grazing management
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(54 KB)Herbage seed production for the period 1980-89 has averaged 20 600 metric tonnes (MT) (range 13 360-34 590). Canterbury has 82% of the total seed area. Production area (1989-90) by species are perennial ryegrass (Lolium perenne)44%; white clover (Trifolium repens) 33%; tall fescue (Festuca arundinacea) 6%; cocksfoot (Dactylis glomerata)5%. New Zealand exports seeds to over 40 countries with Australia; USA and the European Community representing major markets. Proprietary cultivars have increased in number from 5 (1980) to 62 (1989) and in volume from 0.1 to 27.0%) a trend we predict will continue, with proprietary cultivars being an estimated 60-65% of seed volume by 1995. The development of ‘Endosafe’ novel endophytes in ryegrass is expected to double seed usage in New Zealand for a decade as pasture renewal is increased from 250 000 ha to 500 000 ha per year. Opportunities and threats to the New Zealand ‘industry, seed-quality training and research are discussed. Keywords: herbage seed, ryegrass, white clover, endophyte, exports, marketing, seed quality, training
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(92 KB)The activity of white clover axillary buds was studied over a 13 month period in populations from set-stocked (S) and rotationally grazed (R) pastures. Bud activity in the field was observed and the viability of inactive buds was tested in the laboratory. R populations had significantly greater percentages of nodes bearing active buds, potentially active buds and roots. Two kinds of dormancy were identified in axillary buds. For much of the year buds at approximately 26% of nodes were prevented from growing, probably by a combination of correlative factors and the environmental conditions surrounding each bud-site. During spring, very few buds could be stimulated to grow; these buds were regarded as showing the second form of dormancy. The R population had a deeper but less prolonged ‘spring dormancy’. The physiological basis and ecological significance of ‘spring dormancy’ are considered. Keywords white clover, dormancy, axillary buds
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(457 KB)Plantain (Plantago lanceolata) was grown in a radial trial in order to investigate the effect of plant density on seed production. Plant densities ranged from 278 plants/m2 to 17 plants/m2 in 9 arcs. Plants were monitored and harvested individually, thus giving effective high replication (32). Decreasing plant density had a significant positive effect on seed head production (both numbers and size of head), seed yield and plant vigour. Highest seed yield was associated with a density of 17 plants/m2. Keywords: plantain, seed production, plant density, competition, radial trial design
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(448 KB)The New Zealand herbage seed industry is looking to diversify and reduce its almost complete dependence on ryegrass and white clover. This review examines some opportunities and constraints to achieving this industry goal. In the near future, low input sustainable agriculture is likely to create a demand for seed of species such as alsike, Caucasian, zigzag and suckling clovers, crown vetch, velvet grass, white sweet clover, hairy canary clover, birdsfoot trefoil, perennial lupin, yarrow, tagasaste, wheat grass, oat grass, phalaris, paspalum, dogstail and sheep’s burnet. There is also potential for export of herbage legumes such as annual medics, berseem clover, vetches, sainfoin, sulla, lotus and sweet clover, particularly to the Mediterranean region and Australia. The New Zealand seed industry has the strengths required to meet these challenges, and areas of lower fertility and free-draining irrigatable soils such as parts of Canterbury are likely to be highly suitable for non-conventional herbage legume seed production. At present there are important constraints, including lack of seed supply and therefore little demand, very limited seed production information, lack of available financial resources, and competition from overseas producers. These problems are discussed. However, they can be overcome, and by 1995 New Zealand could expect commercial seed production of birdsfoot trefoil, sulla, perennial lupin, serradella, Caucasian and zigzag clovers, velvet grass, smooth and upland bromes, phalaris, paspalum, dogstail, dryland bent, yarrow and sheep’s burnet. Brief seed production information for some of these species is appended. Keywords: herbage legumes and grasses, pasture herbs, forage shrubs, seed production potential, export, research, marketing
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(139 KB)The long term trial, on a Templeton fine sandy loam, is a factorial combination of 3 pasture swards (pure WL320 lucerne, lucerne-‘Grasslands Matua’ prairie grass and lucerne-‘Grasslands Maru’ phalaris) and 2 grazing durations (long and short). The 0.04ha plots were sown in November 1986 with lucerne drilled across the grass rows. For the water use study, in 1988-89, 8 m* mini plots of pure lucerne, lucerne-phalaris, and lucerne-prairie in deep or shallow soil were selected. Pure lucerne plots produced annual dry matter (DM) yields of 12700 kg/ha, lucerne-phalaris 11600 and lucerne-prairie 10400. Deep soils had higher production (12600 kg/ha) than did shallow soils (10900 kg/ha). The lucerne-phalaris mixture had about 75-95% lucerne, while lucerne in the lucerne-prairie mixture ranged from 25% in winter to 65% in summer. The lucerne-prairie plots with deep soils had at last 60% lucerne while shallow soils had as little as 25%. Mean water use efficiency (WUE) was 25, 22 and 20 kg DM/ha/mm for pure lucerne, lucern-ephalaris and lucetne-prairie, respectively. Shallow soils had WUE of 21 kg DM/ha/mm H,O and deep soils 24 kg DM/ha/mm. Soil water extraction ‘patterns differed little in shallow soils, but in deep soils pure lucerne extracted water to at least 100 cm while lucerne-phalaris and lucerne-prairie extracted soil moisture down to about 80 cm. Lucerne and phalaris roots were both found down to 90 cm and from O-20 cm most of the root mass was lucerne. With the lucerne-prairie mixture from O-20 cm, root mass was about 50% for each species and lucerne root mass was significantly reduced below 50 cm. Keywords: lucerne, alfalfa, prairie grass, lucerne-grass mixtures, water use, yield, roots, Medicago saliva, Bromus willdenowii, Phalaris aquatica
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(105 KB)Seed yields of ‘Grasslands Cook’ chewings fescue (Festuca rubra spp. cornmutata) and ‘Grasslands Tasman’ creeping red fescue (Festuca rubra) were increased by immediate
post-harvest grazing or burning. Severe
defoliation (3-5 cm from ground level) by burning, grazing or cutting in autumn and winter, decreased seed yields. Nitrogen increased seed yields, but there were no significant differences (P Significant quantities of phosphorus (P) and
nitrogen (N) are present in the soil microbes
compared with pasture requirements for these
nutrients. Seasonal and fertiliser effects on
microbial P and N were investigated in a
controlled environment (CE) experiment, two
field trials and a glasshouse trial. In the CE
experiment there was a basic seasonal pattern
of storage of P and N by the microbial biomass
over “winter” and release of these nutrients in
“spring”. Climatic variations affected this
pattern in the field trials. Withholding fertiliser
did not affect soil microbial P and N in the field
trials, despite a decline in pasture production of
up to 20%. Soil microbial P and N did decline
in the glasshouse trial, in which a much larger
drop in herbage production (X30%) was
induced by nutrient deficiency.
Keywords soil microbial biomass, microbial
phosphorus, microbial nitrogen, seasonal
effects, withholding fertiliser, plant nutrients Roa tall fescue was sown at Gore to study the effects of viable seeding rate (2.5, 5.0 and 10.0
kg/ha) and row spacing (30 and 60 cm) on seed yield and seed quality over 3 harvest seasons. In the first year after mid-February sowing, seed
yields were low (260 kg/ha), owing to slow establishment and weed competition. The 30-cm row spacing had the highest seed yield in
this year, but there were no differences between viable seeding rates. In the second year the
highest seed yields (800 kg/ha) were from the viable 2.5 and 5.0 kg/ha seeding rates, but there were no differences between row spacings. In
the third year there were no differences in seed yield between viable seeding rates and row
spacing. The cool, moist summer conditions had no adverse effect on seed development; seed weights (3.3 g/1000 seeds) were high for all
treatments each year.
Keywords: ‘Grasslands-Roa’ tall fescue, seed-yields, seed quality, seed rates, row spacings, lodging A simulation model was used to investigate the
effects of various combinations of stocking
rate, drafting weight and lambing season on a
hypothetical dryland farm in Canterbury. A
selection of physical results is presented and
financial impications of alternative
management strategies are briefly discussed.
Stocking rate and lambing time had
considerable effects on animal performance,
with minor effects from drafting weight. Gross
margins were considerably affected by stocking
rate; the highest return was obtained with
conventional lambing at 15 su per ha and
drafting lambs at 30 kg empty body weight.
Keywords model, management strategy, sheep
farm Effects of pasture feeding level during lactation
and over summer on ewe wool growth and
ovulation rate were assessed in 1983-84 and
1984-85. Two levels of pasture feeding
(lactation high and lactation low) from
parturition to weaning (10 weeks) produced 8 to
10 kg liveweight difference in ewe liveweight at
weaning. Groups (n = 40) were offered pasture
allowances of 0.8, 1, 1.4, 2 or 5 kg
DM/ewe/day from weaning until after the
third synchronzied oestrus in April. Ewes on
the lower allowances tended to reach a stable
liveweight and those on 5 kg DM/ewe/day
gained throughout. Other groups were offered
low allowances during summer and then 5 kg
DM/ewe/day after the first recorded oestrus.
Mean dates for synchronised oestrus were 2
March, 19 March and 5 April. Ovulation rate
increased by 0.15 corpora-lutea/ewe ovulating
at each successive oestrus, and increased by
0.047 corpora lutes/ewe ovulating for each kg
increase in liveweight at oestrus. These effects
accounted for 77% of the variation in ovulation
rate between treatments across years. The
effects of flushing, lactation or summer
liveweight change were small and generally
non-significant. Lactation feeding affected
wool growth during lactation as well and had
carryover effects through the summer when
lactation low ewes grew 10% less wool
irrespective of the level of summer feeding.
Keywords ewe, wool growth, ovulation rate,
lactation, summer feeding, liveweight, flushing Plant tissue analysis is useful to assay plant
nutrient status, but has limitations due to
changes in nutrient concentrations with
physiological age, and variation between plant
parts. The Diagnosis and Recommendation
Integrated System (DRIS) uses nutrient ratios
calculated from plant tissue analyses to
evaluate plant nutrient status. It calculates
indices for each nutrient, and ranks them in
order of their deficiency. An exploratory
assessment of DRIS has been conducted for
New Zealand high country pasture using
chemical analysis and yield data from field
trials. In this limited assessment, DRIS
consistently ranked S and P deficiencies in the
same order as indicated by yield responses to
fertiliser treatments. It was generally successful
in distinguishing between deficient and nondeficient
conditions. Results are considered to
justify a more comprehensive evaluation of
DRIS for New Zealand pastures.
Keywords DRIS, plant analysis, P deficiency, S
deficiency This paper reviews some of the current practical
and economic implications of Acremonium
endophytes of ryegrass and tall fescue in New
Zealand grassland agriculture. A historical
perspective of their discovery and possible
future implications of a new “novel”
endophyte strain are also covered.
Keywords Acremonium, endophyte, ryegrass,
Lolium, tall fescue, staggers, Argentine stem
weevil, clover, liveweight gains In a spaced plant trial, plants of 27 cultivars in
their second year of growth were undefoliated
from late winter through spring and their
growth rate determined relative to that of
‘Grasslands Huia’. Variation between cultivars
was large. Cultivars which had higher relative
growth rates than Huia during this period
included some small-leaved frost tolerant
germplasm, although all of these had lower
absolute growth scores than Huia. The second
study measured proportion of clover, leaf size
and stolon growing point densities of 27 white
clover cultivars and breeding lines grown in
mixed species grazed swards during late winter
and spring in two successive years. Once again,
variation between cultivars in spring
performance relative to Huia was large. It was
concluded that there is sufficient variation
available within white clover for improvements
in spring growth relative to Huia to be achieved
by breeding. Nematode Resistant Pitau
consistently had high growth rates relative to Huia in late winter and early spring,but this did
not carry through into late spring. Cultivars
and lines with better late winter growth than
Huia had higher stolon growing point densities
for their respective leaf sizes than poorer, later
winter growers.
Keywords evaluation, mixed swards, spaced
plants, later winter growth, stolon density Weed seeds are the major reason for white
clover (Trifolium repens) seedlots being
downgraded or rejected from certification. The
occurrence of weed species in 537 white clover
seedlots tested at the Official Seed Testing
Station, Palmerston North, was analysed. The
most commonly occurring species were field
madder (Sherardia arvensis), chickweed
(Stellaria media), fathen (Chenopodium
album), sheep’s sorrel (Rumex acetosella) and
scarlet pimpernel (Anagaflis arvensis). The
percentage occurrence of four specified
undesirable weeds including Californian thistle
(Cirsium arvense) and dodder (Cuscuta
epithymum) are reported, and the implications
of seed contamination are discussed.
Keywords: white clover, contamination, weed
seeds A study was done at Canterbury Agriculture and Science Centre, Lincoln, New Zealand, to equate volunteer white clover plant establishment with the decay of the soil seed burden over time. A 5 season break without
clover sowings, if coupled with either annual cultivation or herbicide removal of establishing volunteer plants, reduced contamination potential below that desired to meet certification requirements for first-generation
seed crops. ‘Buried-seed counts’ taken after the last deep cultivation for the change crop should
be in the O-3 seeds per 50 cores range for
breeders’ and basic crops and 4-6 per 50 cores
for first-generation crops. Sowings to produce
breeders’ and basic seed must be in 45-cm row
spacings to facilitate inter-row herbicide
elimination of volunteers. Ministry of
Agriculture and Fisheries Seed Testing Station data on 705 potential change crop sites over 5 seasons, indicated that for breeders basic and first generation, only 31% and 50% of paddocks respectively fell within these ranges, justifying the continued use of this measure as
an indicator of potential for success. For the
1989-90 season, 17% of the 182 first-year
autumn-sown cultivar-change certification
entries were withdrawn because of poor
establishment and/or weed problems, 3% for
wrong sowing methods obviating inspection
a n d 5 % w e r e r e j e c t e d b e c a u s e o f
contamination. Currently, the major limitation
to growing high yielding white clover change
crops, particularly of small-leaved cultivars, is
in making seed multipliers aware of available
technology.
Keywords: white clover, contamination, buried
seed, volunteer plants, certification Download
(611 KB)
Seasonal and fertiliser effects on microbial phosphorus and nitrogen
in soils under pasture
K.W. PERROTT and S.U. SARATHCHANDRAview more
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(607 KB)
Seed production of ‘Grasslands Roa’ tall fescue in Southland
M.J. HICKEYview more
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(382 KB)
Simulation of selected management strategies on
Canterbury sheep farms
J.D. FINLAYSON, O.J. CACHO and A.C. BYWATERview more
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(731 KB)
Spring and summer
and wool growth
pasture feeding and ewe reproduction
K.F. THOMPSON, J.R. SEDCOLE, D. O’CONNELL, K.G. GEENTY and A.R. SYKESview more
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(635 KB)
Testing the diagnosis and recommendation integrated system
(DRIS) on high country white clover-based pastures
M.B. JONES, A.G. SINCLAIR, M.J.S. FLOATE and C.C. BOSWELLview more
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(329 KB)
The impact of Acremonium endophytes in New Zealand, past,
present and future
L.R. FLETCHER, J.H. HOGLLJND and B.L. SUTHERLANDview more
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(1620 KB)
Variation in spring growth within white clover
J.R. CARADUSview more
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(639 KB)
Weed seed contamination in white clover seedlots
J.S. ROWARTH, A.A. JOHNSON, P.T.P. CLIFFORD, and M.P. ROLSTONview more
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(534 KB)
White clover soil seed loads: effect on requirements and
resultant success of cultivar-change crops
P.T.P. CLIFFORD, I.J. BAIRD, N. GRBAVAC and G.A. SPARKSview more
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(519 KB)
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