Climate factors contribute to grassland net primary productivity

Our call set out to enlarge the evidence base and methods for improving and evaluating grasslands in a changing environment as a sustainable ecosystem for all life [...

The impact of fungicide treatment and Integrated Pest Management on barley yields:Analysis of a long term field trials database

This paper assesses potential for Integrated Pest Management (IPM) techniques to reduce the need for fungicide use without negatively impacting yields. The impacts of three disease management practices of relevance to broad acre crops –disease resistance, forecasting disease pressure, and fungicide use – were analysed to determine impact on yield using a long-term field trials database of Scottish spring barley, with information from experiments across the country regarding yield, disease levels, and fungicide treatment. Due to changes in data collection practices, data from 1996 to 2010 were only available at trial level, while data from 2011 to 2014 were available at plot level. For this reason, data from 1996 to 2014 were analysed using regression models, while a subset of farmer relevant varieties was taken from the 2011–2014 data, and analysed using ANOVA, to provide additional information of particular relevance to current farm practice. While fungicide use reduced disease severity in 51.4%of a farmer-relevant subset of trials run 2011–2014, and yields were decreased by 0.62 t/ha on average, this was not statistically significant in 65% of trials. Fungicide use had only a minor impact on profit in these trials, with an average increase of 4.4% for malting and 4.7% for feed varieties, based on fungicide cost and yield difference; potential savings such as reduced machinery costs were not considered, as these may vary widely. Likewise, the1996–2014 database showed an average yield increase of 0.74 t/ha due to fungicide use, across a wide range of years, sites, varieties, and climatic conditions. A regression model was developed to assess key IPM and site factors which influenced the difference between treated and untreated yields across this 18-year period. Disease resistance, season rainfall, and combined disease severity of the three fungal diseases were found to be significant factors in the model. Sowing only highly resistant varieties and, as technology improves, forecasting disease pressure based on anticipated weather would help to reduce and optimise fungicide use

The nitrogen, carbon and greenhouse gas budget of a grazed, cut and fertilised temperate grassland

Intensively managed grazed grasslands in temperate climates are globally important environments for the exchange of the greenhouse gases (GHGs) carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4). We assessed the N and C budget of a mostly grazed and occasionally cut and fertilised grassland in SE Scotland by measuring or modelling all relevant imports and exports to the field as well as changes in soil C and N stocks over time. The N budget was dominated by import from inorganic and organic fertilisers (21.9 g N m−2 a−1) and losses from leaching (5.3 g N m−2 a−1), N2 emissions (2.9 g N m−2 a−1), and NOx and NH3 volatilisation (3.9 g N m−2 a−1), while N2O emission was only 0.6 g N m−2 a−1. The efficiency of N use by animal products (meat and wool) averaged 9.9 % of total N input over only-grazed years (2004–2010). On average over 9 years (2002–2010), the balance of N fluxes suggested that 6.0 ± 5.9 g N m−2 a−1 (mean ± confidence interval at p > 0.95) were stored in the soil. The largest component of the C budget was the net ecosystem exchange of CO2 (NEE), at an average uptake rate of 218 ± 155 g C m−2 a−1 over the 9 years. This sink strength was offset by carbon export from the field mainly as grass offtake for silage (48.9 g C m−2 a−1) and leaching (16.4 g C m−2 a−1). The other export terms, CH4 emissions from the soil, manure applications and enteric fermentation, were negligible and only contributed to 0.02–4.2 % of the total C losses. Only a small fraction of C was incorporated into the body of the grazing animals. Inclusion of these C losses in the budget resulted in a C sink strength of 163 ± 140 g C m−2 a−1. By contrast, soil stock measurements taken in May 2004 and May 2011 indicated that the grassland sequestered N in the 0–60 cm soil layer at 4.51 ± 2.64 g N m−2 a−1 and lost C at a rate of 29.08 ± 38.19 g C m−2 a−1. Potential reasons for the discrepancy between these estimates are probably an underestimation of C losses, especially from leaching fluxes as well as from animal respiration. The average greenhouse gas (GHG) balance of the grassland was −366 ± 601 g CO2 eq. m−2 yr−1 and was strongly affected by CH4 and N2O emissions. The GHG sink strength of the NEE was reduced by 54 % by CH4 and N2O emissions. Estimated enteric fermentation from ruminating sheep proved to be an important CH4 source, exceeding the contribution of N2O to the GHG budget in some years

Grain legume production in Europe for food, feed and meat-substitution

Partial shifts from animal-based to plant-based proteins in human diets could reduce environmental pressure from food systems and serve human health. Grain legumes can play an important role here. They are one of the few agricultural commodities for which Europe is not nearly self-sufficient. Here, we assessed area expansion and yield increases needed for European self-sufficiency of faba bean, pea and soybean. We show that such production could use substantially less cropland (4–8%) and reduce GHG emissions (7–22% current meat production) when substituting for animal-derived food proteins. We discuss changes required in food and agricultural systems to make grain legumes competitive with cereals for farmers and how their cultivation can help to increase sustainability of European cropping systems.</p

Modelling Adaptation to climate change in agricultural systems

Modelling agricultural adaptation to climate change presents a range of challenges for modellers, but is vital to enabling decision makers to understand the potential costs and benefits of applying adaptation measures on-farm (or not) including risks and uncertainties associated with different actions. Here, the first stages of collaborative work undertaken at a workshop held in Braunschweig, Germany in autumn 2015, and subsequent analysis of findings, are reported. Subsequently, a second report will detail the development of these actions into a coherent overview of the state-of-the-art in modelling adaptation. Modellers and experimental researchers from a variety of disciplines (including biophysical and economic modellers from livestock, crop and grassland systems backgrounds) were asked to consider major climate impacts and associated adaptation options, and the challenges to modelling adaptations. Key modelling challenges fell into four main categories: information availability, accessibility of model outputs for stakeholders, technical challenges, and knowledge gaps. Within these categories, lists of specific challenges were compiled. The workshop revealed the diversity of approaches to modelling adaptation, and highlighted the different challenges associated with biophysical versus economic modelling. Understanding the state-of-the-art and key priorities for the modelling of climate change adaptation in agriculture is shown to be a complex and multi-faceted challenge. However, such an overview would provide a road map for stakeholder-driven improvement in modelling, with the potential to inform increased uptake of adaptation measures on-farm in Europe.(The main text will be published in a peer-reviewed journal

Evaluating the Potential of Legumes to Mitigate N2O Emissions From Permanent Grassland Using Process-Based Models

Funding Information: This modeling study was a joint effort of the Models4Pastures project within the framework of FACCE-JPI. Lutz Merbold and Kathrin Fuchs acknowledge funding received for the Swiss contribution to Models4Pastures (FACCE-JPI project, SNSF funded contract: 40FA40_154245/1) and for the Doc. Mobility fellowship (SNSF funded project: P1EZP2_172121). Lutz Merbold further acknowledges the support received for CGIAR Fund Council, Australia (ACIAR), Irish Aid, the European Union, the Netherlands, New Zealand, Switzerland, UK, USAID, and Thailand for funding to the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) as well as for the CGIAR Research Program on Livestock. The NZ contributors acknowledge funding from the New Zealand Government Ministry of Primary Industries to support the aims of the Livestock Research Group of the Global Research Alliance on Agricultural Greenhouse Gases and from AgResearch's Strategic Science Investment Fund (the Forages for Reduced Nitrate Leaching (FRNL) research program). The UK partners acknowledge funding by DEFRA and the RCUK projects: N-Circle (BB/N013484/1), UGRASS (NE/M016900/1), and GREENHOUSE (NE/K002589/1). R.M. Rees and C.F.E. Topp also received funding from the Scottish Government Strategic Research Programme. Lorenzo Brilli, Camilla Dibari, and Marco Bindi received funding from the Italian Ministry of Agricultural Food and Forestry Policies (MiPAAF). The FR partners acknowledge funding from CN-MIP project funded by the French National Research Agency (ANR-13-JFAC-0001) and from ADEME (no. 12-60-C0023). Open access funding enabled and organized by Projekt DEAL Funding Information: This modeling study was a joint effort of the Models4Pastures project within the framework of FACCE‐JPI. Lutz Merbold and Kathrin Fuchs acknowledge funding received for the Swiss contribution to Models4Pastures (FACCE‐JPI project, SNSF funded contract: 40FA40_154245/1) and for the Doc. Mobility fellowship (SNSF funded project: P1EZP2_172121). Lutz Merbold further acknowledges the support received for CGIAR Fund Council, Australia (ACIAR), Irish Aid, the European Union, the Netherlands, New Zealand, Switzerland, UK, USAID, and Thailand for funding to the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) as well as for the CGIAR Research Program on Livestock. The NZ contributors acknowledge funding from the New Zealand Government Ministry of Primary Industries to support the aims of the Livestock Research Group of the Global Research Alliance on Agricultural Greenhouse Gases and from AgResearch's Strategic Science Investment Fund (the Forages for Reduced Nitrate Leaching (FRNL) research program). The UK partners acknowledge funding by DEFRA and the RCUK projects: N‐Circle (BB/N013484/1), UGRASS (NE/M016900/1), and GREENHOUSE (NE/K002589/1). R.M. Rees and C.F.E. Topp also received funding from the Scottish Government Strategic Research Programme. Lorenzo Brilli, Camilla Dibari, and Marco Bindi received funding from the Italian Ministry of Agricultural Food and Forestry Policies (MiPAAF). The FR partners acknowledge funding from CN‐MIP project funded by the French National Research Agency (ANR‐13‐JFAC‐0001) and from ADEME (no. 12‐60‐C0023). Open access funding enabled and organized by Projekt DEAL Publisher Copyright: ©2020. The Authors. Open access funding enabled and organized by Projekt DEALPeer reviewedPublisher PD

Priorities for mitigating greenhouse gas and ammonia emissions to meet UK policy targets

Agriculture is essential for providing food and maintaining food security while concurrently delivering multiple other ecosystem services. However, agricultural systems are generally a net source of greenhouse gases and ammonia. They, therefore, need to substantively contribute to climate change mitigation and net zero ambitions. It is widely acknowledged that there is a need to further reduce and mitigate emissions across sectors, including agriculture to address the climate emergency and emissions gap. This discussion paper outlines a collation of opinions from a range of experts within agricultural research and advisory roles following a greenhouse gas and ammonia emission mitigation workshop held in the UK in March 2022. The meeting identified the top mitigation priorities within the UK’s agricultural sector to achieve reductions in greenhouse gases and ammonia that are compatible with policy targets. In addition, experts provided an overview of what they believe are the key knowledge gaps, future opportunities and co-benefits to mitigation practices as well as indicating the potential barriers to uptake for mitigation scenarios discussed

Model evaluation in relation to soil N2O emissions: An algorithmic method which accounts for variability in measurements and possible time lags

AbstractThe loss of nitrogen from fertilised soils in the form of nitrous oxide (N2O) is a side effect of modern agriculture and the focus of many model-based studies. Due to the spatial and temporal heterogeneity of soil N2O emissions, the measured data can introduce limitations to the use of those statistical methods that are most commonly employed in the evaluation of model performance. In this paper, we describe these limitations and present an algorithm developed to address them. We implement the algorithm using simulated and measured N2O data from two UK arable sites. We show that possible time lags between the measured and simulated data can affect model evaluation and that their consideration in the evaluation process can reduce measures such as the Mean Squared Error (MSE) by 30%. We also analyse the algorithm's results to identify patterns in the estimated lags and to narrow down their possible causes

Increasing crop rotational diversity can enhance cereal yields

9 Pág.Diversifying agriculture by rotating a greater number of crop species in sequence is a promising practice to reduce negative impacts of crop production on the environment and maintain yields. However, it is unclear to what extent cereal yields change with crop rotation diversity and external nitrogen fertilization level over time, and which functional groups of crops provide the most yield benefit. Here, using grain yield data of small grain cereals and maize from 32 long-term (10–63 years) experiments across Europe and North America, we show that crop rotational diversity, measured as crop species diversity and functional richness, enhanced grain yields. This yield benefit increased over time. Only the yields of winter-sown small grain cereals showed a decline at the highest level of species diversity. Diversification was beneficial to all cereals with a low external nitrogen input, particularly maize, enabling a lower dependence on nitrogen fertilisers and ultimately reducing greenhouse gas emissions and nitrogen pollution. The results suggest that increasing crop functional richness rather than species diversity can be a strategy for supporting grain yields across many environments.G.V., R.B. and S.H. acknowledge FORMAS grants 2018-02872 and 2018-02321. TMB acknowledges USDA AFRI grant 2017-67013-26254. LTEs managed by SRUC were supported by the Scottish Government RESAS Strategic Research Programme under project D3-, Healthy Soils for a Green Recovery. Swedish LTEs were funded by the Swedish University of Agricultural Sciences (SLU). We thank the Lawes Agricultural Trust and Rothamsted Research for data from the e-RA database. The Rothamsted Long-term Experiments National Capability (LTE-NC) was supported by the UK BBSRC (Biotechnology and Biological Sciences Research Council, BBS/E/C/000J0300) and the Lawes Agricultural Trust. The Woodslee site was supported by the Agro-Ecosystem Resilience Program (Agriculture & Agri-Food Canada) and field management provided by field crews over 6 decades is appreciated. La Canaleja LTE (Spain) was supported by RTA2017-00006-C03-01 project (Ministry of Science and Innovation. El Encín LTEs were supported by Spanish Ministry of Economy and Competitiveness funds (projects AGL2002-04186-C03-01.03, AGL2007-65698-C03-01.03, AGL2012-39929-C03-01 of which L. Navarrete was the P.I). R.A., A.G.D. and E.H.P. are also grateful to all members of the Weed Science Group from El Encín Experimental Station for their technical assistance in managing the experiments. The Brody/Poznan University of Life Sciences long-term experiments were funded by the Polish Ministry of Education and Science. We acknowledge the E-Obs dataset from the EU-FP6 project UERRA (http://www.uerra.eu) and the Copernicus Climate Change Service, and the data providers in the ECA&D project (https://www.ecad.eu/).Peer reviewe

Cereal yield gaps across Europe

peer-reviewedEurope accounts for around 20% of the global cereal production and is a net exporter of ca. 15% of that production. Increasing global demand for cereals justifies questions as to where and by how much Europe’s production can be increased to meet future global market demands, and how much additional nitrogen (N) crops would require. The latter is important as environmental concern and legislation are equally important as production aims in Europe. Here, we used a country-by-country, bottom-up approach to establish statistical estimates of actual grain yield, and compare these to modelled estimates of potential yields for either irrigated or rainfed conditions. In this way, we identified the yield gaps and the opportunities for increased cereal production for wheat, barley and maize, which represent 90% of the cereals grown in Europe. The combined mean annual yield gap of wheat, barley, maize was 239 Mt, or 42% of the yield potential. The national yield gaps ranged between 10 and 70%, with small gaps in many north-western European countries, and large gaps in eastern and south-western Europe. Yield gaps for rainfed and irrigated maize were consistently lower than those of wheat and barley. If the yield gaps of maize, wheat and barley would be reduced from 42% to 20% of potential yields, this would increase annual cereal production by 128 Mt (39%). Potential for higher cereal production exists predominantly in Eastern Europe, and half of Europe’s potential increase is located in Ukraine, Romania and Poland. Unlocking the identified potential for production growth requires a substantial increase of the crop N uptake of 4.8 Mt. Across Europe, the average N uptake gaps, to achieve 80% of the yield potential, were 87, 77 and 43 kg N ha−1 for wheat, barley and maize, respectively. Emphasis on increasing the N use efficiency is necessary to minimize the need for additional N inputs. Whether yield gap reduction is desirable and feasible is a matter of balancing Europe’s role in global food security, farm economic objectives and environmental targets.We received financial contributions from the strategic investment funds (IPOP) of Wageningen University & Research, Bill & Melinda Gates Foundation, MACSUR under EU FACCE-JPI which was funded through several national contributions, and TempAg (http://tempag.net/)