Emmanuel Frossard

ETH Zurich | ETH Zürich · Department of Environmental Systems Science

This study was conducted to identify the dendrometric variables highly correlating with above-ground (AGB), below-ground (BGB) and total (TB) biomass of tea grown in Uva and Up Country Sri Lanka, develop allometric models to estimate AGB, BGB and TB of tea plants, and to investigate the applicability of already developed allometric models in other...

Soil system properties control the fate of essential Zn and toxic Cd, which can have pervasive influences on ecosystem health. However, direct evidence of the spatial distribution of trace metals within the organo-mineral soil architecture is lacking, though this knowledge is important to better predict the fate of trace metals in ecosystems. Here,...

At treeline, plant life forms and species are abruptly changing from low stature plants in the tundra to trees in forests. Our study assesses how this shift in vegetation affects the quality and elemental composition of the litter layer and consequently, the microbial processing and nutrient release during decomposition. We sampled litter layers al...

Soil phosphorus (P) directly impacts major sustainability outcomes, namely crop yields, water quality, and carbon sequestration. Optimally managing P to improve sustainability outcomes requires a mechanistic understanding of P availability and transfer, alongside high-resolution spatial data. However, it is unclear if current measurement techniques...

Isotope source tracing enables to accurately determine the fate of nutrients that are applied with fertilizers to soils. While this approach is well established for major nutrients such as nitrogen, it is not yet established for trace metals. Here, we aimed to determine the fate of the micronutrient zinc (Zn) and the contaminant cadmium (Cd) that w...

Laser ablation in combination with an inductively coupled plasma time-of-flight mass spectrometer (LA-ICP-TOFMS) is an upcoming method for rapid quantitative element mapping of various samples. While widespread in geological applications, quantification of elements in biotissues remains challenging. In this study, a proof-of-concept sample preparat...

Problem: Wheat (Triticum aestivum L.) yields may be reduced by projected rainfall decline due to climate change as well as environmental protection demands for less nitrogen (N) fertilizer inputs. Research question: Therefore, our study aims to determine how projected decreases in rainfall due to climate change and the reduction of N fertilizer inp...

Treelines advance due to climate warming. The impacts of this vegetation shift on plant–soil nutrient cycling are still uncertain, yet highly relevant as nutrient availability stimulates tree growth. Here, we investigated nitrogen (N) and phosphorus (P) in plant and soil pools along two tundra–forest transects on Kola Peninsula, Russia, with a docu...

Cover crops are typically thought to increase the P nutrition of crops. However, there are mixed reports on this with some studies reporting a negative effect. An improved understanding of cover crop residues and their P release dynamics could offer new insight with the benefit of improved management for optimal P availability in cropping systems....

Animal manures are valuable multi‐nutrient fertilisers, but their short‐term nitrogen (N) use efficiency (NUE) by plants is low, bearing the potential of harmful N losses to the environment, such as nitrate (NO 3 ‐ ) leaching. To develop strategies to increase the NUE of cattle slurry, a comprehensive understanding of slurry N dynamics in the soil‐...

Background and aims Cereals can be made safer and more nutritious by reducing cadmium (Cd) and enhancing zinc (Zn) levels. To respectively regulate the accumulation of these chemically similar elements in grains, it is essential to understand the differences between Cd and Zn allocation to grains. Methods In durum wheat (Triticum durum), dual-isot...

The majority of organic P (Porg) in soil is considered to be part of soil organic matter (SOM) associations, but its chemical nature is largely ‘unresolved’. In this study, we investigated the Porg composition in different SOM fractions of a Gleysol soil using the Humeomics sequential chemical fractionation (SCF) procedure combined with nuclear mag...

Organic and conventional cropping systems differ in type and amount of nitrogen (N) inputs, which may affect efficiency and sustainability of N use. In the DOK (bio-Dynamic, bio-Organic, Konventionell) field experiment, organic and conventional cropping systems have been compared since 1978 at two fertilization levels, with level 2 being typical fo...

Dietary deficiency of selenium is a global health threat related to low selenium concentrations in crops. Despite the chemical similarity of selenium to the two more abundantly studied elements sulfur and arsenic, the understanding of its accumulation in soils and availability for plants is limited. The lack of understanding of soil selenium cyclin...

This article deals with Friedrich Albert Fallou (1794–1877), a lawyer by education with a strong interest for soil and geology who published “Pedologie oder allgemeine und besondere Bodenkunde” in 1862, that is, 20 years before Dokuchaev's (1883) “Russian Chernozem.” He is known for having coined the term of “pedology” but his role in the developme...

Animal manures are suspected to be a major source of nitrate leaching due to their low nitrogen use efficiency (NUE) by crops. However, actual measurements of nitrate leaching from animal manure under field conditions are scarce. In an on-farm field trial in Switzerland over 2.5 years, we used ¹⁵N labelling to trace the fate of N from cattle slurry...

Abstract : Peatlands are known to perform essential economical, societal and regulating functions. Once they are drained to provide optimal crop growth conditions, a series of degradation processes is generated. To counteract degradation of these soils, the use of amendment, based on plant material (straw, wood chips, biochar) was proposed. In th...

Phosphorus (P) acquisition is key for plant growth. Arbuscular mycorrhizal fungi (AMF) help plants acquire P from soil. Understanding which factors drive AMF-supported nutrient uptake is essential to develop more sustainable agroecosystems. Here we collected soils from 150 cereal fields and 60 non-cropped grassland sites across a 3,000 km trans-Eur...

Aquaponics combines hydroponic crop production with recirculating aquaculture. These systems comprise various compartments (fish tank, biofilter, sump, hydroponic table, radial flow settler and anaerobic digester), each with their own specific environmental pressures, which trigger the formation of unique microbial communities. Triplicated aquaponi...

Drained cultivated peatlands have been an essential agricultural resource for many years. To slow and reduce the degradation of these soils, which increases with drainage, the use of plant-based amendments (straw, wood chips, and biochar) has been proposed. Literature on the effects of such amendments in cultivated peatlands is scarce, and question...

Carbon is a key element for the functioning and productivity of tropical soils. While the impact of organic inputs on carbon storage in these soils is known, little is known about the contribution of non-cultivated trees. In this study, we measured carbon content in non-cultivated trees (VC), soil organic carbon (SOC) and soil total nitrogen (TN) i...

Nitrogen (N) and potassium (K) are known to be important for root and tuber crops but their interactions have not yet been studied in Dioscorea spp. A field experiment was conducted on a Luvisol, in Sri Lanka, over two consecutive seasons in 2013/14 and 2014/15 with D. alata (cv. ‘Raja Ala’). The study was designed to assess the effects of combined...

Targeted use of animal manures as a nitrogen (N) fertilizer is challenging because of their poorly predictable N fertilizer value. An enhanced understanding of their N transformation processes in soil under field conditions is necessary to better synchronize N availability and crop N demand. ¹⁵ N labeled cattle slurry, produced by feeding a heifer...

Due to increasing nitrogen (N) deposition from the atmosphere, temperate forests are progressively becoming phosphorus (P) limited. Trees take up P mainly from the soil solution, which soil microorganisms can replenish by mineralizing organic P through enzymatic hydrolysis (e.g. using phosphatases). We investigated how bacterial (including phosphat...

The chemical nature of most organic P (Porg) in soil remains ‘unresolved’ but is accounted for by a broad signal in the phosphomonoester region of solution ³¹P nuclear magnetic resonance (NMR) spectra. The molecular size range of this broad NMR signal and its molecular structure remain unclear. The aim of this study was to elucidate the chemical na...

Yam (Discorea spp.) is a staple food crop in Africa that requires fertile soils and an annual rainfall of about 1,500 mm. However, in the semi-arid North-West of Burkina Faso, farmers produce yam in continuous rotation on degraded soils with annual rainfall of 610–960 mm. Understanding this local know-how can help improve yam cultivation in other r...

Yam (Dioscorea spp.) is a staple food crop and a source of income for millions of people in West Africa. Traditionally, in West Africa, yams are grown without any external inputs, leading to low tuber yields. The rapid decrease of tuber yield observed after the first yam cropping season has been ascribed to nutrient depletion and/or to the accumula...

Leaching is one major pathway of phosphorus (P) and nitrogen (N) losses from forest ecosystems. Using a full factorial N×P fertilization and irrigation experiment, we investigated the leaching of dissolved organic and inorganic P (DOP and DIP) and N (DON and DIN) from organic layers (litter, Oe/Oa horizons) and mineral A horizons at two European be...

Our study aimed at understanding the utilization of research knowledge generated in sustainable development research. Drawing on a sample of 54 recent research projects, we investigated how and by whom the knowledge was used, what changes were achieved, and how non-academic actors were involved. As a conceptual framework we combined a concept of "s...

The majority of soil organic P is typically that of “unresolved” phosphomonoesters, which are associated with organic P (Po) in large molecular weight (MW) fractions. However, the composition of this pool of Po remains unclear and could contain more than one component. Our aim was to identify the number and nature of components in soil extracts of...

Manure and sewage sludge are known to add significant amounts of zinc (Zn) and other metals to soils. However, there is a paucity of information on the fate of Zn that derives from complex organic fertilizers in soil–plant systems and the contribution of these fertilizers to the Zn nutrition of crops. To answer these questions, we grew Italian ryeg...

Current understanding of phosphorus (P) dynamics is mostly based on experiments carried out under steady-state conditions. However, drying-rewetting is an inherent feature of soil behavior, and as such also impacts P cycling. While several studies have looked at net changes in P pool sizes with drying-rewetting, few studies have dynamically tracked...

Low soil fertility is challenging the sustainable production of yam and other staple crops in the yam belt of West Africa. Quantitative soil measures are needed to assess soil fertility decline and to improve crop nutrient supply in the region. We developed and tested a mid-infrared (mid-IR) soil spectral library to enable timely and cost-efficient...

Applying mineral phosphorus (P) fertilizers introduces a considerable input of the toxic heavy metal cadmium (Cd) into arable soils. This study investigates the fate of P fertilizer derived Cd (Cddff) in soil-wheat systems using a novel combination of enriched stable Cd isotope mass balances, sequential extractions, and Bayesian isotope mixing mode...

Purpose Green manuring can increase the plant available fraction of zinc (Zn) in soil, making it a potential approach to increase wheat Zn concentrations and fight human Zn deficiency. We tested whether green manure increases the ability of both the native soil bacteria and inoculated Zn solubilizing bacteria (ZSB) to mobilize Zn. Methods Wheat wa...

Soil microbial community coalescence, where entire microbial communities mix and interact under new conditions, is a widespread phenomenon whose applicability for targeted root microbiome assembly has not been studied. Whether soil mixing can lead to predictable outcomes for community assembly and functioning of specific functional groups, for exam...

Phosphorus (P) acquisition is key for global food production. Arbuscular mycorrhizal fungi (AMF) help plants acquire P and are considered key for the design of sustainable agroecosystems. However, how the functioning of AMF varies across agricultural soils and responds to management practices is still unknown. Here, we collected soils from 150 cere...

Leaching is one major pathway of phosphorus (P) and nitrogen (N) losses from forest ecosystems. Using a full factorial N×P fertilization and irrigation experiment, we investigated the leaching of dissolved organic and inorganic P (DOP and DIP) and N (DON and DIN) from organic layers (litter, Oe/Oa horizons) and mineral A horizons at two European be...

The role of diffuse phosphorus (P) losses from agricultural land gained importance since technical and constructional measures in urban areas and industry have reached their potential in temperate regions. Phy-toremediation strategies are a new suggestion to effectively reduce soil legacy P but until now, there is a lack of estimates on the time su...

Phosphomonoesterases play an important role in the soil phosphorus (P) cycle since they hydrolyze P monoester to phosphate. Their activity is generally measured in soil extracts, and thus, it remains uncertain how mobile these enzymes are and to which extent they can be translocated within the soil profile. The presence of phosphomonoesterases in s...

Phosphorus (P) is an essential element to all living beings but also a finite resource. P-related problems center around broken P cycles from local to global scales. This paper presents outcomes from the 9th International Phosphorus Workshop (IPW9) held 2019 on how to move towards a sustainable P management. It is based on two sequential discussion...

Purpose Green manuring can increase the plant available fraction of zinc (Zn) in soil, making it a potential approach to increase wheat Zn concentrations and fight human Zn deficiency. We tested whether green manure increases the ability of both the native soil bacteria and inoculated Zn solubilizing bacteria (ZSB) to mobilize Zn. Methods Wheat was...

Ecological intensification of organic rooibos cultivation in South Africa - An interdisciplinary research project on plant-microbe interactions funded by the Mercator Research Program (https://worldfoodsystem.ethz.ch/research/research-programs/MRP.html, https://www.stiftung-mercator.ch) Fact Sheet/Project Outline: https://ethz.ch/content/dam/ethz/...

Soil drying and rewetting (DRW) events are expected to occur at higher frequencies because of alterations in climate patterns. Readily extractable inorganic and microbial soil phosphorus (P) pools may be affected due to rapid changes in soil water availability. We aimed to determine how soil P dynamics are affected by repeated soil DRW using a sand...

New management practices must be developed to improve yam productivity. By allowing non-destructive analyses of important plant traits, image-based phenotyping techniques could help developing such practices. Our objective was to determine the potential of image-based phenotyping methods to assess traits relevant for tuber yield formation in yam gr...

Low soil fertility is challenging the sustainable production of staple crops in the yam belt of West Africa. Quantitative soil measures are needed to assess soil fertility decline and to improve crop fertilization management in the region. We developed and tested a mid-infrared (mid-IR) soil spectral library to enable timely and cost-efficient asse...

The presence and transformations of nitrogen (N) in the environment depend on a variety of environmental factors but are also strongly influenced by anthropogenic activities such as modern agriculture. Understanding N transformations within the context of agricultural systems is crucial for efficient use thereof. The aim of this study was to invest...

Background An aquaponic system couples cultivation of plants and fish in the same aqueous medium. The system consists of interconnected compartments for fish rearing and plant production, as well as for water filtration, with all compartments hosting diverse microbial communities, which interact within the system. Due to the design, function and op...

Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradie...

Management practices must be developed to improve yam production sustainability. Image-based phenotyping techniques could help developing such practices based on non-destructive analyses of important plant traits. Our objective was to determine the potential of image-based phenotyping methods to assess traits relevant for tuber yield formation in y...

To improve phosphorus (P) fertilization and environmental assessments, a better understanding of release kinetics of solid‐phase P to soil solution is needed. In this study, Fe (hydr)oxide‐coated filter papers (Fh papers), isotopic exchange kinetics (IEK) and chemical extractions were used to assess the sizes of fast and slowly desorbing P pools in...