The Value of Seismic Data in Conventional and Unconventional Fields

The paper illustrates the value of seismic data in different environments after assessing the benefits and costs of processes such as seismic acquisition, seismic processing and seismic interpretation. Global examples from conventional and unconventional fields are discussed to show how seismic data plays a significant role in determining low-risk and high-reward wells and also eliminating the high-risk and low-reward wells. This paper shows an example of a conventional field in the state of Kansas, USA, where the net present value (NPV) increased by more than 17 times when 3D seismic data was acquired, while in an unconventional field the commercial success rate rose from 30% to 70% due to 3D seismic acquisition. However, two offshore fields in the Republic of Trinidad and Tobago are discussed to show that the NPV as impacted by advanced seismic processing was more than 111 ($M). Another example comes from Viking Field, a conventional field in Canada, where the NPV was increased from 3800 ($M) to 5000 ($M) when the seismic data was re-processed. Furthermore, the value of investing in seismic data was investigated and quantified by comparing two synthetically modeled scenarios in Saudi Arabia. Overall, the four examples from North America, Central America and Saudi Arabia illustrate that investment in seismic data has a positive impact on both conventional and unconventional fields. That provides strong evidence to encourage more investments in geophysical technologies.

Quantifying the influence of management strategies on surface radiation budgets and energy patterns in tea fields

The surface energy balance from canopy to landscape scales in crop fields plays an essential role in surface-atmosphere interactions, and it is strongly influenced by the management strategies and field practices of farmers. To characterize how different agricultural practices of farmers affect the microenvironment in perennial crop fields, long-term observation of the radiation budget and energy components under different field practices was undertaken in two neighboring tea fields with different management strategies (a conventional operation and an organic-certified field managed by different farmers) in northern Taiwan. The results showed that the difference in the radiation budget in these two tea fields was minor (only 1% for net radiation), but the differences in the energy components were more significant (sensible heat was 10% lower and latent heat was 25% higher in the organic-certified field than in the conventional field) due to highly distinct practices in these two fields. This finding implies that the organic-certified application could lower the partitioning of sensible heat flux and increase the latent heat flux, thereby reducing the temperature variation and decreasing the vapor pressure deficit. The organic-certified field reduced the surface heating in terms of the long-term energy patterns. This study’s findings also indicate that field practices in conventional field can increase the sensible heat flux (51.5% at noon time) on short-term time scales, compared with only 9.6% in organic-certified field. Furthermore, this study offers a comprehensive understanding of tea field practices, a scientific basis for in-field water conservation, and a quantitative analysis for modeling from micro to regional scales.

A robust field-based method to screen heat tolerance in wheat

Wheat crops are highly sensitive to elevated temperatures, particularly during pollen meiosis and early grain filling. As the impact of heat stress greatly depends on the developmental stage of a crop, wheat germplasm ranking for heat tolerance in field experiments may be confounded by variation in developmental phase between genotypes at the time of heat events. Deploying an artificial-photoperiod-extension method (PEM) has allowed screening of diverse genotypes at matched developnemtal phases during natural heat events despite phenological varations. Irrigated experiments with 32 wheat genotypes were conducted in south-east Queensand, Australia with either (i) the PEM or (ii) conventional field plots. The Ppaired PEM and conventional field plot trials were sown at differentwith serial sowing dates from June to September.. In the PEM, plants were sown in single rows or in small plots and artificial supplemental lighting was installed at one end of each row/plot, extending day length to 20 h close to the lights. The intensity of supplementary lighting diminished as the distance from the lights increased, and induced a gradient of flowering times along each row/plot. Spikes of each genotype were tagged when they flowered. Late-sown crops received more heat shocks during early and/or mid-grainfilling than earlier sowings, and suffered significant yield losses. Significant genotypic differences in heat tolerance ranking were observed between PEM versus conventional plot screening. Individual grain weight of the tested wheat genotypes was strongy correlated in the PEM plots experiencing a similar degree of heat, but the correlation was either poor or negative in conventional plot trials. With PEM, we successfully quantified the impact post-flowering heat on individual grain weight of wheat genotypes with the heat events occurring precisely at a specific developmental stage. The PEM results produced robust field based rankings of genotypes for heat tolerance within trials experiencing similar heat events. This method promises to improve the efficiency of heat tolerance field screening, particularly when comparing genotypes of different maturity types.

Do coronavirus vaccine challenge trials have a distinctive generalisability problem?

Notwithstanding the success of conventional field trials for vaccines against COVID-19, human challenge trials (HCTs) that could obtain more information about these and about other vaccines and further strategies against it are about to start in the UK. One critique of COVID-19 HCTs is their distinct paucity of information on crucial population groups. For safety reasons, these HCTs will exclude candidate participants of advanced age or with comorbidities that worsen COVID-19, yet a vaccine should (perhaps especially) protect such populations. We turn this cliché on its head. The truth is that either an HCT or a field trial has intrinsic generalisability limitations, that an HCT can expedite protection of high-risk participants even without challenging them with the virus, and that an important route to obtaining results generalisable to high-risk groups under either strategy is facilitated by HCTs.

Islands in de Sitter space

We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica copies of the de Sitter geometry, and find a competition between conventional field theory entanglement entropy and the surface area of extremal “islands” in the de Sitter geometry. The black hole and cosmological horizons both play a role in generating such islands in the backreacted geometry, and have the effect of stabilizing the entropy growth as required by monogamy. We first show this in a scenario in which the de Sitter spatial section has been decompactified to an interval. Then we consider the compact geometry, and argue for a novel interpretation of the island formula in the context of closed universes that recovers the Page curve. Finally, we comment on the application of our construction to the cosmological horizon in empty de Sitter space.

The diversity of entomopathogenic fungi collected from leaves and rhizospheres of rice implementing integrated pest management

Afandhi A, Pertiwi EP, Purba DP, Widjayanti T, Leksono AS. 2020. The diversity of entomopathogenic fungi collected from leaves and rhizospheres of rice implementing integrated pest management. Biodiversitas 21: 2690-2695. Rice is an important food source for most of the world’s population. However, its production often faces pest and disease problems. This study aimed to determine the diversity of entomopathogenic fungi from the leaves and rhizospheres of rice plants, implementing applied integrated pest management (IPM), and to test the pathogenicity of insect fungi species against Spodoptera litura and Tenebrio molitor larvae collection. Entomopathogenic fungi were collected from the leaves and rhizospheres of two rice fields: a field in which IPM is implemented and a conventional field. A total of 24 species were collected from the leaves and rhizospheres in three locations. Pathogenicity test against S. litura larvae was conducted using the Beauveria sp. isolate, whereas pathogenicity test against T. molitor was conducted using the other isolates. Paddy fields in which IPM has been implemented have higher diversity and species richness compared with a conventional field. Location 1 (3 years of IPM implementation) has the highest diversity (2.04 of leaf collection and 1.65 of rhizosphere collection), location 2 has the lowest fungi diversity collected from rhizosphere, whereas location 3 (conventional implementation) has the lowest diversity of leaf collection (1.68). Laboratory testing of Beauveria spp. against S. litura revealed that all species were effective for pest control. Entomopathogenic fungi collected from leaves (Paecilomyces sp.) increased T. molitor mortality by 60%, whereas those isolated from rhizospheres had no effective control of the pest.

Exploring field methods for the assessment of soil condition and soil function in order to estimate ecosystem service and natural capital value across organic and conventional field sites

<p>It is widely recognised that the intensification of agriculture has had significant impacts on soil condition and function, negatively affecting soil structure, fertility and biological diversity<strong>. </strong>Such impacts have contributed to reduced soil carbon storage, hydrological function, the storage of nutrients, the filtration of pollutants and potential crop productivity. It is therefore important that agricultural systems adapt to ensure the provision of food alongside multiple other critical ecosystem services (ES). Developing our understanding of how to quantify soil function in a given state is important in calculating the value of soil ES and natural capital (NC) under different management scenarios. It is critical for both the establishment of cost effective agri-environment policies and in driving sustainable on-farm decision making at management appropriate scales. </p><p>This study aims to examine how field methods, used for the assessment of soil condition and function, can be applied to determine (i) How baseline soil condition measurements relate to soil function across organic and conventional field sites and (ii) Whether enhanced soil function is observed in agricultural soils under organic agriculture and if so, whether the potential economic benefits could offset the loss in crop productivity.</p><p>The study was conducted at Clinton Devon Estate in South West England. Nine conventional and nine organic fields, reflecting the main rotational land uses on the estate, were selected. Baseline soil samples were collected from each field in winter 2018 for the analysis of; total carbon (TC), total nitrogen, plant available phosphorus, soil texture, pH and bulk density (BD). Land management data was collected from the farmers for each field. Four soil functions/services were selected for monitoring; nutrient filtering and retention, soil organic matter decomposition, carbon storage and crop production. Crop yields for maize, cereals and grass silage were collected from each of the soil sampled points immediately ahead of harvest in 2019. BD and TC from each sample were used to estimate carbon storage.  Three sites from each field were selected for the assessment of soil organic matter decomposition using the standardised and globally applied Tea Bag Index method (Keuskamp et al., 2013). A smaller sub-set of six fields (three organic and three conventional) were selected for the determination of nutrient filtering and retention. Porous pots, ten replicates per field site, were installed below crop rooting depths in October 2018 for monitoring through the 2018 – 2019 and 2019 – 2020 drainage seasons. A sample of soil pore water was extracted (fortnightly) and analysed for nitrate, nitrite, ammonia and phosphate, allowing a comparison of nutrient leaching between sites. </p><p>The data from this study will be presented for the assessment of whether quantification of soil functions at the field scale can help in the identification of useful baseline indicators and contribute to the valuation of soil ES and NC. </p><p> </p><p> </p><p><strong>References: </strong></p><p>Keuskamp, J.A., Dingemans, B.J.J., Lehtinen, T., Sarneel, J.M. and Hefting, M.M. (2013), Tea Bag Index: a novel approach to collect uniform decomposition data across ecosystems. Methods Ecol Evol, 4: 1070-1075. doi:10.1111/2041-210X.12097</p>