Cet article examine les options dont disposent les banques centrales pour gérer les arbitrages entre la satisfaction des préférences légitimes des utilisateurs en matière de confidentialité et l’atténuation du risque d’intégrité financière, lorsqu’elles conçoivent une monnaie numérique de banque centrale de détail (MNBCD). Les particuliers pourraient ne pas utiliser une MNBCD qui n’offrirait pas le même niveau de confidentialité que les espèces, mais les autorités nationales sont fondées à craindre qu’une MNBCD autorisant des paiements anonymes ne facilite les transactions financières illicites. D’un point de vue technique, les systèmes de MNBCD peuvent servir de support à des transactions totalement transparentes, sous pseudonymes ou anonymes, ou à des approches hybrides qui permettent l’anonymat jusqu’à des limites de montant spécifiques. La plupart des banques centrales qui ont lancé ou testent une MNBCD ont adopté cette dernière approche. L’article compare un certain nombre de façons de la mettre en œuvre dans le cas des MNBCD qui ont été lancées ou qui sont en cours de test. Il traite aussi de quelques nouvelles approches qui n’ont pas encore été testées.

IntroductionCover crop services depend on biomass production and species composition of the cover crop stand. In this study, we investigated the interactions in shoot biomass of dual cover crop mixtures and their competitiveness to suppress weeds before winter under different growing conditions.MethodsA field experiment was performed on sandy loam soil in Triesdorf, Germany, for two consecutive years. The cover crop species white mustard (Sinapis alba L.), oil radish (Raphanus sativus var. oleiformis L.), phacelia (Phacelia tanacetifolia J.), Egyptian clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.), field pea (Pisum sativum L.), and field bean (Vicia faba L.) were grown in pure stands or dual mixtures. Cover crops were sown in August, and shoot biomass was harvested at the end of the vegetation period. Cover crop shoot biomass was dried, and the share of each species and the sown test weed (Brassica napus L.) were determined.ResultsThe share of shoot biomass of a cover crop species in dual-species mixtures was closely related to its shoot biomass in its pure stand. In both years, mustard and phacelia showed similar interactions in shoot biomass production when growing with a second species. Regarding competitiveness against weeds, cruciferous species outperformed other cover crop species and could suppress weeds even if they were mixed with a less competitive partner. Weed suppression of mixtures with phacelia depended on the second component in the mixture and was more effective in a dry season. Legume species, especially Egyptian clover and common vetch could not suppress weeds in a pure stand.DiscussionOur results show that species with high weed suppression potential as single stands retain this ability in dual cover crop mixtures, regardless of the suppression potential of the second species that completes the mixture.

This paper explores the feasibility of a fiat stablecoin that provides similar privacy guarantees to cash. We show how individuals in a stablecoin privacy pool can exchange small amounts of value within pre-assigned limits outside the view of third parties, such as banks, central banks, crypto exchanges, regulators, or other parties, in a regulatorily compliant way. High privacy guarantees and compliance with limits are ensured in a trustless way via the use of cryptographic zero-knowledge proofs.

Background With the increasing development of sophisticated precision farming techniques, high-resolution application maps are frequently discussed as a key factor in increasing yield potential. However, yield potential maps based on multiple soil properties measurements are rarely part of current farming practices. Furthermore, small-scale differences in soil properties have not been taken into account. Methods To investigate the impact of soil property changes at high resolution on yield, a field trial has been divided into a sampling grid of 42 plots. The soil properties in each plot were determined at three soil depths. Grain yield and yield formation of winter wheat were analyzed at two sites. Results Multiple regression analyses of soil properties with yield measures showed that the soil contents of organic carbon, silt, and clay in the top and subsoil explained 45–46% of the variability in grain yield. However, an increasing clay content in the topsoil correlated positively with grain yield and tiller density. In contrast, a higher clay content in the subsoil led to a decrease in grain yield. A cluster analysis of soil texture was deployed to evaluate whether the soil´s small-scale differences caused crucial differences in yield formation. Significant differences in soil organic carbon, yield, and yield formation were observed among clusters in each soil depth. Conclusion These results show that small-scale lateral and vertical differences in soil properties can strongly impact crop yields and should be considered to improve site-specific cropping techniques further.

This is a data set of soil properties and plant properties of winter wheat. The data derived from a long-term field trial for the year 2016 at the Asendorf field station 70 km north of Hanover, Germany (49 m above sea level, 52°45′48.4′′N 9°01′24.3′′E) and a field site in Triesdorf, located in Northern Bavaria (450 m a.s.l., 49°12'36.5"N 10°38'33.9"E). Data includes soil (OC, bulk density, texture, pH-value) and plant data (grain yield, thousand grain weight, tillers per m², spikes per m²). All methods and data will be described in an upcoming journal article in the Journal Plant and Soil (DOI:10.1007/s111104-023-06212-2).

The digital euro is not a monolithic project. On the contrary: The fields of application are broad, and possible solutions are diverse. This paper provides an overview of use cases, application domains, and infrastructures for the digital euro that differ significantly. A comparison with solutions for the digital dollar and the digital yuan leads to the conclusion that, in the most extreme case, the euro could become a regional currency for Europe. The main reason for this argument is the design and prioritization of current approaches within Europe as well as the European Central Bank's digital euro project, and that stablecoin approaches seem to be neglected as solutions for the digital euro.

Distributed ledger technology (DLT) enables a wide range of innovative industrial use cases and business models, such as through programmable payments and the seamless exchange of assets, goods, and services. To exploit the full potential of a DLT-based European economy, it is crucial to integrate the euro into DLT networks. In this paper, we propose a framework for developing payment solutions for a DLT-based European economy. To this end, we decompose the digital payments value chain into three pillars: (1) contract execution system, (2) digital payment infrastructure, and (3) monetary unit. Based on this framework, we systematically compare account- and token-based payment solutions, including a bridge solution, e-money tokens, synthetic central bank digital currencies (CBDCs), and a central bank digital currency (CBDC). Taking into account current circumstances, we conclude that no individual payment solution will be sufficient to address all emerging use cases. Instead, a broad array of payment solutions will emerge and co-exist. These solutions will apply to a variety of different use cases and will be launched at different points in time.

Winter catch crops are grown to scavenge nutrients over a period of unfavorable growth conditions and to conserve nutrients for subsequent release to the following main crop. Since environmental conditions have a strong impact on the growth and nutrient capture in roots and shoots of individual catch crop species, we anticipated that mixtures will be more durable and efficient in nutrient capture due to compensatory effects among component species. We tested this hypothesis and determined the nitrogen and phosphorus accumulation in the shoots and roots of four catch crop species grown in pure vs. mixed stands at two sites for two or three years. Element concentrations were determined in the root and shoot biomass of each species and used to calculate the nutrient pool fixed in the root or shoot biomass. A qPCR-based technique was applied to quantify the root biomass of individual species based on species-specific DNA sequences. Despite considerable variation across environments, the overall plant biomass of white mustard (Sinapis alba), lacy phacelia (Phacelia tanacetifolia) and bristle oat (Avena strigosa) was similar and higher than that of Egyptian clover (Trifolium alexandrinum). While pure stands varied 6- to 24-fold in shoot biomass depending on environmental conditions, the variation was only ~3-fold for catch crop mixtures, with less pronounced variation in the root biomass. In general, the root biomass was comparable to the shoot biomass in each species. Roots contributed 26–46% of the nitrogen and 36–48% of the phosphorus to the total accumulation of these nutrients in the catch crop biomass, thus emphasizing the importance of plant roots as belowground nutrient pool for potential carry-over of nutrients to the subsequent crop. Although the mixture was mostly dominated by two of the four species, namely mustard and phacelia, it captured similar or even larger amounts of nutrients than the best-performing pure stand under any growth condition. This was the case for shoot- and for root-bound nutrients. Our results indicate that catch crop mixtures have higher durability than pure cultures to environmental variations. The amount of nitrogen captured by the mixture meets the average postharvest nitrogen that is left over by a wide range of cash crops, thus emphasizing that catch crop mixtures represent an efficient nutrient management tool in crop rotations.

This paper analyzes the monetary policy of the European Central Bank (ECB) both before and after the outbreak of the global financial crisis in 2008. In the literature, researchers typically select one Taylor rule-based model to analyze monetary policy of central banks and to derive determinants for the interest rate setting. However, uncertainty about the choice of this respective model is typically neglected. In contrast, we apply a Bayesian model averaging (BMA) approach to extend the Taylor rule to account for model uncertainty driven by heterogeneity in the ECB’s decision-making body, the Governing Council. Our results suggest the following: First, the ECB focuses on the inflation rate when setting interest rates. Second, economic activity indicators were in the focus of the ECB before the financial crisis. Third, over the last decade, the role of economic activity decreased, indicating that inflation is the main driver of monetary policy decisions in the post-crisis period. Fourth, when setting interest rates, central bankers appear to consider more than one model.

Most central banks in advanced economies consider issuing central bank digital currencies (CBDCs) to address the declining use of cash and to position themselves against increased competition from Big Tech companies, cryptocurrencies, and stablecoins. One crucial design dimension of a CBDC system is the degree of transaction privacy. Existing solutions are either prone to security concerns or do not provide full (cash-like) privacy. Moreover, it is often argued that a fully private payment system and, in particular, anonymous transactions cannot comply with anti-money laundering (AML) and countering the financing of terrorism (CFT) regulation. In this paper, we follow a design science research approach (DSR) to develop and evaluate a holistic software-based CBDC system that supports fully private transactions and addresses regulatory constraints. To this end, we employ zero-knowledge proofs (ZKP) to impose limits on fully private payments. Thereby, we are able to address regulatory constraints without disclosing any transaction details to third parties. We evaluate our artifact in interviews with leading economic, legal, and technical experts and find that a regulatorily compliant CBDC system that supports full (cash-like) privacy is feasible.

This paper analyzes the monetary policy of the Federal Reserve (Fed) and the Bank of England (BoE) both before and after the global financial crisis. In contrast to extant literature, we use a Bayesian model averaging (BMA) approach that does not rely on one underlying empirical model but accounts for model uncertainty around the selection of the empirical model. Accounting for heterogeneity in the monetary policy bodies of these central banks, we estimate approximately 33,000 different empirical models for the Fed and 4,000 for the BoE and derive, in the end, one aggregated reaction function for each central bank. Our results suggest the following: First, both central banks appear to consider more than one model when setting interest rates. Second, while the Fed seems to mainly focus on inflation and, most of the time, economic activity, the BoE seems to focus only on economic activity. Third, applying BMA provides valuable additional explanatory power for the interest rate setting of the Fed by accounting for additional models. However, for the BoE, using a BMA approach does not provide substantial benefits compared to conventional empirical techniques.

Zusammenfassung Seit der Einführung von Bitcoin 2008 und vieler anderer Kryptowährungen ist eine neue Welle innovativer Zahlungsprojekte im Gange, darunter Innovationen wie Libra — als supranationaler Stablecoin konzipiert — und digitale Zentralbankwährungen. Diese privaten und öffentlichen Projekte sind durch verschiedene Wechselbeziehungen miteinander verbunden. Bitcoin hat sich bislang nicht zu einem weit verbreiteten Zahlungsmittel entwickelt, unter anderem wegen der erheblichen Preisvolatilität. Im Gegensatz dazu soll Libra ein eher konventionelles Zahlungsmittel mit engen Beziehungen zum bestehenden Bankensektor werden, was viele Fragen zur Geld- und Finanzstabilität aufwirft. Digitale Zentralbankwährungen könnten als Reaktion des öffentlichen Sektors auf diese privaten Projekte angesehen werden, um die vorherrschende Rolle der Zentralbanken im Währungssystem der Zukunft zu sichern.

Catch crops increase plant species richness in crop rotations, but are most often grown as pure stands. Here, we investigate the impacts of increasing plant diversity in catch crop rotations on rhizosphere C input and microbial utilization. Mustard ( Sinapis alba L.) planted as a single cultivar was compared to diversified catch crop mixtures of four (Mix4) or 12 species (Mix12). We traced the C transfer from shoots to roots towards the soil microbial community and the soil respiration in a 13 C pulse labelling field experiment. Net CO 2 -C uptake from the atmosphere increased by two times in mix 4 and more than three times in mix 12. Higher net ecosystem C production was linked to increasing catch crop diversity and increased belowground transfer rates of recently fixed photoassimilates. The higher rhizosphere C input stimulated the growth and activity of the soil microbiome, which was investigated by phospholipid fatty acid (PLFA) analyses. Total microbial biomass increased from 14 to 22 g m −2 as compared to the fallow and was 18 and 8% higher for mix 12 and mix 4 as compared to mustard. In particular, the fungal and actinobacterial communities profited the most from the higher belowground C input and their biomass increased by 3.4 and 1.3 times as compared to the fallow. The residence time of the 13 C pulse, traced in the CO 2 flux from the soil environment, increased with plant diversity by up to 1.8 times. The results of this study suggest positive impacts of plant diversity on C cycling by higher atmospheric C uptake, higher transport rates towards the rhizosphere, higher microbial incorporation and prolonged residence time in the soil environment. We conclude that diversified catch crop mixtures improve the efficiency of C cycling in cropping systems and provide a promising tool for sustainable soil management.

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Die fortschreitende Digitalisierung hat nun auch das Geldsystem erreicht. Das Aufkommen von Kryptowerten hat zahlreiche Vorteile aufgezeigt, die nun auch in das konventionelle Geldsystem ubertragen werden sollen.

Die Ankundigung des von Facebook initiierten Stablecoin “Libra” 2019 wird teilweise als Wendepunkt fur den traditionellen Finanzsektor wahrgenommen. Auch Zentralbanken diskutieren derzeit intensiv die Einfuhrung eigener digitaler Wahrungen, sog. digitaler Zentralbankwahrungen (CBDC). Philipp Sandner, Jonas Gros, Philipp Schulden und Lena Grale, Frankfurt School Blockchain Center, beleuchten die Wahrnehmung dieser Zahlungsinitiativen durch Befragung von mehr als 50 hochrangigen Fachexperten und untersuchen die Auswirkungen von digitalem, programmierbarem Geld auf europaische Banken.