Pasture Yield Research Articles

Use of traditional, modern, and hybrid modelling approaches for in situ prediction of dry matter yield and nutritive characteristics of pasture using hyperspectral datasets

To optimise grazing livestock nutrition, it is necessary to know both the available dry matter yield and the nutritive characteristics of pasture at the farm-scale in near real time. Previous studies have shown the potential of using field spectrophotometers that measure the reflectance of light across the visible to near infrared spectrums to gather information on pasture dry matter yield (DMY) and nutritive characteristics. This study sought to calibrate and validate new mathematical models for ten parameters including dry matter yield and nine nutritive characteristics of relevance to ruminant nutrition. As a part of the analysis process, two innovative approaches were tested: the use of a hybrid modelling approach where partial least squares regression (PLSR) outputs were used as support vector regression (SVR) inputs; and, the inclusion of covariate data. These approaches were compared with traditional stand-alone PLSR and SVR modelling approaches without covariates. The study was undertaken in six predominantly perennial ryegrass pastures on a single farm in the temperate zone of South-Eastern Australia. A total of 204 pasture samples were scanned with a field spectrophotometer over several spring growth stages in late 2019 and subsequently analysed by wet chemistry to obtain reference nutritive values. The raw reflectance spectra were initially pre-processed using a variety of techniques and then used to test the four kinds of chemometric models. In cross validation, hybrid models showed a superior fit for all variates in comparison to the other model types tested. However, the differential was reduced in independent validation where, out of 10 best-performing models for dry matter yield and key nutrient properties, six were produced by the hybrid modelling, three from SVR and one from PLSR. For every hybrid model that was built, adding covariate(s) consistently improved model performance but the increase was small (a reduction in normalised root mean square error (RMSE) of -0.36 % on average for all properties considered). The best performing models were comparable with other published literature with normalised RMSE of prediction ranging from 1.7 – 23.1 % (a mean of 9.7%). Well-predicted variates included metabolisable energy, digestible energy, DMY, and crude protein. Fibre fractions, ash and dry matter were less well-predicted but still had acceptable normalised RMSE values (< 10 %) while carbohydrate fractions were the poorest predicted variates. It was concluded that hybrid modelling in chemometric analyses can modestly improve accuracy and shows promise as an alternative to more traditional approaches. Using covariates also improved accuracy, but the additional time and effort to gather such information outweighed the minor benefits of inclusion.

Pasture production, persistence of legumes and lamb growth in summer‐dry hill pastures

AbstractPasture legumes that persist under challenging agroecological conditions are crucial to ensure high lamb growth rates in dryland pastures. Pasture and lamb production from binary and diverse mixtures (Mix) of tall fescue (TF) with white clover (Whc), balansa clover (Bc), subterranean clover (Sc) and birdsfoot trefoil (Bft) were compared in a summer‐dry hill site in Corvallis, Oregon over a two‐year period. In 2018, all pasture combinations provided similar lamb liveweight gains (LWG, mean 177 g/day) in the first half of spring. Lambs in TF‐Bc and TF‐Mix pastures grew 31 to 41 g/day faster than those grazing TF‐Sc, TF‐Whc and TF‐Bft in the second half of spring (p &lt; .05). Overall, TF‐Bc and TF‐Mix had higher (p &lt; .05) legume contents (32% and 37% respectively) compared to other pasture combinations. In spring 2019, lambs that grazed the TF‐Mix and TF‐Whc pastures had higher LWG than those on other pastures (p &lt; .05). The superior lamb growth rates were associated with the higher legume content and pasture quality maintained into the late spring period. Overall, the legume content of all pastures decreased over the course of the two‐year trial, with the decline being substantial for balansa clover. The present study confirmed that a high legume content of pastures leads to greater lamb growth rates. Total annual yields of pastures that had greater legume contents were superior to others (p &lt; .05). Thus, a combination of self‐regenerating annual clovers with perennial legumes in pasture mixtures may ensure a higher legume content and longer persistence in dryland hill pastures.

APSIM-Tropical Pasture: A model for simulating perennial tropical grass growth and its parameterisation for palisade grass (Brachiaria brizantha)

Tropical grasses are used as forage, to produce energy from biomass, for land restoration and carbon sequestration, among other applications. Many modelling approaches have been employed to simulate tropical grasses growth, but these have several limitations that must be solved by adapting them or creating new models. This study aimed to develop a tropical pasture model in the Agricultural Production Systems Simulator (APSIM) modelling framework, and to parameterise it to simulate Brachiaria brizantha ‘BRS Piatã’ growth, under grazing and cut-and-carry management. For this, three field experiments were conducted in the South-east of Brazil where pasture growth was measured in a cut-and-carry system, with irrigated and rainfed treatments, and in a rainfed grazing system. Model evaluation was performed through precision and accuracy indices and simulation errors. Under cut-and-carry management, forage productivity was estimated with R2 values from 0.89 to 0.94, Willmott agreement indices between 0.97 and 0.98, and Nash-Sutcliffe Efficiency values of 0.88 to up to 0.92. This demonstrates the capacity of the APSIM-Tropical Pasture model to simulate tropical pastures. Simulation of phenology, early growth after sowing, partitioning and senescence during flowering, and reallocation and retranslocation of plant dry matter and nitrogen were important aspects for this capacity. Then, APSIM-Tropical Pasture can be used to simulate tropical pastures, but several requirements for further improvements have been identified, such as to improve the simulations of flowering for palisade grass, N effects on pasture yield, reallocation and retranslocation processes. Under grazing management, forage productivity was estimated with R2 = 0.80, Willmott agreement index of 0.91, and Nash-Sutcliffe Efficiency value of 0.62. Despite these reasonable results, simulations presented problems, since does not take into account the effect of grazing animals on pastures. This indicates that, in its current form, APSIM-Tropical Pasture is not able to simulate pastures under grazing effectively. However, this simulation of grazed system was important to identify main modelling constraints and direct future research to improve knowledge of processes and interactions needed for pasture model development.

Global pattern and drivers of nitrogen saturation threshold of grassland productivity

Abstract Ecosystem productivity usually exhibits first increase and then saturated response to increasing nitrogen (N) additions, yet the broad‐scale pattern and potential drivers of the N saturation threshold are little investigated. By synthesizing N addition experiments with at least four N‐input levels from the global grasslands, we applied the quadratic‐plus‐plateau model to fit the above‐ground net primary productivity (ANPP)–N rate relationship, and estimated the saturation threshold for N rate (critical N rate, NCR) and ANPP (maximum ANPP, ANPPmax) from the inflection point where ANPP no longer statistically increased with N rate for individual experiments. Based on these estimations, we investigated the spatial pattern and driving factors of NCR and ANPPmax. The mean NCR and ANPPmax were 15.0 and 477.0 g m−2 year−1, respectively, but varied substantially among single‐site experiments. Management strategies (e.g. biomass harvest, different N forms and addition frequencies) minimally influenced both parameters. Structural equation models demonstrated that the spatial differences in NCR and ANPPmax were mainly explained by aridity index, and soil carbon (C)/N ratio also predicted the variation in NCR. Given that grasslands are important not only for the trend and variability of the land C sink but also for the maintenance of pasture yield, the pattern and controls of NCR and ANPPmax, as revealed by the current study, are crucial for constructing robust predictions of C sink capacity and improving N fertilizer management in grasslands.

Novel Antifungal Activity of Lolium-Associated Epichloë Endophytes.

Asexual Epichloë spp. fungal endophytes have been extensively studied for their functional secondary metabolite production. Historically, research mostly focused on understanding toxicity of endophyte-derived compounds on grazing livestock. However, endophyte-derived compounds also provide protection against invertebrate pests, disease, and other environmental stresses, which is important for ensuring yield and persistence of pastures. A preliminary screen of 30 strains using an in vitro dual culture bioassay identified 18 endophyte strains with antifungal activity. The novel strains NEA12, NEA21, and NEA23 were selected for further investigation as they are also known to produce alkaloids associated with protection against insect pests. Antifungal activity of selected endophyte strains was confirmed against three grass pathogens, Ceratobasidium sp., Dreschlera sp., and Fusarium sp., using independent isolates in an in vitro bioassay. NEA21 and NEA23 showed potent activity against Ceratobasidium sp. and NEA12 showed moderate inhibition against all three pathogens. Crude extracts from liquid cultures of NEA12 and NEA23 also inhibited growth of the phytopathogens Ceratobasidium sp. and Fusarium sp. and provided evidence that the compounds of interest are stable, constitutively expressed, and secreted. Comparative analysis of the in vitro and in planta metabolome of NEA12 and NEA23 using LCMS profile data revealed individual metabolites unique to each strain that are present in vitro and in planta. These compounds are the best candidates for the differential bioactivity observed for each strain. Novel endophyte strains show promise for endophyte-mediated control of phytopathogens impacting Lolium spp. pasture production and animal welfare.

ALTURA DE PLANTAS E DIÂMETRO DE COLMOS DE SORGO FORRAGEIRO IRRIGADO EM FUNÇÃO DE CORTES

ALTURA DE PLANTAS E DIÂMETRO DE COLMOS DE SORGO FORRAGEIRO IRRIGADO EM FUNÇÃO DE CORTES&#x0D; &#x0D; &#x0D; JARDEL HENRIQUE KIRCHNER1; ADROALDO DIAS ROBAINA2; MARCIA XAVIER PEITER3; ROGÉRIO RICALDE TORRES4; WELLINGTON MEZZOMO5 E RICARDO BENETTI ROSSO6&#x0D; &#x0D; 1 Eng. Agrônomo, Doutor, Professor do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Rua Nelsi Ribas Fritsch, nº 1111, bairro Esperança, Ibirubá, RS, Brasil, CEP: 98200-000, jardel.kirchner@ibiruba.ifrs.edu.br.&#x0D; 2 Eng. Agrônomo, Doutor, Professor Titular do Departamento de Engenharia Rural, UFSM, Avenida Roraima, nº 1000, bairro Camobi, Santa Maria, RS, Brasil, CEP: 97195-000, diasrobaina@gmail.com.&#x0D; 3 Eng. Agrônoma, Doutora, Professora Associada do Departamento de Engenharia Rural, UFSM, Avenida Roraima, nº 1000, bairro Camobi, Santa Maria, RS, Brasil, CEP: 97195-000, mpeiter@gmail.com.&#x0D; 4 Eng. Agrônomo, Doutor, Professor do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Rua Eng. João Viterbo de Oliveira, nº 3061, Zona Rural, Vacaria, RS, Brasil, CEP: 95219-899, rogerio.torres@vacaria.ifrs.edu.br.&#x0D; 5 Eng. Agrônomo, Mestre, Doutorando no Programa de Pós-Graduação em Engenharia Agrícola, UFSM, Avenida Roraima, nº 1000, bairro Camobi, Santa Maria, RS, Brasil, CEP: 97195-000, wmezzomo@hotmail.com.&#x0D; 6 Eng. Agrônomo, Doutor, Professor no Instituto Federal Catarinense, Rodovia SC 283 - km 17, Concórdia, SC, Brasil, CEP: 89703-720, ricardo.rosso @ifc.edu.br. &#x0D; &#x0D; &#x0D; 1 RESUMO&#x0D; &#x0D; A obtenção de elevadas produtividades de pastagens é essencial para a manutenção dos níveis alimentares de rebanhos bovinos. A altura de plantas e o diâmetro de colmos caracterizam-se como determinantes no sucesso produtivo da pastagem pela quantidade de massa produzida. Um dos fatores que alteram esses índices são as precipitações irregulares, tornando necessária a reposição da demanda através da irrigação. O objetivo do trabalho foi avaliar o diâmetro de colmos e a altura de plantas sob diferentes condições hídricas e cortes no sorgo forrageiro, em dois anos agrícolas no estado do Rio Grande do Sul. Foram conduzidos dois experimentos nos anos agrícolas de 2015/2016 e 2016/2017 em Santa Maria (RS), e foram avaliadas as alturas de plantas e os diâmetros de colmos em seis condições hídricas (não irrigado, 25, 50, 75, 100 e 125 % da ETo), em três períodos de cortes (50, 80 e 110 dias após a semeadura) em delineamento blocos ao acaso. Foram encontradas diferenças estatisticamente significativas para a variação da altura de plantas e também do diâmetro de colmos, tanto conforme a lâmina de irrigação, quanto na sequência de cortes.&#x0D; &#x0D; Palavras chave: pastagem irrigada, capacidade de rebrote, irrigação.&#x0D; &#x0D; &#x0D; KIRCHNER, J. H.; ROBAINA, A. D.; PEITER, M. X.; TORRES, R. R.; MEZZOMO, W.; ROSSO, R. B.&#x0D; HEIGHT OF PLANTS AND DIAMETER OF STEMS OF SORGHUM FORAGE IRRIGATED BY CUTS&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; 2 ABSTRACT&#x0D; &#x0D; Achieving high pasture yields is essential for maintaining feed levels in cattle herds. Plant height and stem diameter are determinants of pasture production success by the amount of mass produced. One of the factors that change these rates is irregular rainfall, making it necessary to replenish demand through irrigation. The objective of this work was to evaluate stem diameter and plant height under different water conditions and forage sorghum cuts in two agricultural years in the state of Rio Grande do Sul. Two experiments were conducted in the agricultural years of 2015/2016 and 2016/2017 in Santa Maria / RS, and plant heights and stem diameters were evaluated in six water conditions (non-irrigated, 25, 50, 75, 100 and 125% of ETo), in three cutting periods (50, 80 and 110 days after sowing) in a randomized block design. Statistically significant differences were found for plant height and stem diameter variation, both according to irrigation depth and cut sequence.&#x0D; &#x0D; Keywords: irrigated pasture, regrowth capacity, irrigation.

Crecimiento de los pastos Cayman y Cobra en diferentes niveles salinos de NaCl, en invernadero

Los suelos salinos afectan el crecimiento y rendimiento de los pastizales y disminuyen la disponibilidad de forrajes para la alimentación animal. Objetivo: Evaluar la emergencia, crecimiento y producción de biomasa de los pastos Cayman (BR/1752) y Cobra (BR/1794) en condiciones de estrés salino inducido por la sal NaCl a siete niveles de conductividad eléctrica (CE): 0, 2, 4, 6, 10, 12 y 15 dS m-1. Metodología: en invernadero, se establecieron macetas experimentales con agrolita, sembradas a una densidad de 25 semillas por maceta para evaluar la emergencia; posteriormente se realizó un aclareo para dejar tres plantas por maceta en un diseño completamente al azar. El riego consistió en reponer el agua perdida por evapotranspiración, mediante el suministro de agua destilada. El experimento abarcó un periodo de 60 días durante los cuales se determinó la altura y el diámetro del tallo, número de hijuelos, el número de hojas, la longitud de raíz y producción de biomasa. Los resultados indican que al aumentar la conductividad eléctrica de las soluciones salinas, ambos pastos disminuyeron de manera diferencial el porcentaje de emergencia, la altura y el diámetro del tallo, el número de hijuelos y el número de hojas, con una disminución en la producción de biomasa de las plantas, más pronunciado en pasto Cayman que en pasto Cobra. Entre cultivares se presentaron diferencias de tolerancia; ya que en el pasto Cayman esta disminución se produjo a CE ≥ 10 dS m-1, mientras que en el pasto Cobra la producción de biomasa fue afectada signif icativamente (P = 0.05) a partir de CE ≥ 12 dS m-1.

Bioactive carbon improves nitrogen fertiliser efficiency and ecological sustainability

Agriculture’s most pressing challenge is raising global food production while minimising environmental degradation. Nutrient deficiencies, principally nitrogen (N), limit production requiring future increases in fertiliser use and risk to proximal non-agricultural ecosystems. We investigated combining humate with urea, globally the most widely used N-suppling fertiliser, in a four-year field study. Humate increased pasture yield by 9.8% more than urea and significantly altered soil microbial diversity and function. Humate increased N retention suggesting microbial sequestration may lower N leaching and volatilisation losses. Humic microbial bio-stimulation could feasibly increase fertiliser efficiency and development of ecologically sustainable agriculture.

Remote Sensing Applications for Insurance: A Predictive Model for Pasture Yield in the Presence of Systemic Weather

A robust predictive model for crop yield is essential for designing a commercially viable index-based insurance policy. Index-based insurance for crops is still at a relatively infant stage, and more research and development is needed in order to address a main limitation, which is referred to as basis risk. Traditionally, ground weather station measurements have been the most common approach used in weather indices, and this approach has often led to high levels of basis risk. Recent advances in satellite-based remote sensing provide new opportunities to use publicly available and transparent “big data,” to potentially make index-based insurance policies more relevant by reducing basis risk. This is the first article to provide a comprehensive comparison of 13 pasture production indices (PPIs), including those developed based on satellite-derived vegetation and biophysical parameter indices using data products from the Moderate Resolution Imaging Spectroradiometer (MODIS). A validation protocol is established, and a unique dataset covering the period 2002 to 2016 from a network of pasture clip sites in the province of Alberta, Canada, is used to demonstrate new applications for insurance based on remote sensing–derived data. The results of the satellite-derived PPIs are compared to PPIs based on ground weather station data as benchmarks, which to date are the most common design for index-based insurance. Overall, the satellite-based indices report higher correlations with the ground truth forage yield data compared to the weather station PPIs. As an example, in 2015 and 2016 the best performing satellite-based PPIs produced correlations close to 90%. When considering the whole sample period, the highest overall average correlation is 62.0% for the biophysical parameter PPI based on FPAR 500-m MODIS, and the lowest overall average correlation is 43.8% for the vegetation PPI based on EVI 250-m MODIS. Comparatively, the highest correlation reported for the weather station indices is for precipitation, at 12.51%. Other predictive models based on principal component analysis and shrinkage methods (such as lasso, ridge regression, and elastic net) are considered to address the issues of variable selection and dimension reduction in insurance design. This research makes an important contribution to the field of actuarial science and insurance, because it highlights potential new opportunities for insurance design and predictive analytics using large and comprehensive satellite datasets that remain relatively unexplored to date in insurance practice. Though forage is used as the example here, the research could be extended to other crops, and other areas in the property and casualty sector, including for fire and flood.

Changing patterns of pasture production in south-eastern Australia from 1960 to 2015

The seasonal pattern of pasture production and its variability from year to year are important for pasture-based livestock production systems in south-eastern Australia because they influence key strategic decisions such as stocking rate and timing of the reproductive cycle. In this study, the effects of observed climate variations over the period 1960–2015 on pasture growth patterns were investigated by using a biophysical modelling approach. Pasture growth rates were simulated using DairyMod biophysical software at five sites ranging from high-rainfall, cool temperate at Elliott in Tasmania to medium-rainfall, warm temperate at Wagga Wagga in southern New South Wales. Annual pasture yields showed a small increasing rate of 50 kg DM/ha.year at Elliott and 40 kg DM/ha.year at Ellinbank (P &amp;lt; 0.05), whereas other sites showed no significant trend over time. A cross-site analysis of seasonal average pasture growth rates predicted under four different discrete periods of 14 years each showed that winter growth has increased steadily through time (P = 0.001), and spring pasture growth rate has decreased (P &amp;lt; 0.001) in 2002–15 compared with the earlier periods. Year-to-year pasture yield variability (coefficient of variation) during autumn and spring seasons has also increased (P &amp;lt; 0.05) across sites in the period 2002–15 compared with 1998–2001. At each site, the number of spring days with water stress (growth limiting factor_water &amp;lt;0.7) was ~10 times greater than the number of days with temperature stress (growth limiting factor_temperature &amp;lt;0.7). There was an increase in the number of days with water stress at Wagga Wagga, and increased heat stress at Wagga Wagga and Hamilton (P &amp;lt; 0.05) in the most recent period. These results highlight the importance of incorporating more heat-tolerant and deep-rooting cultivars into pasture-based production system. Although previous studies of climate-change impact have predicted increasing winter growth rates and a contraction of the spring growing season in the future (2030), this study provides clear evidence that these changes are already occurring under the observed climate in south-eastern Australia.

Effects of cutting height managements on yield and composition of different annual pastures

ABSTRACT This study aimed to evaluate the effects of different pre-cutting and residual heights of Pearl millet, Sudangrass, and Sorghum pastures on yield, morphological and chemical composition. The experimental design was the randomized blocks, with four experimental units per treatment. It was evaluated three species of forage: 1) Pearl millet (MIL; Pennisetum americanum); 2) Sudangrass (SUD; Sorghum sudanense); and 3) Sorghum (SOR; Sorghum bicolor); and two cutting managements: I) 50:20 - cutting height at 50 cm and 20 cm residual height; and II) 85:10 - cutting height at 85 cm and 10 cm residual height. Managements of cutting height affected neither forage yield per cut nor total forage yield. Sudangrass had less cuts than MIL and SOR when submitted to the 50:20 management. The 85:10 management increased stem proportion and leaf to stem ratio, and reduced leaf proportion in comparison with the 50:20 management. The 50:20 management reduced forage contents of fiber and organic matter, and increased forage contents of crude protein and total digestible nutrient. Sorghum exhibited greater nutritive value due to increased leaf proportion. The 50:20 management increased number of cuts and improved nutritive value of forages, regardless of species evaluated in this study.

Improving the productivity of degraded pasture land through demonstration of legume forage over sowing: The case of Ayba pasture land, South Tigray, Ethiopia

The study was undertaken in Northern Ethiopia, at Emba Alaje District, to assess forage yield of the natural pasture over sown with adapted legume forage. The design was a single plot design and the treatments were farmers’ practice and Vicia sativa over sown. A total of 60 quadrats of 1 by 1 m2 size were used for herbaceous species composition, above ground biomass and dry matter yield and analyzed by t-test equal variances using R-software. Over sowing legume forage increased dry matter yield significantly as compared with the farmers’ practice pasture land. The higher dry matter yield was recorded for pasture land over sown with Vicia sativa (3.43 ton/ha). Vicia sativa over sown also increased the basal cover of herbaceous (2.28) compared to farmers’ practice (1.47). Similarly, the Vicia sativa over sown pasture land had significantly (p < 0.001) higher forage biomass than the farmers’ practice area. Results from the comparative analysis also indicated that Vicia sativa over sown on the degraded grazing land had a higher cost effective than the existing farmers’ practice as the calculated net return was found to be positive. It is, therefore, concluded that over sowing degraded grazing land with Vicia sativa improves biomass yield, and it is also cost-effective as compared with farmers’ practice. Therefore, based on the finding of the study it is highly recommended that the concerned governmental and nongovernmental organization should give emphasis to promote Vicia sativa over sown for the rehabilitation of degraded pasture land.

Estimation method of yield, height and nutrition of pasture of grass types using visible light images

Estimation method of yield, height and nutrition of pasture of grass types using visible light images

Participatory evaluation of improved pastureland interventions in Ayba pastureland, South Tigray: Implication for pastureland enhancement

The participatory evaluation was conducted to assess the forage yield of the natural pasture in degraded grazing land through the application of urea, manure and Vicia sativa over sown with farmers...

Effects of Phosphorus Fertilizer Solubility on Pastures Yield and Quality in Andisols

Phosphate rock (PR) and triple superphosphate (TSP) are options for phosphorus (P) fertilization of crop and pasture production systems. However, to our knowledge, no studies have compared P sources with different solubilities in field trials to date. The aim of this study was to compare the effect of PR and TSP on forage yield, P uptake and nutritive quality of pastures growing in Andisols. Three experiments were conducted in southern Chile, analysing the factorial combination of two P sources (PR and TSP) and four P rates (0–328 kg P ha−1). Results showed that cumulative dry matter production in year 1, year 2 and total was significantly (p ≤ 0.05) affected by P dose, time of cut and the interaction of both variables, indicating that PR is as effective as TSP in acid soils. The treatments did not show significant differences among themselves (p ≥ 0.05) in foliar P concentration, P uptake, P apparent recovery efficiency and nutritive quality of pastures evaluated. The highest P apparent recovery efficiency was obtained with 22 kg P ha−1 and 44 kg P ha−1 independent of the phosphate fertilizer applied. A P demand factor of 2.7–3.1 kg P Mg−1 dry matter was estimated. All these information will be useful to improve P fertilization managements of pastures growing in Andisols.

Using a two-price market value method to value extra pasture DM in different seasons

The challenges of estimating the value of growing and using extra pasture to the farm business often necessitates using complex systems modelling of individual farms. In this paper, a straightforward market value method is outlined, where technical substitutes for which there is a defined market price are used as proxies to estimate an equivalent value for extra pasture used in a farm system. The method can be useful for all grazed livestock production systems where substitutes for pasture are purchased and sold. The two-price approach presented advances on previous applications of using market values by accounting for differences in the value of extra pasture DM used on farm in different seasons. The value per extra kg DM harvested in seasons when pasture typically limits livestock production, for example during summer/autumn in temperate environments, and used on farm equates to the market price of the replacement cost as purchased supplementary feed. This is the maximum the extra pasture DM could be worth when used in the farm system. Conversely, the value per extra kg DM harvested in spring when extra pasture is likely to be in surplus of livestock requirements, equates to its market price if sold, as standing hay for example, termed the salvage value. This two-price approach was applied to value the previously published seasonal DM yield differences of 19 perennial ryegrass cultivars, compared to an industry standard cultivar, grown in three regions of Victoria, Australia. Results were then compared to the value of extra pasture DM previously estimated using system simulation analyses of three farms and applied to the same perennial ryegrass data set. The difference in the value of extra pasture DM estimated using the two methods ranged from $0.01/kg DM to $0.24/kg DM. Overall, the two-price method estimated an extra $24 to $200/ha.year benefit over the industry standard cultivar for the 19 cultivars across the three regions, similar to the extra $0 to ∼ $180/ha.year estimated by the previous system simulation analysis. The two-price market value method can be an efficient way to estimate the value of extra seasonal DM yield of pasture, with results easily generalised across a range of farming systems.

Physiological response of Secale cereale L. seedlings under freezing-thawing and alkaline salt stress.

Freezing-thawing and saline-alkaline are the major abiotic stress for the pasture in most high-latitude areas, which are serious threats to the yield of pasture. In this study, the osmotic adjustment substances, membrane lipid peroxidation, and antioxidant enzymes activities of rye (Secale cereale L., cv. Dongmu-70) seedlings under different treatments: CK (no treatment), SC (Na2CO3 treatment), FT (freezing-thawing treatment), and FT+SC (combined Na2CO3 and freezing-thawing treatments), were investigated. At the freezing stage, the content of MDA and proline, the activity of APX, SOD, and POD increased with the decrease of the temperature in the leaves of rye seedlings in FT and FT+SC treatments and reached the maximum value at - 5 °C. In addition, the content of protein and H2O2, CAT activity reached the maximum value at 0 °C; the damage is larger under low temperature stress at 0 °C and - 5 °C in rye seedling. At the thawing stage, the content of MDA and H2O2 in seedling leaves decreased in FT and FT + SC treatments. These results demonstrated that proline content and antioxidant enzymes activities could play an important role in protecting cytomembrane and scavenging ROS respectively in rye under alkaline salt stress and freezing-thawing stress. The result also indicated rye seedlings were subjected to a freezing-thawing stress which resulted in a reversible (recoverable) injury.

Relationships between sheep liveweight production and dry matter yield for lucerne-based pastures in spring

A five-year dryland grazing experiment explored the relationship between sheep liveweight (LWt) production and dry matter (DM) yield of lucerne-based pastures in spring. In 2011, a randomised complete block experiment with a lucerne monoculture, a lucerne/brome mix and a lucerne/cocksfoot mix were established at Ashley Dene, Canterbury and replicated six times. Pastures were managed under dryland conditions. Ewes with twin lambs at foot grazed in spring and LWt production, DM yield and botanical composition were quantified.Regression analysis showed total DM feed on offer accounted for only 11% of the observed variation in spring LWt production. Subsequent analysis of the botanical composition of the three pastures showed total feed on offer in spring was unaffected by pasture treatment in four out of five years. However, yield of the lucerne component on offer was 77–230% greater in the monoculture than the mixes in Years 3–5. Brome yields declined from Year 3 and did not recover. By Year 5, weeds accounted for 41% of the feed on offer in spring in the lucerne/brome mix. Net spring ewe + lamb liveweight production increased at a rate equivalent to 246 kg LWt +71 kg LWt per tonne of lucerne DM on offer (R2 = 0.83). There was no effect of pasture type. Where possible lucerne should be established as a monoculture to maximise liveweight gain. A runout stand was overdrilled with a companion grass to extend the productive stand life. The loss of lucerne over time indicated renewal should be initiated within 2–3 years of oversowing to ensure LWt production is not compromised.

The Effects of Various Improvement Methods Applications on Herbage Yield of Natural Pastures

In this study, which was performed on an over-grazing pasture in Şanlıurfa under the influence of a dry climate, the effects of different breeding methods such as natural(control), fertilization, insemination, fertilization+insemination+insemination+insemination + release on natural pastures were investigated. In order to increase the yield potential of Natural Pastures in the research area, manure, seedling, fertilization+seedling, fertilization+seedling+version methods were applied on both protected and grazing fields. Using the transect method, key plant species in the region were determined. As a result of the research, according to two-year averages, the highest dry grass yield in grazing area was 47.98 kg/da fertilized seedlings and the lowest yield was 21.40 kg/da natural (control) seedlings. According to two-year averages, the highest dry grass yield in the protected area was obtained from 171.29 kg/da manure, and the lowest value was obtained from 82.77 kg/da natural (control) pasture. According to the results of breeding methods applied in the field of research; in addition to protecting pasture areas, a suitable fertilization is required. In addition, it was concluded that the desired result could be achieved by making a regular grazing according to the rules of grazing amanjman.

Pasture restoration improvement methods for temperate degraded pastures and consequences of the climatic seasonality on soil–pasture complex

AbstractShort persistence of renovated pastures is a major problem for pastoral production systems. Pasture species establishment, species performance and persistency and their relationships with soil–water attributes following pasture improvement methods were evaluated over two years. Fertilised naturalised pasture (FNP), non‐fertilised naturalised pasture (NFNP),Lolium perenne–Trifolium repenscultivated pasture (CP),L. perenne–T. repensdirect‐drilled pasture (DP), andBromus valdivianus,Holcus lanatus,Dactylis glomerata,L. perenneandT. repensdirect‐drilled pasture (DDP) were established as a randomised complete block design. Pastures were limed, fertilised and sheep‐grazed. Plant growth compensatory mechanisms, by decreasing tiller number and increasing tiller size, equalised pasture yield during the establishment. In both years, the improved pastures yield was greater than that of NFNP. In the second year, DDP and FNP reached the higher pasture growth rate, with a seasonality diminishment. During the second summer, soil matrix potential at 0–20 cm soil profile exceeded the permanent wilting point, resulting in the pasture growth rate of NFNP and the sown pastures ranging from 0.0 to 3.6 kg DM/ha per day, while for FNP, it was 17.8 kg DM/ha per day. Sown species, fast‐growing species spontaneous colonisation and growth were all stimulated in the improved pastures over species that tolerate stress, improving agronomical and ecological pasture features.