In Southland lambs are processed from November to May, resultmg in inefficient use of processing facilities and an inability to meet some market requirements for a continuous supply of product. However, spreading of lamb slaughter is hindered by the seasonal pattern of pasture growth and climatic conditions in Southland. Grasslands Diviston DSIR, Mervyn Dillon and Challenge Meats Ltd are now co-operating in a programme to overcome the pasture growth and cllmatlc constraints to extend the period of lamb slaughter in Southland. In the first part of the study silage alone or m various combmatlons wth gram was fed to lambs in wmter. Silage-fed lambs wth a high proportion of grain grew at the best and most consistent rates. Silage-fed lambs without grain supplements had inconsistent weight gams and a growth response so vanable that treatments ended early. Weight gains for grass-fed lambs were affected by preconditioning on to silage and reduction in the feed supply during wmter. However, pasture-fed lambs still produced the heaviest carcasses and greatest returns. Carcass grades had to be monitored closely to achieve maximum returns. Keywords: Southland, out-of-season lamb. lamb production. writer feeding
In a series of trials at Grasslands Gore, over 10 years, the late-flowering tetraploid red clover ‘Grassland Pawera’ was more productive and persistent than other red clover cultivars. The strong summer growth of Pawera meets the need for heavy-weight lamb feed and high quality forage for conservation in intensive sheep farming systems in Southland. Lenient. infrequent defoliation is necessary to maximise DM production and persistence of Pawera. The most compatible of the grasses evaluated was ‘Grasslands Roa’ tall fescue. However, ‘Grasslands Nui’ ryegrass will still be the major grass sown with Pawera owing to its widespread acceptance. In ryegrass mixtures, sowing rates of 5-7 kg/ha of red clover were needed to optimise establishment and subsequent yield. Evidence of oestrogenic activity of Pewera to sheep prompted Grasslands Division to select within Pawera for a low formononetin cultivar. Keywords: red clover, Pawera. Hamua, Turoa. G21. G22, G27. oestrogenic activity, Nui ryegrass, Roa tall fescue, Maru phalaris. Southland, sheep grazing, frequency, intensity, quality. seasonal growth
Between 1975 and 1982, 320 white clover lines from overseas and New Zealand were evaluated for agronomic potential in southern regions of New Zealand. Two distinct types showed promise. Persistent ecotypes with small leaves and many stolons had an active spring-summer growth pattern suited to the climate of OtagwSouthland Productive types (‘Grassland Huia’ selections, Mediterranean and French material) had larger leaves with fewer stolons, competed well with grass, were tolerant to leaf diseases but lacked persistence. In 1983, a hybridisation programme combined the desirable features of both persistent and productive types. The best Fl and F2 hybrid lines had a dense morphology, produced 20% greater sprinpsummer yields than the standard Huia and showed good leaf disease tolerance. In 1985, 58 superior plants were selected and polycrossed. The bulk seed from this isolation formed a new we-release cultivar called Southern selection. The selection is being compared with HUM in wards under rotational grazing at Gore. In the 1987/00 year, the selection produced 9% greater spring-summer and annual clover yields than Huia. Improved clover herbage yield was a consequence of rapid stolen development over spring. Grass and total herbage yields from the two clover-based pastures were similar. The trial will be continued in order to obtain long-term production data Keywords: white clover, ‘Grasslands Huia’. Southern selection, ryegrass, breeding, productivity, persistence
Applying 50 kg N/ha to dryland ryegrass-white clover pasture in autumn in each of four years resulted in an increased carrying capacity over the control for the last two years of 137 kg liveweight per ha at minimum in December, with an early spring peak of 211 kg extra liveweight per ha. Despite higher stocking rates on N-treated pastures in the later years. feed on offer at grazing was greater from early winter until the onset of severe drought, typically 8 months later. This improved level of feeding lifted ewe bodyweights post lambing by at least 4 kg. These higher ewe body weights were associated with significantly higher birth weights of twin lambs. Daily growth rates of these lambs. in a flock averagmg better than 175% lambing, were in excess of 260 g/head when ewe bodyweights were over 60 kg post lambing. Keywords: Nitrogen fertiliser, sheep grazing, lamb growth rates
SolIs and pastures were sampled at 96 sites in the Kaiwera district, an area having 12 soil types typical of eastern Southland and South Otago. Analyses indicated that ill-thrift in lambs could be due to low cobalt (Co) Intake. Upland (>300 m a.s.1.) topsoils had lower EDTA extractable Co than lowland topsoils and analysis of soil profile samples indicated that Co had been leached from upper horlzons of upland soils. Upland pastures contained much less Co than lowland pastures and Co concentration was much lower in February than in October. Sheep grazing on upland pasture had very low vitamin B 12 status from October to June and this coincided with low pasture Co concentration Sheep grazing on lowland pasture had adequate vitamin B l2, although pasture Co concentration fell to below 0.06 mg/kg for a short period in summer. We conclude that sheep grazed on upland pastures for long periods need supplementary Co or vitamin B 12 or need to be rotattonally grazed on lowland pasture to build up adequate reserves of vitamin 8, 2 Keywords: ill-thrift. sheep, vitamin B,2, pasture cobalt, seasonal variation
Crown rust infection of 11 perennial ryegrass cultivars vaned significantly and consistently over 6 sites. ‘Grasslands Ariki,’ the new cultivar ‘Yatsyn’ and Grasslands selections G26 and G33 were less infected than ‘Grasslands Nui’, ‘Ellett’ or ‘Grasslands Ruanui’. ‘Droughtmaster’ and ‘Marathon’ proved more susceptible than most. Keywords: Crown rust, Puccinia coronata. perenmal ryegrass
Two Dorycnium species. 0. hirsutum and 0. pentaphyltum. have been under trial since the mid-1970s. They show most promise on North Island yellow-brown sands and the drier browngrey/ yellow-gray earth soils of the South island. Both species, native to the Mediterranean region. are perennial with deep taoroots. They are adapted best to drought-prone. free draining, weakly acid to alkaline soil types; heavy, wet soils are not tolerated. Severe winter frosting has little effect on Dorycnium. Major advantages of Dorycnium are the ability of plants to establish and grow in low fertility soils and the provision of an evergreen winter plant cover. Establishment has been successful both by oversowing and direct seedmg on to diverse sites including depleted grassland and newly formed road batters. More extensive farm trials are planned for Dorycnium because of its ability to provide stock and bee forage under cold, dry, low soil fertility conditions. Keywords: Dorycnium, leguminosae, pastur rejuvenation, soil conservation, semi-arid revegetation. nitrogen fixation. forage, browse, Hunter strip seeder
Two trials in the Nelson province with 6 alternative phosphate(P) fertilisers and 4 sulphur (S) fertilisers measured initial and residual responses ovar 3 seasons and used the results to determine appropriate topdressing frequencies, from which economic implications could be determined. P and S treatments were applied at 50 kg total element/ha for all alternatives in a randomised block design with 4 replicate.s Appropriate basal fertillsers were applied, and plots were mown at intervals for 2% years. Superphosphate was an effective P fertiliser at both sites, but at the lower rainfall yellow brown earth site at Dovedale the intermediate solubility P fertiliser Longlife Super and Phospate PARPR and the low solubility P fertilisers Sechura and North Carolina RPR caught up with Superphosphate by years 2 and 3. At the high rainfall Collingwood site on a pakihi soil Superphosphate and Longlife super responded significantly in year 1 only while there were no significant responses to the other 4 P fertilisers at any stage. Gypsum S was an effective source of S at both sites, but tended to be exceeded by elemental S forms at Collingwood. There were however, no significant differences between the four S ferfilisers at either site. The economic analysis of all products, assuming a PS requirement of 1 : l and appropriate spreading frequencies, shows Superphosphate to be the most cost effective at the time of analysis. Keywords: yellow-brown earth, pakihi. cost effectiveness, phosphorus, sulphur, fertilisers, economics
Two sheep grazing trials, at Awarua, Southland. and at Wairakei, central North Island, on selenium (&)-deficient and Se-retentive soils under a rainfall of about 1000 mm were used to test the duration of effectiveness of a mixture of standard and controlled-release Selcote Se granules applied at 0.5 kg/ha each. Selenium concentrations in blood of ewes and lambs were maintained above deficiency levels for 2 years in both trials. Peak values were observed or inferred from both rapid-release and slow-release granules. The pattern of pasture Se was consistent with blood Se values where sampling was sufficiently intensive to allow for the low rate of granule application. Keywords: Pasture, ewes, lambs, yellow-brown pumice soils, lowland yellow-brown earths, Selcote.
Ryegrass seed lines with (+E) and without (-E) the fungal endophyte Acremonium lolii were sown with white clover. Fewer clover seedlings survived under +E ryegrasses irrespective of whether the plots were mown or grazed. The dominant contrast was an inverse competitive relationship between grass yield and clover seedling survival. A further component unexplained by effects of defoliation or competition is interpreted as an allelopathic effect. Two pot trials, using wheat, were established to determine it there was any residual effect of +E wards on following crops. Wheat grown in soil with a history of +E or-E ryegrass with clover produced higher yields from the-E than the +E soil. However, wheat grown on soil from previously clover-free pastures showed no difference between +E and -E. Residual effects on wheat crops are therefore interpreted as being related to lower nitrogen fertility, as a result of reduced clover growth in +E pastures. Keywords: Ryegrass, endophyte, white clover. competition, vigour. allelopathy, soil nitrogen, wheat yield, Acremonium lolii
Two lotus and 4 clover cultivars were oversown at 3 tussock sites ranging in altitude from 460 to 1040 m. The sites were initially similar in soil chemical characteristics, aspect and topography, so that differences were attributable mainly to increasing severity of climate. The objectives were to determine the extent to which legume choice is affected by(a) lime to raise so11 pH, and(b) increasing seventy of climate. In the first year’Grasslands Pawera’ red clover wards were outstanding at the lower sites. With time the superiority of Pawera was overtaken by ‘Grasslands Maku’ and Maitland lotus. Maku swards were outstanding in the absence of lime (UP to 5.5 t DM/ha at 460 m. and up to 2 t DM/ha at 760 m) in years 2-3-4, and Maitland lotus swards produced up to 5 t DM/ha with lime at the lowest site, but did not perform well without lime. At the highest site. lotus-based pasture did not perform consistently as well as the white clover wards. At all sites lime greatly mcreased both the legume content of the swards and total pasture production for at least 4 years. Generally Maitland lotus gave the greatest and Maku lotus the least responses to lime. Keywords: lotus, clover, Maku, Maltland. Huia, Tahora. Pawera. Tetra, lime, altitude, tussock grasslands, legumes
The effects on pasture production of 4 liquid fertilisers, Maxicrop, N-Fix, Response and Plant Plasma and two proprietary solid fertilisers Naturmix and Wright’s Mix were examined in a series of 3 trials over a *-year period near the Ruakura Agriculture Centre. None of the liquid materials significantly affected total pasture production over the trial periods This is consistent with international summaries of trials with seaweed and fish extracts which concluded that such materials have no consistent effect of practical benefit on pasture and crop production. Plant Plasma applied at 10 times the recommended rate, boosted pasture production in the first harvest after each application, as did Plant Plasma at the normal rate after one of the applications. The proprietary fertilisers performed as could be predicted from their nutrient contents. In a grazing trial near Te Kuiti. Response Extra* had no significant effects on any of 8 measures of animal performance, or on pasture production in that trial or in an associated small-plot trial. None of the liquid or proprietary solid fertilisers applied at recommended rates, had consistent effects on pasture botanical and chemical composition or soil test levels. Keywords: seaweed extracts fish extracts, low analysis fertilisers, pasture production, animal production
Ryegrasses have dominated seed mixtures since the inception of pastoral farming in New Zealand largely because perennial ryegrasses are easily established, and persistent under a wide range of climatic and management conditions. Annual ryegrasses have vigorous seedling growth and can provide valuable high quality feed during the cool seasons. These virtues make ryegrass easily thk most important grass in New Zealand agriculture. This review traces the history of ryegrass use and development form the early days of bush burn mixtures to the present day array of bred cultivars Areas of research covered in the review include: (1) The selection and breeding of cultivars (2) Management effects on density and persistence (3) Physiology (responses to light, temperature and mineral nutrition) (4) Ryegrass diseases (5) Ryegrass pests (6) The ryegrass endophyte (7) Ryegrass herbage quality The concluding section examines the role ryegrasses are to play in diverse modern agricultural systems, and hence the goals for breeders.
The importance of white clover in New Zealand pastoral agriculture cannot be overstated. It is the major source of nitrogen and by its presence improves pasture quality and balances seasonal growth of grass species. Because of its importance a considerable effort has been put into research on white clover over the past 50 years in New Zealand. This assay reviews the major advances made in white clover use and research from an historical perspective and summarises current understanding and possible future developments. Keywords: white clover, review, history, soil fertility, N cycling, N fixation, nutrition. growth, population structure, management, performance, breeding, pests and diseases, quality.
A series of trials in Taupo, Wairarapa, and Southland showed that ‘Grasslands Maru’ phalaris (Phalaris aquatica L.) was well suited to dry hill country. It yielded as well as or better than ‘Grasslands Nui’ ryegrass and resident swards on an annual basis, being particularly productive in winter, spring and summer. Its spread by rhizomes ensured good swards which remained productive even under set-stocking. Maru suppressed grass grub numbers and continued to produce well under grass grub attack. Responses to fertiliser were good, but withholding fertiliser did not suppress Maru to any greater extent than other pasture grasses. These trials have shown that the seasonal and annual yields of Maru can add flexibility and improved production to hill country farming. Keywords: ‘Grasslands Maru phalaris. seasonal production, grass grub, fertiliser, persistence, shelter, hill country
By 1938 a small herbage seed industry was well established in New Zealand after the introduction of a system of seed certification and the establishment of a Government plant breeding station. Production increased rapidly during the 194Os, to level off and fluctuate around 22,000 tonnes annually. Perennial ryegrass and white clover now dominate production. and research on these 2 species is presented to illustrate advances in research and practices of seed production. In ryegrass over the last 50 years we have gained an understanding of the physiology of flowering. and the use of herbicides, fungicides, nitrogen fertiliser, plant growth regulators, and post harvest drying systems are widespread. In white clover, growth and the detrimental influence of high soil fertility and/or soil moisture are now understood. Pollination and insect pest control, grass removal, and causes of harvesting losses have been studied and incorporated into seed production. Keywords: herbage seed, perennial ryegrass. white clover
The integration of dairy beef with daitying in the southern South Island is a successful means of increasing stocking rates to maximise pasture utilisation when an increase in dairy cow numbers is not practical or economic. However the 1987-88 gross margins illustrate the vagaries of the beef market and the significant effect the schedule can have on the viability of integrating dairy beef even though there was considerable optimism at the start of the dairy season. In previous years the gross margin for bull beef, when the schedule has been about $2.OO/kg was closer to $lOOO/ha During the past season the nursecow option looks the most favourable in economic terms, allows for more management flexibility than bull beef and achieves the aim of maximising pasture utilisation. Keywords: dairy beef, dairying, bull beef
My wife and I have been actively farming in the Menzies Ferry District for 12 years. The property is 211 ha in total, with the dairy unit comprising 85 ha. A married couple are also employed on the farm. My property backs on to the Mataura River. Ninety-nine percent of the property floods in a loo-year flood - there have been three such floods in the last 10 years.
Recent assessments of the relative importance of stocking rate. stocking policy and grazing management on the output from pastoral systems are used as a starting point to argue the need for objective pasture assessments to aid control of livestock enterprises to meet production targets. Variations in stocking rates, stocking policy and other management practices all provide alternative means of control of pasture conditions which are the major determinants of pasture and animal performance. Understanding of the influence of pasture conditions on systems performance should provide a better basis for management control and for Communication between farmers, extension officers and researchers. Keywords: Stocking rate, pasture condition, pasture cover
A spreadsheet teed budgeting model and gross margin analysis were used to plan an outof- season lambing system for a Manawatu sheep farm. Of the systems investigated, a 30% winter lambing option was predicted to be the optimum for pattern of pasture cover and returns. Poor sheep pariormanoe in the first season of winter lambing (1988) reduced winter stocking rate by 20% and spread lambing dates to reduce peak spring teed demand for the second season. Total income in 1987 was estimated to be $8284 lower than it the traditional lambing policy had been maintained, mainly because higher returns for early-season lambs were insufficient to compensate for production losses resulting from reductions in sheep numbers wintered. The transition to winter lambing required major changes to winter grazing management, increased expenditure on animal health and meant that two tooths entering the early lambing flock had to be grown taster. Regular monitoring of pastures and animal performance was an important component in developing the new farming system. Keywords: spreadsheet modelling. teed budgeting. transition management, out-of-season lambing.
The New Zealand Grassland Association (NZGA) was formed in 1931 and since then has held 50 annual conferences and provided a forum for the discussion of agricultural problems and the latest research findings A membership of almost 1500 makes it one of the largest organisations of its kind in the world and the annual proceedings is distributed to members in over 40 countries. This paper reviews the history of the NZGA its achievements, goals and possible future directions. Keywords: New Zealand, communication, grassland farming
An on-farm investigative development approach is advocated and described as a relevant method to improve industry awareness and understanding of alternative pasture species and cultivars for South Island hill and high country pastoral systems and thereby improve their currently slow or sporadic rate of adoption. On-farm investigative development trials aim at effectively bridging gaps between plant breeder, agronomist, consultant and farmer. They closely integrate research objectives and extension through the establishment of large-scale experiments with pasture plants and pasture systems on farms, in close co-operation with key farmers. They are of sound experimental design and yet large enough to be defined as a production system, contributing significantly to the livestock feeding goals of the ccroperating farmer. Such trials are an integral part of the cc-operative (DSIR/MAF) Lotus corniculatus breeding programme. Three of them, each located in ,a different environmental/geographic zone, are described. Keywords: Large-scale trials, alternative pasture species, Lotus corniculatus, plant breeding/ plant selection, South Island hill and high country.
Out-of-season lambing The optimum time This depends on feed supply. Considerable planning and feed supply management are required. Because pasture is the cheapest source, northern regions are likely to be more suited to out-of-season lambing. Livestock problems would need consideration, including getting ewes to cycle by drug use or by natural means. Climate and weather changes were seen as being a physical constraint with regular extremes of drought, flood and cold spells, and the long term possibility of the greenhouse effect upsetting climate patterns. The market was seen as being the major constraint, and the current state of the market makes it financially unattractive for farmers to take on additional risks and costs.
The origin of the horticultural strain of Lupinus polyphyllus is outlined and New Zealand investigations showing its potential as a pasture legume suited to moister, low fertility high country both in revegetation and as grazing are briefly reviewed. Provisional management guidelines on site selection, establishment, management, animal use and seed production are given. Keywords: high country, Lupinus polyphyllus, soil fertility, Russell lupin
The performance of 55 Lotus pedunculatus Cav. and 33 Trifolium repens L lines of diverse type and origin was assessed on acid, infertile soils on the East Otago Plateau at 3 sites representing an altitudinal sequence of increasing severity of climate. Among the L pedunculatus lines, a diploid NZ selection 04701 showed the best combination of attributes with high herbage yields, moderate rhizome spread at the highest sites and considerable tolerance to out-of-season frosting. G4701, its tetraploid equivalent G4702 and a selection from within the cultivar ‘Grasslands Maku’ for rapid germination at low temperatures, produced the highest yields averaged over the 3 sites in the altiludinal sequence. The use of these lines is likely to enhance the role of lotus in tussock grassland pasture systems. Within white clover, a hybrid line C5413. which has been.included in the pre-release Southern white clover cultivar G26. performed well, indicating that it has wide adaptability for both fertile lowland and low-fertility hill and high country situations on the southern South Island. The Southland Selection C5844, which is derived from Southland ecotypes, had the best combination of attributes for the East Otago Plateau. This selection merits serious consideration for release as a ‘Tahora-like’ cultivar for moist, infertile hill and high country in the southern South Island. Keywords: Trifolium repens, Lotus pedunculatus. evaluation, herbage yield, spread, dominance, frost damage, South Island.
To optimise production at reduced input costs, retain flexibility and continue farming profitably has never been more difficult for farmers, or more important. Retaining the motivation to consistently achieve and the importance of decision making under pressure are two vitally important factors to continued profitability. With a succession of climatic adversities hitting the nation over recent years, it has become increasingly obvious that for many to survive, a major change in attitude is needed. With cash-flow being unpredictable and lumpy, no protective devices previously enjoyed and no cash reserves to fall back on, there is little room for complacency. The last major drought in the Hawke’s Bay region highlighted the need for farmers to become aware of the value of decision making. This paper uses drought as the medium to convey the importance of planning and decision making on performance, production and income, as it is a common adversity to which most in the industry can relate. This paper demonstrates the crucial part decision making plays in mitigating the worst effects of drought to ensure a speedy return of normal stock carrying and continuity of income. Keywords: drought, decision making, planning
Hill pasture renovation methods have been restricted in the past to surface oversowing of unaltered, trampled or burnt pastures. Unfortunately the old pasture recovers and may compete vigorously with the establishing new species, slowing pasture improvement. The availability of suitable herbicides has opened up a new opportunity for hill pasture development. Herbicide applied before oversowing can minimise the competition and allow the new species to establish more easily. The benefits include reduced time to attain optimal stocking rates and improved establishment control, but these are offset by higher initial costs. The technical aspects of the herbicide establishment methods are overshadowed by the economic factors which control the profitability of the programme, however successfully applied. As the cash flow patterns differ between the tradrtional renovation and the herbicrdebased techniques, changes in interest rates and prices have differential effects. Real interest rates below 7% make both methods profitable but are more favourable to the herbicide technique at 1987 prices, Also, price increases favour the herbicide method. Among other issues affecting the speed and profitability of development and ultimate gain, management skull is found to be crucial and dominates both establishment methods. Keywords: hill pastures, renovation, herbicides, interest rates, management skill, profitability
A range of short-term ryegrasses. including the Grasslands cultivars Moata, Paroa. Tama and Manawa, and Progrow and Corvette, were evaluated at 4 sites in Northland, Waikato and Bay of Plenty. At three of the sites comparisons were also made with Ellett or’Grasslands Nui perennial ryegrasses. Tama and Progrow had strong winter growth but later were relatively poor. Moata and Paroa had stronger spring growth than Tama or Progrow. The persistence beyond one year of Moata and Paroa in grazed pastures was poor. Corvette, an Italian ryegrass ecotype from near Tauranga, had consistently higher yields than Manawa, Moata or Paroa This sometimes increased total pasture yields. Corvette also had ability to persist at least 4 years after sowing. None of the short-term ryegrasses gave summer or autumn productivity as high as Nui or Ellett ryegrasses. A mixture of Ellett and Corvette showed seasonal growth characteristics of both cultivars, implying a production advantage over either sown alone. This paper advocates re-evaluating the role of short-term ryegrasses in the Auckland Province, consequent on the apparent ability of Corvette to co-exist with perennial ryegrasses. Keywords: Italian ryegrass. Moata, Paroa, Te Puna. Corvette, Tama, Progrow, Manawa, Nui, Ellett, persistence
Trials under sheep and dairy cow grazing in mid Canterbury examined the effectiveness of mcludmg new white clover cultivars with ryegrass in a non-arable (spray, top-cultivate and drill) pasture renewal. Five weeks after sowing, 13% of white clover plants had originated from regrowing stolons in the sheep pasture; in dairy pasture the figure was over 50%. Initially including a white clover cultivar increased total dry matter yield. However after 3 years there was no difference in total dry matter yield from plots sown with ryegrass but no clover. ‘Grasslands Kopu’ white clover outproduced ‘Grasslands Huia’ by only 4% and 1% in dairy and sheep pastures respectively and had a slightly greater white clover content. Control plots initially had a lower clover percentage than the sown cultivars. but by the third year it tended to be greater. The greater average length of leaflets in Kopu plots indicated that the cultivar was present throughout both trials. It is suggested that the inclusion of white clover in non-arable pasture renewal wll give economic returns only if seed costs are low. Keywords: ‘Grasslands Kopu’. ‘Grasslands Huia’, white clover, pasture renewal, irrigation
The perlormance of ‘Grasslands Matua’ prairie grass was compared under lax and hard grazing by sheep. Pasture utilisation and tiller densities were measured to determme If l”cremng utllsatlon would result I” sward decline Lax grazmg permitted ward persistence but resulted m only 56% pasture utilisatlon Hard grazmg at 75% pasture ut!llsatlon resulted m less total herbage harvested, owng primarily to ward decline. Nevertheless, it was shown that hard grazing can improve pasture utilisation without affecting sward persistence of grazing 1s delayed until new replacement tillers have appeared This allows significantly greater pasture utll1satlon than lax grazing and maintains prawe grass tiller density, Keywords: Bromus willdenoii Kunth. grazing intensity, pasture persistence, tiller appearance. Matua pra,w grass
A novel, simple technique for screening plants using simulated hill soil protiles is described. Three large bins were constructed and a soil profile built up in each using layers of hill subsoil and topsoil compacted to field bulk density. 2100 ryegrass plants were transplanted at 5 cm spacing in each ot the three bins. This technique has enabled controlled manipulation of soil fertility, development of simulated pure ward conditions and identification of individual plants. It has been used successfully to screen the hill ryegrass collection held at Whatawhata Research Centre for response to nitrogen and drought. Keywords: hill soils, ryegrass. nitrogen, drought, plant screening, soil profiles
Species dominance and sheep grazing days relative to fertiliser costs are given for the first 6 years of 2 trials at Lake Tekapo. Both were sown in a multiple species mixture. Trial I examined 27 different annual P and S levels; Trial II examined 30 combinations of 5 superphosphate levels, 3 sheep grazing intensities and 2 stocking methods. Pastures were mostly legume dominant, and species differences were related to P fertiliser and stocking method. Perennial (Russell) lupin (Lupinus poflyphyllus) dominated at all low to medium fertiliser rates, alsike clover (Trifolium hybridum) at intermediate rates, and cocksfoot (Dactylis glomerata) and white clover (T repens) at high ferttliser rates. The stocking rate achieved was related to both S and P rates. Greatest fertiliser efficiency (returns v. costs) was at low annual rates of 4-5 kg P plus 16-25 kg S/ha. Keywords: lupin, cost-benefit, cocksfoot, alsike clover, phosphate, sulphur, sheep grazing management, fertiltser efficiency.
In a pot trial to investigate stolen formation in perennial ryegrass (Lolium perenne L.). 4 genotypes of ryegrass tested all formed stolons. After burial with approximately 30 mm soil in August, cutting and burial, or cutting alone, stolen numbers in November were 18.8 and 3 (SED 3) per plant, respectively. In a grazed ryegrass sward stolen lengths were measured at intervals between May 1987 and April 1988, and for hard and lax grazed plots respectively, were 58 and 96 m/m2 in May, increased to 137 and 164 m/m2 in December, then declined to 47 and 74 ml m2 in April 1998. Active stolon formation in the field began when tillers were buried by earthworm activity and stock trampling in winter. It appears that stolen formation in ryegrass is a response to a seasonal cycle of burial similar to that for white clover. Studies of tagged tillers indicated a pattern of sward renewal in early summer by rapid production of large numbers of tillers from stolons at the base of dying flowering tillers. Other research results suggest that this pattern of sward renewal in perennial ryegrass may be widespread. Implications for grazing management are briefly discussed. Keywords: tiller appearnace rate, perennation, carbohydrate, perennial ryegrass, stolen formation
The germination rate of ‘Grasslands Maku’ lotus (Lotus pedunculatus Cav. syn L uliginosus) was assessed at constant temperatures of 20°C, 15°C, 10°C and a fluctuating temperature of 5/10°C (16 h/8 h per day). Germmation rate declined with temperature. Maximum germmation level was reached by 2 weeks at 20°C and 15°C. but at 10°C only 30% of seeds, and at 5/1O”C only 1% had germinated by this stage. Large seeds of Maku germinated faster than small seeds. Seedlot thousand seed weights of Maku lotus parent plants varied from 0.78 to 0.96 g and germmation rates of these lots at 5/10°C were associated wth seed size. Maku and 4 other lotus selections had much lower germination rates than two Lotus corniculatus cultivars and an interspecific hybrid selection G.4712. G.4702 (another tetraploid) germinated more rapidly than other lotus selections and Maku. These results indicate the need for production of quality Maku lotus seed, especially in terms of seed size, and for selection to improve germination rate. Keywords: Maku lotus, germination, temperature
The role of cobalt (Co) and vitamin B 12 in animal nutrition is well understood, but the practical questions of predicting when and where a defnency is likely, and the most effective preventive strategy, remain unanswered in Southland and Otago. The incidence of Co deficiency in the region has recently increased, particularly where the problem had not previously been recognised In a long term maintenance Co topdressing experiment at Woodlands Research Station, pasture Co concentrations have been monitored since 1982 and lamb growth measured in two seasons. Cobalt deficiency has been observed only in the two driest seasons. It is postulated that soil manganese may influence the seasonal availability of Co to pasture plants. The effect of Co topdressing on pasture Co levels in the season of application was very short lived. Rate of cobalt sulphate application affected peak pasture concentration but had little effect on the duration of the pasture response. Lambs grazing treated plots did not gain a substantial reserve of vitamin 8, 2 Timing of Co application in relation to the likely period of deficiency is very Important. Keywords: pasture mineral content, lamb growth rate, vitamin B, 2, cobalt
Recent dairy farm survey data suggest the sodium (Na) concentration in pastuies could be too low to maintain stock health on a number of farms. Trials have been established on three major soil groups in the Waikato to study: (a) the rates of NaCl rauired to raise Na concentrations in pasture; (b) the time required to do this; (c) the duration of the response; and (d) the effect of KCi on Na uptake. Na uptake in pasture was rapid initially, reaching a peak some 6 weeks after application. Thereafter the Na concentration in pasture declined gradually but after 30 weeks was still some 2 to 3 times the initial Na concentration. Soil Na levels followed a similar trend. Conclusions to date suggest an annual topdressing of NaCl at 100 kg/ha wll provide an adequate Na concentration in the pasture for animal health and production on a range of Walkato soils. In practice salt can be applied alone or mixed with other fertilisers. Where potassium is already high some replacement of NaCl for KCI in the fertiliser mixture can be considered. Regular monitormg by pasture analysts is recommended. Although salt applications will increase the Na content in the pasture, animal responses to Na supplementation have yet to be conclusively demonstrated. Research is planned with dairy cows in the Waikato to investigate this important aspect. Keywords: Salt, sodium chloride, pasture sodium, ryegrass, white clover pastures, topdressing, dairy cows
The analysis of mixed pasture species has proven to be a useful guide to plant and animal nutrition. Fourteen or more elements can be analysed in plants and the results used to correct any potential problem. In Southland low Ca MQ. Co and Se are the main problems in animal nutrition, with low Sand MO the main deficiencies in plant nutrition. Most elements in pasture vary with soil temperature in a predictable way and this effect can be used to alert farmers of potential problems with animal nutrition, Keywords: trace elements, pasture analysis, fertiliser requirements
Over the past 25 years farmers in South Otago have raised the carrying capacity of native undeveloped tussock land from 0.6 su/ha to 15 su/ha through techniques of cultivation and oversowing. The success has been achieved by a whole range of mterrelated operations, which have evolved from cultivating ploughable undeveloped tussock land and sowing into pastures with white clover/fyegrass cultivars. and oversowing the rougher undeveloped hills with similar Pasture species. Soils of the region lacked molybdenum and phosphate, and topdressing with molybdlc superphosphate greatly increased white clover yields. In the 1950s animal production was based on breeding and selling store stock, but today the emphasis is on retaining stock and fattening for export The results of development over the last two to three decades have put the farmers in a good position to meet the future, especially the economic problems facing the industry. Keywords: molybdenum, oversowing. grarmg management, productivity, cultivars, tussock hill country
To ascertain the maximum production of grass/clover pastures over a range of altitudes on OtagO hill country, and the increase obtainable by applying nitrogen (N). 4 trials were set up at intervals from 730 m to 1190 m altitude, on yellow-brown earth soils of the Dunstan set on Loch Linhe station overlooking Lake Wakatlpu. The trials were oversown with a grass/clover mixture. The effects of fertilizing with adequate phosphate(P) and sulphur (S), with and without lime. and with and without N. was investigated. Yields were compared with those at other sites in Otago at similar altitudes Responses to P and S only were noted in year 1 and no altitude-related trend was evident Production in years 2 and 3 however showed a clear altitude-related trend. Without N maximum production ranged from 6390 kg/ha at 730 m to 1690 kg/ha at 1190 m. Yields with N were 8130 kg/ha at 730 m and 4150 kg/ha at 1190 m, i.e N increased yields by 27% to 146%; the greatest percentage increase was at highest altitude. Maximum production decreased by about 865 kg/ha per 100 m of altitude increase Lime depressed yields at the lower altitude sites and raised yields at the higher altitude sites, but only at the most acid site (topsoil pH 4.9) with N was the yield difference due to lime statistically significant. Yields of clover/grass pastures obtainable with adequate P and S fertiliser without added lime, are greater than at sites of comparable attitude in east and north Otago. Soil temperature measurements indicate that higher temperatures are the likely cause of the higher production Areas of favourable climate and soils, such as the one studied, will probably give the greatest return on investment in fertitiser. Climatic maps of hill country are needed to help predict production potential. Keywords: hill country, Otago, fertiliser, pasture yields, yellow-brown earths
Four white clover cultivars ‘Grasslands tluia’, ‘Grasslands Tahora’, ‘Grasslands Kopu’ and ‘Grasslands Pit& were evaluated at Grasslands Division, Gore, for 4 years, under 2 grazing managements. Year round rotational grazing was compared with rotational grazing incorporating a 1 P-week period of set stocking during spring. Huia was the best cultivar under both grazing managements. Tahora yields were comparable with those of Huia in spring and summer, and ryegrass yields were best in Tahora wards. The larger leaved and less stoloniferous Kopu and Pitau were not suited to the climatic conditions or the mtensive sheep grazing practices of the region. Keywords: Trifolium repens, Huia, Tahora, Pitau. KOPU, grazing management, stolon morphology, persistence, sheepfarming
Three separate experiments evaluating ‘Grasslands Moata’ (Lolium multiflorum Lam.) during autumn and winter in Southland are discussed. In two, establishment, productivity and persistence of Moata was compared with ‘Grasslands Nui’ perennial ryegrass (Lolium perenne L.). ‘Grasslands Manawa’ short rotation ryegrass (L perenne x L. multiflorum) and ‘Grasslands Paroa’ (L. multiflorum Lam.) and ‘Concord’ Italian ryegrasses. The third experiment compared ram lamb performance on Moata and Nui. Moata and Concord established rapidly, both producing 30% greater autumn/winter growth in the first year than Paroa and Manawa. However in the second autumn/winter Moata outyielded the other cultivars by 14%. Moata also outyielded Nui perennial ryegrass during autumn/winter by an average of 10% over two years. Lambs grazing Moata during winter had higher liveweight gains than those on Nui (223 ct. 139 g/head/day), a result of higher feed intakes of Moata compared with Nui (2.01 ct. 1.65 kg/ head/day). The differences in feed intake were related to the in vitro digestibility of the two ryegrasses (79% for Moata cf 69% for Nui) and the crude protein levels of the herbage (22.6% for Moata cf 19.3% for Nui). Keywords: Italian ryegrass. pasture quality, cool-season growth, animal performance, Acremonium endophyte