Weed seed predation in organic and conventional cereal fields

Granivores can consume a large proportion of newly produced weed seeds in crop fields each year. If substantial, granivores can help to exhaust the seed bank and thus contribute to long-term weed control. In northern Germany, however, annual seed losses tend to be smaller and granivore density lower than elsewhere. To investigate if high land-use intensity could be involved, seed predation rates were measured using Lolium multiflorum Lam. as a model seed in three organic and three conventional cereal fields located close to each other. In addition, seed predation was measured at different distances from the field edge and exclosure cages were used to determine the relative contributions of vertebrates and invertebrates to seed consumption.As expected for cereal crops, seed predation rates increased from early spring to early summer and then decreased again. Seed predation by invertebrates was comparable to that in other studies, but seed predation by vertebrates, mainly rodents, was much lower, suggesting that low seed predation rates in northern Germany may have been caused by lower mouse activity, concurring with low mouse density. Results with regard to the effect of distance to the field edge were variable and difficult to interpret. Observed responses may be linked to predator identity, with rodents foraging preferentially near field edges, and invertebrates away from field edges or indifferently. Farming system (organic vs. conventional) had little or no effect on seed predation rates.Reasons for the low density of seed predators and low seed predation rates observed are unknown, but it is likely that some unidentified detrimental factor is involved in the organic fields or the impoverished landscape as a whole. Keywords: Biological weed control, carabid beetles, distance to field edge, farming system, miceSamenfraß in Getreide auf ökologisch und konventionell bewirtschafteten FeldernSamenfraß durch Granivoren kann zu hohem Verlust neuproduzierter Unkrautsamen führen. Falls dies in beträchtlichem Maße geschieht, verringert Samenfraß den Samenbankeintrag substantiell und trägt damit zur langfristigen Unkrautregulierung bei. In Norddeutschland scheinen die jährlichen Samenverluste und die Prädatorendichten jedoch geringer zu sein als anderenorts. Um zu untersuchen, ob die hohe Landnutzungsintensität hierfür ursächlich sein könnte, wurden Samenfraßraten unter Nutzung von Lolium multiflorum Lam. als Modellsamen auf drei ökologisch und drei konventionell bewirtschafteten, räumlich nah beieinander liegenden Getreidefeldern ermittelt. Darüber hinaus wurde der Samenfraß in unterschiedlichen Abständen zum Feldrand erfasst. Ausschlusskäfige wurden genutzt, um zwischen dem Samenfraß durch Vertebraten und Invertebraten unterscheiden zu können.Wie im Getreideanbau zu erwarten, stieg die Samenfraßrate vom Frühling bis zum Sommer an und sank dann wieder. Der Samenfraß durch Invertebraten war vergleichbar mit dem anderer Studien. Die Samenprädation durch Vertebraten, hier hauptsächlich Nagetiere, war hingegen deutlich niedriger, ebenso die erfasste Aktivitätsdichte. Die zu beobachtenden niedrigen Samenfraßraten in Norddeutschland könnten demnach durch niedrige Vertebraten-Aktivitätsdichten beeinflusst sein. Die Ergebnisse bezüglich der Wirkung des Feldrandabstands waren unterschiedlich und schwer zu interpretieren. Die beobachteten Unterschiede könnten mit der Prädatorenart zusammenhängen, da Nagetiere bei der Nahrungssuche Feldränder und Invertebraten mehr die Feldmitte bevorzugen oder überall zu finden sind. Die Bewirtschaftungsform (ökologisch vs. konventionell) hatte wenig oder keinen Einfluss auf die Samenfraßraten.Die Gründe für die beobachteten geringen Samenprädatorendichten und Samenfraßraten sind unbekannt,aber es ist wahrscheinlich, das gegenteilig wirkende Einflüsse auf den ökologischen Feldern oder die verarmte Landschaft als Ganzes als Ursache in Frage kommen.Stichwörter: Abstand zum Feldrand, Bewirtschaftungsformen, Biologische Unkrautbekämpfung, Laufkäfer, Mäus

Nachhaltigkeitsbewertung von Bodennutzungen und Bodenfunktionen

Böden stehen im Spannungsfeld verschiedener Ziele der nachhaltigen Entwicklung. Neben der Produktivität als Beitrag zur Ernährungssicherheit geht es um den Erhalt der Funktionsfähigkeit terrestrischer Ökosysteme und um den Beitrag zum Klimaschutz durch Kohlenstoffspeicherung und Verminderung von Treibhausgasemissionen. Eine Nachhaltigkeitsbewertung erfordert die Analyse, wie Bodenfunktionen sich durch das Management von Böden verändern, und welche Folgen für die Ziele der nachhaltigen Entwicklung entstehen. Im Rahmen des Forschungsprogramms „BonaRes – Boden als nachhaltige Ressource für die Bioökoonomie“ haben wir einen analytischen Rahmen entwickelt, um die Wirkungen von Bodenbewirtschaftungen und Bodenfunktionen auf Nachhaltigkeitsziele zu bewerten und Trade-offs zu identifizieren. Während die systemischen Wechselwirkungen zwischen Bodenbewirtschaftung und Bodenfunktionen Gegenstand einer anderen Arbeitsgruppe sind, geht es hier um die Wechselwirkungen zwischen den natürlichen und gesellschaftlichen Systemen. Der Bewertungsansatz nutzt das DPSIR (Driver-Pressure-State-Impact-Response) Konzept als Grundstruktur und kombiniert die beiden komplementären Ansätze der Ökosystemleistungen und der Ressourceneffizienz miteinander. Die Verbindung zwischen Bodenfunktionen und Nachhaltigkeitszielen wird damit für verschiedene Zeit- und Raumdimensionen abbildbar. Wir stellen den analytischen Rahmen vor und geben erste Beispiele für seine Anwendung

Ecosystem services and disservices provided by small rodents in arable fields: effects of local and landscape management

1. In agriculture, both valuable ecosystem services and unwanted ecosystem disservices can be produced by the same organism group. For example, small rodents can provide biological control through weed seed consumption but may also act as pests, causing crop damage. 2. We studied the hypothesised causal relationships between ecosystem services (removal of weed seeds) and disservices (removal of wheat and crop damage) derived by small rodents (voles and mice) at multiple spatial scales. At the landscape scale, we studied the effects of landscape compositional and configurational heterogeneity along the former inner German border in east and west Germany on the abundance of voles and mice and their related ecosystem services and disservices. At the local scale, we studied how this abundance and ecosystem functions are affected by management intensity (organic vs. conventional winter wheat), associated differences in crop characteristics and edge effects. 3. Linear mixed effects models and path analysis show that voles drive ecosystem disservices, but not ecosystem services, in agricultural fields. Daily wheat seed removal by voles was influenced by increasing wheat height and was almost three times higher than weed seed removal, which was not related to local or landscape-scale effects. 4. Abundance of voles and associated crop damage decreased with lower crop density and higher wheat height, which were associated with organic farming. Abundance of voles and crop damage were highest in conventional fields in west Germany. 5. Synthesis and applications. As the ecosystem disservice of wheat seed consumption by voles and mice must be considered mainly during crop sowing, management before harvest should focus on decreasing the pest potential of voles’ but not mice. Our results suggest that densities of voles and their ecosystem disservices could be reduced by having fields with low crop density and high wheat height, practices associated with organic farming. Surrounding landscapes with low compositional and configurational heterogeneity could further reduce voles’ pest potential, but with probable negative effects on farmland biodiversity

Arable Land Tenancy and Soil Quality in Germany: Contesting Theory with Empirics

Soils are under increasing utilization pressure, and soil governance is an important element to maintain soil functions and prevent the degradation of soil quality. However, scientific studies about soil governance are rare. In this paper, we focus on the governance mechanism of land rent. Here, a major theoretical assumption is that landowners have higher incentives to maintain soil quality than leaseholders. By using data for German arable land at the county level, we contrast theoretical assumptions about the relationships between landowners, leaseholders and soil quality with empirical evidence based on correlations between arable land rent prices, rent proportions and yield potential. The main finding is that the empirical data contradict the theoretical assumptions to a large degree, i.e., no clear relationship could be discerned between the three parameters of arable land soil quality, rent price and rent proportion. We discuss possible explanations for the revealed contradictions based on the state of research and highlight the need for future research to better understand the potential of arable land tenancy as a governance mechanism for sustainable soil management

Assessment and Governance of Sustainable Soil Management

The globally increasing demand for food, fiber, and bio-based products interferes with the ability of arable soils to perform their multiple functions and support sustainable development. Sustainable soil management under high production conditions means that soil functions contribute to ecosystem services and biodiversity, natural and economic resources are utilized efficiently, farming remains profitable, and production conditions adhere to ethical and health standards. Research in support of sustainable soil management requires an interdisciplinary approach to three interconnected challenges: (i) understanding the impacts of soil management on soil processes and soil functions; (ii) assessing the sustainability impacts of soil management, taking into account the heterogeneity of geophysical and socioeconomic conditions; and (iii) having a systemic understanding of the driving forces and constraints of farmers’ decision-making on soil management and how governance instruments may, interacting with other driving forces, steer sustainable soil management. The intention of this special issue is to take stock of an emerging interdisciplinary research field addressing the three challenges of sustainable soil management in various geographic settings. In this editorial, we summarize the contributions to the special issue and place them in the context of the state of the art. We conclude with an outline of future research needs

Policy-Feedback: Risikomanagement-Instrumente in einer transformierenden Agrarpolitik

Die Studie untersucht das Potenzial von Risikomanagement-Instrumenten, Policy-Feedback zu erzeugen, wodurch ein Politikwandel in der Zukunft stabilisiert werden kann (Lock-in Effekt). Die durchgeführte Qualitative Comparative Analysis (QCA) von 25 staatlich geförderten landwirtschaftlichen Risikomanagement-Instrumenten in OECD-Ländern identifiziert Bedingungen, die zu einem Lock-in-Effekt implementierter Politikinstrumente führen können. Dies eröffnet eine neue Argumentationslinie in der Diskussion über die Subventionierung von landwirtschaftlichem Risikomanagement in der Agrarpolitik, welche die Wechselwirkung mit einkommensstützenden Politikinstrumenten in den Blick nimmt

Assessment and Governance of Sustainable Soil Management

The role of soils for achieving the Sustainable Development Goals is multifarious. Soils are the essential basis for food and biomass provision in support of food security (SDG 2) and energy security (SDG 7). Soil carbon sequestration is paramount for climate action (SDG 13). Soil-mediated water purification and retention, nutrient and matter cycling, and soils habitat functions are essential for maintaining ecosystem services and biodiversity (SDG 15). Healthy soils perform well in all these functions simultaneously. However, the globally increasing demand for food, fiber, and bio-based products poses massive challenges to soil health. Minimizing trade-offs between biomass production and soil health requires systemic approaches to assessment and governance of sustainable soil management in agriculture and food systems. It provides interdisciplinary insights into key questions: What are the impacts of agricultural management practices on sustainability targets in specific geophysical and socio-economic contexts? What are the opportunities and risks of future trends such as climate change, digitalization, and emerging technologies for soil management and soil health? How can institutions and governance instruments be improved to enable decision makers to take action on sustainable soil management? The book was initiated in the frame of the National German research program ‘BonaRes—Soil as a sustainable resource for the bioeconomy’, and it is meant to trigger interdisciplinary thinking

Towards an enhanced indication of provisioning ecosystem services in agro-ecosystems

Provisioning ecosystem services play a vital role in sustaining human well-being. Agro-ecosystems contribute a significant share of these services, besides food and fodder and also fuel and fibre as well as regulating and cultural ecosystem services. Until now, the indication of provisioning ecosystem services of agro-ecosystems has been based almost only on yield numbers of agricultural products. Such an indication is problematic due to several reasons which include a disregard of the role of significant anthropogenic contributions to ecosystem service co-generation, external environmental effects and strong dependence on site conditions. We argue for an enhanced indication of provisioning ecosystem services that considers multiple aspects of their delivery. The conceptual base for such an indication has been made by prior publications which have been reviewed. Relevant points were taken up in this article and condensed into a conceptual model in order to develop a more holistic and expanded set of indictors, which was then exemplarily applied and tested in three case studies in Germany. The case studies represent different natural conditions, and the indicator set application showed that ecosystem services (ES) flow—in terms of output alone—does not characterise agro-ecosystems sufficiently. The proposed aspects of provisioning ecosystem services can give a fuller picture, for example, by input-output relationships, as it is possible by just using single indicators. Uncertainties as well as pros and cons of such an approach are elaborated. Finally, recommendations for an enhanced indication of provisioning ecosystem services in agro-ecosystems that can help to integrate agricultural principles with ideas of sustainability and site-specific land use are derived

Operationalizing water-energy-food nexus research for sustainable development in social-ecological systems: an interdisciplinary learning case in Central Asia

In social-ecological systems, natural resource management can be characterized by trade-offs across sectors and sustainability targets. The water-energy-food (WEF) nexus concept makes explicit various trade-offs in order to maximize synergies of interventions. However, there are few successful examples of its operationalization in research settings. Here, we explore in a learning setting if sustainability impact assessment (SIA) protocols can be a useful process to be used to adopt a systemic, interdisciplinary perspective to operationalize WEF nexus in research for sustainable development. The process and method adopted of SIA protocol, evaluated for five exemplary WEF nexus cases in Central Asia during a week-long international workshop, adequately addressed the complexity of WEF interrelationships and associated sustainability issues, and facilitated a comparative case study analysis across scales. Results within this process highlight that water governance was critical for large-scale transboundary WEF nexus management, while land and soil management were decisive for minimizing trade-offs at local levels. Issues of interdisciplinarity, complexity, uncertainty, and reflection on impacts were adequately addressed, but challenges remain in the consideration of ethics and the design of transparent, multi-actor cooperation. Most importantly, this exercise showed that employment of the process of SIA protocol supported disciplinary experts to work across disciplines and take a systemic approach for analyzing WEF nexus