Hydroponic fodders as alternative feeds for ruminants to reduce ruminal methane emissions: An in vitro study.

Malate, a precursor in the ruminal propionate production pathway, competes with methanogenesis for metabolic hydrogen, offering a way to reduce ruminal methane (CH) production in ruminants. However, cost considerations hinder widespread use of malate in ruminant diets. An alternative approach involves use of transient malate levels generated during seed germination via the glyoxylate cycle.

Zn and Cd labelled green manure to determine the fate and dynamics of zinc and cadmium in soil-fertilizer-crop systems.

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 were applied with an organic fertilizer to a soil-wheat system.

In Vitro Fossilization for High Spatial Resolution Quantification of Elements in Plant-Tissue Using LA-ICP-TOFMS.

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 preparation method is presented in which plant-tissues are fossilized in order to solidify the complex biotissue matrix into a mineral-like matrix.

Plant-soil interactions alter nitrogen and phosphorus dynamics in an advancing subarctic treeline.

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 documented elevation shift of birch-dominated treeline by 70 m during the last 50 years.

Recycling nutrients from organic waste for growing higher plants in the Micro Ecological Life Support System Alternative (MELiSSA) loop during long-term space missions.

Space agencies are developing Bioregenerative Life Support Systems (BLSS) in view of upcoming long-term crewed space missions. Most of these BLSS plan to include various crops to produce different types of foods, clean water, and O while capturing CO from the atmosphere. However, growing these plants will require the appropriate addition of nutrients in forms that are available.

Understanding soil selenium accumulation and bioavailability through size resolved and elemental characterization of soil extracts.

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 cycling is largely due to the unavailability of methods to characterize selenium species in soils, especially the organic ones.

Microbial diversity across compartments in an aquaponic system and its connection to the nitrogen cycle.

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 aquaponic systems were used to investigate the microbial community composition during three lettuce growing cycles.

Agricultural management and pesticide use reduce the functioning of beneficial plant symbionts.

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.

The Use of Stable Zinc Isotope Soil Labeling to Assess the Contribution of Complex Organic Fertilizers to the Zinc Nutrition of Ryegrass.

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 ryegrass in the presence of ZnSO, sewage sludge, and cattle and poultry manure in an acidic soil from Heitenried, Switzerland, and an alkaline soil from Strickhof, Switzerland, where the isotopically exchangeable Zn had been labeled with Zn.

Towards circular phosphorus: The need of inter- and transdisciplinary research to close the broken cycle.

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.

Tracing the fate of phosphorus fertilizer derived cadmium in soil-fertilizer-wheat systems using enriched stable isotope labeling.

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 (Cd) in soil-wheat systems using a novel combination of enriched stable Cd isotope mass balances, sequential extractions, and Bayesian isotope mixing models. We applied an enriched Cd labeled mineral P fertilizer to arable soils from two long-term field trials with distinct soil properties (a strongly acidic pH and a neutral pH) and distinct past mineral P fertilizer application rates.

Environmental parameters and microbial community profiles as indication towards microbial activities and diversity in aquaponic system compartments.

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 operation mode of the individual compartments, each of them exhibits unique biotic and abiotic conditions.

Geographical patterns of root nodule bacterial diversity in cultivated and wild populations of a woody legume crop.

There is interest in understanding how cultivation, plant genotype, climate and soil conditions influence the biogeography of root nodule bacterial communities of legumes. For crops from regions with relict wild populations, this is of even greater interest because the effects of cultivation on symbiont communities can be revealed, which is of particular interest for bacteria such as rhizobia. Here, we determined the structure of root nodule bacterial communities of rooibos (Aspalathus linearis), a leguminous shrub endemic to South Africa.

Experimental assembly reveals ecological drift as a major driver of root nodule bacterial diversity in a woody legume crop.

Understanding how plant-associated microbial communities assemble and the role they play in plant performance are major goals in microbial ecology. For nitrogen-fixing rhizobia, community assembly is generally driven by host plant selection and soil conditions. Here, we aimed to determine the relative importance of neutral and deterministic processes in the assembly of bacterial communities of root nodules of a legume shrub adapted to extreme nutrient limitation, rooibos (Aspalathus linearis Burm.

Quantitative measures of myo-IP in soil using solution P NMR spectroscopy and spectral deconvolution fitting including a broad signal.

Inositol phosphates, particularly myo-inositol hexakisphosphate (myo-IP6), are an important pool of soil organic phosphorus (P) in terrestrial ecosystems. To measure concentrations of myo-IP6 in alkaline soil extracts, solution 31P nuclear magnetic resonance (NMR) spectroscopy is commonly used. However, overlap of the NMR peaks of myo-IP6 with several other peaks in the phosphomonoester region requires spectral deconvolution fitting (SDF) to partition the signals and quantify myo-IP6.

The Use of Q-ICPMS to Apply Enriched Zinc Stable Isotope Source Tracing for Organic Fertilizers.

Organic fertilizer applications can contribute to Zinc (Zn) biofortification of crops. An enriched stable isotope source tracing approach is a central tool to further determine the potential of this biofortification measure. Here, we assessed the use of the widely available quadrupole single-collector ICPMS (Q-ICPMS, analytical error = 1% relative standard deviation) and the less accessible but more precise multicollector ICPMS as reference instrument (MC-ICPMS, analytical error = 0.

Insights from invasion ecology: Can consideration of eco-evolutionary experience promote benefits from root mutualisms in plant production?

Mutualistic plant-microbial functioning relies on co-adapted symbiotic partners as well as conducive environmental conditions. Choosing particular plant genotypes for domestication and subsequent cultivar selection can narrow the gene pools of crop plants to a degree that they are no longer able to benefit from microbial mutualists. Elevated mineral nutrient levels in cultivated soils also reduce the dependence of crops on nutritional support by mutualists such as mycorrhizal fungi and rhizobia.

Understanding fertilizer adoption and effectiveness on maize in Zambia.

Increased fertilizer use will likely be crucial for raising and sustaining farm productivity in Africa, but adoption may be limited by ineffectiveness under certain conditions. This article quantifies the impacts of soil characteristics on maize response to fertilizer in Zambia using a nationally representative sample of 1453 fields, combining economic, farm management and soil analysis data. Depending on soil regimes, average maize yield response estimates range from insignificant (0) to 7 maize kg per fertilizer kg.

Phosphorus Allocation to Leaves of Beech Saplings Reacts to Soil Phosphorus Availability.

Decreasing phosphorus (P) concentrations in leaves of beech ( L.) across Europe raise the question about the implications for forest health. Considering the distribution of beech forests on soils encompassing a broad range of nutrient availability, we hypothesized that this tree species exhibits high phenotypic plasticity allowing it to alter mass, and nutrient allocation in response to local nutrient availability.

Predicting Phosphate Release from Sewage Sludge Ash Using an Ion Sink Assay.

Thermochemical treatments allow production of sewage sludge ash (SSA) rich in P and low in heavy metals, which could be recycled in agriculture. Our objective was to quantify P release from SSA using ion sink assays and to relate these results to P speciation in SSA and plant P uptake. Anion and cation exchange membranes saturated with different counterions (HCO, Na, and H) were used to create a gradient in pH, P, or cation concentration between SSA particles and the surrounding solution.

Zinc Absorption From Agronomically Biofortified Wheat Is Similar to Post-Harvest Fortified Wheat and Is a Substantial Source of Bioavailable Zinc in Humans.

Background: Limited data exist on human zinc absorption from wheat biofortified via foliar (FBW) or root (hydroponically fortified wheat, HBW) zinc application. Stable isotope labels added at point of consumption (extrinsic labeling) might not reflect absorption from native zinc obtained by intrinsic labeling.

Objectives: We measured fractional and total zinc absorption (FAZ, TAZ) in FBW and HBW wheat, compared with control wheat (CW) and fortified wheat (FW).

Long-term organic matter application reduces cadmium but not zinc concentrations in wheat.

Wheat is a staple food crop and a major source of both the essential micronutrient zinc (Zn) and the toxic heavy metal cadmium (Cd) for humans. Since Zn and Cd are chemically similar, increasing Zn concentrations in wheat grains (biofortification), while preventing Cd accumulation, is an agronomic challenge. We used two Swiss agricultural long-term field trials, the "Dynamic-Organic-Conventional System Comparison Trial" (DOK) and the "Zurich Organic Fertilization Experiment" (ZOFE), to investigate the impact of long-term organic, mineral and combined fertilizer inputs on total and phytoavailable concentrations of soil Zn and Cd and their accumulation in winter wheat (Triticum aestivum L.

The Fate of Zn in Agricultural Soils: A Stable Isotope Approach to Anthropogenic Impact, Soil Formation, and Soil-Plant Cycling.

The supplementation of Zn to farm animal feed and the excretion via manure leads to an unintended Zn input to agricultural systems, which might compromise the long-term soil fertility. The Zn fluxes at three grassland sites in Switzerland were determined by a detailed analysis of relevant inputs (atmospheric deposition, manure, weathering) and outputs (seepage water, biomass harvest) during one hydrological year. The most important Zn input occurred through animal manure (1076-1857 g ha yr) and Zn mass balances revealed net Zn accumulations (456-1478 g ha yr).

Towards an understanding of the Cd isotope fractionation during transfer from the soil to the cereal grain.

Cd in soils might be taken up by plants, enter the food chain and endanger human health. This study investigates the isotopic fractionation of major processes during the Cd transfer from soils to cereal grains. Thereto, soil, soil solution, wheat and barley plants (roots, straw and grains) were sampled in the field at three study sites during two vegetation periods.

Using isotopes to trace freshly applied cadmium through mineral phosphorus fertilization in soil-fertilizer-plant systems.

Applications of mineral phosphorus (P) fertilizer can lead to cadmium (Cd) accumulation in soils and can increase Cd concentrations in edible crop parts. To determine the fate of freshly applied Cd, a Cd source tracing experiment was conducted in three soil-fertilizer-wheat systems by using a mineral P fertilizer labeled with the radio isotope Cd and by exploiting natural differences in Cd stable isotope compositions (δCd). Source tracing with stable isotopes overestimated the proportion of Cd in plants derived from the P fertilizer, because the isotope ratios of the sources were not sufficiently distinct from those of the soils.