Agricultural diversification of biogas crop cultivation

For all types of agricultural land-use, more diverse cropping systems are required, with respect to the maintenance of ecosystem values such as biodiversity conservation and climate change adaptation. This need for greater agricultural diversity is clearly illustrated by biogas crop cultivation. In Germany, maize currently dominates biogas crop cultivation due to its outstanding methane yield performance. However, the ecosystem value of maize cultivation decreases if good agricultural practices are ignored. Additionally, the poor aesthetical value of maize has led to biogas production gaining a negative reputation in society. To increase the diversity of biogas crop cultivation, alternative biogas crops such as amaranth and wild plant mixtures need to be investigated with respect to both yield performance and biogas substrate quality. The research objective of this study was the development of strategies for agricultural diversification of biogas crop cultivation. For this purpose, the following research questions were formulated: 1. How does amaranth perform as a biogas crop compared to maize and what are the major opportunities for and obstacles to the large-scale implementation of amaranth cultivation? 2. How does the spatial diversification legume intercropping perform in amaranth compared to maize and what are the major opportunities for and obstacles to its practical implementation? 3. How do perennial wild plant mixtures perform in biomass production with respect to yield, quality and species diversity in the long term and what are the relevant agronomic factors? 4. How do available models perform in the prediction of specific methane yield of different crops based on their lignocellulosic biomass composition and how could they be improved? To address research questions 1 and 2, field trials with amaranth and maize were conducted in southwest Germany in the years 2014 and 2015. Amaranth established well in both years. Its dark red inflorescences attracted many insects such as honeybees, wild bees and bumble bees. Therefore, a systematic implementation of amaranth into biogas crop rotations could significantly improve their socio-ecological value in terms of biodiversity conservation and landscape beauty. However, amaranth showed significantly lower dry matter yields (DMY) and specific methane yields (SMY), together resulting in lower methane yields than maize in both years. Therefore, breeding and an optimization of agricultural practices such as sowing density, planting geometry and fertilization management are required to make amaranth more competitive in comparison to maize. To address research question 2, the amaranth field trials mentioned above also included treatments of legume intercropping with runner bean (RB, Phaseolus vulgaris L.) and white clover (WC, Trifolium repens, L.). The RB and WC developed equally well in amaranth and maize each year. For both amaranth and maize, the RB share of total DMY was low (5-10%) and did not significantly affect the total DMY. By contrast, WC had a significant negative effect on the DMY. Overall, the spatial diversification legume intercropping could considerably improve the socio-ecological value of amaranth cultivation in terms of biodiversity conservation, greenhouse gas (GHG) mitigation and soil protection. For research question 3, two different wild plant mixtures (WPM) were cultivated on three sites in southwest Germany from the years 2011 to 2015. At each location, the WPM showed great potential for both biodiversity conservation and ecosystem resilience. Numerous insect species were observed in the WPM stands each year, indicating WPM as a relevant cropping system for habitat networking. Furthermore, the aesthetic appearance of the WPM stands over the years demonstrated the potential positive effect WPM cultivation could have on the public perception of biogas production. The DMY of the WPM varied strongly depending on (i) the initial composition of species sown, (ii) the establishment procedure, (iii) the environmental conditions, (iv) the pre-crop, and (v) the number of predominant species. WPM were found to have low demands for fertilization and crop protection. Thus, WPM appear a promising low-input cropping system for the promotion of biodiversity conservation, habitat networking, soil and water protection, GHG mitigation and climate change adaptation. However, high DMY gaps remain a challenge for the practical inclusion of WPM in existing biogas cropping systems. With respect to research question 4, a meta-analysis revealed that available models proved to be much less precise than expected. Although outperforming all available models, the correlation of the new models was still low (up to r = 0.66). It was also found that non-linear terms are of less importance than crop-specific regressors including the intercept. This indicates that across-crop models including crop-specific configurations could help to improve the identification of alternative crops and cropping systems for a more diverse biogas crop cultivation in the future.Für alle landwirtschaftlichen Nutzrichtungen werden vielfältigere Anbausysteme erfordert, insbesondere im Hinblick auf Ökosystemfunktionen wie die Förderung der Agrarbiodiversität und die Vorbereitung auf landwirtschaftlich relevante Folgen des Klimawandels. Dieser Mehr-bedarf landwirtschaftlicher Vielfalt wird insbesondere beim Anbau von Biogaspflanzen in Deutschland deutlich, wo derzeit Mais aufgrund seiner hervorragenden Methanertrags-leistung dominiert. Der Ökosystemwert des Maisanbaus nimmt jedoch ab, wenn die gute fachliche Praxis nicht eingehalten wird. Darüber hinaus führte der geringe ästhetische Wert von Mais zu einem negativen Ruf der Biogasproduktion in der Gesellschaft. Um die Vielfalt der Anbausysteme für die Biogasproduktion zu erhöhen, müssen alternative Biogaspflanzen wie Amaranth und Wildpflanzenmischungen hinsichtlich ihrer Ertragsleistung und der Biogassub-stratqualität untersucht werden. Das Forschungsziel dieser Studie war die Entwicklung von Strategien zur landwirtschaftlichen Diversifizierung von Anbausystemen für die Biogaspro-duktion. Zu diesem Zweck wurden die folgenden Forschungsfragen formuliert: 1. Welches Potential bietet Amaranth als Biogaspflanze im Vergleich zu Mais und was sind die größten Chancen und Herausforderungen einer großflächigen Implementierung des Amaranthanbaus? 2. Wie ist die "Leguminosen-Mischkultur" als räumliche Diversifizierung bei Amaranth im Vergleich zu Mais zu beurteilen und was sind die größten Chancen und Herausforderungen für deren praktische Umsetzung? 3. Was leisten mehrjährige Wildpflanzenmischungen bei der Biomasseproduktion in Bezug auf Ertrag, Qualität und Artenvielfalt langfristig und was sind relevante agronomische Faktoren? 4. Wie eignen sich verfügbare Modelle zur Vorhersage des spezifischen Methanertrags ver-schiedener pflanzlicher Biogassubstratarten auf Grundlage ihrer Faserzusammensetzung und wie können die Modelle verbessert werden? Um Forschungsfragen 1 zu beantworten, wurden Feldversuche mit Amaranth und Mais im Südwesten Deutschlands in den Jahren 2014 und 2015 durchgeführt. Der Amaranth hat sich in beiden Jahren gut etabliert. Seine dunkelroten Blütenstände zogen viele Insekten wie Honigbienen, Wildbienen und Hummeln an. Eine systematische Implementierung von Ama-ranth in bestehende Biogas-Fruchtfolgen könnte daher ihren sozial-ökologischen Wert im Hinblick auf Biodiversitätsschutz und Landschaftsästhetik deutlich verbessern. Amaranth zeig-te jedoch deutlich niedrigere Trockenmasseerträge (TME) und spezifische Methanerträge als Mais, was in beiden Jahren zu niedrigeren Methan-Hektarerträgen führte. Daher sind weitere Züchtungsmaßnahmen sowie eine fortwährende Optimierung der Anbaumethode hinsichtlich relevanter Anbaufaktoren wie Saatdichte, Pflanzgeometrie und Düngemanagement erforder-lich, um Amaranth im Vergleich zu Mais wettbewerbsfähiger zu machen. Um Forschungsfrage 2 zu beantworten, beinhalteten die oben genannten Amaranth-Feldver-suche auch Leguminosen-Mischkultur-Varianten mit Stangenbohne (SB, Phaseolus vulgaris L.) und Weißklee (WK, Trifolium repens, L.). SB und WK entwickelten sich in Amaranth und Mais jedes Jahr gleichermaßen gut. Sowohl für Amaranth als auch für Mais war der SB-Anteil am gesamt-TME gering (5-10%) und hatte keinen signifikanten Einfluss auf den gesamt TME. Im Gegensatz dazu hatte WK einen signifikanten negativen Einfluss auf den TME. Insgesamt könnte die Leguminosen-Mischkultur als räumliche Diversifizierung den sozial-ökologischen Wert des Amaranthanbaus in Bezug auf Biodiversitätsschutz, Treibhausgasminderung und Bodenschutz erheblich verbessern. Für Forschungsfrage 3 wurden zwei verschiedene Wildpflanzenmischungen (WPM) an drei Standorten im Südwesten Deutschlands in den Jahren 2011 bis 2015 angebaut. An jedem Standort zeigten die WPM ein großes Potenzial für den Biodiversitätsschutz und die Resilienz der Ökosysteme. In den Pflanzbeständen der WPM wurden jedes Jahr zahlreiche Insekten-arten beobachtet, was auf ein großes Potential von WPM für die Habitat-Vernetzung im Landwirtschaftlichen Raum hinweist. Darüber hinaus zeigte das ästhetische Erscheinungsbild der Pflanzbestände der WPM im Laufe der Jahre, welche potenziell positiven Auswirkungen der Anbau von WPM auf die öffentliche Wahrnehmung der Biogasproduktion haben könnte. Der TME der WPM variierte stark in Abhängigkeit von (i) der anfänglichen Kombination ausge-säter Arten, (ii) dem Etablierungsverfahren, (iii) den Umweltbedingungen, (iv) der Vorkultur und (v) der Anzahl dominanter Arten. Ferner wurde festgestellt, dass WPM einen geringen Bedarf an Düngung und Pflanzenschutz haben. Insgesamt zeigten sich beide WPM als viel-versprechende Anbausysteme zur Biomasseproduktion unter Aspekten der Förderung des Biodiversitätsschutzes, der Habitatvernetzung, des Boden- und Gewässerschutzes, der Treib-hausgasminderung und der Anpassung an den Klimawandel. Tendenziell niedrige TME bleiben jedoch eine Herausforderung für eine großflächige Implementierung von WPM in bestehende Biogas-Fruchtfolgen. In Bezug auf Forschungsfrage 4 ergab eine Meta-Analyse, dass alle verfügbaren Modelle ungenauer waren als erwartet. Zwar waren die neu entwickelten Modelle besser, wiesen aber noch immer eine geringe Korrelation auf (bis r = 0,66). Es wurde auch festgestellt, dass nicht-lineare Parameter von geringerer Bedeutung sind als pflanzenart-spezifische Regressoren ein-schließlich des Gesamteffekts. Dies deutet darauf hin, dass pflanzenart-übergreifende Modelle einschließlich pflanzenart-spezifischer Konfigurationen dazu beitragen könnten, die Identifizierung alternativer Pflanzenarten und Anbausysteme für eine Diversifizierung des Biogaspflanzenanbaus in Zukunft zu verbessern

Low-Input Estimation of Site-Specific Lime Demand Based on Apparent Soil Electrical Conductivity and In Situ Determined Topsoil pH

Site-specific liming helps increase efficiency in agricultural production. For adequate determination of the lime demand, a combination of apparent soil electrical conductivity (ECa) and topsoil pH can be used. Here, it was hypothesized that this can also be done at low-input level. Field measurements using the EM38 MK I (Geonics, Canada) were conducted on three experimental sites in north Germany in 2011. The topsoil pH was measured based on two approaches: on the field using a handheld pH meter (Spectrum-Technologies Ltd., Bridgend, UK) with a flat electrode (in situ), and in the lab using standard equipment (ex situ). Both soil ECa (0.4-35.9 mS m-1) and pH (5.13-7.41) were heterogeneously distributed across the sites. The same was true of the lime demand (-1.35-4.18 Mg ha-1). There was a significant correlation between in situ and ex situ determined topsoil pH (r = 0.89; p < 0.0001). This correlation was further improved through non-linear regression (r = 0.92; p < 0.0001). Thus, in situ topsoil pH was found suitable for map-overlay with ECa to determine the site-specific lime demand. Consequently, the hypothesis could be confirmed: The combined use of data from EM38 and handheld pH meters is a promising low-input approach that may help implement site-specific liming in developing countries

Wood-Ash Fertiliser and Distance from Drainage Ditch Affect the Succession and Biodiversity of Vascular Plant Species in Tree Plantings on Marginal Organic Soil

Cutaway peatland is a marginal land, which without further management is an unfavourable environment for plant growth due to low bearing capacity, high acidity and unbalanced nutrient composition of the soil. After wood-ash application, the soil becomes enriched with P and K, creating better conditions for tree growth. In addition to being economically viable, tree plantations ensure long-term carbon storage and promote habitat restoration. In a three-year term, we studied how distance from a drainage ditch and three different doses of wood-ash—5, 10, and 15 tons per hectare—affect the diversity of vascular plants in a tree plantation on a cutaway peatland. Plant species richness, vegetation cover and composition were positively affected by the distance from the drainage ditch and application with fertiliser, but in most cases, fertiliser dose had no significant effect. Both cover and species diversity were not affected by the planted tree species. In a tree plantation, herbaceous plants provide soil fertility by decay and recycling, and reduce mineral leaching in the long term. Since vascular plants play an important role in both the development of habitats and tree growth, it is important to know how multiple factors influence the development of vegetation in tree plantations

Wood-Ash Fertiliser and Distance from Drainage Ditch Affect the Succession and Biodiversity of Vascular Plant Species in Tree Plantings on Marginal Organic Soil

Cutaway peatland is a marginal land, which without further management is an unfavourable environment for plant growth due to low bearing capacity, high acidity and unbalanced nutrient composition of the soil. After wood-ash application, the soil becomes enriched with P and K, creating better conditions for tree growth. In addition to being economically viable, tree plantations ensure long-term carbon storage and promote habitat restoration. In a three-year term, we studied how distance from a drainage ditch and three different doses of wood-ash—5, 10, and 15 tons per hectare—affect the diversity of vascular plants in a tree plantation on a cutaway peatland. Plant species richness, vegetation cover and composition were positively affected by the distance from the drainage ditch and application with fertiliser, but in most cases, fertiliser dose had no significant effect. Both cover and species diversity were not affected by the planted tree species. In a tree plantation, herbaceous plants provide soil fertility by decay and recycling, and reduce mineral leaching in the long term. Since vascular plants play an important role in both the development of habitats and tree growth, it is important to know how multiple factors influence the development of vegetation in tree plantations

Implementing miscanthus into farming systems:A review of agronomic practices, capital and labour demand

Miscanthus is a promising bioeconomy crop with several biomass utilisation pathways. However, its current cultivation area in Europe is relatively low. This is most likely due to a lack of knowledge about the imple- mentation of miscanthus into farming systems. This study reviews current best practices and suitable land areas for miscanthus cultivation. Biomass production costs and labour requirements were evaluated over the whole 20- year cultivation cycle of four utilisation pathways: combustion, animal bedding, and both conventional and organic biogas production. The assessment was performed for two field sizes (1 and 10 ha), two average annual yield levels (15 and 25 t dry matter ha 1), and both green and brown harvest regimes. The maximum attainable annual gross margins are 1657 € ha 1 for combustion, 13,920 € ha 1 for animal bedding, 2066 € ha 1 for conventional and 2088 € ha 1 for organic biogas production. The combustion pathway has the lowest labour demand (141.5 h ha 1), and animal bedding the highest (317.6 h ha 1) due to additional baling during harvest. Suitable cultivation areas include depleted soils, erosion-prone slopes, heavy clay soils and ecological focus areas such as riparian buffer zones and groundwater protection areas. On such sites, miscanthus would (i) improve soil and water quality, and (ii) enable viable agricultural land utilisation even on scattered patches and strips. Due to its low demands and perennial nature, miscanthus is suitable for sustainable intensification of indus- trial crop cultivation in a growing bioeconomy, benefiting soil and water quality, while providing large amounts of biomass for several utilisation pathways

Prospects of Bioenergy Cropping Systems for A More Social-Ecologically Sound Bioeconomy

The growing bioeconomy will require a greater supply of biomass in the future for both bioenergy and bio-based products. Today, many bioenergy cropping systems (BCS) are suboptimal due to either social-ecological threats or technical limitations. In addition, the competition for land between bioenergy-crop cultivation, food-crop cultivation, and biodiversity conservation is expected to increase as a result of both continuous world population growth and expected severe climate change effects. This study investigates how BCS can become more social-ecologically sustainable in future. It brings together expert opinions from the fields of agronomy, economics, meteorology, and geography. Potential solutions to the following five main requirements for a more holistically sustainable supply of biomass are summarized: (i) bioenergy-crop cultivation should provide a beneficial social-ecological contribution, such as an increase in both biodiversity and landscape aesthetics, (ii) bioenergy crops should be cultivated on marginal agricultural land so as not to compete with food-crop production, (iii) BCS need to be resilient in the face of projected severe climate change effects, (iv) BCS should foster rural development and support the vast number of small-scale family farmers, managing about 80% of agricultural land and natural resources globally, and (v) bioenergy-crop cultivation must be planned and implemented systematically, using holistic approaches. Further research activities and policy incentives should not only consider the economic potential of bioenergy-crop cultivation, but also aspects of biodiversity, soil fertility, and climate change adaptation specific to site conditions and the given social context. This will help to adapt existing agricultural systems in a changing world and foster the development of a more social-ecologically sustainable bioeconomy

Evaluating the suitability of marginal land for a perennial energy crop on the Loess Plateau of China

Abstract With a large marginal land area, the Loess Plateau in China holds great potential for biomass production and environmental improvement. Identifying suitable locations for biomass production on marginal land is important for decision‐makers from the viewpoint of land‐use planning. However, there is limited information on the suitability of marginal land within the Loess Plateau for biomass production. Therefore, this study aims to evaluate the suitability of the promising perennial energy crop switchgrass (Panicum virgatum L.) on marginal land across the Loess Plateau. A fuzzy logical model was developed and validated based on field trials on the Loess Plateau and applied to the marginal land of this region, owing to its ability of dealing with the continuous nature of soil, landscape variations, and uncertainties of the input data. This study identified that approximately 12.8–20.8 Mha of the Loess Plateau as available marginal land, of which 2.8–4.7 Mha is theoretically suitable for switchgrass cultivation. These parts of the total marginal land are mainly distributed in northeast and southwest of the Loess Plateau. The potential yield of switchgrass ranges between 44 and 77 Tg. This study showed that switchgrass can grow on a large proportion of the marginal land of the Loess Plateau and therefore offers great potential for biomass provision. The spatial suitability maps produced in this study provide information to farmers and policymakers to enable a more sustainable development of biomass production on the Loess Plateau. In addition, the fuzzy‐theory‐based model developed in this study provided a good framework for evaluating the suitability of marginal land

Environmental and cultivar variability in composition, content and biological activity of phenolic acids and alkylresorcinols of winter wheat grains from a multi-site field trial across Europe

Different factors such as the genotype, environmental conditions, temperature stress, solar radiation and others can influence the phytochemical status of plants. The concentration of phenolic acids and alkylresorciols (ARs) as well as their chemical composition and biological activity have been determined in twelve winter wheat cultivars grown at eight European locations. This was the first winter wheat multi-location field trial of the European Consortium for Open Field Experimentation (ECOFE). Extracts from grain were analyzed using a UPLC-PDA-ESI-MS system (phenolic acids), UPLC-PDA-MS/MS (alkylresorcinols) and TLC-DPPH center dot test with ImageJ program (antiradical activity). The phenolic acid profile consisted of five hydroxybenzoic acid and four hydroxycinnamic acid derivatives, among which ferulic and sinapic acids were predominated. The ARs profile consisted of nine AR derivatives, among which 5-n-heneicosylresorcinol (C21:0) and 5-n-nonadecanylresorcinol (C19:0) were predominated. Our study showed significant differences in phenolic acids and AR content between wheat cultivars, as well as between locations. We observed a positive correlation between the biological activity of extracts and the total amount of phenolic acids and ARs. Two cultivars, Chambo and Julius (average of all sites) and samples from the Spanish site (average of all cultivars) showed the highest content and composition of nutritional substances

Environmental and cultivar variability in composition, content and biological activity of phenolic acids and alkylresorcinols of winter wheat grains from a multi-site field trial across Europe

Different factors such as the genotype, environmental conditions, temperature stress, solar radiation and others can influence the phytochemical status of plants. The concentration of phenolic acids and alkylresorciols (ARs) as well as their chemical composition and biological activity have been determined in twelve winter wheat cultivars grown at eight European locations. This was the first winter wheat multi-location field trial of the European Consortium for Open Field Experimentation (ECOFE). Extracts from grain were analyzed using a UPLC-PDA-ESI-MS system (phenolic acids), UPLC-PDA-MS/MS (alkylresorcinols) and TLC-DPPH• test with ImageJ program (antiradical activity). The phenolic acid profile consisted of five hydroxybenzoic acid and four hydroxycinnamic acid derivatives, among which ferulic and sinapic acids were predominated. The ARs profile consisted of nine AR derivatives, among which 5-n-heneicosylresorcinol (C21:0) and 5-n-nonadecanylresorcinol (C19:0) were predominated. Our study showed significant differences in phenolic acids and AR content between wheat cultivars, as well as between locations. We observed a positive correlation between the biological activity of extracts and the total amount of phenolic acids and ARs. Two cultivars, Chambo and Julius (average of all sites) and samples from the Spanish site (average of all cultivars) showed the highest content and composition of nutritional substances.info:eu-repo/semantics/publishedVersio