Measurement Duration but Not Distance, Angle, and Neighbour-Proximity Affects Precision in Enteric Methane Emissions when Using the Laser Methane Detector Technique in Lactating Dairy Cows

SIMPLE SUMMARY: Methane that is breathed out and eructed from ruminants is a potent greenhouse gas that contributes to climate change. Although metabolic chambers are the “gold standard” for measuring methane from livestock, their application in production farms is very limited. There is a need to develop proxy methods that can be applied in such production environments. The proprietary Laser Methane Detector (LMD) has been trialed for the previous decade and has demonstrated its usefulness as a non-invasive and portable instrument to determine methane output from ruminants. In validating the reliability and stability of the data generated by the LMD, the current study gives answers to some very practical assumptions used in the use of the LMD and enhances the confidence in its use in ruminants. ABSTRACT: The laser methane detector (LMD), is a proprietary hand-held open path laser measuring device. Its measurements are based on infrared absorption spectroscopy using a semiconductor laser as a collimated excitation source. In the current study, LMD measurements were carried out in two experiments using 20 and 71 lactating dairy cows in Spain and Scotland, respectively. The study aimed at testing four assumptions that may impact on the reliability and repeatability of the LMD measurements of ruminants. The study has verified that there is no difference in enteric methane measurements taken from a distance of 3 m than from those taken at a distance of 2 m; there was no effect to the measurements when the measurement angle was adjusted from 90° to 45°; that the presence of an adjacent animal had no effect on the methane measurements; and that measurements lasting up to 240 s are more precise than those taken for a shorter duration. The results indicate that angle, proximity to other animals, and distance had no effects and that measurements need to last a minimum of 240 s to maintain precision

Multi-criteria assessment of integrating legumes into cropping systems across Europe

Integration of legumes into European agricultural systems would diversify the highly specialized cropping systems that are dominated by cereals and increase resource efficiency of agricultural systems. By providing high quality protein for food and feed as well as regulating and supporting services, legumes contribute essential ecosystem services. In order to assess the overall effects of legumes in agricultural systems, it is necessary to consider how legumes are integrated in cropping systems and evaluate the impacts of this integration. As legumes influence the production of other crops in the rotation and as the interaction of legumes are multiplex, an assessment of the cropping system that considers multiple criteria is required. The objective of this work was to assess the impacts of changes in crop rotations through the integration of legumes using cropping systems implemented in practice. We used a multi-actor approach to incorporate the knowledge of a range of legume experienced actors representing value chains with soybean, pea, faba bean, lupin and forages for food and feed and evaluate thereby the role of legumes in crop rotations of diverse systems from Ireland in the West to Ukraine in the East. Within the research process we firstly identified region-specific crop rotations with cultivation techniques based on expert opinion in the 17 different study areas. One rotation representing the current farming without legumes and at least one alternative legume-based crop rotation was specified per region. Secondly, a valid set of indicators was developed, including environmental, economic and agronomic indicators. The indicators were calculated for each cropping system at the rotational level, considering pre-crop effects i.e. adapted N fertilizer application rates and yields. Finally, the cropping system assessment compared current farming practices to legume-based alternatives. Trade-offs and synergies between different indicators e.g. gross margins and N fertilizer use were identified. On average, crop rotations with legumes reduced nitrous oxide emissions by 21% and 26% and N fertilizer use by 26% and 45% in arable and forage systems, respectively. While protein output was increased by 13% and 5%, energy output was reduced by 10% and 9% in arable and forage systems. Gross margin effects of introducing legumes were variable and site specific. Consideration of the full economic value of the crops as feed, subsidies for legumes, and the application of carbon taxes increased the relative performance of the legume-supported systems. The presented cropping system assessment within a multi-actor approach enables an exploration of the opportunities and challenges for integrating legumes in European crop rotations considering the views of local actors and can thereby provide multi-criteria guidance on the validation of potential alternative strategies.[https://pure.sruc.ac.uk/en/publications/multi-criteria-assessment-of-integrating-legumes-into-cropping-sy

Review: Soil compaction and controlled traffic farming in arable and grass cropping systems

There is both circumstantial and direct evidence which demonstrates the significant productivity and sustainability benefits associated with adoption of controlled traffic farming (CTF). These benefits may be fully realised when CTF is jointly practiced with no-tillage and assisted by the range of precision agriculture (PA) technologies available. Important contributing factors are those associated with improved trafficability and timeliness of field operations. Adoption of CTF is therefore encouraged as a technically and economically viable option to improve productivity and resource-use efficiency in arable and grass cropping systems. Studies on the economics of CTF consistently show that it is a profitable technological innovation for both grassland and arable land-use. Despite these benefits, global adoption of CTF is still relatively low, with the exception of Australia where approximately 30% of the grain production systems are managed under CTF. The main barriers for adoption of CTF have been equipment incompatibilities and the need to modify machinery to suit a specific system design, often at the own farmers’ risk of loss of product warranty. Other barriers include reliance on contracting operations, land tenure systems, and road transport regulations. However, some of the barriers to adoption can be overcome with forward planning when conversion to CTF is built into the machinery replacement programme, and organisations such as ACTFA in Australia and CTF Europe Ltd. in Central and Northern Europe have developed suitable schemes to assist farmers in such a process