Data Descriptor : A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.Peer reviewe

Interactions between cover crops and soil microorganisms increase phosphorus availability in conservation agriculture

Aims An essential task of agricultural systems is to im- prove internal phosphorus (P) recycling. Cover crops and tillage reduction can increase sustainability, but it is not known whether stimulation of the soil microbial commu- nity can increase the availability of soil organic P pools. Methods In a field experiment in southwest Germany, the effects of a winter cover crop mixture (vs. bare fallow) and no-till (vs. non-inversion tillage) on microbial P- cycling were assessed with soybean as the main crop. Microbial biomass, phospholipid fatty acids (PLFAs), P cycling enzymes, and carbon-substrate use capacity were linked for the first time with the lability of organic P pools measured by enzyme addition assays (using phosphodi- esterase, non-phytase-phosphomonoesterase and fungal phytase). Results Microbial phosphorus, phosphatase, and fatty acids increased under cover crops, indicating an en- hanced potential for organic P cycling. Enzyme-stable organic P shifted towards enzyme-labile organic P pools. Effects of no-till were weaker, and a synergy with cover crops was not evident. Conclusions In this experiment, cover crops were able to increase the microbially mediated internal P cycling in a non-P-limited, temperate agroecosystems

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Not AvailableSymbiotic (Rhizobia, Frankia, and VAM) or free-living (Azotobacter, and Clostridium) association of plant growth-promoting rhizobacteria (PGPR) and fungi (PGPF) is essential for plant and soil health. Nitrogen (N), phosphorus (P) and potassium (K) as major and iron (Fe) and zinc (Zn) as the minor elements are key to plant health. They are important constituents of plant genetic material (N, P) and chlorophyll content (N, Fe) and important for enzymatic activities (Fe, Zn) and are involved in many biochemical and physiological activities. The ‘microbiome’ around the rhizosphere is specific to plant type and involved in nutrient cycling through various processes such as fixation (N), solubilization, mineralization (P, K) and uptake, with the help of various organic acids (gluconic acid, oxalic acid, and tartaric acid), siderophore activity (Fe uptake) and enzymatic actions (nitrogenase, phytases, and acid phosphatases). Phytohormones essential to plant growth and development are produced by microbes themselves or induce their production via other hormones or communication chemicals, viz., volatile organic compounds (VOCs) like 2-pentylfuran, 2,3-butanediol and acetonin. PGPR (Pseudomonas, Trichoderma and Streptomyces) helps the host plant to fight against various abiotic and biotic stresses by the release of bactericidal and fungicidal enzymes, metabolite accumulation and induced systemic resistance (ISR), systemic acquired resistance (SAR) by phytohormones (jasmonic acid, salicylic acid, and ethylene) and VOCs. Attributing to so many benefits, microbes are increasingly becoming part of sustainable agriculture where PGPR (Rhizobium and Pseudomonas) and fungi (Aspergillus, Trichoderma and VAM) are being used as biofertilizers either single strained or in consortia approach, where the latter is found to be more beneficial for plant and soil health.Not Availabl