Ryegrass Pasture Research Articles

In Vitro Fermentation Patterns and Methane Output of Perennial Ryegrass Differing in Water-Soluble Carbohydrate and Nitrogen Concentrations.

Simple SummaryGlobally, the livestock sector is responsible for 37% of total anthropogenic methane emissions, most of which are produced from enteric fermentation of ruminants. Livestock is also responsible for 65% anthropogenic nitrous oxide and 64% of anthropogenic ammonia emissions. The literature reports several dietary management options to reduce greenhouse gas emissions from ruminants, and potentially improve productivity. However, strategies that aim to reduce the emissions of one specific greenhouse gas can have side effects (increase) on other pollutant gases. In this study, we evaluated the effect of two types of perennial ryegrass (PRG) pastures differing in their concentration of water-soluble carbohydrates (WSC, high (HS) and low (LS)) on the in vitro nitrogen use efficiency in the rumen and on methane emissions. The greater WSC and lower crude protein (CP) concentrations of high sugar pastures modified in vitro rumen fermentation, tending to increase total volatile fatty acids (VFA) production, reduce acetate:propionate ratio and methane (CH4) concentration, and improve nitrogen (N) use efficiency through lower rumen ammonia-N (NH3-N) concentrations. In vivo studies with cattle are required to confirm the potential of these measures to increase the sustainability and reduce the environmental impact of grazing livestock production systems.The objective of this study was to determine the effect of perennial ryegrass (PRG) forages differing in their concentration of water-soluble carbohydrates (WSC) and crude protein (CP), and collected in spring and autumn, on in vitro rumen fermentation variables, nitrogen (N) metabolism indicators and methane (CH4) output, using a batch culture system. Two contrasting PRG pastures, sampled both in autumn and spring, were used: high (HS) and low (LS) sugar pastures with WSC concentrations of 322 and 343 g/kg for HS (autumn and spring), and 224 and 293 g/kg for LS in autumn and spring, respectively. Duplicates were incubated for 24 h with rumen inocula in three different days (blocks). Headspace gas pressure was measured at 2, 3, 4, 5, 6, 8, 10, 12, 18, and 24 h, and CH4 concentration was determined. The supernatants were analysed for individual volatile fatty acids (VFA) concentrations, and NH3-N. The solid residue was analysed for total N and neutral detergent insoluble N. Another set of duplicates was incubated for 4 h for VFA and NH3-N determination. The HS produced more gas (218 vs. 204 mL/g OM), tended to increase total VFA production (52.0 mM vs. 49.5 mM at 24 h), reduced the acetate:propionate ratio (2.52 vs. 3.20 at 4 h and 2.85 vs. 3.19 at 24 h) and CH4 production relative to total gas production (15.6 vs. 16.8 mL/100 mL) and, improved N use efficiency (22.1 vs. 20.9). The contrasting chemical composition modified in vitro rumen fermentation tending to increase total VFA production, reduce the acetate:propionate ratio and CH4 concentration, and improve N use efficiency through lower rumen NH3-N.

Effect of grazing different forage systems prior to and during mating on the liveweight, condition score, conception and reproductive rate of maternal-composite ewe lambs

Context Economic modelling identified that mating of ewe lambs for lambing at 1 year of age has the potential to increase the profitability of sheep-production systems in south-western Victoria. In order to optimise reproductive rates, ewe lambs should weigh at least 35–40 kg, have a condition score (CS) of 3.0 at mating, and be gaining weight (100–150 g/day) during mating. However, typical perennial ryegrass (Lolium perenne L.) pastures in south-west Victoria do not support the attainment of these targets without additional supplementation. Aim Our research aimed to determine how grazing summer-active pastures or brassica (Brassica napus L.) forages affects the liveweight, CS, conception and reproductive rate of ewe lambs when offered before and during mating compared with a system using perennial ryegrass plus supplement. Methods A field experiment was conducted at Hamilton, Victoria, Australia, in 2014 and 2016 testing seven forage treatments replicated four times in a complete block design. The treatments were: canola (B. napus, two treatments of different cultivars), forage brassica, lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.) and perennial ryegrass. Key results Ewe lambs grazing canola or forage brassica had higher (P < 0.05) liveweight gains during the pre-mating and mating periods than those grazing the perennial ryegrass treatment (148 vs 75 g/day in 2014, s.e.m. 17; 139 vs 54 g/day in 2016, s.e.m. 17). In 2014, spring-sown dual-purpose canola, lucerne and chicory resulted in higher (P < 0.05) reproductive rates (144–151%) than the perennial ryegrass treatment (103%); forage brassica and plantain gave intermediate results (128% and 129%). Conclusion Brassica forages (including spring-sown canola), lucerne and chicory can support the attainment of key liveweight and CS targets for successful mating of ewe lambs in autumn. Implications Spring-sown canola is therefore a viable alternative forage for use by livestock producers in southern Australia and presents an opportunity to incorporate an alternative income stream in mixed-farming systems.

PRADERAS DE FESTUCA ALTA Y RYEGRASS EN PASTOREO DE VACAS LECHERAS EN SISTEMAS DE PRODUCCIÓN DE LECHE EN PEQUEÑA ESCALA EN LOS VALLES ALTOS DEL CENTRO DE MÉXICO

<p><strong>Background.</strong> Grazing pastures in small-scale dairy systems reduces feeding costs in these farms in the highlands of central Mexico. Tall fescue (<em>Lolium arundinaceum</em>) is a temperate climate grass resistant to hydric deficit, extreme temperatures, and high stocking rates, which make it attractive for these systems. However, many varieties are susceptible to endophyte infection that may cause toxicosis in cattle, which has not been studied in Mexico. <strong>Objective</strong>. To evaluate grazing of tall fescue pastures of K31 variety susceptible to endophytes, compared to perennial ryegrass (<em>Lolium perenne</em>)<em> </em>cv. Bargala pastures, both associated with white clover (<em>Trifolium repens </em>cv. Ladino). <strong>Methodology.</strong> An on-farm experiment was undertaken with a participant farmer with six Holstein cows with similar number of calvings, stage of lactation, and milk yields (kg/day). Treatments were BGL: grazing for 8 h/day on a perennial ryegrass cv. Bargala pasture and K31: grazing for 8 h/day of a tall fescue cv. K31 pasture. Cows were also supplemented with 4.6 kg dry matter of a commercial concentrate (18% crude protein) and 5 kg fresh basis of chopped green maize forage. A double cross-over design was applied, with three 14 day each experimental periods. <strong>Results.</strong> There were no significant differences (P>0.05) between treatments in chemical composition of pastures or supplementary feeds, nor between animal production variables. <strong>Implications.</strong> The comparison of tall fescue vs ryegrass pastures as alternative temperate pasture to reduce production costs in small-scale milk production systems. <strong>Conclusions. </strong>It is concluded that both grasses have similar performance in these systems.</p>

Effect of Herbage Density, Height and Age on Nutrient and Invertebrate Generalist Predator Abundance in Permanent and Temporary Pastures

The aim of this research was to assess differences in the quantity and quality of herbage and invertebrate generalist predator abundance among permanent and temporary pastures. Two permanent pastures and four temporary ley pastures (either one year or two years since being sown) were monitored weekly for 10 weeks in the spring. Permanent pastures included a diverse range of native UK grass species, and temporary ley pastures were predominantly perennial ryegrass (Lolium perenne) with or without white clover (Trifolium repens). Weekly measurements of herbage height (in centimeters), herbage cover (fresh and dry matter in kg per hectare) and herbage density (fresh and dry matter in kg per hectare per centimeter) were obtained for each field, along with lycosid spider and carabid beetle abundance. Weekly pasture samples were used to obtain nutrient concentrations of dry matter, crude protein, neutral detergent fibre (NDF), acid detergent fibre (ADF), ash, oil, sugars, digestible organic matter in the dry matter (DOMD) and metabolisable energy (ME) in the herbage as a measure of forage quality for grazing or harvesting. A linear mixed model was used to assess the effect of sward age, herbage density and height on herbage production, nutrient concentrations and invertebrate abundance. Although this study showed that permanent pastures were associated with lower nutrient concentrations of crude protein, ash, oil and ME compared to younger and predominantly perennial ryegrass pastures, the older pastures were associated with higher carabid numbers. Furthermore, permanent pastures had a higher density of dry matter herbage compared to younger pastures, and more dense and taller swards were associated with higher lycosid numbers. The study suggests that within pastures of 3 to 20 cm height, increasing the height and density of swards increases both ME and oil concentrations in herbage, therefore enhancing forage nutrient quality. Older and more permanent pastures can be beneficial for plant and invertebrate generalist predator populations, and still provide a useful source of nutrients for forage production.

Carryover of N-fertilization from corn to pasture in an integrated crop-livestock system

ABSTRACT Nutrient-use efficiency in pasture-crop rotations is not well understood. The hypothesis of this research is that nitrogen (N) cycled from the corn crop to the following pasture is not enough to supply the N demand of the pasture, independent of pasture height management. Our goal was to assess the carryover effect of N-fertilization from corn crop to a mixed pasture of black oat and ryegrass managed with two sward heights in an integrated crop-livestock system. The experimental design was a factorial arrangement (2 × 2) of sward height (10 and 25 cm) and N pasture fertilization: 0 kg N ha−1 (representing the carryover of N-fertilization from the corn crop) and 200 kg N ha−1. Accumulated forage dry matter and N concentration increased by 62% and 40%, respectively, in the pasture-fertilized compared with fertilization only in the previous crop phase. The residual effect of N applied to the previous corn crop was not enough to adequately meet the N requirements of the subsequent pasture, thereby reducing forage dry matter accumulation compared with the pasture-fertilized system. Our data suggest that fertilization of the pasture phase is key to better nutrient use efficiency in integrated crop-livestock systems.

Grass Tetany in Cattle

This document is about grass tetany, sometimes called grass staggers or hypomagnesemia, that can be a serious problem in Florida with cattle grazing small grain or ryegrass pastures. The problem is usually confined to lactating cows. It is always associated with an imbalance in the mineral components of blood serum, especially reduced magnesium levels. In Florida, grass tetany is more severe when cattle are grazing young forage, particularly the first flush of growth during December and January. Once the forage becomes more mature, the likelihood of problems is reduced. Grass tetany is apt to appear under conditions of nutritional stress. Placing cattle on winter pasture directly after being on frosted or other low quality pasture may cause such a nutritional stress. First published in April 1997.

Offering subterranean clover can reduce methane emissions compared with perennial ryegrass pastures during late spring and summer in sheep

Sheep production systems in south-west Victoria are based predominantly on perennial ryegrass pastures, resulting in highly seasonal growth and declining feed quantity and nutritive value in late spring and summer. These changes result in reduced animal performance and increased CH4 emissions per kg DM intake. A potential alternative to the feedbase used in south-west Victoria that provides high quality and quantity of feed in late spring and early summer are legume-based pastures, such as clovers and lucerne. This experiment examined the impact of legume-based pastures on the growth rates and CH4 emissions of Maternal Composite ewes during late spring and early summer. In 2014, 240 Maternal Composite ewes grazed either perennial ryegrass (Lolium perenne L.), lucerne (Medicago sativa L.), subterranean clover (Trifolium subterraneum L.) or arrowleaf clover (Trifolium vesiculosum Savi.) pastures for 6 weeks during late spring and early summer (November and December). Sheep grazing subterranean clover were heavier at the end of the experiment than sheep grazing perennial ryegrass. Methane measurements using portable accumulation chambers indicated lower daily CH4 emissions (g/day) from sheep grazing subterranean clover (23.5 g/day) than from sheep grazing lucerne (27.3 g/day) and perennial ryegrass (32.3 g/day) pastures. Methane emissions and liveweight changes appeared to be associated with the nutritive characteristics of the forage offered. Legume-based pastures provide sheep producers in south-west Victoria an option to increase growth rates and decrease CH4 emissions during a period when perennial ryegrass pastures are declining in nutritive value.

Carbohydrate-rich supplements can improve nitrogen use efficiency and mitigate nitrogenous gas emissions from the excreta of dairy cows grazing temperate grass

Temperate pasture species constitute a source of protein for dairy cattle. On the other hand, from an environmental perspective, their high N content can increase N excretion and nitrogenous gas emissions by livestock. This work explores the effect of energy supplementation on N use efficiency (NUE) and nitrogenous gas emissions from the excreta of dairy cows grazing a pasture of oat and ryegrass. The study was divided into two experiments: an evaluation of NUE in grazing dairy cows, and an evaluation of N-NH3 and N-N2O volatilizations from dairy cow excreta. In the first experiment, 12 lactating Holstein × Jersey F1 cows were allocated to a double 3 × 3 Latin square (three experimental periods of 17 days each) and subjected to three treatments: cows without supplementation (WS), cows supplemented at 4.2 kg DM of corn silage (CS) per day, and cows supplemented at 3.6 kg DM of ground corn (GC) per day. In the second experiment, samples of excreta were collected from the cows distributed among the treatments. Aliquots of dung and urine of each treatment plus one blank (control – no excreta) were allotted to a randomized block design to evaluate N-NH3 and N-N2O volatilization. Measurements were performed until day 25 for N-NH3 and until day 94 for N-N2O. Dietary N content in the supplemented cows was reduced by 20% (P < 0.001) compared with WS cows, regardless of the supplement. Corn silage cows had lower N intake (P < 0.001) than WS and GC cows (366 v. 426 g/day, respectively). Ground corn supplementation allowed cows to partition more N towards milk protein compared with the average milk protein of WS cows or those supplemented with corn silage (117 v. 108 g/day, respectively; P < 0.01). Thus, even though they were in different forms, both supplements were able to increase (P < 0.01) NUE from 27% in WS cows to 32% in supplemented cows. Supplementation was also effective in reducing N excretion (761 v. 694 g/kg of Nintake; P < 0.001), N-NH3 emission (478 v. 374 g/kg of Nmilk; P < 0.01) and N-N2O emission (11 v. 8 g/kg of Nmilk; P < 0.001). Corn silage and ground corn can be strategically used as feed supplements to improve NUE, and they have the potential to mitigate N-NH3 and N-N2O emissions from the excreta of dairy cows grazing high-protein pastures.

Urea applied as a foliar spray or in granular form to subtropical dairy pastures of kikuyu (Cenchrus clandestinus) and Italian ryegrass (Lolium multiflorum) in eastern Australia

The nitrogen-use efficiency (NUE) of a fertiliser has implications for pasture growth and the environment. This study aimed to compare application of urea as a foliar spray or in granular form, to kikuyu (Cenchrus clandestinus (Hochst. ex Chiov.) Morrone) and short-rotation ryegrass (Italian ryegrass, Lolium multiflorum Lam.) pastures in the subtropical dairy region of eastern Australia. The first experiment was a replicated grazing study on a site with a high plant-available soil N (75 mg nitrate-N/kg). The granular rate of urea was 46 kg N/ha.month equivalent, and the foliar spray rate was 40% of the granular rate. Pasture growth rate (51 DM/ha.day with foliar spray vs 45 kg DM/ha.day with granules) and pasture consumed (4942 vs 4382 kg DM/ha) were not significantly different between treatments. However, over the 8 months of the study, soil nitrate-N levels fell from 75 to 22 mg/kg on the foliar plots but only fell to 60 mg/kg on the granular plots. The second experiment was a replicated plot-cut experiment on a site with a low plant-available soil N (8.7 mg nitrate-N/kg). The NUE for kikuyu grass was similar for all treatments with a mean of 14.8 kg DM/kg N for the four foliar treatments (high and low, with and without wetting agent) and 17.4 kg DM/kg N for the granular treatment. The NUE for the ryegrass was also similar for all treatments, with a mean of 13.2 kg DM/kg N for the foliar treatments and 15.8 kg DM/ha for the granular treatment. A third experiment, evaluating absorption of foliar-sprayed urea over time, found that &amp;gt;80% of the urea applied to kikuyu was absorbed by 7 h; for ryegrass, the amount absorbed was only ~45% but increased to ~75% if wetting agent was included. We suggest that the lack of benefit in NUE achieved by applying urea as a foliar spray, which contrasts with results from studies in temperate dairy farm systems, is primarily associated with the substantially lower tiller density and hence the smaller canopy area for absorption of the foliar spray by the new regrowth shoots post-grazing.

A comparison of two rotational stocking strategies on the foraging behaviour and herbage intake by grazing sheep

An understanding of the processes involved in grazing behaviour is a prerequisite for the design of efficient grassland management systems. The purpose of managing the grazing process is to identify sward structures that can maximize animal forage daily intake and optimize grazing time. Our aim was to evaluate the effect of different grazing management strategies on foraging behaviour and herbage intake by sheep grazing Italian ryegrass under rotational stocking. The experiment was carried out in 2015 in southern Brazil. The experimental design was a randomized complete block with two grazing management strategies and four replicates. The grazing management treatments were a traditional rotational stocking (RT), with pre- and post-grazing sward heights of 25 and 5 cm, respectively, and a ‘Rotatinuous’ stocking (RN) with pre- and post-grazing sward heights of 18 and 11 cm, respectively. Male sheep with an average live weight of 32 ± 2.3 kg were used. As intended, the pre- and post-grazing sward heights were according to the treatments. The pre-grazing leaf/stem ratio of the Italian ryegrass pasture did not differ between treatments (P > 0.05) (~2.87), but the post-grazing leaf/stem ratio was greater (P < 0.001) in the RN than in the RT treatment (1.59 and 0.76, respectively). The percentage of the non-grazed area was greater (P < 0.01) in post-grazing for RN compared with RT treatment, with an average of 29.7% and 3.49%, respectively. Herbage nutritive value was greater for the RN than for the RT treatment, with greater CP and lower ADF and NDF contents. The total time spent grazing, ruminating and resting did not differ between treatments (P > 0.05), with averages of 439, 167 and 85 min, respectively. The bite rate, feeding stations per min and steps per min by sheep were greater (P < 0.05) in the RN than in the RT treatment. The grazing time per hour and the bite rate were greater (P < 0.05) in the afternoon than in the morning in both treatments. The daily herbage intake by sheep grazing Italian ryegrass was greater (P < 0.05) in the RN than in the RT treatment (843.7 and 707.8 g organic matter/sheep, respectively). Our study supports the idea that even though the grazing time was not affected by the grazing management strategies when the animal behaviour responses drive management targets, such as in ‘Rotatinuous’ stocking, the sheep herbage intake is maximized, and the grazing time is optimized.

PSVII-12 Effect of planting method on forage production of annual ryegrass and stocker performance

Abstract Different planting methods are alternatives for early grazing and/or extend the grazing season of winter pastures. The objective was to evaluate different planting methods on forage and animal performance. In three consecutive years, ryegrass cv. ‘Marshall’ was conventionally planted (33 kg seed/ha), and no-till and broadcast planted on a bermudagrass stand on nine 1.33 ha pastures (3 replicates/treatment). Urea was split applied at a rate of 40 units of N/ha on d 40 after planting and on d 40 after grazing started. Each pasture was continually stocked with five steers (245 ± 12 kg initial BW). Grazing started when ryegrass was at least 25 cm tall and 1,600 kg DM/ha. In the conventional planted pastures, steers were moved out (to a ryegrass pasture) when ground was too soft, returning to experimental pastures when grazing conditions were appropriate. Forage production was greater (P &amp;lt; 0.05) for conventional and no-till (2,800 and 2,389 kg DM/ha) than for broadcast pastures (1,770 kg DM/ha). Planting method and yr affected (P &amp;lt; 0.03) start of grazing. Conventional and no-till planting started 51 and 49 d earlier than broadcasted. In 2 yr, rainfall delayed by 17 d the start of grazing in the conventional planted pastures. Grazing days was greater (P &amp;lt; 0.01) for no-till (95 d) than conventional and broadcast planting (61 and 49 d, respectively). While on experimental pastures, ADG was similar (P = 0.08) between treatments. Due to the difference in grazing days, production per ha was greater (P &amp;lt; 0.01) for no-till (450 kg/ha) than for broadcast and conventional (199 and 241 kg/ha, respectively). No-tilled pastures offered better grazing environment while broadcast pastures had the disadvantages of slow germination and less forage production. Greater number of grazing days on no-tilled pastures allowed for better animal performance and dilution of input costs.

152 Effects of mineral supplementation on performance and serum mineral status in beef steers grazing annual ryegrass

Abstract Thirty six crossbred (predominantly English with some Bos indicus influence) beef steers (initial BW 264.8 + 35.8 kg) were blocked by BW and used in a completely random design to examine the effects of mineral supplementation on performance and serum mineral status in beef cattle grazing annual ryegrass pastures for 84 d. All cattle were withheld from mineral for approximately 60 d prior to the initiation of the study and were allowed to graze dormant bahiagrass pastures (Paspalum notatum), and also had access to bahiagrass hay. On d -1, cattle were weighed and stratified by BW into Light (n = 6 pastures) and Heavy (n = 4 pastures) blocks and returned to their dormant warm season pasture. On d 0, cattle were weighed, a 10 mL blood sample was collected for serum mineral status and cattle were moved to their respective 1.2 ha annual ryegrass treatment pastures. Treatments were randomly assigned to pasture and consisted of CON (no complete mineral supplementation), or MIN (free choice access to a complete beef mineral.) Cattle grazed annual ryegrass for 84 d, after which a final BW was collected as well as a second 10 mL blood sample. Data were analyzed as a mixed model with weight block a random effect and treatment a fixed effect and pasture was the experimental unit. Supplementing MIN tended (P = 0.06) to increase total weight gain at d 84 and increased (P = 0.01) ADG (1.61 vs. 1.67 kg/d for CON and MIN, respectively). Additionally, feeding MIN resulted in increased serum Co, Zn, and Se (P = 0.01) but resulted in no differences in serum Fe and Cu (P &amp;gt; 0.10). Feeding MIN resulted in greater performance and increased some serum mineral levels, however the lack of response in serum Cu to MIN bears further examination.

Índices de nutrição nitrogenada como estratégia de fertilização em pastagens de azevém anual

A principal fonte de alimentação dos ruminantes no Sul do Brasil é proveniente de sistemas pastoris e o azevém anual (Lolium multiflorum Lam.) tem sido utilizado como uma das principais forrageiras para pastoreio no período hibernal. O nitrogênio (N) é o principal nutriente para a manutenção da produtividade e persistência das gramíneas forrageiras, no entanto, este se encontra em baixas concentrações no solo, sendo necessário adicioná-lo na forma de fertilizante químico. Para melhor uso da fertilização, buscam-se ferramentas simples e eficientes para determinar o status nitrogenado da pastagem. O objetivo do trabalho foi determinar o índice de nutrição nitrogenada (INN) do azevém, para validar uma metodologia mais simplificada e eficiente para seu diagnóstico. Os tratamentos foram cinco doses de N (0, 25, 50, 100, 200 kg ha-1) e duas formas de aplicação do fertilizante nitrogenado (única e parcelada). As parcelas com azevém anual submetidas à adubação nitrogenada fracionada apresentaram INN abaixo de um, sugerindo limitação do nutriente no primeiro corte, exceto na dose de 200 kg ha-1 onde os resultados de INN obtidos foram próximos a um, indicando adequado fornecimento de nitrogênio às plantas. Os resultados de INN indicaram que doses de 100 kg/ha-1 de N devem ser aplicadas de forma única em pastagem de azevém anual, para a planta suprir suas necessidades de N no início do ciclo. Houve relação linear entre a concentração de N na última folha completamente expandida e o INN, indicando grande potencial no uso desse método para determinar o status nitrogenado da cultura.

Meta-analyses comparing the nutritional composition of perennial ryegrass (Lolium perenne) and plantain (Plantago lanceolata) pastures

Studies comparing livestock responses to diets containing plantain with traditional ryegrass/clover diets suggest differences in the nutritional composition between the species might explain some of the variation in results. To explore this theory, a meta-analysis was performed to compare the nutritional composition of plantain and perennial ryegrass pastures, and define key differences between the species. Standardised effect sizes (plantain vs ryegrass pastures), expressed as correlation coefficients (r) with values from -1 to +1, and treatment means from 34 studies were determined using a weighted random effects model. Pastures containing plantain had lesser herbage dry matter content than ryegrass pastures across all seasons (mean 13.4 vs. 19.4%, P&lt;0.001; r&lt;-0.65). Structural fibre content was consistently smaller (mean 32.1 vs. 43.4% DM), but non-structural fibre content larger in plantain compared with ryegrass pastures (large effect sizes of r&gt;0.70). There was no difference in total herbage nitrogen concentration (g/100 g DM; r&lt;0.03). However, plantain pastures contained less soluble and degradable nitrogen compared with ryegrass pastures (r&lt;-0.78). Herbage digestibility did not differ significantly between pastures (r=-0.13; P=0.168). Generally, the effect of plantain on nutritional composition was consistent across seasons. Experiments and models investigating the effects of pasture mixes on environmental nitrogen losses ought to include detailed nitrogen and carbohydrate fractions data for accurate interpretation and prediction.

Microalgae and Phototrophic Purple Bacteria for Nutrient Recovery From Agri-Industrial Effluents: Influences on Plant Growth, Rhizosphere Bacteria, and Putative Carbon- and Nitrogen-Cycling Genes.

Microalgae (MA) and purple phototrophic bacteria (PPB) have the ability to remove and recover nutrients from digestate (anaerobic digestion effluent) and pre-settled pig manure that can be Utilized as bio-fertilizer and organic fertilizer. The objective of this study was to compare the effectiveness of MA and PPB as organic fertilizers and soil conditioners in relation to plant growth and the soil biological processes involved in nitrogen (N) and carbon (C) cycling. To this end, a glasshouse experiment was conducted using MA and PPB as bio-fertilizers to grow a common pasture ryegrass (Lolium rigidum Gaudin) with two destructive harvests (45 and 60 days after emergence). To evaluate the rhizosphere bacterial community, we used barcoded PCR-amplified bacterial 16S rRNA genes for paired-end sequencing on the Illumina Mi-Seq. Additionally, we used phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis for the detection of putative functional genes associated with N and soil-C cycling. There was a significant increase in plant growth when the soil was amended with PPB, which almost performed as well as the chemical fertilizers. Analysis of the rhizosphere bacteria after the second harvest revealed a greater abundance of Firmicutes than in the first harvest. Members of this phylum have been identified as a biostimulant for plant growth. In contrast, the MA released nutrients more slowly and had a profound effect on N cycling by modulating N mineralization and N retention pathways. Thus, MA could be developed as a slow-release fertilizer with better N retention, which could improve crop performance and soil function, despite nutrient losses from leaching, runoff, and atmospheric emissions. These data indicate that biologically recovered nutrients from waste resources can be effective as a fertilizer, resulting in enhanced C- and N-cycling capacities in the rhizosphere.

Пропозиції щодо реконструкції парку села Піківець Уманського району

Парк у с. Піківець Уманського району Черкаської області було закладено у 50-60-х роках ХХ ст. у центрі села, а саме біля сільського клубу. Насамперед потрібно провести санітарне рубання та обрізування дерев. Пропонуємо підсіяти мавританський газон, а в місці, де зростає пирій повзучий (Elytrigia repens L.), повністю замінити травостій на газон. Згідно з проектом розширюється стежкова мережа. Запропоновано створення доріжок з бетонної тротуарної плитки завширшки 0,75 та 1,5 м. Деякі стежки виконуватимуть транзитну роль, а деякі сполучатимуть окремі елементи парку. З малих архітектурних форм у парку встановлюємо альтанку для відпочинку. Також запропоновано збільшити кількість лавок, додавши дугоподібну лавку на круглому майданчику, у центрі якого розміщуватиметься клумба. Позаду кругової лавки, у північно-східній частині парку запроектовано створення декоративної групи з кущів. Асортимент рослин для цієї групи включає: Berberis thunbergii DC, Forsythia europaea Deg. et Bald., Pyracantha coccinea (L.) M. Roem, Syringa vulgaris L., Cotoneaster horizontalis Decne. Для клумб використовуємо цибулькові ранньоквітучі види, а також переважно тіньовитривалі багаторічники. Рекомендуємо створити мавританський газон, до складу якого входять: костриця червона (Festuca rubra L.), райграс пасовищний (Lolium perenne L.), тонконіг лучний (Poa pratensis L.), мак польовий (Papaver rhoeas L.), льон великоквітковий (Linum grandiflorum Desf.), ромашка лікарська (Matricaria recutita L.), низькорослі сорти космеї (Cosmos Cav.), чорнобривці мексиканські (Tagetes tenuifolia Сav.), гіпсофіла повзуча (Gypsophila muralis L.), гіпсофіла витончена (Gypsophila elegans M. Bieb.).

The effect of intensive grazing systems on the rising plate meter calibration for perennial ryegrass pastures

The rising plate meter (RPM) is used to measure grass height, which subsequently is used in a calibration equation to estimate herbage mass (HM), an important parameter for optimization of feed management in grazing systems. The RPM is placed on the sward and measures the resistance of the sward toward the plate, which depends not only on grass length, but also on sward structure. The accuracy of the calibration equation for the RPM to estimate HM across grazing systems, however, has not yet been evaluated. Therefore, our aim was to analyze the effect of intensive grazing systems on RPM calibration for perennial ryegrass pastures. To do so, we studied 2 grazing systems: compartmented continuous grazing (CCG) and strip grazing (SG), which differ in key grazing characteristics, such as pre- and post-grazing heights and period of regrowth, that may influence tiller density and vertical flexibility of the sward. The experiment was performed from April until October in 2016 and 2017 with 60 dairy cows, at a fixed stocking rate of 7.5 cows per hectare. To calibrate the RPM, 256 direct measurements of HM >4 cm (i.e., above stubble) were collected by cutting and weighing plots of grass for CCG and SG. Our main interest was in the HM above stubble because this is consumed by cows. Herbage mass <4 cm represents the stubble left after grazing. Differences in HM <4 cm may (partially) explain differences in HM >4 cm between the grazing systems. Therefore, HM <4 cm was additionally measured on 4 out of every 8 plots per grazing system by cutting out quadrats to 0 cm with an electric grass trimmer. Our results showed an average error margin in our calibration equations of 25 to 31%, expressed as the root mean square error of prediction (RMSEP) as a percentage of the observed HM >4 cm. Differences between grazing systems were relatively small, and including grazing system as a factor in the regression model to explain the increase in HM per centimeter of grass did not reduce the RMSEP of the model to any relevant extent. On the other hand, HM <4 cm was significantly greater on CCG compared with SG, with 2,042 kg of DM per hectare for CCG and 1,676 kg of DM per hectare for SG. The HM <4 cm, however, is not used for grazing, and this difference was not reflected in the HM >4 cm. Our results indicate that we can use one region-specific calibration equation for perennial ryegrass pastures across intensive grazing systems, despite relatively large differences in pre- and post-grazing heights and period of regrowth.

Enhanced efficiency fertilisers reduce nitrous oxide emissions and improve fertiliser 15N recovery in a Southern Australian pasture

The effects of reducing nitrogen (N) rates or using enhanced efficiency fertilisers (EEFs) (i.e. urease and nitrification inhibitors, and controlled release fertilisers) on nitrous oxide (N2O) emissions and nitrogen use efficiency (NUE) are not well understood in temperate, rainfed pastures. A field experiment on rainfed ryegrass pasture in southern Australia examined the effect of granular urea N rate (0, 250 and 420 kg N ha−1 over 6 months) and EEF use (at 250 kg N ha−1 with NBPT, DMPP, or polymer coating (PCU)) on N2O emissions, NUE and fertiliser N recovery (using 15N techniques). Cumulative net-N2O emissions increased with N rate from 308 g N2O-N ha−1 (250 kg N ha−1) to 514 g N2O-N ha−1 (420 kg N ha−1). Using EEFs reduced N2O emissions by 22% (NBPT), 44% (DMPP) and 56% (PCU) compared to urea. The emission factor (EF) (kg net N2O-N per kg N applied) was 0.12 for both N rates (250 and 420 kg N ha−1) but reduced with the EEFs to 0.10 (NBPT) and 0.07 (DMPP and PCU) compared to urea.EEF use had no significant impact on biomass or apparent NUE but led to a greater recovery of N in the soil after one month (44.8% (DMPP) and 45.9% (NBPT) compared to urea (33.7%)). Within one month 42% of the N applied as urea (U50) was lost from the plant-soil system, which was reduced with DMPP (32% loss) and NBPT (33% loss). After six months, 52% (U50) to 59% (U84) of the urea N applied was lost.The positive effect of the EEFs on N2O emissions, and the increased recovery of N in the soil-plant system with the EEFs over one month indicates they could provide longer term benefits though soil N storage, and could be applied at lower N rates to achieve NUE benefit.

Effect of sward management on the emissions of CH4 and N2O from faeces of sheep grazing Italian ryegrass pastures

Rotatinuous stocking (RN) management is based on animal ingestive behaviour responses, where optimal pre- and post-grazing sward heights are defined to increase nutrient intake per unit of grazing time. We hypothesized that the optimal sward structure and consequently, a high herbage nutritive value in RN treatment results in a greater faecal nitrogen (N) excretion by sheep and consequently, a greater faecal greenhouse gas (GHG) emissions compared with the traditional rotational stocking (RT) management, which is based on a maximum herbage accumulation and harvest. Therefore, the aim of this study was to evaluate the effect of two grazing management strategies (RN and RT) on the amount of dry matter (DM) faecal excretion, faecal N excretion and faecal GHG (CH4 and N2O) emissions from growing sheep grazing Italian ryegrass pastures. In order to evaluate faecal production and N excretion per animal and per ha, a first experiment (1) was carried out: RT - pre and post-grazing sward heights of 25 and 5 cm, respectively and, RN - pre and post-grazing sward heights of 18 and 11 cm, respectively. A second experiment (2) was carried out to measure the CH4 and N2O fluxes from faeces, using the static chamber method. Daily DM faecal and N excretion per animal were higher (P < 0.001) in RN compared with RT treatment. However, when considered daily DM faecal and N excretion per ha, results were lower (P < 0.001) for the RN than the RT treatment. CH4 and N2O emissions from faeces were higher (P < 0.001) in RN compared with RT treatment, both per animal and per hectare. In conclusion, our study showed that the RN grazing management, based on animal behaviour, resulted in a higher daily N excretion per animal and higher CH4 and N2O emissions from faeces of sheep grazing Italian ryegrass pastures. This study contributes to improve GHG national inventories for the subtropical Brazilian climatic conditions, where estimations from CH4 and N2O emissions factors for faeces from growing sheep grazing Italian ryegrass are markedly lower than the values reported by IPCC Default Tier 1.

Nitrogen Delivery Method and Monensin Effects on Productivity, Nutritive Value, and Botanical Composition of Grazed Annual Ryegrass Pasture

Nitrogen fertilization is a major input cost of forage production, and alternatives that maintain yield and nutritive value would be advantageous. A 3‐yr study was conducted to evaluate forage nutritive value and clover proportion when N fertilizer was replaced partially with interseeded clovers (Trifolium spp.) or protein supplements for stocker cattle grazing annual ryegrass (Lolium multiflorum Lam.). Nitrogen delivery methods with or without monensin included annual ryegrass fertilized with 112 kg N ha−1 in split application (NFERT), and other methods that received 56 kg N ha−1, including annual ryegrass interseeded with crimson clover (CC, Trifolium incarnatum L.) or arrowleaf clover (AC, Trifolium vesiculosum Savi), or grazing cattle supplemented with distillers dried grains plus solubles at a rate of 0.65% body weight daily (DDGS) or whole cottonseed (Gossypium hirsutum L.) at the rate of 0.65% body weight daily (WCS). Clover proportion was greater (P = 0.003) for CC than AC across all 3 yr of the study, and CC was more (P = 0.003) abundant when monensin was fed. Year affected forage in vitro true digestibility (IVTD, P &lt; 0.001) and crude protein (CP, P &lt; 0.001) concentration such that IVTD and CP were greatest in Year 3, intermediate in Year 2, and least in Year 1. Forage degradable intake protein (DIP) concentration was affected by N delivery method (P &lt; 0.001) and year (P &lt; 0.001) such that CC was less than NFERT, DDGS, WCS, and AC, and Year 1 was greatest, Year 2 was intermediate, and Year 3 was the least. Results are interpreted to mean that year affected forage nutritive value more than did N delivery method.