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The objective of this study was to quantify the farm gate nitrogen (N) offset potential of perennial ryegrass (Lolium perenne L.; PRG) white clover (Trifolium repens L.; WC) swards by comparing the herbage and milk production from dairy farmlets that were simulations of full farming systems. A study was established where 120 cows were randomly assigned to 4 farmlets of 10.9 ha (stocking rate: 2.75 cow/ha), composed of 20 paddocks each. Cows were fed 526 kg of DM of concentrate on average each year. The 4 grazing treatments were PRG-only at 150 or 250 kg of N/ha and PRG-WC at 150 or 250 kg of N/ha. Cows remained in their treatment group for an entire grazing season and were re-randomized as they calved across treatments each year. As cows calved in the spring as standard practice in Ireland, they were rotationally grazed from early February both day and night (weather permitting) to mid-November, to a target postgrazing sward height of 4.0 cm. Mean sward WC content was 18.1% and 15.4% for the 150 and 250 kg of N/ha PRG-WC treatments, respectively over the 3-yr period. When WC was included, lowering the N rate did not reduce pregrazing yield, pregrazing height, or herbage removed, but those factors decreased significantly when WC was absent. Total annual herbage DM production was 13,771, 15,242, 14,721, and 15,667 kg of DM/ha for PRG-only swards receiving 150 or 250 kg of N/ha and PRG-WC swards receiving 150 or 250 kg of N/ha, respectively. In addition, when WC was present, compressed postgrazing sward heights were lower (4.10 vs. 4.21 cm) and herbage allowance (approximately 17 kg/cow feed allocation per cow per day) higher than the high-N control (+ 0.7 kg of DM/cow per day). There was a significant increase in milk production, both per cow and per hectare, when WC was included in PRG swards. Over the 3-yr study, cows grazing PRG-WC had greater milk (+304 kg) and milk solids (+31 kg of fat + protein) yields than cows grazing PRG-only swards. This significant increase in milk production suggests that the inclusion of WC in grazing systems can be effectively used to increase milk production per cow and per hectare and help offset nitrogen use. This result shows the potential to increase farm gate N use efficiency and reduce the N surplus compared with PRG-dominant sward grazing systems receiving 250 kg of N/ha, without negatively affecting milk solids yield or herbage production, thus increasing farm profit by €478/ha. [ABSTRACT FROM AUTHOR]

Multispecies swards, comprised of different plant functional groups have comparable production potential to high N input L. perenne swards at reduced N when legumes are included. However, information on the appropriate management of multispecies swards is limited. The effect of differing management practices on the herbage dry‐matter (DM) production and botanical composition of different sward types was investigated using a 3 × 2 × 2 factorial design plot experiment. The experiment consisted of three sward types: L. perenne‐only receiving (LP; 250 kg N ha−1 a−1); L. perenne‐Trifolium repens (LP‐TR); multispecies sward containing L. perenne, Phleum pratense, Trifolium repens, Trifolium pratense, Plantago lanceolata and Cichorium intybus (MSS). LP‐TR and MSS received 90 kg N ha−1 a−1. Harvesting of plot herbage took place every 21 or 28 days to a defoliation height of 4 or 6 cm, over two growing seasons (March to November 2020 and 2021 inclusive). Annual herbage produced by both LP and LP‐TR was not significantly affected by defoliation frequency. However, MSS produced 1923 kg DM ha−1 a−1 more herbage when harvested less frequently. Unsown species contributed significantly less to the herbage DM of MSS compared to LP and LP‐TR and remained similar in 2020 and 2021, whereas the contribution of unsown species to herbage DM increased in LP and LP‐TR from 2020 to 2021, with noxious species more associated with LP and LP‐TR than MSS. Results demonstrate the role of multispecies swards in improving the sustainability of grass‐based agricultural systems in an environment of reduced fertilizer inputs. [ABSTRACT FROM AUTHOR]

Background: In the Western Highlands of Cameroon (WHC), information on the nutritional value of fodder species consumed by ruminants is very limited. Methods: Through interviews with farmers and monitoring of animals on the range, information was obtained on the types of fodder resources consumed by the ruminants. Samples of each forage species were collected in 15 districts, mixed, chopped, and dried in a ventilated oven at 60°C, and then ground for chemical composition analysis. Results: Twenty‐two forage species were identified. Among these species, Vernonia amygdalina (29.43% ± 0.45% dry matter [DM]) and Pennisetum clandestinum (87.21% ± 1.33% DM) were, respectively, the highest in protein and neutral detergent fiber contents. Manihot esculenta was one of the most energy‐rich forages in terms of forage unit for lactation and forage unit for meat production. Hierarchical ascending classification revealed three main groups of forages, respectively, rich in crude fiber (Group 1), protein (Group 2), and energy (Group 3). Conclusions: The present study identified 22 forage species browsed by ruminants in WHC. Further studies should be carried out to determine the antinutritional factors and to evaluate their nutrient value using in vitro or in situ digestibility techniques. [ABSTRACT FROM AUTHOR]

Drought can induce phenotypic plasticity in a range of plant root and shoot traits. These traits have been shown to explain differences in root and shoot litter decomposability between species. However, it is unknown how drought‐induced plasticity of root and shoot traits alters their decomposability.To investigate this issue across a range of species, we grew a grass Lolium perenne, a forb Plantago lanceolata and a legume Trifolium repens common to European temperate grasslands and subjected them to a 5‐week moderate drought treatment. We compared morphological and chemical root and shoot traits of the droughted plants to well‐watered controls. We then conducted a decomposition assay of the senesced root and shoot material over 16 weeks, with mass loss measurements at five timepoints.Drought had significant and sometimes strong effects on morphological and chemical root and shoot traits of all three species, sometimes similar to differences between species and generally in line with a shift to a more resource‐conservative strategy. Drought also increased the labile litter fraction in roots of Lolium perenne, which was associated with a substantial increase in non‐structural carbohydrates. Drought decreased the labile litter fraction in shoots of Plantago lanceolata, but this could not be explained by the traits we measured. Drought effects on litter decomposability were weaker than on plant traits.Our results suggest that plant trait‐mediated effects of drought on litter decomposability can either increase or decrease vegetation feedbacks to climate change. They also show that drought‐induced plasticity in root and shoot traits does not automatically translate into equivalent changes in litter decomposability. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Perennial ryegrass (PRG, Lolium perenne L.) breeding effort in New Zealand (NZ) has increased since c. 1990, resulting in greater functional trait diversity (e.g. heading date, ploidy, and associated Epichloë endophyte strain) in commercial products. This study quantified the variation, associations and interactions in dry matter (DM) yield, nutritive value and persistence‐related traits among commercial cultivar‐endophyte combinations released between 1973 and 2012, as a basis for assessing gains in value being delivered to the pasture‐based livestock industries. Twenty‐four or 28 combinations were compared over 3 years in two trials in each of two regions: Waikato in northern NZ (dryland), and Canterbury in central eastern South Island (irrigated). Cultivar‐endophyte combinations were sown in mixtures with white clover, and pastures were intensively grazed 8–11 times per year by dairy cows. Principal Component Analysis identified 4 distinct clusters for the DM yield variables and for metabolisable energy (ME) content in each of the four trials. A broadly‐adapted group of three late‐season flowering, AR37‐infected diploids with NZ and Spanish breeding backgrounds dominated the highest‐yielding clusters. Tetraploids dominated the high ME content clusters. Interactions with region were observed throughout the data set: the strongest of these was driven by endophyte strain effects in Waikato. High‐yielding cultivar‐endophyte combinations in these trials were also generally high‐yielding in the standard cultivar merit testing system operated in New Zealand, as interpreted via the DairyNZ Forage Value Index. However, alignment was poorer for medium‐ and lower‐yielding cultivar‐endophyte combinations. Several implications for forage evaluation methods and end‐user industries are identified. [ABSTRACT FROM AUTHOR]

Purpose : Nitrogen (N) transfer from white clover (Trifolium repens cv.) to ryegrass (Lolium perenne cv.) has the potential to meet ryegrass N requirements. This study aimed to quantify N transfer in a mixed pasture and investigate the influence of the microbial community and land management on N transfer. Methods: Split root 15N-labelling of clover quantified N transfer to ryegrass via exudation, microbial assimilation, decomposition, defoliation and soil biota. Incorporation into the microbial protein pool was determined using compound-specific 15N-stable isotope probing approaches. Results: N transfer to ryegrass and soil microbial protein in the model system was relatively small, with one-third arising from root exudation. N transfer to ryegrass increased with no microbial competition but soil microbes also increased N transfer via shoot decomposition. Addition of mycorrhizal fungi did not alter N transfer, due to the source-sink nature of this pathway, whilst weevil grazing on roots decreased microbial N transfer. N transfer was bidirectional, and comparable on a short-term scale. Conclusions: N transfer was low in a model young pasture established from soil from a permanent grassland with long-term N fertilisation. Root exudation and decomposition were major N transfer pathways. N transfer was influenced by soil biota (weevils, mycorrhizae) and land management (e.g. grazing). Previous land management and the role of the microbial community in N transfer must be considered when determining the potential for N transfer to ryegrass. [ABSTRACT FROM AUTHOR]

Incorporating plantain with perennial ryegrass and white clover (RGWC) can improve the quality and quantity of grazing pastures; however, the sowing rate could affect the persistence of plantain, pasture yield, and nutritive value in different seasons. The objective of this study was to evaluate the effect of increasing sowing rates of plantain when established with RGWC on the dry matter (DM) yield, botanical composition, nutritive value, and bioactive compounds of the pasture over the first two years after sowing; and to determine the relationship between plantain content and nutritive characteristics in different seasons. The pasture treatments were RGWC, RGWC + low plantain rate (PLL), RGWC + medium plantain rate (PLM), and RGWC + high plantain rate (PLH). The results showed that annual DM yield was similar between treatments. The average plantain content (including leaves and reproductive stem) was 32, 44, and 48% in PLL, PLM, and PLH, respectively. The plantain composition increased in the first 15 months, then declined rapidly to about 20–30% at day 705 after sowing. Compared with RGWC, the plantain-RGWC pastures (PLL, PLM, PLH) had a higher content of organic matter digestibility (OMD), ash, starch, non-structural carbohydrates (NSC), P, S, Ca, Mg, Na, Cl, Zn, B, Co, aucubin, acteoside, and catalpol, while they contained a lower composition of DM%, acid detergent fibre (ADF), neutral detergent fibre (NDF), crude fat (CF), Fe, and Mn. These differences were linearly associated with the content of plantain leaves in the pasture and were higher in summer and autumn than in spring. In conclusion, incorporating plantain into the RGWC pasture can improve herbage nutritive quality, thus potentially increasing farm productivity and environmental benefits. However, further work is required to investigate management interventions to sustain plantain content beyond two years from sowing. [ABSTRACT FROM AUTHOR]

More than 50% of agricultural land is threatened by water erosion in the Czech Republic. With respect to soil erosion, maize (Zea mays L.) belongs to the most problematic crops; one of the possibilities to increase protection against erosion is intercropping. In this study, we attempted to find out the effects of individual intercrops and their mixtures (sown 4--6 weeks after sowing maize) or a mixed culture (maize plus lupine) on the soil losses and surface runoff in the period 2019--2021. The study was realised in a sugar beet growing region (Haplic Luvisol); a field rainfall simulator was used. From the used variants with Lolium perenne L., Trifolium repens L., Vicia villosa Roth, Lolium multiflorum Lam., Festuca arundinacea Schreb., Triticum aestivum L. or a mixture (Vicia villosa plus a Trifolium hybrid diploid), the variants with Lolium perenne, Lolium multiflorum, Vicia villosa or Vicia villosa plus the Trifolium hybrid diploid, established between the maize rows (hybrid maize, cultivar Walterinio) on May 27, were the most efficient in case of both the soil losses and runoff reductions in the year 2019. For example, Triticum aestivum between the maize rows mostly reduced the soil losses and the surface runoff was similar (or higher) compared with the control (maize without any intercrop). The variant with Trifolium repens had mostly higher (or similar) soil loss values (compared with the control); in this variant, the runoff was lower compared with the control. We proved our hypothesis with regards to the higher reduction in the soil losses than with the runoff in the variant with Lolium perenne. The results from the years 2020 (the used variants with Lolium multiflorum, Secale cereale L., Trifolium incarnatum L., Phacelia tanacetifolia Benth., Lolium multiflorum plus Trifolium incarnatum, Lolium multiflorum plus Vicia pannonica Crantz) and 2021 (the variants with Lolium multiflorum, Lolium multiflorum -- early sowing, Secale cereale, Trifolium incarnatum, Phacelia tanacetifolia, Lolium multiflorum plus Trifolium incarnatum, a mixed culture = maize plus Lupinus albus L.) showed the variants with Trifolium incarnatum, the mixture (Lolium multiflorum plus Trifolium incarnatum), Phacelia tanacetifolia (in the year 2020) or the mixture (Lolium multiflorum plus Trifolium incarnatum) and a mixed culture (maize plus Lupinus albus) (2021) had the most positive effect -- the soil loss and surface runoff values were lower when the maize was > 2 m compared with the maize < 1 m. The results obtained in the period 2019--2021 showed the grasses were the most efficient in decreasing the soil losses when the maize was < 1 m and when the maize was > 2 m with the used mixtures. [ABSTRACT FROM AUTHOR]

Carbon (C) cycling is crucial to agroecosystem functioning. Important determinants for the belowground C flow are soil food webs, with microorganisms and microfaunal grazers, i.e., nematodes, as key biota. The present study investigates the incorporation of plant-derived C into the nematode micro-food web under two different cropping systems, grassland (ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.)) and agroforest (willow (Salix schwerinii Wolf and Salix viminalis L)). To quantify the C flux from the plant into the soil micro-food web, grass and willow were pulse-labeled with 13CO2 and the incorporation of 13C into the nematode trophic groups was monitored 3, 7, 14 and 28 days after labeling. The natural stable isotope signals (13C/12C, 15N/14N) were analyzed to determine the structure of the nematode micro-food web. The natural isotopic δ15N signal revealed different trophic levels for omnivores and predators in grassland and agroforest soils. The incorporation of plant C into nematode tissue was detectable three days after 13CO2 labeling with the highest and fastest C allocation in plant feeders in grassland, and in fungal feeders in agroforest soil. C flux dynamics between the aboveground vegetation and belowground micro-food web varied with cropping system. This demonstrates that crop-specific translocation of C affects the multitrophic interactions in the root environment, which in turn can alter soil nutrient cycling. [ABSTRACT FROM AUTHOR]

In sheep production systems, diet type is an important factor affecting the eating quality of the meat produced. The objective of this study was to assess the effect of binary swards on the slaughter performance, descriptive sensory profile, consumer liking and instrumental texture of lamb meat. Five dietary treatments were investigated, perennial ryegrass (Lolium perenne L.; PRG), PRG plus white clover (Trifolium repens L.; PRG+WC), PRG plus red clover (Trifolium pratense L.; PRG+RC), PRG plus chicory (Chicorium intybus L.; PRG+Chic) and PRG plus plantain (Plantago lanceolata L.; PRG+Plan). Post – weaning sixty Texel sired crossbred lambs (n = 12 per dietary treatment) were selected from the main cohort of lambs born in 2022 and further balanced for sex and reared litter size. The M. longissimus thoracis et lumborum (LTL) was obtained from each lamb post-slaughter. Meat samples were analysed by a trained sensory panel, a consumer panel as well as Warner-Bratzler shear force (WBSF) measurements. All data were analysed using a linear mixed model PROC MIXED in SAS. Mean slaughter weights of 46.0 ± 0.36 kg and cold carcass weights of 22.2 ± 0.51 kg were achieved with no differences observed across dietary treatments (P > 0.05). On average, lambs were 217 d of age at slaughter. Lambs finished on PRG and PRG+Plan had similar growth rates, however binary mixtures containing PRG plus any one of WC, RC (P < 0.01) or Chic (P < 0.05) increased average daily gain (ADG) and reduced the number of days required for lambs to reach slaughter (P < 0.05), relative to lambs grazing the PRG monoculture. Meat from PRG+Plan lambs was scored lower by the trained sensory panel for initial tenderness (P < 0.001) and overall tenderness (P < 0.001) when compared to meat from any other dietary treatment. Consumers scored meat from PRG or PRG+WC lambs higher for tenderness (P < 0.05) and flavour (P < 0.01) in comparison to meat produced from PRG+Plan lambs. Relative to meat from PRG+Plan lambs, PRG, PRG+WC and PRG+Chic lamb meat scored higher for overall liking (P < 0.01) when assessed by the consumer panel. Results show that companion forage inclusion increased lamb growth performance in the post-weaning period thus reducing age at slaughter. However, findings suggest that the addition of plantain to the grazed sward may negatively affect the eating quality of lamb meat, highlighting the need to consider diet type in tandem with meat eating quality when selecting finishing systems for pasture fed lambs. • Companion forage inclusion generally increased average daily gain post-weaning and reduced age at slaughter. • Meat from lambs grazing perennial ryegrass and plantain received lower scores for sensory tenderness when assessed by the trained and consumer panels. • Meat quality attributes must be considered when selecting lamb-finishing diets. [ABSTRACT FROM AUTHOR]

Policy measures have been taken to improve water quality in the Netherlands. These measures include the abolishment of derogation, which allowed dairy farmers to go beyond the maximum application of 170 kg nitrogen (N) from organic fertiliser per hectare, and additional measures of the 7th Nitrates Action program. Grass-clover swards, known for their symbiotic N fixation, could be a strategy to deal with stricter N policies and can potentially improve the environmental sustainability and economic viability of Dutch dairy farms. The aim was to assess the effects of stricter N policies on the farm structure, farm income and environmental performance of a representative Dutch dairy farm on a sandy soil, and to assess the effect of incorporating perennial ryegrass-red white clover (GC rw) swards and perennial ryegrass-white clover (GC w) swards into the grassland management of this farm using a model. A whole-dairy farm linear programming model was used with the objective function to maximize farm income. The model was combined with a farm nutrient balance and life-cycle assessment to determine the impact on nutrient surpluses and greenhouse gas emissions. We modelled a representative Dutch dairy farm with perennial ryegrass (PRG) before and after implementing stricter N policies. Thereafter, the implications of implementing GC rw and GC w swards was assessed. Including the policy measures increased the share of maize land (+12%), decreased the number of dairy cows (-9 cows), reduced farm income (€-18,858 yr-1), led to similar greenhouse gas emissions (∼800 kg carbon dioxide equivalents (CO 2 -eq) per tonne (t) of fat and protein corrected milk (FPCM)), and resulted in a lower N surplus (-65 kg ha-1 yr-1) and phosphate surplus (-4.4 kg ha-1 yr-1) for a scenario with only PRG. The use of GC rw and GC w swards could partly compensate for the reduction in farm income (€+9,255 up to +14,706 yr-1). A combination of PRG, GC rw and GC w resulted in the highest farm income. The use of grass-clover swards only had the most positive effect on greenhouse gas emissions (767 kg CO 2 -eq t-1 FPCM) and N surplus (113 kg ha-1 yr-1). Sensitivity analysis showed the importance of yields and feed characteristics on the obtained farm income. Grass-clover swards might partly compensate for the negative economic consequences of stricter N policies for Dutch dairy farms. Furthermore, implementing grass-clover swards reduced the GHG emission intensity of milk, but not always nutrient surpluses per hectare of farm land. [Display omitted] • Grass-clover swards might be a strategy for dairy farmers to deal with stricter nitrogen policies in the Netherlands. • Economic and environmental effects of stricter nitrogen policies were quantified with a whole farm model. • Number of cows, labour income and nutrient surpluses decreased under stricter policies. • Grass-clover swards improved labour income and carbon footprint but not always nutrient surpluses. [ABSTRACT FROM AUTHOR]

Legume-based forage plant mixtures are known to increase biomass production over the mixture species grown as pure stands (overyielding), which has partly been attributed to enhanced nitrogen availability by legumes. However, the relative importance of underlying processes of these positive diversity effects and their drivers are not fully understood. Here we assessed if outcome and causes of diversity effects depend on the legume-species genetic identity. Over five years, we cultivated different white clover (Trifolium repens) populations, a grass and forb species in pure stands and clover-based mixtures and recorded biomass yield. Complementarity and selection effects of mixtures and relative yields of mixture species were calculated based on both unfertilized and nitrogen-fertilized non-leguminous pure stands. Results showed that the clover population altered the overall strength of diversity effects as well as the direction and magnitude of their temporal trends, at least for the grass component of mixtures. Differences in diversity effects between clover populations diminished when fertilized instead of unfertilized non-leguminous pure stands were considered. Hence, a part of these differences likely results from dissimilar effects of clover populations on nitrogen availability. The findings reveal the possibility to improve overyielding of legume-based forage plant mixtures by decisions on legume-species genetic identity. [ABSTRACT FROM AUTHOR]

Keywords: Clover; grass; legumes; forage; alfalfa; herbicide resistance; buttercup; chicory; proximal hyperspectral sensing EN Clover grass legumes forage alfalfa herbicide resistance buttercup chicory proximal hyperspectral sensing 249 251 3 05/17/22 20220801 NES 220801 In this special issue of NZJA, we have collected papers that focus on new science in the discipline of plant sciences. Ranunculus acris control in dairy pasture - a comparison of herbicides, plant growth promoters, a bioherbicide and pregraze mowing. Clover, grass, legumes, forage, alfalfa, herbicide resistance, buttercup, chicory, proximal hyperspectral sensing Continuing the legume theme, Gerard et al. ([7]) present an interesting data set comparing yields of eight perennial clover cultivars under field conditions over two years. [Extracted from the article]

The effect of soil environment on cultivars compatibility was evaluated in a cutting field experiment during two growing seasons. A factorial combination of four perennial ryegrass (Lolium perenne L.; PR) and three white clover (Trifolium repens L.; WC) cultivars were grown on deep (DSS) and shallow (SSS) soils under irrigated conditions. Measurements included herbage accumulation (HA), root attributes, leaf chlorophyll content, and interception of photosynthetic radiation. The PR–WC compatibility was affected by soil environment. In both soil sites and growing seasons, the WC + PR herbage accumulations were similar but with different PR and WC partial accumulation. In DSS, the partial PR HA was 22% less than that observed in SSS; the partial WC HA was almost twice in DSS relative to SSS. In SSS, the WC stolon growing point numbers, stolon length, and stolon biomass increased 60, 88, and 94% relative to DSS, respectively. In the same way, the mixed sward increased root biomass and root length density, which was considered as a mechanism for improving plant resources capture from the soil. At cultivar level, the PR–WC compatibility was affected mainly by WC cultivar, and the effect of PR cultivar was fairly weak. The medium‐leaved WC cultivar 'Will' showed the greatest compatibility with PR, particularly with cultivar 'Bealey'. These results are valuable when designing new management strategies for mixed sward production in marginal environments. Modern cultivars of PR have capacity for adapting to marginal environments; however, it is necessary to improve the competitive ability of WC to capture soil resources under marginal soil conditions. Core Ideas: Understanding compatibility of perennial ryegrass and white clover cultivars allows for optimized mixed sward herbage accumulation.Modern cultivars of perennial ryegrass have capacity for adapting to marginal environments.Mixed sward changes its phenotypic expression in marginal environments. [ABSTRACT FROM AUTHOR]

The nutrient use efficiency of perennial ryegrass (Lolium perenne L.) (PR) and white clover (Trifolium repens L.) (WC) cultivars can affect the grass-legume compatibility of different cultivar combinations, thus impacting the sustainability of animal production systems, especially on marginal soils. The objective of this work was to evaluate N, P, and K absorption efficiency (NAE, PAE, and KAE) and use efficiency (NUE, PUE, and KUE). This study included two experiments with the same full factorial treatment structure (4 PR cultivars x 3 WC cultivars) in a randomized complete block design under field conditions and a completely randomized pot design. The field cutting experiment was carried out on sites with two contrasting soil depths and the pot experiment was conducted under shade conditions. Results showed nonsignificant (P > 0.05) factor interactions for DM yield and both nutrient absorption and use efficiency. The NAE and PAE of PR 'Extreme' and 'Bealey' were higher under field conditions than pot conditions. In the field experiment, NAE of WC 'Will' (2.33 kg DM ha-1)/mg N kg-1)) tended to be similar (P < 0.05) to other cultivars in deep soil, but was significantly higher (P < 0.001) than 'Ladino' and 'Bounty' in shallow soil (0.70 kg DM ha-1)/mg kg-1). The evaluation of NUE and PUE under field conditions and KUE under pot conditions showed that PR 'Bealey' and WC 'Ladino' reached higher values. In conclusion, results showed a cultivar effect on nutrient use efficiency in PR/WC mixtures, which had an impact on PRWC compatibility, mainly due to the higher absorption efficiency of PR 'Bealey' and WC 'Will', both of which exhibited the highest degree of compatibility for total DM yield. [ABSTRACT FROM AUTHOR]

Perennial ryegrass (Lolium perenne L.) is cultivated in many countries for its high yield and good quality forage. Its cultivars have specific functional traits, such as phenology, growth habit and rate, which affect the competitiveness and productivity of mixtures. The cultivation of new cultivars of perennial ryegrass or mixtures of cultivars in swards is one of the complementary measures to improve the condition of swards. The study was aimed to determine the productivity potential of three newer, less investigated Lithuanian perennial ryegrass (Lolium perenne L.) cultivars 'Elena DS', 'Raminta', 'Verseka', and cultivar mixtures in single-species swards and in mixtures with legumes - white and red clover. The experiment was set up in the central part of Lithuania in the Nemoral climate zone. Mineral fertilisers were not used for the mixtures with legumes, singlespecies crops were fertilised with N150 kg ha-1 yr-1. Over the two experimental years, the average dry matter yield of perennial ryegrass was 8.00 t ha-1 for the 'Elena DS', 7.4 t ha-1 for 'Verseka', 6.9 t ha-1 for 'Raminta' and 7.4 t ha-1 for the cultivar mixture. In the 1st year of sward use, the productivity of the perennial ryegrass cultivars did not differ significantly. In the 2nd year, the productivity of 'Elena DS' was significantly higher compared with that of the other cultivars cultivated in single-species crops. The influence of functional traits of the cultivars was significant in the first year of cultivation and persisted in single-species swards but not in mixtures from the second year onwards. The plants of the cultivar 'Elena DS' allowed the development of clover in the mixture, resulting in an increase in herbage productivity and crude protein content. The results of the experiment suggest that a mixture of perennial ryegrass cultivars can be used in swards, as a similar dry matter yield was recorded compared to a single-cultivar swards. However, the benefits of swards may vary from season to season, and more research is needed to assess the impact of a mixture of cultivars on grass productivity and quality with ageing of swards and accumulation in different environmental conditions. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of perennial ryegrass (Lolium perenne L.; PRG) ploidy and white clover (Trifolium repens L.) inclusion on milk production, dry matter intake (DMI), and milk production efficiencies. Four separate grazing treatments were evaluated: tetraploid PRG only, diploid PRG only, tetraploid PRG with white clover, and diploid PRG with white clover. Individual DMI was estimated 8 times during the study (3 times in 2015, 2 times in 2016, and 3 times in 2017) using the n -alkane technique. Cows were, on average, 64, 110, and 189 d in milk during the DMI measurement period, corresponding to spring, summer, and autumn, respectively. Measures of milk production efficiency were total DMI/100 kg of body weight (BW), milk solids (kg of fat + protein; MSo)/100 kg of BW, solids-corrected milk/100 kg of BW, and MSo/kg of total DMI. Perennial ryegrass ploidy had no effect on DMI; however, a significant increase in DMI (+0.5 kg/cow per day) was observed from cows grazing PRG-white clover swards compared with PRG-only swards. Sward white clover content influenced DMI as there was no increase in DMI in spring (9% sward white cover content), whereas DMI was greater in summer and autumn for cows grazing PRG-white clover swards (+0.8 kg/cow per day) compared with PRG-only swards (14 and 23% sward white clover content, respectively). The greater DMI of cows grazing PRG-white clover swards led to increased milk (+1.3 kg/cow per day) and MSo (+0.10 kg/cow per day) yields. Cows grazing PRG-white clover swards were also more efficient for total DMI/100 kg of BW, solids-corrected milk/100 kg of BW, and MSo/100 kg of BW compared with cows grazing PRG-only swards due to their similar BW but higher milk and MSo yields. The results highlight the potential of PRG-white clover swards to increase DMI at grazing and to improve milk production efficiency in pasture-based systems. [ABSTRACT FROM AUTHOR]

Sheep farmers can increase production levels as a means to improve economic outcomes. However, this intensification can potentially result in more nitrogen (N) leaching which is at odds with the increasing pressure on farmers to reduce the quantity of N lost into the environment. Therefore, there is increasing interest in the use of alternative forages, such as Italian ryegrass and plantain, which could potentially allow farmers to increase production while decreasing N leaching. This study quantified and compared the quantity of N leaching under sheep grazing four different forages: perennial ryegrass/white clover (RGWC), Italian ryegrass/WC (IRWC), plantain/WC (PWC) and a winter brassica. Five replicates of each forage were established on plots of 800 m2 (40 m x 20 m). Each plot had an independent mole-pipe drain system with tipping-bucket monitoring equipment at the end of the pipe drain. Drainage volume and N concentrations (nitrate-N: NO 3 ⁻-N; ammonium-N; total-N) in drainage water were measured to estimate N losses. The forages were grazed according to the best management practice for each forage type over a two-and-a-half-year period (Year 1: July-December 2019; Year 2: January-December 2020; and Year 3: January-December 2021). In the first two years of this study, NO 3 ⁻-N leaching losses under IRWC and PWC were very small (ranging from 0.4 to 0.5 kg N/ha), and they were not different (P > 0.05) from those under RGWC. However, in Year 3, the leaching losses under IRWC and PWC treatments were greater (P < 0.05) than those under RGWC. This increased leaching was probably due to the need to re-establish these pastures. As part of renewing these swards, the IRWC and PWC plots were fallow during the key late summer-autumn period. In contrast, NO 3 ⁻-N leaching losses under brassica forages (3.5–6.4 kg N/ha) were greater (P < 0.05) than under RGWC (0.5–1.5 kg N/ha). Overall, the leaching losses measured under sheep grazing the forages were much smaller than those commonly reported by dairy studies. [Display omitted] • In recent years, there has been significant concern regarding the leaching of nutrients from grazing systems. • This study quantified the amount of nitrogen leaching lost in drainage water from sheep grazing four different forages. • Mole-and-pipe drainage systems were used to monitor drainage volume and collect samples. • Overall, leaching losses under sheep grazing forages were small. • Modern sheep grazing systems may offer mitigation options for dairying areas with high NO 3 - leaching. [ABSTRACT FROM AUTHOR]

The aim of the paper is to highlight the role of natural germoplasm resource of the species Lolium perenne by adapting it to a wide variety of abiotic conditions. The impact of the presence of the species together with other legume species such as Trifolium repens in the construction of multifunctional temperate climate associations is also studied. The concept of meadow multifunctionality has developed with the reconsideration of their sustainability character in terms of an emphasis on the negative impact on the environment. Land use change in recent decades, the abandonment of grazing and the decline of traditional agricultural practices or afforestation are a major threat to biodiversity. Often the bispecific dominance between Lolium perenne and Trifolium repens is improve both feed quality and soil quality due to the added value of fixing atmospheric nitrogen. The species of Lolium perenne due to its high ecological plasticity is thus considered to be particularly important especially due to the fact that it covers a wide range of environmental conditions thus developing models of great genetic diversity which leads to a development of genomic resources. Lolium perenne is thus adapted to defoliation, fertilization and growth cycles, which is particularly important because defoliation through animal grazing can have major effects on the structure and functioning of grassland ecosystems affecting the production of shoots and root rotation of communities. of plants, but also photosynthetic rates and carbon allocation in plants: energy flow in the plant-soil system. Thus, the highlighting of the qualities of Lolium perenne species are important premises for the genetic progress of this species but especially for understanding the natural functioning of plant associations dominated by it, which leads to environmentally friendly management practices. [ABSTRACT FROM AUTHOR]

White clover (Trifolium repens L.) is at a disadvantage to perennial ryegrass (Lolium perenne L.; PRG) due to its limited cold tolerance and low growth rates at colder temperatures, which can affect subsequent spring herbage dry matter (DM) availability. The effect of PRG ploidy on white clover morphology and growth over winter, and its subsequent recovery in spring and the following growing season, is poorly understood. The objective of this study was to compare the effect of white clover inclusion and PRG ploidy on sward structure, plant morphology and growth of PRG--white clover swards over winter. Four swards (diploid PRG only, tetraploid PRG only, diploid PRG--white clover and tetraploid PRG--white clover) were evaluated over a full winter period (November-February) at a farmlet scale. The PRG ploidy had no effect on herbage DM production, white clover content or tissue turnover (P > 0.05) over winter. However, white clover inclusion caused a significant decrease in herbage DM production (P < 0.001; -254 kg DM/ha) and tiller density (P < 0.001; -1,953 tillers/m2) over winter. Stolon mass was not affected by PRG ploidy (P > 0.05); however, stolon length and number of leaves per stolon were affected by PRG ploidy (P < 0.05). Including white clover in PRG swards can alter winter sward dynamics, potentially causing difficulties in subsequent spring management and performance due to the reduced over-winter growth rate when compared with PRG. [ABSTRACT FROM AUTHOR]

In New Zealand, a commonly sown pasture combination is perennial ryegrass with white clover. The hydrothermal time model (HTT) was used to quantify germination under different temperature (T) and water potential (WP) conditions for white clover 'Nomad' and perennial ryegrass 'Stellar AR1'. Seeds were germinated in vitro under a range of T × WP combinations, and HTT models were fitted to germination time course data. Rapid germination of white clover under optimum T and WP was reflected by a much lower value for its HTT constant compared with perennial ryegrass (10.8 vs 80.7 MPa °C d). However, the lower base water potential for perennial ryegrass (−1.29 vs −0.495 MPa) and a higher threshold temperature for thermoinhibition (21.8 vs 18.3°C), meant that predicted perennial ryegrass germination was more resilient in warm dry conditions. HTT models can be used to assist decisions about the timing of perennial ryegrass and white clover sowing. [ABSTRACT FROM AUTHOR]

We tested whether selection of ryegrass for reduced root hair length and density would reduce root competition on white clover for phosphate (P). A Rhizosheath Selection Tool was used to select two ryegrass populations with contrasting root hair traits. These were grown at five soil P levels in a glasshouse experiment and rhizosheath trait selection had no effect on growth or shoot P concentrations. The ryegrass populations were also grown with white clover in soils with Olsen P12 or 19 mg L−1. In the Olsen P12 soil, clover grown with the smaller rhizosheath ryegrass had significantly heavier shoots and contained more P than clover grown with the larger rhizosheath ryegrass. In the Olsen P19 soil differences in ryegrass rhizosheath had no effect on clover growth. The results showed that under the experimental conditions, grass-clover competition for soil P could be modified by the rhizosheath traits of ryegrass. [ABSTRACT FROM AUTHOR]

This experiment investigated the feasibility of using herb-clover mixes to enable early weaning of lambs at ∼60 days of age. Over two years, twin lambs weighing more than 16 kg were allocated to three treatments: ryegrass pastures until 90 days-of-age, herb-clover mix until 90 days-of-age or weaned at ∼60 days of age onto herb-clover mix. In 2014, lambs offered the herb-clover mix, weaned at 60 or 90 days, were heavier at 90 days than lambs grazing on pasture with their dams. In 2015, lambs that weaned early onto the herb-clover mix were lighter at the same age as lambs that remained with their dam, but they still achieved a commercial weight. Ewes weaned early were heavier at weaning than ewes suckling lambs on ryegrass pasture in both years. Under some conditions, early weaning of lambs onto a herb-clover mix can be an effective alternative to conventional weaning on ryegrass pasture. [ABSTRACT FROM AUTHOR]

In order to examine the ecological effects of planting grass in kiwifruit orchards in Shiyan, Hubei Province, we selected two kiwifruit orchards located in Changpingtang and Gaoling villages as study sites. We assessed the effects of two grass planting methods, namely, artificial and natural grass planting, and selected white clover and ryegrass as artificial grass types. The effects of artificial and natural grass planting on soil nutrients, weed species and quantity, and fruit yield and quality were compared and analyzed. The results showed that compared with natural grass planting, artificial grass planting could effectively reduce the number and quantity of weed species, particularly in response to planting white clover. It also increased the contents of soil organic matter, alkali-hydrolyzed nitrogen, available phosphorus, and available potassium in the two kiwifruit orchards, and reduced the pH value of alkaline soil. Furthermore, of the two artificial grass types assessed, ryegrass was found to have a better effect on reducing soil pH than white clover. However, neither of the grass planting methods had a significant effect with respect to improving soil temperature, or fruit yield and quality, although artificial grass planting was found to significantly increase soil humidity in the Gaoling kiwifruit orchard（P<0.05）. With an extension of planting time, planting ryegrass clearly increased the contents of soil alkali-hydrolyzed nitrogen, available phosphorus, and available potassium. The findings of this study revealed that compared with planting natural grass and white clover, planting ryegrass was more suitable for kiwifruit orchards in Shiyan, Hubei Province. [ABSTRACT FROM AUTHOR]

Context: High nitrogen (N)-fertiliser application levels and high stocking rates have been shown to optimise herbage dry-matter (DM) production in grass-only systems. Conversely, swards including white clover (Trifolium repens L.) are commonly suited to production systems at low N-fertiliser application levels (<150 kg N/ha) and low stocking rates (fewer than two livestock units (LU) per hectare). Despite this, the use of N fertiliser on grass–clover swards has generally increased during the past few decades, particularly in more intensively managed swards under dairy farming. Increasing inorganic N decreases sward white clover content in grass–clover swards, and increasing stocking rate on grass–clover swards can result in damage to white clover plants. However, under high N-application levels, a high stocking rate can also potentially minimise the negative effects of increased grass growth on sward white clover content. Aims: The objective of the present study was to investigate the persistency of white clover in an intensive animal-grazing system, under a high N-fertiliser application level (250 kg N/ha) and at a high stocking rate (2.75 LU per hectare) over a 3-year period (2014–2016). Methods: The study was a 2 × 2 factorial design, consisting of two perennial ryegrass ploidies (diploid, tetraploid) and two white clover treatments (grass-only, grass–clover). Four sward treatments (diploid-only, tetraploid-only, diploid + clover, tetraploid + clover) were evaluated over a full grazing season at a system scale. Sward measurements were taken at each grazing occasion for 3 years. Key results: Over the 3 years, grass–clover swards produced an additional 1468 kg DM/ha when compared with grass-only swards. Sward white clover content decreased by 17% over the three study years. Conclusions: This decrease in sward white clover content led to a decrease in contribution to cumulative herbage DM production. Implications: Although the present study showed that white clover inclusion can increase herbage DM production at high N-fertiliser application levels, in association with high stocking rates, the initial extra herbage DM production on grass–clover swards decreased each year. Further studies should be undertaken to investigate whether the decline in white clover persistence observed is progressive over a longer time period. White clover can improve herbage dry matter production in grass-based milk production systems. This study investigated the persistency of white clover under a high N-fertiliser application level and at a high stocking rate. White clover inclusion initially increased herbage DM production under these conditions; however, the initial extra herbage DM production on grass–clover swards decreased each year. [ABSTRACT FROM AUTHOR]

Grazed grass is considered the cheapest feed available for dairy cows in temperate regions, and to maximise profits, dairy farmers must utilise this high-quality feed where possible. Recent research has reported that including white clover (Trifolium repens L.) in grass swards can have a positive effect on milk production. The aim of the present study was to quantify the effect of tetraploid and diploid perennial ryegrass (Lolium perenne L.; PRG) swards sown with and without white clover on the milk production of grazing dairy cows. Four grazing treatments were used for the study; tetraploid-only PRG swards, diploid-only PRG swards, tetraploid PRG with white clover swards and diploid PRG with white clover swards. Thirty cows were assigned to each treatment and swards were rotationally grazed at a stocking rate of 2.75 cows/ha and a nitrogen-fertiliser application rate of 250 kg/ha annually. There was no significant effect of ploidy on milk production. Over the present 4-year study, cows grazing the PRG–white clover treatments had greater milk yields (+597 kg/cow.year) and milk-solid yield (+48 kg/cow.year) than cows grazing the PRG-only treatments. This significant increase in milk production suggests that the inclusion of white clover in grazing systems can be effectively used to increase milk production of grazing dairy cows. Recent research has reported that perennial ryegrass (PRG) ploidy and white clover inclusion in grazing swards can have a positive effect on milk production. In the present study, cows grazing PRG–white clover swards had greater milk yields than did cows grazing PRG-only swards, while grass ploidy had no effect. This significant increase in milk production from PRG–white clover swards suggests that the inclusion of white clover in grazing systems can be effectively used to increase milk production. [ABSTRACT FROM AUTHOR]

This study compared the fertiliser effects of different types of liquid anaerobic digestates on the growth of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), and on soil's primary plant macronutrients and microbial abundance. A factorial design with seven fertilisers and one control (five liquid anaerobic digestates, undigested cattle slurry, calcium ammonium nitrate (CAN) 27% N, and no fertiliser) and four plant schemes (monocultures of perennial ryegrass and white clover, a mix of both, and bare soil) were tested. Plant (forage yield, leaf area index (LAI), canopy height and root mass) and soil (concentrations of total N, Morgan's extracted P and K) responses were measured, as well as soil bacterial/archaeal (16S) and fungal (18S) gene copy numbers (GCN). Digestates and cattle slurry with different chemical compositions, when balanced in terms of the quantity of dry matter applied, had comparable forage yield responses (p > 0.05), with higher yields than CAN mostly observed in ryegrass and mixed vegetation (p < 0.05). The presence of white clover contributed to higher soil N (p < 0.05). Soil available P was increased by biofertiliser applications (p < 0.05). Soil available K was influenced by the interaction between biofertiliser and type of plant (p < 0.05), with ryegrass/mixed swards showing lower K concentrations than white clover and bare soil. Soil bacterial (16S) GCN responded to the interaction between fertiliser/vegetation (p < 0.05), while archaeal (16S) and fungal (18S) GCN only to the type of vegetation (p < 0.05). The application of anaerobic digestates showed low direct impacts on the microbial GCN of the soil, mostly influenced by type of vegetation. The biofertilisers showed comparable performances and effects, despite substantial differences between their chemical compositions, indicating a possible complex matrix of interactions between fertiliser-plant-soil-environment. • Different types of anaerobic digestates drove comparable forage yield responses. • Ryegrass showed better response to anaerobic digestates fertilisation than white clover. • Anaerobic digestate application had low influence on soil microbial numbers. • The type of vegetation had strong influence on soil microbial numbers. [ABSTRACT FROM AUTHOR]

Dry matter (DM) production of multispecies swards compared to perennial ryegrass (Lolium perenne; PRG) swards under intensive grazing warrants investigation as it is relatively unknown. A 5 × 2 factorial experiment, with five sward types and two defoliation methods, was used to investigate the effect of grazing versus cutting on dry matter (DM) production of multispecies and PRG‐only swards. Five sward types were established namely: a PRG‐only sward, receiving 250 kg N ha−1 year−1 (PRG250), and a PRG‐only sward (PRG90), a two‐species sward with PRG and white clover (Trifolium repens; PRGWC), a six‐species sward (6S) and a nine‐species sward (9S), each receiving 90 kg N ha−1 year−1. Cutting plots measured 1.95 × 10 m and grazing plots measured 10 × 10 m. All plots were harvested concurrently every 21–30 days from April‐November for two years (2015 and 2016). A strip from the grazing plots was cut for DM yield determination prior to turning in cattle for grazing. There was an interaction between sward type and defoliation method (p < .01), whereby there was no effect of defoliation method on the PRG‐only swards, however, the annual DM production of PRGWC, 6S and 9S swards reduced under grazing compared to cutting (p < .001; on average 1,929 kg DM/ha lower). Multispecies swards had lower DM production under grazing compared to cutting, while the DM yield of PRG‐only swards was unaffected by defoliation method. [ABSTRACT FROM AUTHOR]

Grazed grass is the cheapest feed available for dairy cows in temperate regions; thus, to maximize profits, dairy farmers must optimize the use of this high-quality feed. Previous research has defined the benefits of including white clover (Trifolium repens L.) in grass swards for milk production, usually at reduced nitrogen usage and stocking rate. The aim of this study was to quantify the responses in milk production of dairy cows grazing tetraploid or diploid perennial ryegrass (Lolium perenne L.; PRG) sown with and without white clover but without reducing stocking rate or nitrogen usage. We compared 4 grazing treatments in this study: tetraploid PRG-only swards, diploid PRG-only swards, tetraploid with white clover swards, and diploid with white clover swards. Thirty cows were assigned to each treatment, and swards were rotationally grazed at a farm-level stocking rate of 2.75 cows/ha and a nitrogen fertilizer rate of 250 kg/ha annually. Sward white clover content was 23.6 and 22.6% for tetraploid with white clover swards and diploid with white clover swards, respectively. Milk production did not differ between the 2 ploidies during this 4-yr study, but cows grazing the PRG-white clover treatments had significantly greater milk yields (+596 kg/cow per year) and milk solid yields (+48 kg/cow per year) compared with cows grazing the PRG-only treatments. The PRG-white clover swards also produced 1,205 kg of DM/ha per year more herbage, which was available for conserving and buffer feeding in spring when these swards were less productive than PRG-only swards. Although white clover is generally combined with reduced nitrogen fertilizer use, this study provides evidence that including white clover in either tetraploid or diploid PRG swards, combined with high levels of nitrogen fertilizer, can effectively increase milk production per cow and per hectare. [ABSTRACT FROM AUTHOR]

• Red clover inclusion to a grass sward improved pre-weaning lamb performance. • Clover or herb inclusion to a grass sward improved post-weaning lamb performance. • Days to slaughter was reduced by grazing binary sward types. • Ewe performance was largely similar across all sward types studied. Ireland's competitive advantage in sheepmeat production is based on the efficient and cost effective production and utilisation of pasture. The objective of this study was to assess the influence of binary mixtures of perennial ryegrass (Lolium perenne L.) plus a companion forage on ewe and lamb performance at pasture. Five sward mixtures were compared, namely; i) perennial ryegrass (Lolium perenne L.;PRG), ii) PRG plus white clover (Trifolium repens L.;PRG + WC), iii) PRG plus red clover (Trifolium pratense L.;PRG + RC), iv) PRG plus plantain (Plantago lanceolate L.;PRG + Plan) and v) PRG plus chicory (Chicorium intybus L.;PRG + Chic). Five farmlets with one sward treatment assigned to each were established which 23 ewes plus their lambs grazed from March to December for the years 2018 to 2021 inclusive. Farmlets were rotationally grazed, stocked at 11.5 ewes/ha and received 130 kg nitrogen/ha/year. Lambs were weaned on average at 15 weeks of age. Post-weaning a leader-follower grazing system was implemented with lambs grazing ahead of the ewes. Post weaning, lambs were weighed fortnightly and drafted at a live weight of 42 kg in June and increasing by 1 kg per month thereafter to produce a target carcass weight of 20 kg. Results show that lamb lifetime average daily gain (ADG) was greater for lambs grazing all binary sward mixtures relative to grazing PRG. Relative to PRG, lamb lifetime ADG was increased by between 17 g/day (PRG + Plan; P < 0.01) to 31 g/day (PRG + RC, and PRG + Chic; P < 0.001) and subsequently the number of days required to reach slaughter (DTS) was reduced by between 15.8 days (PRG + Plan; P < 0.01) to 28.6 days (PRG + RC; P < 0.001) with the addition of a companion forage. As a result of lower DTS, the average total number of anthelmintic treatments administered per lamb was significantly reduced for lambs grazing on all of the binary sward mixtures relative to PRG (P < 0.001). Scanned litter size and ewe milk yield were similar across all sward types as were ewe body weight (BW) and body condition score (BCS) from mating up until 6 weeks post-lambing (P > 0.05). Of the ewes retained from one production year to the next, those grazing PRG + WC, PRG + RC and PRG + Plan had a greater BW than those grazing PRG at the second mating event (P < 0.05), whilst, PRG + RC, PRG + Plan and PRG + Chic ewes had a greater BCS than PRG ewes (P < 0.05). These results suggest the suitability of binary sward mixtures under an intensive sheep grazing system to improve ewe and lamb performance at pasture. [ABSTRACT FROM AUTHOR]

• Urine volume and N concentration influences relative N loading onto the soil. • Forages with low DM% present an opportunity to modulate cows' urination behavior. • Feeding chicory or plantain had a positive effect on milk production in dairy cows. • Cows fed the herbs urinated more often and greater volumes per day than ryegrass. • Urinary N concentration was lower from cows grazing the herbs than ryegrass. Urine patches from ruminant livestock are risk areas for soil nitrogen (N) loss from grazed pastures. Urine volume and N concentration at any given urine event influences the relative N loading onto the soil. Forages such as chicory (Cichorus intybus L.) and plantain (Plantago lanceolata L.) with high water and mineral content present an opportunity to modulate urination behaviour and urinary nitrogen (UN) excreted into the environment. This study compares urination patterns, milk production and N use efficiency, of cows grazing chicory, plantain, or ryegrass (Lolium perenne L.) with 13% white clover (Trifolium repens L.; RGWC) herbage. Fifty-four Friesian x Jersey cows in late lactation were blocked into replicated groups of six cows, and offered one of three pasture types. Automated urine sensors measuring urine volume and timing were affixed to approximately 10 random cows per treatment for 24 h. Milk yield was similar for all treatments (19.1 ± 0.52 kg/cow.day), but milk solids production (protein + fat) were greater from cows grazing chicory than RGWC (1.86 vs 1.72 kg MS/cow.day, P < 0.01) while plantain was intermediate (1.76 kg MS/cow.day). There was large variation in urine event volume (0.13–11.6 l per event), though mean urine volume per event was similar for each treatment (3.01 ± 0.3 l per event; P = 0.24). Water, sodium and potassium intakes from herbage was greatest for chicory compared with plantain or RGWC. Frequency of urination increased with increasing water, sodium and potassium intakes and cows grazing chicory and plantain urinated more often (28.6 and 21.2 events/cow.day, respectively) than those grazing RGWC (13.9 events/cow.day, P < 0.05). Consequently, cows grazing chicory excreted 1.5 and 2.4 times more urine per day (P < 0.01) than cows grazing plantain and RGWC, respectively. Apparent N intake was similar between cows grazing chicory and RGWC, but greater than cows grazing plantain. However, UN concentrations from cows grazing chicory and plantain were similar (P > 0.05), but substantially lower than RGWC (1.3 vs 4.8 g/kg; P < 001). The reduction in UN in cows grazing herbs is mainly attributed to increased number of urinations, which resulted in urine dilution. The combination of similar urine volume per event in all three forages, frequent urinations and substantially lower UN concentration in cows grazing the forage herbs indicate a benefit from forage herbs to reduce N load onto pasture. [ABSTRACT FROM AUTHOR]

The aim of this research was to assess the potential of using perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) forages containing plantain (Plantago lanceolata L.) (PRGWC + Plantain) to mitigate nitrate (NO3−) leaching in grazed grassland. Lysimeter studies were carried out to determine NO3− leaching losses from the PRGWC + Plantain forage, compared with the standard perennial ryegrass and white clover forage (PRGWC) under three different irrigation conditions (flood, rotorainer and pivot). Fresh dairy cow urine (700 kg N ha−1) was applied to these lysimeters in early summer (December) and late summer (February). Nitrogen (N) dynamics and the abundance of ammonia oxidising bacteria (AOB) and archaea (AOA) were also determined in companion mini-plots alongside the lysimeters. Nitrate leaching losses from the PRGWC + Plantain forage were 82% lower than those from the PRGWC forage when urine was applied in December and 74% less when urine was applied in February (P < .05). This was possibly due to the release of biological nitrification inhibitors by plantain which slowed down the nitrification process and this, combined with a lower drainage volume, was largely responsible for the lower NO3− leaching losses in the PRGWC + Plantain forages. The three different irrigation schemes did not significantly affect NO3− leaching losses under the two forage types. These results demonstrate the potential of using PRGWC + Plantain forages as an effective mitigation option for NO3− leaching in grazed grasslands. [ABSTRACT FROM AUTHOR]

Increasing herbage dry‐matter (DM) production and utilization on‐farm improves efficiency and sustainability. The objective of this study was to investigate the effect of perennial ryegrass, Lolium perenne L., ploidy and white clover, Trifolium repens L., inclusion on herbage DM production and utilization in an intensive animal grazing system, with high nitrogen (N) inputs (250 kg N ha−1) and a high stocking rate (2.75 livestock units ha−1). The study was a 2 × 2 factorial design, consisting of diploid and tetraploid cultivars sown as grass‐only and grass‐white clover to give four sward treatments (diploid‐only, tetraploid‐only, diploid‐white clover, tetraploid‐white clover). These were evaluated at each grazing occasion (8–10 per year) for 3 years (2014–2016). Tetraploid‐white and grass‐white clover swards had a lower sward density (−9 and −8 kg DM cm−1, respectively) and perennial ryegrass tiller density (−820 and −1,436 tillers m−2, respectively) leading to lower postgrazing sward heights (−0.15 and −0.41 cm, respectively), and maintained a superior nutritive value when compared with diploid‐only and grass‐only swards respectively. White clover inclusion resulted in higher productivity characterized by increased herbage DM production (+1,468 kg DM ha−1), improved nutritive value and increased utilization across the three grazing seasons. Varying sward composition with perennial ryegrass ploidy led to improved nutritive value and favourable grazing characteristics in tetraploid swards. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Including forage legumes in dairy systems can help address increasing environmental/economic concerns about perennial ryegrass monoculture pastures. This work investigated the effect of substituting fresh‐cut grass with increasing quantities of fresh‐cut white clover (WC) on milk fatty acid (FA) profile and transfer efficiency of dietary linoleic (LA) and α‐linolenic (ALNA) acids to milk fat. Three groups of three crossbred dairy cows were used in a 3 × 3 crossover design. Dietary treatments were 0 g kg−1 WC + 600 g kg−1 grass, 200 g kg−1 WC + 400 g kg−1 grass, and 400 g kg−1 WC + 200 g kg−1 grass. All treatments were supplemented with 400 g kg−1 concentrates on a dry matter basis. Cows had a 19‐day adaptation period to the experimental diet before a 6‐day measurement period in individual tie stalls. RESULTS: Increasing dietary WC did not affect dry matter intake, milk yield or milk concentrations of fat, protein or lactose. Milk polyunsaturated FA concentrations (total n‐3, total n‐6, LA and ALNA) and transfer efficiency of LA and ALNA were increased with increasing dietary WC supply. CONCLUSION: Inclusion of WC in pastures may increase concentrations of nutritionally beneficial FA, without influencing milk yield and basic composition, but any implications on human health cannot be drawn. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

• Multispecies increased forage intake and milk production of dairy cows. • Urinary N% was 20% lower when cows consumed multispecies. • Cows offered clover forages had a higher N intake and lower N use efficiency. • Perennial ryegrass resulted in the highest milk and N use efficiency. The objective of this experiment was to assess the impact of forage type on the DMI and milk production of mid-late lactation dairy cows. Perennial ryegrass (Lolium perenne) (PRG), PRG and white clover (Trilfolium repens) (PRGWC) and multispecies forage containing PRG, timothy (Phleum pratense), WC, red clover (Trifolium pratense), chicory (Cichorium intybus), and plantain (Plantago lanceolata) (MULTI), were compared using 24 cows in a three-period Latin square changeover design experiment. Cows were acclimatized to dietary treatments for 14 days, before entering a 21-day sampling period. Animals were housed indoors throughout the experiment, with access to forage treatments via computerized feeding boxes that recorded daily forage fresh weight intake and feeding behavior. Forage was harvested using a zero-grazer and feed boxes filled throughout the day. Forage dry matter was determined daily and forage DMI subsequently calculated. Milk yield (MY) was recorded daily, with milk composition (fat, protein, lactose) measured weekly. Once per sampling period, blood and rumen samples were collected. The partitioning of dietary nitrogen into milk, feces and urine was assessed for 6-days in each sampling period. Data was analyzed in SAS using PROC MIXED and checked for normality using UNIVARIATE. Forage botanical composition changed from period 1 to period 2 and 3, leading to significant differences in chemical composition between periods. Despite this, dry matter intake was consistently higher (P <0.05) for MULTI (20.14 kg DM) and PRGWC (18.30 kg DM) compared to PRG (17.06 kg DM). Offering cows MULTI increased daily MY (21.20 kg/d; P <0.001) compared to PRG (20.28 kg/d) and PRGWC (20.19 kg/d). Cows offered PRG made fewer visits to the feed box (P <0.001) and had a reduced meal size (kg/visit) (P <0.001) compared to PRGWC and MULTI. Offering cows MULTI reduced UN concentration (%) by 20% compared to either PRG or PRGWC. Perennial ryegrass resulted in higher dietary nitrogen use efficiency (NUE) compared to PRGWC or MULTI, though this effect was not consistent between periods. These results show that multispecies forages can increase milk production when offered to cows housed indoors. However, despite MULTI resulting in a lower UN concentration, cows offered PRG had a higher dietary NUE, likely due to a lower N intake. [ABSTRACT FROM AUTHOR]

Herbage accumulation (HA) data from four sites were combined to (1) address the hypothesis that adjustments to the New Zealand Forage Value Index to account for grass-clover interactions are not required and (2) explore the main effects of clover and nitrogen (N) fertiliser treatments on pasture productivity. In summer and autumn, pastures based on mid-season heading ryegrass cultivars consistently supported a greater clover content than pastures based on late heading cultivars. However, the clover ×  cultivar interaction was significant in only 2 of 17 HA data sets available for analysis. Thus, the hypothesis is supported. Compared with ryegrass monocultures, mixtures yielded an additional 2.4 (in the Low-N treatment) and 1.2 (High-N treatment) t DM/ha/year. Apparent N transfer from clover to grass was 79 (Low N) and 27 (High N) kg N/ha/year, derived from estimated N fixation efficiencies of 66 (Low N) and 50 (High N) kg N/t clover DM grown. [ABSTRACT FROM AUTHOR]

This paper describes how the core treatments in the national experimental design (all combinations of with/without clover and high/low nitrogen (N)) were implemented at an irrigated Canterbury site and monitored for three years. There was a consistent N × clover interaction, caused mainly by substantially lower yields in the Low N without clover treatment compared with all other treatments. At the phenotypic contrast level, the main effect of perennial ryegrass heading date on white clover content was significant in four of the nine seasonal data sets available: on these occasions, mixtures based on mid-season heading cultivars had higher clover content than later season-heading cultivars. However, this difference was not sufficient to cause any clover × cultivar interactions in herbage accumulation. Hence, the hypothesis that relative yield rankings of ryegrass cultivars do not differ when ryegrass is grown in monoculture or in mixture with white clover is supported. [ABSTRACT FROM AUTHOR]

The implementation and monitoring of the treatments in the core experiment (eight perennial ryegrass cultivars grown under four combinations of plus/minus clover and high/low nitrogen (N)) at a dryland Waikato site is described. The N x clover interaction was significant in 10 of the 17 seasonal or total annual herbage accumulation (HA) data sets available, caused by substantially lower annual HA in the low N minus clover treatment compared with all other treatments. Five significant scaling-type clover × cultivar interactions in HA were evident. In all cases, HA was greater in plus clover than minus clover treatments, but more so for some cultivars than others. However, the interactions were not consistent across seasons, and different cultivars or phenotypic contrast groups were involved in many cases. The hypothesis that relative HA rankings of ryegrass cultivars do not differ when ryegrass is grown in monoculture versus mixtures with white clover is supported. [ABSTRACT FROM AUTHOR]

This experiment, implemented at a Southland site representative of the lower South Island, New Zealand, and monitored for three full years from 2012/2013 to 2015/2016, was one of four throughout New Zealand that investigated the yield and nutritive value rankings of perennial ryegrass cultivars sown with or without white clover and with high (225 kg N/ha/annum) or low (50 kg N/ha/annum) application rates of nitrogen fertiliser. High inputs of nitrogen (N) fertiliser increased annual total dry matter (DM) yields and seasonal yield in 12 out of 18 measurement occasions. Adding white clover increased both annual dry matter yield and seasonal yield in 7 out of 18 measurement occasions. An interaction between clover and N input occurred on 10 occasions. Over time, the low N minus clover treatment became progressively lower yielding compared with the other three treatments. Ryegrass cultivar by clover interactions occurred in the latter half of the experiment. When analysed using ryegrass characteristics, early- and late-heading ryegrass cultivars produced similar yields when sown without clover, but late-heading ryegrass cultivars had a higher yield than early-heading pastures when sown with white clover (P < .001). Tetraploid ryegrasses had lower yields than diploid ryegrasses when sown without clover (P = .001). This difference was reduced when white clover was included. There was no significant interaction with ryegrass morphology when sown with white clover, as dense ryegrass cultivars always had a higher yield than open ryegrass cultivars (P = .005). Interactions occurred between N input levels and ryegrass cultivar. These occurred in early spring or late spring of each year. Analysis by ryegrass characteristics identified consistent interactions. Ryegrass cultivars with a late-heading date were higher yielding than early-heading cultivars at low N inputs (P = .029), but they were not different at high N inputs. Diploid and tetraploid ryegrass cultivars were similar with low N inputs, but diploid cultivars out-yielded tetraploid cultivars at high N inputs (P = .005). Significant interactions between N inputs and white clover addition affected herbage nutritive value but this did not extend to consistent interactions with ryegrass cultivar. Invertebrate pest numbers were generally low and unlikely to have influenced clover/ryegrass interactions or cultivar ranking. Results from this site suggest that ranking of ryegrass cultivars needs to account for both the inclusion of clover and variation in N fertiliser input. [ABSTRACT FROM AUTHOR]

The development of economic indexing systems for ranking cultivars of forage species requires new knowledge of factors that may influence the scaling of agronomic data collected in controlled, small-plot evaluation trials to whole farm systems. In the case of perennial ryegrass indexing, one such knowledge gap is the effect of growing clover with ryegrass on the relative rankings of different ryegrass cultivars. The objective of the investigation reported in this series was to test whether the relative yield rankings of perennial ryegrass (Lolium perenne L.) cultivars representing the range in phenotypes now available to New Zealand farmers as a result of recent breeding differed when those cultivars were grown in monocultures (as per standard protocols for cultivar yield trialling systems such as the National Forage Variety Trials) versus mixtures of grass and clover. This paper presents the rationale for the investigation by reviewing developments in perennial ryegrass breeding and evaluation in the context of grass-clover relationships in grazed pasture systems. The papers that follow report results from a multi-year, multi-site investigation comparing the yield, nutritive value and other productivity-related variables of eight perennial ryegrass cultivars grown with or without white clover (monoculture versus mixture respectively) at two levels of nitrogen fertiliser. Key considerations in the design of the experiment on which the investigation was based are discussed. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the associative effects between fresh perennial ryegrass and fresh white clover on intake and digestion in sheep. Five proportions of ryegrass and white clover, ranging from 0 to 1 in 0·25 increments ( DM basis), were allocated to two groups of five sheep according to a replicated 5 × 5 Latin square design, and intake behaviour and digestive parameters including methane ( CH4) emissions were measured. Feeding behaviour was affected through increased forage intake when the proportion of white clover was increased, and there were positive associative effects on intake, eating time and eating rate during the main meals consumed immediately after feed was given. These effects seemed to be related to a greater motivation to eat, rather to more efficient digestion, as no difference on DM digestibility (average 766 g kg−1) was detected. There were no differences in CH4 yield (average 18·1 g kg−1 DM intake) among the treatments. The optimal proportion of white clover fed with ryegrass to optimize intake and digestion was between 0·25 and 0·50. These results indicate that mixing perennial ryegrass and white clover positively affects forage intake in sheep and their motivation to eat. [ABSTRACT FROM AUTHOR]

Background and aims: Nitrogen balances are useful tools to increase our understanding of soil N processes and the efficiency of plants in taking up animal urine-N. This study aimed to investigate the effect of forage type on the fate of autumn-applied urine-N (700 kg N ha). Methods: In a 17-month lysimeter study the recoveries of N in herbage, leachate, nitrous oxide, and soil + roots (at the end of the trial) were determined for three forage types: perennial ryegrass-white clover (RGWC, Lolium perenne L. -Trifolium repens L.), Italian ryegrass (Italian RG, Lolium multiflorum Lam.), and lucerne ( Medicago sativa L.) under simulated autumn grazing. Results: We recovered 81.5-85.5% of the N applied in the urine. Italian RG had the greatest amount of urine-N recovered in the herbage (49.5%) and the least recovered in leachate (16.8%) making it the most efficient of the three forages for utilizing urine-N. For RGWC, herbage and leachate recoveries were 40.1% and 23.7% , respectively. Lucerne was the least efficient with recoveries of N in herbage and leachate equaling 18.4% and 52.5%, respectively. Conclusions: This study demonstrates that Italian ryegrass could offer benefits in reducing urine-N leaching losses through its ability to take up more urine-N over winter. [ABSTRACT FROM AUTHOR]

Decreasing reliance on fertiliser Nitrogen (N) is key to enhancing the sustainability of pasture-based agricultural systems. This study assesses the effect of sward type on annual and seasonal herbage dry-matter (DM) production potential, sown species and unsown species contribution to herbage DM under an intensive dairy-calf to beef system. Three sward types were investigated in a farmlet experiment: Lolium perenne (LP; 205 kg N ha-1 a-1); L. perenne-Trifolium repens (LP-TR); multispecies sward consisting of L. perenne, Phleum pratense, T. repens, Trifolium pratense, Cichorium intybus and Plantago lanceolata (MSS). L. perenne-T. repens and MSS each received 92 kg N ha-1 a-1. Herbage samples were collected for DM production and botanical composition determination at each grazing. Further quadrat sampling was undertaken on three occasions per grazing season (early-, mid- and late-season), to enumerate the unsown species composition of swards and changes in bare ground. Over the course of the two-year study, LP, LP-TR and MSS produced annual herbage DM yields of 9950, 10,650 and 12,600 kg DM ha-1 a-1 respectively, despite reducing fertiliser N application to LP-TR and MSS by 55% compared to LP. The average proportional contribution of grass species to MSS' herbage DM remained constant, the clover content of MSS increased, while the herb content decreased from 2020 to 2021. Seasonally, the proportional contribution of L. perenne and P. lanceolata to MSS' herbage DM declined as the grazing season progressed, the contribution of T. repens and T. pratense increased and that of P. pratense and C. intybus remained similar. In LP-TR, T. repens ' proportional contribution to herbage DM increased from 2020 to 2021, while L. perenne 's proportional contribution declined. Seasonally, the proportional contribution of L. perenne to the herbage DM of LP-TR declined as the grazing season progressed, while the proportion of T. repens ' increased. The contribution of dead plant material to herbage DM increased across all swards in the second year but did not differ between sward types. Sward type did not affect the proportional contribution of unsown species by functional group to herbage DM. These results demonstrate that under a relatively-intensive beef grazing system, MSS receiving reduced N compared to LP monocultures, and the same N compared to LP-TR swards, produce more herbage DM, and do not have a greater weed (unsown species) burden. Overall, our findings demonstrate the potential of MSS to 'produce more while using less', a key requirement of sustainable grazing systems. • The performance of a six species multispecies sward (MSS) was tested for two years. • The performance of MSS was compared to that of a perennial ryegrass monoculture (LP) and LP-white clover mixture (LP-TR). • MSS demonstrate potential for higher DM production from lower N inputs compared with LP. • MSS swards did not show signs of increased unsown species to LP despite a lack of herbicide application. • Legumes persist well, however herbs do not under an intensive, rotationally grazed dairy calf to beef system. [ABSTRACT FROM AUTHOR]

Phosphorus (P) loss from highly fertilised grazed pastures can impair surface water quality. High P concentrations in grazed pastures are maintained to boost legume production, but systems that use monocultures of grass and clover can be more profitable and decrease P losses by lowering soil P in grassed areas. In contrast with using a direct drill to establish new pastures, conventional cultivation can lower topsoil P quickly and can be used as part of a farm re-grassing programme every six years. We tested if the potential for low P losses (measured by water extractable P; WEP) could be maintained over six years in pastures (ryegrass and white clover monocultures and a ryegrass and clover mixed sward) despite being fertilised (10, 35 and 100 kg P ha-1) and grazed. Cultivation (0–20 cm) decreased WEP and Olsen P in all three pastures and P rates by 30–50 % compared to direct drill and maintained this decrease for six years. A threshold in Olsen P (22 mg L-1) was noted where WEP concentrations increased at a greater rate relative to Olsen P than below. This threshold was like the critical point in Olsen P for 97 % relative yield in the pastures (22–28 mg L-1) and could be used to advise on cultivation and P fertiliser strategies to help avoid the potential for P loss without significantly compromising yield. The data indicated that cultivation could be used to quickly establish and maintain lower soil P concentrations as part of a strategy to decrease P losses and improve profit by using a split grass-clover system. • Phosphorus runoff from land can impair surface water quality. • Splitting pastures into monocultures maintains production and enables low P plants to grow in runoff prone areas. • Conventional cultivation can be used to quickly decrease enriched soil P for low P plants. • Potential for runoff was maintained despite fertiliser P and grazing returns over 6-year period. • Conventional cultivation is a suitable method for re-grassing programme to lower runoff P losses. [ABSTRACT FROM AUTHOR]

• Multispecies had a higher dry matter degradability than grass/grass-clover forages. • Rumen pH was below 6.0 for longer when cows consumed multispecies. • Perennial ryegrass-white clover resulted in higher rumen ammonia throughout the day. • Multispecies can support milk production but may result in lower milk fat. An experiment was conducted to compare the rumen fermentation and degradability of three forage treatments. A perennial ryegrass (PRG; Lolium perenne), perennial ryegrass and white clover (Trifolium pratense) (PRGWC) and multispecies forage (MULTI), containing two grass species; perennial ryegrass and timothy (Phleum pratense); two clover species; white clover and red clover (Trifolium repens); and two herb species; chicory (Cichorium intybus) and plantain (Plantago lanceolata), were compared. Six rumen fistulated lactating dairy cows were used in a replicated 3 × 3 Latin square experiment consisting of 3 periods lasting 21-days. Cows were allowed ad libitum access to fresh forage and offered 2.71 kg DM concentrate each day. During days 1 – 14 of each period, cows were acclimatized to dietary treatments before entering a 7 – day sampling period. Indwelling rumen pH probes were inserted into the rumen of each cow on day 15 and 16. Rumen fluid samples were taken on day 18 every 2 h for rumen volatile fatty acid and ammonia nitrogen (NH 3 N) analysis. Forage dry matter (DM) and crude protein (CP) degradability was assessed via in sacco incubation beginning on day 19 of each period. Treatment had no effect on dry matter intake (DMI) or milk yield. There was no difference in mean rumen pH between treatments. The rumen pH of cows offered MULTI was below pH 6.0 for a higher percentage of time than the other treatments, however the concentration of acetic acid in the rumen of cows was similar between treatments. Effective degradability (ED) of DM was higher (P = 0.003) for MULTI (0.77) compared to PRG (0.68) and PRGWC (0.66). The soluble CP fraction of MULTI and PRGWC was significantly lower than that of PRG (P = 0.007), though PRGWC had the highest rumen ammonia concentration of all treatments (P = 0.002). MULTI had the highest ED and rate of DM degradation in the rumen, and lowest soluble CP of all treatments. Multispecies forages can support milk production in lactating dairy cows; however, care must be taken to ensure adequate dietary NDF due to the low fiber concentration and highly degradable nature of the forage. [ABSTRACT FROM AUTHOR]

Over a three year period the performance of lambs being finished on three sward treatments were compared. The three treatments included (i) ‘Grass-clover mixture’; perennial ryegrass ( Lolium perenne L.) and white clover ( Trifolium repens ) (ii) ‘Plantain-clover mixture’; plantain ( Plantago lanceolata ), white clover and red clover ( Trifolium pratense ) (iii) ‘Chicory-plantain-clover mixture’; plantain, chicory ( Cichorium intybus L.), white- and red-clover. Each year was divided into five grazing periods namely; winter, early spring, late-spring, summer and autumn with only the Grass-clover mixture being utilised in the winter due to the growth profile and management requirements of the herb species. Over the three year period, a total of 3353 kg live weight per ha was produced on the Grass-clover mixture, which was less (P < 0.05) than the 3838 kg/ha produced with the Plantain-clover mixture or 3768 kg/ha on the Chicory-plantain-clover mixture. Similarly over the three year period, 1270 kg of carcass weight gain per ha was produced on the Grass-clover mixture, which was less (P < 0.05) than the 1706 kg/ha produced with the Plantain-clover mixture or 1732 kg/ha with the Chicory-plantain-clover. This indicates that farmers aimed at lamb finishing can have some confidence that when utilising these herb-clovers mixtures they can increase lamb and meat productivity for at least three years. [ABSTRACT FROM AUTHOR]

Growth rates of weaned bull calves in late summer/early autumn can be low in a ryegrass/white clover-based system. This experiment compared the liveweight gain of weaned bull calves (n = 18 per treatment per year, in 3 replicates of 6 bulls) grazed on a herb sward comprised of chicory, plantain, red clover and white clover with bulls grazed on either pasture supplemented with 1.8 kg DM/day of concentrate, or pasture without supplementation. The experiment was repeated over three years. Bulls grazed on the herb sward grew faster (P < .05) than bulls grazed on pasture with or without concentrate supplementation. Liveweight gain of bulls grazed on pasture was less than for bulls supplemented with concentrate in two of the three years (P < .05). A herb sward is a better quality alternative to late summer/early autumn pasture, and could be used to increase liveweight gain of bulls during this period. [ABSTRACT FROM AUTHOR]

Aims: Increasing the input and turnover of root tissue is considered to be one method that may increase carbon (C) inputs and storage in soil. The use of herbicide during pasture renewal (periodic re-sowing of pasture) is expected to increase root inputs and turnover as plants die. The objective of this study was to quantify the short-term impact of pasture renewal on root turnover and C input to soil of ryegrass-clover pastures. Methods: Pastures were labelled in the field using a C isotope pulse labelling method within 1 m clear chambers. Five daily labelling events were carried out during one week in paired treatment plots within 3 replicate paddocks. One plot per paddock was sprayed with herbicide and then the pasture was renewed by direct drilling of seed. The C of roots and soil (0-100 mm) was measured at regular intervals over an 89-day period. Results: Herbicide application caused an initial rapid turnover time of 17 days followed by a slower turnover time of 524 days, compared to unsprayed pasture which had a root turnover of 585 days. Faster root turnover following herbicide application resulted in greater cumulative C input to soil over 89 days with approximately double the C input in the sprayed treatment (3238 ± 378 kg C ha) compared to the unsprayed treatment (1726 ± 540 kg C ha). Conclusions: The use of glyphosate during pasture renewal increased root turnover and resulted in a greater short term cumulative C input to soil. This study provides the first values of root turnover and C input to soil during a pasture renewal event in New Zealand pasture systems and contributes to the understanding of how pasture roots may influence the soil C input following plant death in grassland systems. [ABSTRACT FROM AUTHOR]

A set of 18 × 0.5 ha paddocks at the DairyNZ research farm in Hamilton made up from three replicates of six sward mixes had pasture collected weekly from 31 January 2012 to 9 May 2012 and spore counts ofPithomyces chartarumwere determined. Low diversity (LD) meant that the paddock was sown with a single grass species (tall fescue, high sugar cultivar, ryegrass) and white clover. High diversity (HD) meant that the paddock was sown with a single grass species and white clover plus prairie grass, chicory, plantain and lucerne. The study aims were to assess the benefit of diversity and sward type in the control of facial eczema. There was no difference in spore counts over time between high diversity and low diversity pastures (P = 0.43). Both tall fescue paddocks (LD and HD) showed a lower spore count over time in comparison with low diversity ryegrass (P = 0.055 and 0.05). [ABSTRACT FROM AUTHOR]

• 13C-CO 2 was pulsed labeled in an agroforestry system. • PLFA biomarker 16:1ω5c was enriched with 13C in soil under grassland. • 13C incorporation into gram positive bacteria was higher under willow compare to grassland and rape. • Gram negative bacteria utilized the highest relative amount of 13C. • Microbial utilization of 13C depends on vegetation types in an agroforestry system. The release of organic compounds from plant roots (rhizodeposits) and their subsequent utilization by soil microbial communities is a key process linking atmospheric and terrestrial carbon (C) and nutrient cycling. However, the effects of land-use types on rhizodeposit-mediated alteration of microbial community structure and its consequences for soil C cycle are still, largely, unknown. Therefore, we used 13C-PLFA-SIP to evaluate the rhizosphere C fluxes to microorganisms in a monoculture crop (oilseed rape, Brassica napus L.), a mixed grassland (dominated by Lolium perenne L. mixed with clover Trifolium repens L.), and a tree (willow, Salix schwerinii E.L. Wolf and Salix viminalis L.) within an agroforestry system. Though harboring similar total microbial biomass, less 13C was recovered in microorganisms in soil under willow (0.017 % of 13C input) after 14 days as compared to rape (0.03 %) and grassland (0.09 %). Across three land use types, gram negative bacteria incorporated most of the 13C (28–42 % of total 13C labeled PLFAs), followed by fungi and gram positive bacteria (12–18 %) and less abundance groups (e.g. actinomycetes, <5 %). The arbuscular mycorrhizal fungal biomarker 16:1ω5c was enriched with 13C in soil under grassland (8 % of total 13C labeled PLFAs). The 13C incorporation into gram positive bacteria was higher in soil under willow than under grassland and rape. By contrast, 42 % of total 13C labeled PLFAs were attributed to gram negative bacteria in soil under rape. Overall, our results demonstrated that pronounced differences in microbial community structure and subsequent microbial C utilization between land-use types could affect soil C cycles and storage. [ABSTRACT FROM AUTHOR]