Journal of New Zealand Grasslands 2019-01-06T23:11:47+13:00 Dr Ruth Falshaw Open Journal Systems <p>ISSN:&nbsp;2463-2880 (online); 2463-2872 (print)</p> <p>The <em>Journal of New Zealand Grasslands</em> publishes peer-reviewed research papers and invited reviews with a focus on temperate grassland research. The scope of the journal includes all aspects of pastoral research&nbsp;including agronomy, soils, animals, agricultural extension and farm-systems research.</p> <p>Practical papers&nbsp;based on farming practices may also be included, if relevant.</p> <p>The Journal is published by the New Zealand Grassland Association (NZGA). The aim of the NZGA is <em>“to enhance pastoral agriculture”</em> by providing a forum for communication of science, technology and knowledge. Formed in 1931, the NZGA facilitates discussion on grassland farming, and promotes the value of research and its application. Our membership includes a wide range of scientists, consultants, agribusiness and farmers – making it truly <strong><em>“fuelled by science and tempered by experience.”</em></strong></p> <p>The Journal has been published since 1932 (prior to 2015 as the <em>Proceedings of the NZ Grassland Association</em>) so provides a long-term resource reflecting agricultural research and innovation.&nbsp;All past papers are freely available from the <a href="">NZGA</a> website.</p> <p><em><strong>Open access:</strong></em> All articles published by the&nbsp;<em>Journal of New Zealand Grasslands</em>&nbsp;are freely and permanently accessible online immediately upon publication.</p> NZGA President's Address 2017 2018-12-13T20:46:25+13:00 David R Stevens <p>&nbsp;&nbsp;</p> 2018-11-21T23:43:23+13:00 ##submission.copyrightStatement## Levy Oration – 2017 2018-12-13T20:45:49+13:00 Stephen L Goldson <p>&nbsp;&nbsp;</p> 2018-11-21T23:50:31+13:00 ##submission.copyrightStatement## Balancing the extremes – a brief history of the Pukaki area 2018-11-22T00:04:48+13:00 Simon J Cameron <p>&nbsp;&nbsp;</p> 2018-11-22T00:04:48+13:00 ##submission.copyrightStatement## Merino sheep of the South Island high-country: past, present and future 2018-11-22T12:36:33+13:00 William H Sutherland 2018-11-22T12:36:33+13:00 ##submission.copyrightStatement## Farming in a challenging physical and social environment 2018-11-22T12:45:45+13:00 Randall J Aspinall 2018-11-22T12:45:45+13:00 ##submission.copyrightStatement## Natural history features of the high-country and drylands of the South Island, New Zealand 2018-11-26T15:29:21+13:00 William G Lee <p>The high-country and dryland zone of the South&nbsp;Island of New Zealand includes the Southern Alps<br>and eastern mountains and basins. Formed by post-Pliocene tectonic, glacial and alluvial processes, these<br>areas contain a range of landforms across extreme climatic gradients. Diverse habitats support plants<br>and animals which have a distinctive and long natural&nbsp;history. New Zealand’s short (c. 700 years) history<br>of human land use has been highly disruptive for&nbsp;indigenous biodiversity. We have misunderstood the<br>eco-evolutionary vulnerabilities of the native biota,&nbsp;the extent of environmental limits, and the impacts of<br>introduced weeds and pests. Recent large-scale capture&nbsp;of water and addition of nutrients for agriculture are<br>excluding indigenous biodiversity in many ecosystems.&nbsp;Predicted climate change and competition for water<br>resources will exacerbate agricultural impacts, but the&nbsp;remaining indigenous biodiversity can be resilient if<br>representative areas are protected.</p> 2018-11-22T15:32:30+13:00 ##submission.copyrightStatement## The story of Tara Hills high-country research 2018-11-23T00:17:04+13:00 Bruce E Allan Hazel M Chapman J M Keoghan <p>The 3340 ha Tara Hills high-country station near&nbsp;Omarama was a Government owned research facility<br>between 1948 and 2005. Here we present the story of&nbsp;the rise and fall of Tara Hills; turned from a depleted<br>wasteland into the vibrant research centre of the 1980s,&nbsp;it was eventually sold to commercial interests in the<br>early 2000s. By the early 1980s, Tara Hills had 14&nbsp;permanent staff and was internationally recognised as a<br>model for dryland farm development, experimentation&nbsp;and demonstration. However, subsequent changes in<br>emphasis for New Zealand farming resulted in a decline&nbsp;in dryland research and to the inevitable sale of this<br>high-country station. We summarise the broad range of&nbsp;research and its outcomes associated with Tara Hills,<br>spanning soils, pasture species, their establishment&nbsp;and production, irrigation, grazing management,<br>animal breeds, animal production and genetics, and&nbsp;farm systems. The changing face of New Zealand’s<br>agricultural research and extension is an integral part&nbsp;of this story.</p> 2018-11-23T00:17:04+13:00 ##submission.copyrightStatement## Ecology and consequences of invasion by non-native (wilding) conifers in New Zealand 2018-11-27T12:09:39+13:00 Duane A Peltzer <p>Invasion by non-native woody species into largely treeless vegetation such as grasslands and shrublands is widespread, and has prompted both research and management in response. Here I review the current situation of invasions by non-native Pinaceae, better known as ‘wilding conifers’ in New Zealand, and how both research and management are working to better understand and manage these invaders. The success of wildings is explained by a combination of history (e.g., deforestation of previously woody vegetation), biological traits of the species (rapid growth and early reproduction), and propagule pressure (introduction effort). Wildings represent a major land use change affecting about 2 million ha, including many grasslands, rare ecosystems and subalpine habitats. Wilding invasions into grasslands have profound impacts on biological diversity, but also have important ecosystem impacts including legacy effects belowground by altering nutrient cycling and soil biota. Recent expanded efforts are underway to control and co-ordinate management to avoid or mitigate the negative impacts of wilding conifers. The long-term value of managing invasions, and whether additional management interventions are needed to restore grasslands or woody vegetation is in progress, but is urgently needed given recent moves to widely establish new woody vegetation at large scales in New Zealand.</p> 2018-11-27T12:09:38+13:00 ##submission.copyrightStatement## Agricultural intensification, ownership, and landscape change in the Mackenzie Basin 2018-12-03T10:26:51+13:00 Ann Brower Rowan Sprague Marion Vernotte Hamish McNair <p>This article investigates the role of shifting land&nbsp;ownership in landscape change in New Zealand’s Mackenzie Basin. It was hypothesised that ownership&nbsp;patterns influence landscape transformation; and changes in ownership lead to landscape changes.&nbsp;Satellite imagery was used to trace recent landscape changes quantifying a change from brown extensive&nbsp;pastoralism to green irrigated pasture. It was concluded that the change in land ownership following land&nbsp;reform allowed for about half of this agricultural intensification since 2003. Aggregating intensification&nbsp;on new freehold land with that on current pastoral lease changes the story; Crown decisions about disposition&nbsp;or intensification of Crown land account for two-thirds of intensification since 2003. Hence, if current&nbsp;trends in the Mackenzie are to change, the Crown must examine its decision patterns. Change in some form&nbsp;seems likely. The results presented speak to who has the power to make change. The choice and the power reside&nbsp;somewhere in the space between the Commissioner of&nbsp;Crown Lands and the Minister of Land Information.&nbsp;</p> 2018-11-30T00:00:00+13:00 ##submission.copyrightStatement## A case for integrating indigenous biodiversity into on-farm planning 2018-11-30T20:20:43+13:00 Fleur JF Maseyk Estelle J Dominati Alec D Mackay <p>A considerable proportion of remaining indigenous&nbsp;species-dominant vegetation occurs on farmland in<br>private ownership outside of the public conservation&nbsp;estate. This is particularly true of lowland settings,<br>where native ecosystem representation is critically low.&nbsp;An opportunity exists to link indigenous biodiversity<br>outcomes on private land with the need to improve&nbsp;the delivery of broad ecosystem services from<br>farm systems, at the same time reducing farming’s&nbsp;environmental footprint and improving farm resilience<br>to major climatic events. This discussion paper (i)&nbsp;highlights the current status of indigenous biodiversity<br>on-farm (ii) explores the current status of research&nbsp;on the integration of indigenous biodiversity into<br>existing farm planning initiatives and (iii) demonstrates&nbsp;through two case studies, the potential contribution of<br>indigenous biodiversity to economic, environmental,&nbsp;cultural and social outcomes on and beyond the<br>farm. While the condition and function of indigenous&nbsp;vegetation contributes to conservation outcomes, this<br>is just one, albeit important, relevant farm system&nbsp;outcome.</p> 2018-11-30T20:20:43+13:00 ##submission.copyrightStatement## The role of the New Zealand Grassland Association in communicating science to the grassland industry: history, lessons and directions 2018-12-13T20:46:53+13:00 Marie J Casey David R Stevens Derrick J Moot David F Chapman Graham A Kerr Warren McG King Aaron Meikle Laurie Copland Alistair D Black Jo I Kerslake <p>&nbsp;&nbsp;</p> 2018-11-30T20:23:09+13:00 ##submission.copyrightStatement## Effects of perennial (‘Russell’) lupins on soil nitrogen and carbon in acid high-country soils 2018-11-21T23:54:31+13:00 Xueying Che Jim L Moir Alistair D Black H. Sheng X. Li <p>Many high-country soils in the South Island have low soil&nbsp;pH and high exchangeable Al concentrations, limiting establishment and persistence of pasture and forage&nbsp;legumes. Perennial lupin (<em>Lupinus polyphyllus</em>) is able to grow in acidic soil (pH&lt;5.6) with high levels&nbsp;of exchangeable Al (Al&gt;3ppm, 0.01 CaCl<sub>2</sub>) toxic to most other legumes. This study examined the effects of&nbsp;perennial lupin stands of varying ages on soil nitrogen (N) and carbon (C) concentrations (0-15 cm). Eight&nbsp;lupin sites, varying in age, and neighbouring long-term pasture sites were soil sampled and analysed for N and&nbsp;C concentrations. Sites planted with perennial lupin had significantly (P&lt;0.001) higher total soil N (%) and soil&nbsp;mineralisable N (kg/ha) compared to adjacent pasture soils at the eight sites. Soil N status also declined with&nbsp;increasing soil depth in both lupin and pasture soils linked with plant residue accumulation in the topsoil.&nbsp;Soil N level generally increased with increasing lupin stand age (P&lt;0.001), though the oldest (30 years)&nbsp;site did not fit this trend. This study provides strong evidence that lupins substantially increase soil total&nbsp;and labile soil N. Results indicate that perennial lupins may be a suitable and important species to develop poor&nbsp;quality soils on South Island high-country farms.</p> 2018-11-13T19:06:22+13:00 ##submission.copyrightStatement## Dry matter yield of dryland and irrigated mixtures of Caucasian clover, white clover and perennial ryegrass over 5 years at Lincoln University 2018-11-13T22:29:44+13:00 Alistair D Black Richard J Lucas <p>This experiment investigated the effects of Caucasian clover (CC), white clover (WC), perennial ryegrass (RG) and their mixtures on dry matter (DM) yield under dryland and irrigated conditions over 5 years (1st July-30th June) at Lincoln University. Seven mixtures of the three species (three pure, three binary and one ternary) were sown in November 1999, grown with and without irrigation, and grazed by sheep. Total annual DM yield in Years 2-6 (2000/2001-2004/2005) was analysed. Clover-RG mixtures yielded more than the average monoculture yields of their constituent species (over-yielding). This diversity effect was 1.8-7.0 t DM/ha for WC-RG over all 5 years and 2.7-4.6 t DM/ ha for CC-RG in Years 3-6. There was no additional yield benefit from the three-species mixture. Diversity effects were due to synergistic interactions between the clovers and RG, which were similar for CC and WC once established. The interspecific interactions persisted despite changes in botanical composition across irrigation levels and years.</p> 2018-11-13T00:00:00+13:00 ##submission.copyrightStatement## Dry matter yield of six perennial legume species in response to lime over 3 years at Glenmore Station, Mackenzie Basin 2018-11-13T22:45:21+13:00 Saman Berenji Annamaria Mills Jim L Moir Keith M Pollock Will Murray Emily Murray Derrick J Moot <p>The production and persistence of legumes which may improve South Island high-country pasture in the Mackenzie Basin were studied. The initial soil test results confirmed toxic levels of aluminium (9 mg/kg, 0-150 mm soil depth) that has prevented the development of large areas of land traditionally grazed by merino sheep and beef cattle. A 3-year field experiment was direct-drilled in December 2012 with five rates (0, 0.5, 1, 2, and 4 t/ha) of surface applied lime and six legumes (lucerne, ‘Russell’ lupin, Caucasian clover, white clover, balansa, and <em>Lotus pedunculatus</em>) in three replicates. In Year 1, balansa clover and Russell lupin were the highest yielding legumes (7 t DM/ha), regardless of lime application rates. In Year 2 ‘Russell’ lupin was the highest (10.4 t DM/ha). Caucasian clover produced 4.6 t DM/ha and white clover and lucerne around 4.0 t DM/ha. Balansa clover (1.4 t DM/ha) and <em>Lotus pedunculatus</em> (2.5 t DM/ha) were the lowest yielding and they did not recover or persist after the initial grazing by merino sheep. These results confirmed that ‘Russell’ lupin and Caucasian clover thrived without the application of lime in this acidic soil with high Al levels.</p> 2018-11-13T22:42:36+13:00 ##submission.copyrightStatement## Seed yield and subsequent emergence pattern of subterranean clover cultivars in response to summer rain 2018-11-15T00:15:44+13:00 Carmen SP Teixeira Richard J. Lucas Derrick J. Moot <p>At Lincoln University, Canterbury, seven subterranean cultivars rated in Australia as having different levels of ‘hardseedeness’ were established. Monocultures were sown in autumn and allowed to grow and set seed. Seed yields ranged from 340 to 1050 kg/ha. Heavy rain in early January 2016 resulted in a “false strike” of ≤ 4.0% of seeds during the subsequent dry February. A second emergence event in March also resulted in a “false strike” with a further 7 to 15% of total seeds lost. However, cultivars established &gt;1000 seedlings/m2 after early winter rain, which is considered adequate for future persistence. Emergence was consistent with Australian hardseededness rankings. Cultivars with hardseed ranks &lt;4 may be more suitable for dryland systems in New Zealand due to their early emergence and the ability to exploit the late summer and autumn rains.</p> 2018-11-15T00:15:43+13:00 ##submission.copyrightStatement## Establishment, production and regeneration of subterranean clovers at in the Mackenzie Basin, New Zealand 2018-11-15T00:25:17+13:00 Sonya T Olykan Richard J Lucas Carmen SP Teixeira Richard A Subtil Derrick J Moot <p>The ‘Red Flats’ on Omarama Station in the Mackenzie Basin, has a winter cold, summer dry environment and soils with low plant available water (&lt;60 mm in the top 1 m), and low pH(H<sub>2</sub>O) (5.2) and high aluminium (8 mg/kg) below 75 mm. The site received 3 t of lime, 300 kg sulphur-super, boron (B), molybdenum (Mo) and herbicides to eliminate hieracium (<em>Hieracium pilosella)</em>. Twelve cultivars of subterranean clover (<em>Trifolium subterraneaum</em>), ‘Bolta’ balansa clover (<em>T. michelianum</em>), and perennial ‘Rossi’ red clover (<em>T. pratense</em>), were direct-drilled in February 2016. Over the next 3 years their frost tolerance, productivity and persistence were compared with the resident haresfoot clover (<em>T. arvense</em>). Balansa and the subterranean clovers all survived the 2016 and 2017 winters. The subterranean clovers maximum yield was 4.3 t DM/ ha after successful germination in February 2016 when sufficient rain extended the spring growing season into November. Subterranean clover cultivars from subspecies <em>subterraneum </em>yielded well in 2016, averaging 3.3 t DM/ha, as did the <em>brachycalycinum </em>‘Antas’ with 3 t DM/ha. During the short season of 2017, the <em>subterraneum </em>ssp. cultivars ‘Denmark’ and ‘Karridale’ established the highest ground covers and ‘Antas’ the lowest. In 2018, ‘Antas’ had the lowest emergence rate and autumn yield. ‘Karridale’ had the highest re-establishment rate and the <em>yanninicum </em>‘Trikkala’ the highest autumn yield (1.3 t DM/ha). Cultivars with low hardseededness ratings were the most successful at re-establishment in autumn 2017. Balansa clover was also persistent. In the favourable 2016 growing season the late-flowering resident haresfoot clover grew into early summer and yielded 3.7 t DM/ha. Red clover yielded 1 t DM/ha in 2016, but did not persist. Results suggest that medium-late flowering softer seeded subterranean clover cultivars and ‘Bolta’ balansa clover, are suitable for this environment.</p> 2018-11-15T00:25:17+13:00 ##submission.copyrightStatement## An on-farm study of the herbage quality and sward characteristics of plantain-clover mixes during late summer and autumn and resulting lamb growth rates 2018-11-15T00:30:58+13:00 Lydia M Cranston Peter D Kemp Steve T Morris Brennon A Wood <p>An on-farm study investigated the herbage quality and sward characteristics of plantain-clover mixes and resulting lamb growth rates during late summer and autumn. Three farms were chosen, each with a minimum of 10 ha of plantain-clover mix (<em>Plantago lanceolata </em>‘Ceres Tonic’, <em>Trifolium pratense, Trifolium repens</em>) used for lamb finishing. Each farm managed the plantain-clover mix area using their routine management without advice or comment from research staff. Throughout autumn, at approximately monthly intervals on the three farms, the pre- and post-grazing herbage masses, botanical composition, herbage quality, plantain dry matter content, secondary chemical composition and lamb growth rates were monitored. A low percentage of clover in the sward, a high percentage of dead stem material and a low crude protein concentration in plantain during dry periods, were identified as the most likely causes of low lamb liveweight gains during autumn. Grazing management during spring that maintains control of plantain stems and encourages the presence of clover, appears to be a key management technique for ensuring high lamb liveweight gains on plantain-clover mixes in late summer and autumn.</p> 2018-11-15T00:30:57+13:00 ##submission.copyrightStatement## The concentration of bioactive compounds in Plantago lanceolata is genotype specific 2018-11-17T22:28:24+13:00 Lisa A Box H Glenn Judson <p>Plantain (<em>Plantago lanceolata</em>) is known to contain bioactive compounds including verbascoside (acteoside), aucubin and catalpol. Limited New Zealand data are available to quantify the concentrations of secondary plant compounds in cultivars of plantain. This experiment compared secondary plant compound concentrations for five cultivars or breeding lines of plantain and the botanical distribution of these compounds over a year. For all cultivars verbascoside concentration was greatest, aucubin intermediate and catalpol lowest. The concentration of catalpol and verbascoside in leaf tended to be greater for the cultivars ‘Hercules’ and ‘Endurance’ compared with ‘Elite 2’, ‘PG742’ and ‘Tonic’. However, ‘Hercules’ and ‘Endurance’ tended to have lower concentrations of catalpol and verbascoside in scape (reproductive material from base to seedhead). The difference among cultivars in aucubin concentration was small. This experiment suggests that leaf concentration of catalpol and verbascoside is genotype specific.</p> 2018-11-15T00:41:47+13:00 ##submission.copyrightStatement## Plantain silage quality under variable management practices 2018-11-17T22:38:52+13:00 Nur Rizqi Bariroh Racheal H Bryant Alistair D Black <p>Two studies investigated the effect of regrowth and additives on preservation and quality of plantain ensiled in spring using a micro-silage technique. Study 1 compared the effect of regrowth at four (4L), five (5L) or six leaf (6L) appearance. Study 2 compared fertilisers: 20 kg N/ha (20N), 20N plus potassium and phosphorus (20NPK) or 40 kg N/ha with P and K (40NPK) and additives: cellulose enzyme (ENZ), molasses (MOL), Biosil (BIO) or no additives (CON). After 180 days, wet chemistry was performed on all silages. Silages were dark brown and had a sweet smell, though fermentation was limited with an average pH of 5.2 and 5.8 in Study 1 and 2, respectively. However, pH declined (P&lt;0.05) with early harvest, and use of N fertiliser or additives. Harvesting plantain for silage following a long regrowth is not recommended as the high stem content at this time contributed to low crude protein and low digestibility.</p> 2018-11-17T00:00:00+13:00 ##submission.copyrightStatement## Specific genotypes of plantain (Plantago lanceolata) vary in their impact on sheep urine volume and nitrification in the urine patch 2018-11-18T00:05:09+13:00 H Glenn Judson Patricia M Fraser Michelle E Peterson Grant R Edwards <p>Plantain has the potential to reduce nitrate leaching through a number of mechanisms. In an indoor study, sheep were offered either perennial ryegrass or different plantain genotypes while aiming to achieve similar dry matter and water intakes. Supplementary water was sprayed on the feed to achieve the latter objective. Animals fed two cultivars (‘Tonic’ and ‘Agritonic’, marketed as “Ecotains” with claims around the potential to reduce nitrate leaching, and breeding lines (from a breeding program aimed at improving aspects of leaching mitigation) produced significantly more urine (4925 and 4887 ml/day, respectively) than those fed a range of commercial plantain cultivars (averaging 4333 ml/day) or perennial ryegrass (3993 ml/day). These results suggest the plantains marketed as “Ecotains” and those in the environmental breeding program may have diuretic effects on sheep, thereby reducing the concentration of nitrogen in the urine. In a soil incubation experiment, urine from sheep grazing either perennial ryegrass or ‘Agritonic’ plantain was applied to soil microcosms (70 ml vials containing 20 g of soil). Urine from sheep grazing the plantain, showed a slower overall nitrification rate (especially in the first 28 days post-application) when a significantly lower proportion of the urinary N was converted to nitrate. Both these observations support the use of specific genotypes of plantain to assist in reducing nitrate leaching.</p> 2018-11-17T23:08:04+13:00 ##submission.copyrightStatement## Soil aluminium toxicity in New Zealand pastoral farming – a review 2018-11-17T23:22:05+13:00 Jeff D Morton Jim L Moir <p>As most New Zealand pastoral soils are acidic, aluminium (Al) can be present at high concentrations and restrict plant root growth and shoot yield. In field trials, Al toxicity in white clover has been associated with CaCl2-extractable soil Al levels of 3-5 ppm or exchangeable soil KCl-extractable levels of 1-2 me/100g, when soil pH levels were below 5.5-5.7 in the top 75 mm. Lucerne is less tolerant of Al toxicity than white clover and ryegrass, which in turn are less tolerant than <em>Lotus </em>spp<em>., </em>arrow leaf, subterranean, Caucasian, Persian and gland clovers, and naturalised adventive annuals such as cluster, haresfoot, striated and suckling clovers. Soil Al toxicity generally increases with soil depth. Soil pH is a reliable indicator of soil Al and, on average, can be increased by 0.1 units/tonne/ha of applied lime to reduce soil Al to below the toxic range. Lime application is the most effective strategy where it can be ground-applied. A key limitation of ground-applied lime to reduce Al toxicity is that its movement down the soil only occurs slowly except in high rainfall areas. Soil Al and pH levels and legume content in hill soils varies according to slope and aspect and there is an opportunity to differentially apply lime by air to areas with low soil pH and more legume, for the best economic return.</p> 2018-11-17T00:00:00+13:00 ##submission.copyrightStatement## Soil pH, exchangeable aluminium and legume yield responses to deep-placed lime at Omarama Station 2018-12-20T10:20:26+13:00 Daniel L Hendrie Jim L Moir E John Stevens Alistair D Black Derrick J Moot <p>The passive moment of lime down the soil profile in dryland is slow so a machine was developed to directly inject lime into soil, and was tested it at Omarama Station. Pelleted lime was injected at simultaneous depths of 5-10 cm and 20-25 cm below the soil surface at rates of 0 (control), 500, 1000, and 2000 kg/ha and these treatments were compared with 1000 kg/ha of surface-applied pelleted lime. The growth of lucerne, ‘Russell’ lupins and festulolium was recorded over 3 years. The deep-placed lime increased soil pH and reduced Al levels at soil depths of 25 and 30 cm, whereas for the surface-applied lime this was only the case in the top 7.5 cm of the soil. The deep-placed lime increased the growth of lucerne in the second and third years of the experiment. The lucerne was out-yielded by ‘Russell’ lupins in each year, which were unaffected by the application of lime.</p> 2018-11-17T00:00:00+13:00 ##submission.copyrightStatement## Soil acidity and aluminium in South Island high and hill country: new data and future needs 2018-11-21T23:53:39+13:00 Jim L Moir Derrick J Moot Amy E Whitley Alistair D Black Daniel L Hendrie <p>Soil extractable aluminium (Al) concentrations can have a strong impact on the establishment, growth and persistence of pasture legumes. This has become clear in New Zealand high and hill-country, where legumes are scarce and failing to persist in acid soils with high Al levels. For the last decade a research programme has been conducted at Lincoln University focused on legume growth and persistence in acid, high Al concentration soils. Research has examined several aspects of soil acidity and Al toxicity and screened and evaluated a range of legume species, identifying several that show promise in their growth and persistence under acidic and high Al concentrations, in addition to harsh climatic environments. This paper summarises this extensive body of research and also suggests some future research topics for addressing the growing challenge of increasing soil acidity and soil Al faced by increasing numbers of producers.</p> 2018-11-19T00:09:14+13:00 ##submission.copyrightStatement## A field survey of soil pH and extractable aluminium in the Ashburton Lakes Catchment, Canterbury, New Zealand. 2018-11-26T15:26:53+13:00 Amy E Whitley Peter C Almond Jim L Moir Monica Giona Bucci Josh Nelson Derrick J Moot <p>Soil extractable aluminium (Al) concentrations&nbsp;have a strong impact on the establishment, growth<br>and persistence of pasture legumes. A survey of&nbsp;21 soil profiles in the Ashburton Lakes catchment<br>was conducted to determine the key factors driving&nbsp;extractable Al concentrations. The mean Al (0.02 M<br>CaCl2) concentration was 7.8 mg/kg with the highest&nbsp;values in the top 50 cm of the soil profile. However,<br>there was considerable variation among sites. Landform&nbsp;age, rainfall and depth were all important variables for<br>extractable Al (but R2 was low), while landform type was&nbsp;not. The highest Al concentrations in the 20 cm depth<br>zone were found at the wettest sites in the catchment&nbsp;where rainfall was ≥ 1266 mm and where pH was lowest.<br>Farmers in this catchment could use this knowledge to&nbsp;determine which areas of their farms are most susceptible&nbsp;to elevated Al concentrations and at what depth. This&nbsp;would assist in determining which areas could be targeted&nbsp;for development and which are unsuitable.</p> 2018-11-26T00:00:00+13:00 ##submission.copyrightStatement## Exploring the link between more negative osmotic potential and ryegrass summer performance 2018-11-26T15:36:28+13:00 L Vishna Y Weerarathne Wencheng Dong Minghe Nie Yan Wang Ignacio F Lopez Cory Matthew <p>This paper outlines recent research studying within-population variation in selected New Zealand perennial ryegrass cultivars, for traits related to tolerance of summer moisture deficit. Two clonal replicates of 220 genotypes from ‘Grasslands Nui’ (Nui, n=50), ‘Grasslands Samson’ (Samson, n=80), and ‘Trojan’ (n=90) were exposed to 1 month of moisture deficit challenge, with plant water relations measurements performed to evaluate putative drought-response mechanisms. Water use of individual genotypes ranged from &lt;100 to &gt;1000 g water/g DM indicating large within-population variation for this trait. Mean water use efficiency (WUE) was for Nui, Samson, and Trojan, respectively, 424±16, 412±10, and 319±9 g water/g DW (P&lt;0.001), suggesting that commercial plant breeding may have indirectly reduced water use in modern cultivars without specific focus on water relations. Principal component analysis indicated more negative osmotic potential may contribute to reduced water use while maintaining yield under water deficit, giving a potential focus for future breeding selection targeting summer water deficit tolerance.</p> 2018-11-26T15:36:27+13:00 ##submission.copyrightStatement## The measurement of perennial ryegrass persistence 2018-12-03T10:30:52+13:00 Michael B Dodd David F Chapman Cameron I Ludemann Wendy Griffiths Katherine N Tozer Liam Donnelly <p>Poor persistence in perennial ryegrass has been identified as a major limitation to pasture productivity, particularly in the upper North Island. Persistence can best be defined as the continuity of forage yield relative to a cultivar’s potential. Though there is limited evidence of differences in persistence between cultivars, there is interest in including persistence in the DairyNZ Forage Value Index. This requires an agronomically robust metric of persistence, measured over a suitable time frame and connected to economic value. Five candidates are evaluated: plant populations, tiller populations, basal cover, ground score and annual dry matter yield. Scarcity of long-term data is a major limitation to development of performance values for persistence, and must be addressed. The four abundance-based measures also lack a clear connection to economic values, from the limited data available. A persistence metric is proposed, that relates medium-term dry matter yield to short-term dry matter yield, for which perennial ryegrass functional type and cultivar differences are demonstrated.</p> 2018-11-26T15:38:15+13:00 ##submission.copyrightStatement## Persistence of ryegrass, tall fescue and cocksfoot following sequential annual sowings: pasture yield, composition and density in 3 establishment years under sheep grazing in Canterbury 2018-12-03T10:35:23+13:00 Thomas M R Maxwell Grant R Edwards Gerald P Cosgrove <p>A long-term pasture persistence trial, consisting of&nbsp;repeated annual sowings, commenced in Canterbury in 2015 and is planned to continue until 2024. Preliminary&nbsp;results of the first 3 years sowings are reported. Each annual sowing used the same randomised block design&nbsp;of eight perennial ryegrass cultivars, one tall fescue and one cocksfoot cultivar, replicated four times. Grasses&nbsp;were drilled into a cultivated seedbed in autumn, with white clover broadcast-sown, then rolled with a&nbsp;Cambridge roller. Except for one 3-week spell in spring and in autumn to accumulate herbage to measure DM&nbsp;yield, botanical composition, morphology and sward density, plots were continuously stocked with sheep&nbsp;to maintain a 3-8 cm sward height from late-August to late-May. Results from the first 12 months following&nbsp;each of the three annual sowings (2015, 2016 and 2017) indicate establishment year had a greater influence on&nbsp;DM yield, botanical composition, grass leaf and stem proportions, and basal cover than did grass species or&nbsp;cultivar. Accumulating data from successive annual sowings and continued monitoring of each will help&nbsp;identify the long-term effect and difference between establishment years, as well as grass persistence traits&nbsp;for inclusion in the Forage Value Index ranking of perennial ryegrass cultivars.</p> 2018-12-01T13:57:19+13:00 ##submission.copyrightStatement## Regrassing trends and drivers in the New Zealand dairy industry 2018-12-03T10:33:58+13:00 Michael B Dodd David F Chapman Graeme Ogle <p>Pasture renewal is an important strategy for farmers to&nbsp;improve the yield of home-grown forage. This paper quantifies long-term national and regional trends in&nbsp;regrassing within the dairy sector and links these patterns to suggested major drivers, using simple&nbsp;regression analysis. Dairy farm financial data relevant to regrassing expenditure were sourced from annual&nbsp;dairy sector economic reports and DairyBase, while regional potential evapotranspiration deficit data were&nbsp;sourced from climate records and cropping data from a recent MPI report. Real and relative expenditure on&nbsp;regrassing has increased over this period, and appears to be positively associated with both cropping activity&nbsp;and drought severity, particularly in some North Island regions. The emergent picture is one of a complex of&nbsp;interacting drivers (climate, production, prices, forage products, soils and time) which fuel a vicious cycle of&nbsp;poor persistence and resowing. This situation draws attention to the need for solutions to protect regrassing&nbsp;investments.</p> 2018-12-01T14:10:37+13:00 ##submission.copyrightStatement## A new winter active crop to improve soil nitrogen uptake 2018-12-03T14:51:47+13:00 John R Caradus Adrian Russell Tim J Chapman Lisa Wood Paul Bowater <p>Nutrient losses due to leaching are often greatest when soils are wet and draining, mainly during winter and often after summer crops are harvested or grazed in autumn and early-winter. Cover crops such as oats have been used as a management option to reduce nitrogen leaching, but the degree of benefit is largely dependent on management for achieving high crop yields. Triticale, due largely to its ryecorn parentage, has a deep root system resulting in an excellent nutrient scavenging ability. The breeding of a new and unique triticale cultivar, T100 (marketed under the brand name of ‘WinterMax’), with proven winter activity and early establishment vigour provides an improved option for nutrient ‘trapping’ compared with existing winter cover crops. Field trials were sown in autumn or winter after maize cropping or with differing levels of applied nitrogen, at two sites in Canterbury. The winter-active triticale removed 19, 21, 28, 35 and 45% more nitrogen from wet soils than another triticale, oats, ryecorn, wheat and annual ryegrass, respectively.</p> 2018-12-03T14:51:47+13:00 ##submission.copyrightStatement## Exploring options to reduce nitrogen leaching while maintaining profitability within a Canterbury farm business comprising several distinct enterprises 2018-12-04T12:37:43+13:00 Pierre C Beukes Taisekwa Chikazhe J Paul Edwards <p>This paper reports on a study evaluating the effects of nitrogen (N) mitigations on N leaching and profitability across all hectares of a farm business consisting of a dairy platform, dairy support and beef blocks. Two different models were used, each with their own strengths and weaknesses. Mitigation options focussed on N fertiliser use, plantain-ryegrass-clover diverse pastures, cropping regime, and animal and feed movements between the blocks. A combination of less N fertiliser, replacing kale with fodder beet for wintering to reduce the crop area, an oats catch-crop following autumn-harvested fodder beet, diverse pastures on a proportion of platform and support blocks, and wintering non-pregnant cows on the beef block reduced N leaching by 19%. Profitability was not affected by these mitigations. Profitability did not increase, but N leaching did, when changing to an all-dairy business model. Nitrogen leaching reductions can be achieved if all enterprises implement some or all of these mitigations.</p> 2018-12-04T00:00:00+13:00 ##submission.copyrightStatement## Urine patch size and nitrogen load: effects on nitrogen uptake from the urine patch in plantain and ryegrass/white clover pastures 2018-12-04T12:44:50+13:00 Mark A Shepherd Bill T Carlson <p>Field measurements from micro-plots (0.20 - 0.36 m2) of perennial ryegrass/white clover and of pure plantain were used to mimic a urine patch (UP) and to test the effects of UP nitrogen (N) load and size on pasture N offtake. Urine N offtake was greater with plantain than with standard pasture; however, the relative contribution to uptake from the wetted area and surrounding edge was the same for both species. Most (&gt;90%) of the apparent offtake of urine N by plantain and standard pastures was within 20 cm of the edge of the UP. For the two urine patch sizes tested, edge contribution to urine N offtake was on average about 30% of the total from the UP, but was higher for at 600 kg N/ha urine N (45%) than at 300 kg N/ha (18%). Understanding this edge contribution is important for model improvement, and for the development of mitigations to decrease N leaching.</p> 2018-12-04T12:41:40+13:00 ##submission.copyrightStatement## Comparing nitrogen management on dairy farms – Canterbury case studies 2018-12-04T12:51:25+13:00 Ina B Pinxterhuis J Paul Edwards <p>Five Canterbury dairy farmers participate in the Forages for Reduced Nitrate Leaching programme (FRNL) to co-develop options for less environmental impact. Farm practices were adapted and new mitigation options were implemented. To assess farm environmental performance, the Overseer model was used to estimate nitrogen (N) leaching, N surplus and N conversion efficiency (NCE) for each farm and each year. When discussing the results with farmers, it appeared that these indicators for environmental performance are limited when comparing farm management strategies. The Overseer estimates include N fixation, which is influenced by model assumptions, and N leaching, estimates that strongly depend on soil type and climate entered into the model. To enable better comparisons between farms and years, a simplified N surplus and NCE were calculated using farmer recorded N inputs and N outputs, i.e. fertiliser, imported supplement, production and exported supplements. Effects of improved management and new mitigation options are presented. Four of the farms improved their N surplus and NCE and three reduced their Overseer-estimated N leaching over 3 years (2014, 2015 and 2016).</p> 2018-12-04T12:51:25+13:00 ##submission.copyrightStatement## Potential of catch crops to reduce nitrogen leaching in New Zealand winter grazing systems 2018-12-05T12:07:47+13:00 Brendon J Malcolm Peter L Carey Edmar I Teixeira Paul R Johnstone Shane C Maley John M de Ruiter <p>Winter grazing of fodder beet and kale is common practice in many regions of New Zealand. However, large quantities of urine-nitrogen (N) is returned by livestock onto bare soil during grazing at a period when the risk of drainage is high. Results from recent field trials in the Canterbury region show that sowing a catch crop directly after winter forage grazing can reduce N leaching losses by up to 49% compared with fallow soil, as well as offer significant gains in feed production, via additional annual production from the catch crop. However, the magnitude of effectiveness varies in response to crop management, catch crop genotype, soil type and seasonal weather conditions. For example, early-sown cereal genotypes adapted to lower temperatures provide the greatest potential to reduce leaching. This summary also highlights three important areas for future research: (i) overcoming the practical challenges of establishing catch crops in unfavourable conditions, (ii) development of biophysical models that can predict outcomes over a wide range of production systems and conditions, and (iii) quantification of other processes in the N cycle causing changes in N leaching, e.g. microbial immobilisation of N.</p> 2018-12-05T00:00:00+13:00 ##submission.copyrightStatement## Changes in estimated value of perennial ryegrass cultivar/ endophyte combinations in the DairyNZ Forage Value Index when metabolisable energy contents specific to culitvar groups are included 2018-12-05T12:12:12+13:00 Cameron I Ludemann Cáthal M Wims David F Chapman <p>Further development of the DairyNZ Forage Value Index (FVI) requires accounting for genetic variation in the nutritive value of ryegrass herbage in addition to the current weightings on dry matter production traits. Performance values for metabolisable energy content (PV ME) have been identified as the most appropriate variables to use for this purpose. In this study an assessment was made of the effect of including cultivar group (mid-heading date diploid, late-heading date diploid and tetraploid) PV ME in FVI ranking calculations of eligible perennial ryegrass (<em>Lolium perenne</em>) cultivars. Incorporation of the seasonal ME trait into the FVI has resulted in changes in rankings of those cultivars. Although correlations were strong (0.74 for Upper South Island to 0.92 for Upper North Island) between rankings of cultivars using the current FVI and the FVI with cultivar group PV ME, marked improvements have been made in the rankings of tetraploid cultivars. On-farm persistence implications (not yet included in the FVI) of selecting tetraploid cultivars will need to be included if the ME trait is included in the FVI.</p> 2018-12-05T12:12:12+13:00 ##submission.copyrightStatement## High lipid perennial ryegrass growth under variable nitrogen, water and carbon dioxide supply 2018-12-05T12:21:23+13:00 Zac D Beechey-Gradwell Somrutai Winichayakul Nick J Roberts <p>A novel strategy to increase the metabolisable energy content of pasture species has been the development of a GM technology (‘High metabolisable energy’ or HME), which when expressed in the leaves of perennial ryegrass, increases leaf lipids up to 6-7% of DW (approximately double ‘normal’ levels). Remarkably, increased rates of photosynthesis and growth also occur in these plants. The industry strategy is to perform field trials overseas to establish the value proposition for New Zealand. Here, results are presented from preliminary growth-chamber pot trials which reveal the influence of the HME technology on perennial ryegrass growth under different levels of N, H<sub>2</sub>O and CO<sub>2</sub> supply. HME increased perennial ryegrass growth under high N supply, limiting and non-limiting H<sub>2</sub>O supply, and with ambient and elevated CO<sub>2</sub> supply. Possible HME growth mechanisms and their practical implications are discussed. Progress on the 2017 field trial in the USA using offspring from the HME crossing programme is also discussed.</p> 2018-12-05T12:21:23+13:00 ##submission.copyrightStatement## Controlling variegated thistle in East Coast North Island hill-country 2018-12-06T21:44:04+13:00 Katherine N Tozer Rose M Greenfield Mike B Dodd Trevor K James Catherine A Cameron <p>Variegated thistle can dominate north-facing slopes on North Island East Coast hill-country reducing pasture production and livestock carrying capacity. On a hill-country sheep and beef property near Gisborne, the herbicides 2,4-D + clopyralid were applied in early-May by knapsack in combination with a June aerial application of 2,4-D ester. This was more effective than a single June aerial application of 2,4-D ester in reducing the abundance of variegated thistle and enabling grasses from the seedbank to colonise the bare ground in the herbicide-treated patches. Mixtures of grasses, legumes and herbs, oversown onto bare patches previously occupied by thistle plants, did not establish on a north-facing slope. While they did establish on a south-facing slope, the sown species did not persist, most likely due to selective grazing. To establish competitive pasture, natural germination from the seedbank may be less risky than oversowing seed into thistle patches, if desirable species are present in the seedbank.</p> 2018-12-06T21:44:04+13:00 ##submission.copyrightStatement## Metabolisable energy concentration in perennial ryegrass pastures: multi-site analysis of effects of cultivar, nitrogen fertiliser and white clover content 2018-12-06T21:52:26+13:00 Gerald P Cosgrove Julia M Lee David F Chapman David R Stevens Laura Rossi Warren M King Grant R Edwards <p>To include metabolisable energy (ME) as a nutritive value factor for ryegrasses in the Forage Value Index (FVI) requires data for New Zealand cultivars on the effects of environmental and management factors on cultivar ranking. This study tested the hypothesis that variation among cultivars, and so ranking, is not influenced by environment, nitrogen (N) fertiliser level or the presence or absence of white clover. Eight cultivars, grown with or without white clover and at two levels of N fertiliser in grazed pastures in Waikato, Manawatū, Canterbury and Southland, were sampled seasonally over 3 years and analysed for ME. There were clover, N and cultivar main effects on ME in most seasons, however, there were no interactions that affected cultivar ranking, indicating that data from field evaluation systems based on monocultures are reliable for the purposes of the FVI. However, data for absolute ME concentration are required from multiple sites to account for the observed cultivar × environment interactions.</p> 2018-12-06T21:52:25+13:00 ##submission.copyrightStatement## Yield benefits of pasture mixtures with species drilled in the same and alternate rows 2018-12-07T11:11:00+13:00 Alistair D Black S Anderson S K Dalgety C A Hassall T S Myint S R Vreugdenhil <p>This study investigated the effect of sowing species in alternate drill rows on dry matter (DM) yield of pasture mixtures. Seven mixtures of ‘Base’ perennial ryegrass, ‘Tonic’ plantain and ‘Apex’ white clover (three pure, three binary and one ternary) were drilled into plots in March 2015 at Lincoln University. Binary and ternary mixtures were also sown with species in alternate drill rows. Ryegrass-white clover and plantain-white clover mixtures yielded more than the average monoculture yields of their constituent species (over-yielding). This diversity effect averaged 7.01 t DM/ha in Year 1 (2015/2016) and 3.45 t DM/ha in Year 2 (2016/2017) of sown yield (total minus weeds) when species were drilled together. Diversity effects were due to synergistic interactions and white clover interacted more strongly with plantain than ryegrass. There was no additional yield benefit from increasing the number of species from two to three in the mixture, and from sowing species in alternate rows.</p> 2018-12-07T11:11:00+13:00 ##submission.copyrightStatement## Emergence and control of gorse seedlings after the 2017 Port Hills fire 2019-01-06T23:11:47+13:00 Breanna J O Taylor Keith M Pollock Derrick J Moot <p>An experiment on the Port Hills, Canterbury, after mature gorse was burnt in the fires of February 2017, showed an oversown Italian ryegrass mix out-competed the rapidly germinating gorse seedlings. The shaded gorse seedling population reached a peak of 680 plants/m<sup>2</sup> in June, declining to ~450 plants/m<sup>2</sup> in October compared with &gt;600 plants/m<sup>2</sup> in the unshaded plots. As soil moisture dropped in summer, the gorse seedling population decreased to 10 plants/m<sup>2</sup> by March 2018, compared with 73 plants/m<sup>2</sup> in the unshaded plots. Gorse seedlings that had been shaded by Italian ryegrass had shorter roots and lower dry weights than those grown without competition. The oversown mix was more successful on the south than north-facing slope where more bare ground enabled patches of gorse to re-establish. The oversowing of Italian ryegrass was shown to be a viable option to control gorse particularly after an unplanned burn that removed the fences and water supply.</p> 2018-12-07T00:00:00+13:00 ##submission.copyrightStatement## Developing new tools for pasture plant breeding 2018-12-08T00:04:03+13:00 Brent A Barrett Marty J Faville Kioumars Ghamkhar Marcelo J Carena <p>The rate of genetic gain represented in the Forage Value Index of perennial ryegrass (<em>Lolium perenne</em>) is a major factor underpinning sustained profitability in pastoral farming. Effective new technologies for trait data acquisition and parent plant selection are used in many animal and crop improvement programmes to lift the rate of gain, but have yet to be developed and integrated in forage breeding. For forage improvement, hypotheses tested were: a) genomic selection (GS) offers a viable breeding strategy, and b) key enabling technologies for non-destructive, high-throughput phenotyping (HTP) in the field will improve trait data acquisition. To evaluate GS, extensive molecular marker and phenotypic datasets in structured populations of perennial ryegrass were developed. Phenotypic data for seasonal dry matter yield (DMY), the core trait in the Dairy NZ Forage Value Index, were obtained replicated field trials. Data on heading date (HD) as a useful trait to assess the efficacy of GS for simply inherited traits, were also collected. Genomic prediction models were developed for seasonal DMY and HD. Application of GS for HD was effective in selecting for both early and late heading, with movement of up to 7 days in a single generation of selection. The HTP research used iterative development of computational methods supporting a repeatable, non-invasive means of accurately and rapidly measuring DMY of perennial ryegrass in single row plots. These findings demonstrate effective genetic prediction and phenotyping approaches which may enable breeders to lift the rate of genetic gain in perennial ryegrass.</p> 2018-12-08T00:04:03+13:00 ##submission.copyrightStatement## Changes in soil carbon in hill-country under contrasting phosphorus fertiliser and sheep stocking rates 2018-12-08T00:11:54+13:00 Alec D Mackay Ronaldo Vibart Catherine McKenzie <p>Carbon (C) measurements were analysed for soil sampled to two depths (0-75 and 75-150 mm) in 2003 and again in 2014 in three of the farmlets of a long-term phosphorus (P) fertiliser and sheep grazing experiment at the AgResearch Ballantrae Hill Country Research Station. The farmlets received either 125 kg/ ha/year of single superphosphate (SSP) from 1975-1979 and none since (LFNF), or the same amount of SSP applied as for LFNF from 1975-1979 and 125 kg SSP/ha/year since 1980 (LFLF), or 625 kg/ha/year of SSP applied from 1975-1979, and 375 kg SSP/ha/year since 1980 (HFHF). Carbon concentration in soil at both sampling depths was not affected by differences in P fertiliser inputs and sheep stocking rate, but there were significant (P&lt;0.001) slope x farmlet and aspect x farmlet interactions. Data from this long-term study provide science, policy and industry with invaluable insights into the changes in soil C stocks in pastoral hill-country soils.</p> 2018-12-08T00:11:54+13:00 ##submission.copyrightStatement##