Plantain as a GHG mitigation option: N2O, C and GHG balances from an intensively grazed New Zealand dairy pasture

<p>Agricultural greenhouse gas (GHG) emissions account for almost half of New Zealand’s total emissions, and therefore considerable attention has been given to identifying and testing mitigation options. At plot scale, plantain (Plantago lanceolate L.) in the pasture sward has been demonstrated to reduce nitrous oxide (N<sub>2</sub>O) emissions but has not been tested at paddock scale on an operating farm. Our aim was to test the efficacy of a pasture sward containing >30% plantain as a GHG mitigation option at paddock scale (2.5-3 ha) on a year-round rotationally grazed commercial dairy farm in the Waikato region of New Zealand. Utilising eddy covariance measurements of CO<sub>2</sub>, N<sub>2</sub>O and CH<sub>4</sub> coupled to farm management records, N<sub>2</sub>O, carbon (C) and GHG balances (sign convention: positive value = emission to the atmosphere) were calculated for two adjacent paddocks – a control paddock containing an existing ryegrass/clover sward (RC), and a paddock that underwent renovation with the establishment of a ryegrass/clover/plantain sward (RCP). Establishment of RCP was via spraying and direct drilling and occurred in March 2018 (autumn). For the establishment period between initial herbicide application and the first grazing of the new RCP sward 66 days later, N<sub>2</sub>O emissions were 2.58 kg N ha<sup>-1</sup> compared with 1.69 kg N ha<sup>-1</sup> for the RC paddock. During the same period, C losses from the RCP paddock were greater than from the RC paddock (2.40 t C ha<sup>-1</sup> for RCP and 1.29 t C ha<sup>-1</sup> for RC) primarily due to reduced photosynthetic inputs associated with the herbicide application. The GHG budget (including enteric methane emissions from feed grown and eaten in the paddock) during the 66 day establishment period was an emission of 6.56 t CO<sub>2</sub>-eq ha<sup>-1</sup> for RC and 9.85 t CO<sub>2</sub>-eq ha<sup>-1</sup> for RCP. Unfortunately, the RCP sward establishment was poor, and after one year, total pasture production was unexpectedly lower than RC. Additionally, plantain accounted for <7% of the total RCP dry matter production. N<sub>2</sub>O, C and GHG balances for RCP in the first year following (and including) establishment were 6.61 kg N ha<sup>-1</sup> y<sup>-1</sup>, 3.25 t C ha<sup>-1</sup> y<sup>-1</sup> and 21.40 t CO<sub>2</sub>-eq ha<sup>-1</sup> y<sup>-1</sup> respectively, while for RC they were 7.21 kg N ha<sup>-1</sup> y<sup>-1</sup>, 0.95 t C ha<sup>-1</sup> y<sup>-1</sup> and 13.29 t CO<sub>2</sub>-eq ha<sup>-1</sup> y<sup>-1</sup>. Due to the poor establishment of plantain, any N<sub>2</sub>O and GHG benefits of this species were unable to be initially concluded, but additional plantain was sown and measurements are ongoing. However, we did identify several relevant findings: any N<sub>2</sub>O/GHG benefits of plantain must firstly offset emissions (including C losses) associated with the establishment of the sward (>3 t CO<sub>2</sub>-eq ha<sup>-1</sup> in this study), and furthermore, there is a risk that should the establishment be poor, GHG emissions can be considerably greater (and pasture production lower) than an existing pasture.</p>

ADAPTATION WORKS TO AVOID THE FLOODING OF PIAZZA SAN MARCO (VENICE): PHYSICAL MODEL TESTS TO EVALUATE OVERTOPPING DISCHARGE

According to the management of the Mo.S.E. system, the water level in the Venetian lagoon is maintained below a certain threshold, that however does not guarantee the complete defense of the main Piazza. Flooding of the Piazza is presently tolerated, although limitedly to a minor extent, and can/will be avoided only thanks to additional adaptation works. One of the possible flooding mechanisms is the wave overtopping, and this note investigates the efficiency, as possible mitigation option, of a small temporary barrier placed along the S. Marco quay.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/wiSF2B81wIM

Natural Fibre Polymer Composites – A Game Changer for the Aviation Sector?

As part of the efforts to reduce the environmental impacts caused by the aviation sector, the use of bio-based instead of fossil-based materials has been assessed as a possible mitigation option. Natural Fibre Polymer Composites have proven to have a higher environmental performance in the automotive sector and are emerging as an option for weight reduction in aircraft. This study quantifies, though Life Cycle Assessment, the environmental performance of specific flax-based composite panels intended for aircrafts as interior fitting elements (i.e. partition panels, tray tables, baggage compartments) compared to a glass fibre/epoxy composite with a honeycomb core. Through system expansion, the fate of co-products issued from the production of the flax fibre technical textile used as reinforcement in the biocomposite material were considered in the assessment. Results showed that for an application in the aeronautics sector, the weight of the panels is the upmost critical parameter shaping the overall environmental performance of panels. Focusing on the panel production only, the biocomposite panel showed a higher environmental performance in the categories of climate change and marine eutrophication compared to the conventional panel, and the fire suppressant agent was identified as the main contributor to the environmental impacts of the bio-based panel. Yet these gains were negligible when considering the full life cycle of the panels, due to the higher weight (14%) of the bio-based panels; which is linked to the bio-based panel being at a prototype stage.In order to improve the environmental performance of the biocomposite panel and thus reduce its weight, it was shown relevant to optimize geometry of the panel itself, especially its core, so less resin could be used.

The Climate and Nutritional Impact of Beef in Different Dietary Patterns in Denmark

There is public focus on the environmental impact, and in particular, the emissions of greenhouse gases (GHG), related to our food consumption. The aim of the present study was to estimate the carbon footprint (CF), land use and nutritional impact of the different beef products ready to eat in different real-life dietary patterns. Beef products accounted for 513, 560, 409 and 1023 g CO2eq per day, respectively, in the four dietary patterns (Traditional, Fast-food, Green, and High-beef). The total CFs of these diets were 4.4, 4.2, 4.3 and 5.0 kg CO2eq per day (10 MJ), respectively. The Green diet had almost the same CF as the Traditional and the Fast-food diets despite having the lowest intake of beef as well as the lowest intake of red meat in total. A theoretical substitution of beef with other animal products or legumes in each of these three diets reduced the diets’ CF by 4–12% and land use by 5–14%. As regards nutrients, both positive and negative impacts of these substitutions were found but only a few of particular nutritional importance, indicating that replacing beef with a combination of other foods without a significant effect on the nutrient profile of the diet is a potential mitigation option.

Manure happens: re-examining mitigation potential from waste-to-resource in agricultural ecosystems

<p>Using animal waste (manure) for soil amendments have been recognized as an efficient strategy for farm management, as well as for soil preservation and greenhouse gas (GHG) emissions mitigation. It is believed that manure can improve soil quality, increase soil organic carbon (SOC) level and therefore potentially mitigate GHG emissions. However, recent studies reported that use of manure in the field can cause large amount of nitrous oxide (N<sub>2</sub>O) emissions which in many cases offset the amount of SOC sequestered in agricultural ecosystems and eventually lead to net GHG emissions. In this report, we intended to investigate this management related mitigation option holistically, by modeling the full GHG budgets from a life cycle perspective. GHG emissions and some reactive gases (e.g., VOCs, NO) were specifically included in the manure life cycle. By re-examining the system boundary in previous studies, we show that use of manure does not necessarily cause large GHG emissions as previously reported. Net GHG emissions or mitigation potentials depend on not only SOC and N<sub>2</sub>O emissions <em>in situ</em>, but also emissions and reactive gases beyond the farmgate and those would have been released anyway.</p>

Effects of crop residue on carbon dioxide, methane and nitrous oxide emissions on cultivated peat soils

<p>Peatlands cover three percent of the global land surface. However, they store significant amounts of carbon (C), approximately 30%. Peatlands are drained to support agricultural production. It’s estimated that agriculture exploits approximately 20% of peatlands worldwide. The exploited peatlands are significant emitters of carbon dioxide (CO<sub>2</sub>) and nitrous oxide (N<sub>2</sub>O). In Europe, agriculture is the second largest contributor of greenhouse gas (GHG) emissions. In addition to GHG emissions, we are fast losing productive peatlands; it’s estimated by 2050, a third of productive peatlands will be lost. Loss of productive peatlands will affect productivity and food security.</p><p>To prolong use of peatlands, ploughing in of crop residue, either from the previous season or specially grown crop, is often considered a mitigation option. Nevertheless, there is concern that fresh organic matter (FOM) might accelerate decomposition of existing organic. This study assesses effects of FOM on the emissions of CO<sub>2</sub>, methane (CH<sub>4</sub>) and N<sub>2</sub>O in a cultivated peatland. A mesocosm experiment was carried out using intact cores with added FOM and manipulated water table (WT), -20 and -50 cm.</p><p>The results show there is an effect of both WT and FOM on emissions. CO<sub>2</sub>, CH<sub>4</sub>, and N<sub>2</sub>O emissions differ in the different WT treatments. The -20 cm cores produced more methane than the -50 cm.  It is evident that leaving crop residue and then ploughing it in does not have the desired effect as it led to increased emissions.</p>