Boden als Grundlage unserer Ernährung

Ein entscheidender Faktor für die Nahrungsmittelproduktion ist, worauf und woraus etwas wächst. Inwiefern hat der Boden Einfluss auf die Landwirtschaft? Wie sieht es in unseren Schweizer Böden aus

Mycorrhizal fungi as natural bio-fertilizers: How to produce and use

This technical handbook provides an easy to follow guide describing the process on how to produce home-made mycorrhizal inoculants using different types of propagation units and how inoculants can be applied as bio-fertilizers in the nursery and during field transplantation for improving the growth and stress tolerance of crop plants

Nitrogen transformations and its underlying microbial communities in differently managed soils under future projected rainfall variability

Soil microbial communities play a fundamental role in maintaining a broad range of soil functions and ecosystem services. Especially nutrient provisioning to cultivated crops are of prime interest in agricultural contexts in order to maintain the production of food, fibre and fuel for the ever increasing human population. Since Nitrogen (N) is the most limiting nutrient in agroecosystem and it’s cycling and availability is highly dependent on microbial driven processes, we investigated the impact of farming systems on related ecosystem processes and herein involved soil microbial communities. Considering global climate change, also the potential to withstand rainfall variability was assessed

Prediction of nitrogen mineralization from novel bio-based fertilizers using chemical extractions

Bio-based fertilizers (BBFs) are an increasingly important source of nutrients in agriculture, promoted by the new EU fertilizer regulation aiming to enable a circular bioeconomy. Predicting the mineralization-dependent nutrient release of BBFs is critical for their appropriate use and to minimize environmental losses. We assessed mineralizable nitrogen (N) and carbon (C) of a representative selection of 32 BBFs and evaluated a set of chemical extraction methods to predict their N mineralization dynamics. In 84-day aerobic incubations, cumulative mineral N release varied between −13 and 100 % of amended N. Mineralized C ranged from 10 % to 117 % of amended C. Based on the dynamics of N and C mineralization, BBFs were classified into five significantly different groups. Among the tested chemical indicators of N mineralization from BBFs, cold and hot water presented the lowest extraction intensities, followed by hot potassium chloride and hot sulfuric acid extractions, while C:N ratio is based on total contents. Mineral N released almost immediately was best predicted by cold water extractable N, while hot sulfuric acid extractable N and C:N ratio predicted N released after the first two weeks and after 84 days, respectively. The combination of these three indicators was able to discriminate BBFs into four out of five mineralization classes. Such a cost-effective yet accurate estimation of N mineralization dynamics from BBFs can therefore be used as a basis to inform farmers on suitable timing and amount of BBF application, improving the synchrony between N release from BBFs and crop N demand

Evaluation of six phosphorus extraction methods for compliance testing of recycled P fertilizers

Phosphorus (P) recycling for fertilizer production addresses the dependency on phosphate rock and mitigates P losses to the environment. However, predicting plant-available P in recycled fertilizers is challenging due to their diverse chemical composition. This study aimed at identifying the most suitable P extraction method for fertilizer compliance testing, considering their correlation with actual fertilization efficiency, as well as their simplicity, throughput, recognition and cost. Studies on fertilizer P compliance testing often lack recommendations on minimum P extractability threshold values. Here, thresholds are calculated based on actual fertilization efficiency of a large, chemically diverse set of recycled P fertilizers, many of which are already marketed. Thirty recycled P fertilizers were extracted with H2O, neutral ammonium citrate (NAC), electro-ultrafiltration (EUF), ferrihydrite-filled membranes (iron bag; IB), sodium bicarbonate (NaHCO3) and diffusive gradients in thin films (DGT). The mineral replacement value (MRV) of the fertilizer set was previously evaluated in three pot experiments at a fertilization rate of 50 mg kg−1 soil. MRV correlations with the extractions methods showed similar results for all besides H2O, which cannot be a reliable indicator for P availability. Fertilizers were classified as efficient or inefficient based on their MRV exceeding or falling below 60 % of the triple superphosphate reference value. The minimum P extractability threshold value (MPETV) for each method was based on the efficiency classification and it minimized the number of misclassified fertilizers. NAC, with a 60 % extractable minimum P threshold value, was the most adequate method for compliance testing, despite its overestimation of iron phosphate availability

Biologische REvitalisierung von Obstbäumen

Inhalt - BIOREV - Methodik - Nützliche Mikroorganismen - Nützliche Mikroorganismen - Funktionen - Physikalische Auflockerung des Bodens - Produkte-Qualitätscheck - Feldversuche -Versuchsdesign - Erhebung der mikrobiellen Aktivität - Fazit - Indirektes Management – Anwendung von Pflanzenkohle - Indirektes Management durch Bewirtschaftungsmethode

Fertilization efficiency of thirty marketed and experimental recycled phosphorus fertilizers

Recycling phosphorus (P) from waste streams like sewage sludge, animal manures or food industry by-products is required to sustain soil fertility without depleting non-renewable P resources. Several technologies are available for P recovery, leading to fertilizers differing in P solubility and bioavailability. In this study, thirty fertilizers obtained through different technologies were tested to assess if their fertilization efficiency was equivalent to mineral soluble fertilizer applied as triple superphosphate (TSP). The main selection criteria were (1) ensuring a wide chemical diversity, and (2) choosing products already on the market or at a late stage of development, to encompass a representative selection of current and future recycled fertilizers. The products were classified according to their organic carbon content and neutral ammonium citrate (NAC), and the main P species of each fertilizer was determined through K-edge and L2,3-edge X-ray absorption near edge structure spectroscopy (XANES). Three pot experiments with wheat, barley and ryegrass were conducted in three growing substrates with contrasting properties, all within a pH range of 5.8–6.9. Fertilizers containing ammonium magnesium phosphate, monoammonium phosphate, monocalcium phosphate, and dicalcium phosphate type species as dominant P species showed a similar fertilization efficiency to TSP, while fertilizers with hydroxyapatite, tricalcium phosphate, phytic acid or iron phosphates as their main P species had lower fertilization efficiencies. We conclude that while the trend towards high-efficiency, refined inorganic recycled P fertilizers is positive, lower-performing, mostly unrefined fertilizers must be assessed in light of their long-term P supply potential and additional benefits to soil health owing to their content of organic matter and other nutrients

Low-input soil management increases yield and decreases CO2-emissions but aggravates risk of nitrate leaching and diseases in winter wheat cropping systems under climate change

Understanding how climate change will affect crop performance is critical to ensure global food security and sustainability. Empirical data is key to anticipate the impact of climate change on cropping systems, but multifactorial climate change experiments remain scarce. In this study, the growth of winter wheat was examined in two agricultural soil management systems: one with long-term low organic inputs and the other one with high organic inputs. The wheat was grown in these differentially managed soils in an Ecotron, where the plant-soil mesocosms were subjected to three different climatic conditions. These conditions represent a gradient of ongoing climate change, simulating the weather patterns of the years 2013, 2068, and 2085 respectively. This approach allows to study the combined effects of projected increases in temperature, atmospheric CO2-concentrations, solar irradiation and altered precipitation patterns on the cropping system (wheat growth, grain yield, rhizosphere processes, greenhouse gases, disease dynamics). The low-input system outperformed the high-input system with higher yields and lower CO2-emissions in the future climates. On the other hand, the risk for plant diseases and nitrate leaching was also increased in the low-input system. To reduce the environmental impact of high-yielding cropping systems in the future it is therefore essential to identify management practices which allow fertiliser application and nutrient buffering without necessarily increasing organic inputs, like fertigation or biological nitrification inhibition. Under both here studied soil management systems the wheat plants developed natural coping mechanisms such as enhanced root growth and increased levels of proline and silicon to mitigate the adverse effects of environmental and biotic stresses. Unravelling the molecular mechanisms that trigger such inherent plant defences is a further interesting target for breeding future crops. Adapting crop rotations and cover crops to the shorter wheat cycle in the future is also an opportunity to break disease cycles

Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced

Three new species of arbuscular mycorrhizal fungi discovered at one location in a desert of Oman : Diversispara omaniana, Septoglomus nakheelum and Rhizophagus arabicus

Three new species of arbuscular mycorrhizal (AM) fungi (Glomeromycota) were isolated from soil samples collected from a hyperarid sandy plain of South Arabia. Morphological characteristics of the spores clearly differentiated them from closely related AM species. Molecular analyses were performed on rDNA sequences obtained from single spores including a similar to 1700 bp region comprising partial SSU, ITS, partial LSU and the similar to 600 bp ITS region only. The phylogenetic trees based on these regions showed that the three species belong to well described genera but are clearly distinct from known species. Consequently, we describe them here as Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus spp. nov. D. omaniana and R. arabicus were isolated from the native, arid habitat, while S. nakheelum was isolated from a nearby irrigated date palm plantation. The discovery of three new species of AM fungi from this location suggests that a number of additional undescribed AM taxa may be present in such desert ecosystems. Further work to understand the diversity and functional significance of these new AM taxa may offer new opportunities for conservation, re-vegetation, and sustainable agriculture in extremely arid environments