Electronic Noses: From Advanced Materials to Sensors Aided with Data Processing

Funded by BBSRC. Grant Number: LK0863 Natural Environment Research Council (NERC) Carbo-BioCrop project. Grant Number: NE/H01067X/1 MAGLUE project

/pdf/environmental-costs-and-benefits-of-growing-miscanthus-for-22mhifpvg6.pdf

Environmental costs and benefits of growing Miscanthus for bioenergy in the UK

The increasing demand for biomass for the production of bioenergy is generating land-use conflicts. These conflicts might be solved through spatial segregation of food/feed and energy producing areas by continuing producing food on established and productive agricultural land while growing dedicated energy crops on so called “surplus” land. Ambiguity in the definition and characterization of surplus land as well as uncertainty in assessments of land availability and of future bioenergy potentials is causing confusion about the prospects and the environmental and socio-economic implications of bioenergy development in those areas. The high level of uncertainty is due to environmental, economic and social constraints not yet taken into account and to the potentials offered by those novel crops and their production methods not being fully exploited. This paper provides a scientific background in support of a reassessment of land available for bioenergy production by clarifying the terminology, identifying constraints and options for

/pdf/bioenergy-from-surplus-land-environmental-and-socio-economic-2y67bb54n5.pdf

Bioenergy from “surplus” land: environmental and socio-economic implications

Soil organic carbon (SOC) change can be a major impact of land use change (LUC) associated with biofuel feedstock production. By collecting and analyzing data from worldwide field observations of major LUCs from cropland, grassland, and forest to lands producing biofuel crops (i.e. corn, switchgrass, Miscanthus, poplar, and willow), we were able to estimate SOC response ratios and sequestration rates and evaluate the effects of soil depth and time scale on SOC change. Both the amount and rate of SOC change were highly dependent on the specific land transition. Irrespective of soil depth or time horizon, cropland conversions resulted in an overall SOC gain of 6–14% relative to initial SOC level, while conversion from grassland or forest to corn (without residue removal) or poplar caused significant carbon loss (9–35%). No significant SOC changes were observed in land converted from grasslands or forests to switchgrass, Miscanthus, or willow. The SOC response ratios were similar in both 0–30 and 0–100 cm soil depths in most cases, suggesting SOC changes in deep soil and that use of top soil only for SOC accounting in biofuel life cycle analysis (LCA) might underestimate total SOC changes. Soil carbon sequestration rates varied greatly among studies and land transition types. Generally, the rates of SOC change tended to be the greatest during the 10 years following land conversion and had declined to approach 0 within about 20 years for most LUCs. Observed trends in SOC change were generally consistent with previous reports. Soil depth and duration of study significantly influence SOC change rates and so should be considered in carbon emission accounting in biofuel LCA. High uncertainty remains for many perennial systems and forest transitions, additional field trials, and modeling efforts are needed to draw conclusions about the site- and system-specific rates and direction of change.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcbb.12237

Soil carbon sequestration and land use change associated with biofuel production: empirical evidence

This paper reviews five related types of analysis, namely (i) sensitivity or what-if analysis, (ii) uncertainty or risk analysis, (iii) screening, (iv) validation, and (v) optimization. The main questions are: when should which type of analysis be applied; which statistical techniques may then be used? This paper claims that the proper sequence to follow in the evaluation of simulation models is as follows. 1) Validation, in which the availability of data on the real system determines which type of statistical technique to use for validation. 2) Screening: in the simulation‘s pilot phase the really important inputs can be identified through a novel technique, called sequential bifurcation, which uses aggregation and sequential experimentation. 3) Sensitivity analysis: the really important inputs should be subjected to a more detailed analysis, which includes interactions between these inputs; relevant statistical techniques are design of experiments (DOE) and regression analysis. 4) Uncertainty analysis: ...

Sensitivity analysis and related analyses: A review of some statistical techniques

The use of biomass for energy production is considered a promising way to reduce net carbon emissions and mitigate climate change. However, land-use change to bioenergy crops can result in carbon emissions from soil and vegetation in amounts that could take decades to compensate. Perennial grasses such as Miscanthus offer a possible solution to this problem as measurements on experimental plots planted with Miscanthus have shown significant carbon sequestration in the soil. It can, however, be expected that sequestration potentials in commercial use might differ from those measured in experimental plots due to different farming practices and soil characteristics. For this study, Miscanthus plantations on 16 farms in SE Ireland as well as on-farm controls representing the former land-use (grassland and tillage) have been examined. The Miscanthus plantations were 2–3 years old. Soil organic carbon (SOC) content and a number of soil properties were measured and the amount of Miscanthus-derived carbon was determined using the 13C natural abundance method. On both former tillage fields and grasslands, although there were no significant differences in SOC contents between Miscanthus and control sites, it was shown that 2–3 years after Miscanthus establishment, 1.82 ± 1.69 and 2.17 ± 1.73 Mg ha−1 of the SOC under former-tilled and former grassland respectively were Miscanthus-derived. Mixed-effects models were used to link the total SOC concentrations and Miscanthus-derived carbon to the land-use parameters as well as to soil properties. It was shown that on control sites, pH had an effect on total SOC. In the case of Miscanthus-derived carbon, the initial SOC content, pH, former land-use and crop age had significant effects.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1757-1707.2011.01117.x

Soil carbon sequestration during the establishment phase of Miscanthus × giganteus: a regional‐scale study on commercial farms using 13C natural abundance

In Ireland, Miscanthus A� giganteus has the potential to become a major feedstock for bioenergy production. However, under current climatic conditions, Ireland is situated on the margin of the geographical range where Miscanthus production is economically feasible. It is therefore important to optimize the yield and other ecosystem services such as carbon sequestration delivered by the crop. A survey of commercial Miscanthus fields showed a large number of areas with no Miscanthus crop cover. These patches can potentially lead to reduced crop yields and soil carbon sequestration and have a significant negative impact on the economic viability of the crop. The aim of this research is to assess patchiness on a field scale and to analyse the impacts on crop yield and soil carbon sequestration. Analysis of aerial photography images was carried out on six commercial Miscanthus plantations in south east Ireland. The analysis showed an average of 372.5 patches per hectare, covering an average of 13.7% of the field area. Using net present value models and a financial balance approach it was shown that patchiness has a significant impact on payback time for initial investments and might reduce gross margins by more than 50%. Total and Miscanthus-derived soil organic carbon was measured in open patches and adjacent plots of high crop density showing significantly lower Miscanthus-derived carbon stocks in open patches compared to high crop-density patches (0.47Mg C haâ��1 Â± 0.42 SD and 0.91Mg C haâ��1 Â± 0.55 SD). Using geographic information system (GIS) it was shown that on a field scale Miscanthus-derived carbon stocks were reduced by 7.38% Â± 7.25 SD. However, total soil organic carbon stocks were not significantly different between open patches and high crop density plots indicating no impact on the overall carbon sequestration on a field scale over 3â��4 years since establishment for these Miscanthus sites.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/gcbb.12084

Assessing the impact of within crop heterogeneity ('patchiness') in young Miscanthus x giganteus fields on economic feasibility and soil carbon sequestration

/pdf/analysis-of-the-severe-drought-in-ireland-in-2018-470rumwkym.pdf

Analysis of the severe drought in Ireland in 2018

Summary

In recent years the use of biomass for energy production has become an increasingly important measure for mitigating global change. However, the scientific debate has been inconclusive with regard to the risks and benefits of bioenergy use. There is particular concern that land-use change to bioenergy production can lead to increased CO2 emissions. These emissions result from the loss of vegetation and the soil disturbance. The use of Miscanthus x giganteus as a bioenergy feedstock offers a possible solution, as it shows a large soil carbon (C) sequestration potential. The aim of the present study was to analyse the impacts of land-use change to Miscanthus on soil fractions and associated soil organic carbon (SOC). Four young commercial Miscanthus sites, as well as adjacent sites representing the former land-use, in SE Ireland were analysed for changes in SOC stocks and newly sequestered Miscanthus-derived C. The fraction with which the SOC is associated significantly influenced its decomposability and turnover time. Using the 13C natural abundance method, we found that newly sequestered C was found mainly as particulate organic matter (79.7% of Miscanthus-derived C) and therefore in a labile state with short turnover times. No significant differences were found in the distribution of the different soil fractions and SOC between the Miscanthus and the control sites, and it was shown that the share of fractions on the bulk soil as well as the proportion of the SOC associated with these fractions in young Miscanthus sites depends mainly on the previous land-use.

Assessing the impacts of the establishment of Miscanthus on soil organic carbon on two contrasting land-use types in Ireland

Assessing the performance of three frequently used biogeochemical models when simulating N2O emissions from a range of soil types and fertiliser treatments

Jesko Zimmermann

Papers

Soil carbon sequestration during the establishment phase of Miscanthus × giganteus: a regional‐scale study on commercial farms using 13C natural abundance

Assessing the impact of within crop heterogeneity ('patchiness') in young Miscanthus x giganteus fields on economic feasibility and soil carbon sequestration

Analysis of the severe drought in Ireland in 2018

Assessing the impacts of the establishment of Miscanthus on soil organic carbon on two contrasting land-use types in Ireland

Assessing the performance of three frequently used biogeochemical models when simulating N2O emissions from a range of soil types and fertiliser treatments