Soil carbon sequestration under long-term rice-based cropping systems of purple soil in Southwest China

Carbon sequestration in agricultural soils is a complex process controlled by farming practices, climate and some other environment factors. Since purple soils are unique in China and used as the main cropland in Sichuan Basin of China, it is of great importance to study and understand the impacts of different fertilizer amendments on soil organic carbon（SOC） changes with time. A research was carried out to investigate the relationship between soil carbon sequestration and organic carbon input as affected by different fertilizer treatments at two long-term rice-based cropping system experiments set up in early 1980 s. Each experiment consisted of six identical treatments, including（1） no fertilizer（CK）,（2） nitrogen and phosphorus fertilizers（NP）,（3） nitrogen, phosphorus and potassium fertilizers（NPK）,（4） fresh pig manure（M）,（5） nitrogen and phosphorus fertilizers plus manure（MNP）, and（6） nitrogen, phosphorus and potassium fertilizers plus manure（MNPK）. The results showed that annual harvestable carbon biomass was the highest in the treatment of MNPK, followed by MNP and NPK, then M and NP, and the lowest in CK. Most of fertilizer treatments resulted in a significant gain in SOC ranging from 6.48 to 2 9.13% compared with the CK, and raised soil carbon sequestration rate to 0.10–0.53 t ha–1 yr-1. Especially, addition of manure on the basis of mineral fertilizers was very conducive to SOC maintenance in this soil. SOC content and soil carbon sequestration rate under balanced fertilizer treatments（NPK and MNPK） in the calcareous purple soil（Suining） were higher than that in the acid purple soil（Leshan）. But carbon conversion rate at Leshan was 11.00%, almost 1.5 times of that（7.80%） at Suining. Significant linear correlations between soil carbon sequestration and carbon input were observed at both sites, signifying that the purple soil was not carbon-saturated and still had considerable potential to se questrate more carbon.

Opportunities and challenges of organic flow battery for electrochemical energy storage technology

For flow batteries(FBs), the current technologies are still expensive and have relatively low energy density, which limits their large-scale applications. Organic FBs(OFBs) which employ organic molecules as redox-active materials have been considered as one of the promising technologies for achieving lowcost and high-performance. Herein, we present a critical overview of the progress on the OFBs, including the design principles of key components(redox-active molecules, membranes, and electrodes) and the latest achievement in both aqueous and nonaqueous systems. Finally, future directions in explorations of the high-performance OFB for electrochemical energy storage are also highlighted.

FAIR + FIT: Guiding Principles and Functional Metrics for Linked Open Data(LOD) KOS Products

Purpose:To develop a set of metrics and identify criteria for assessing the functionality of LOD KOS products while providing common guiding principles that can be used by LOD KOS producers and users to maximize the functions and usages of LOD KOS products.Design/methodology/approach:Data collection and analysis were conducted at three time periods in 2015–16,2017 and 2019.The sample data used in the comprehensive data analysis comprises all datasets tagged as types of KOS in the Datahub and extracted through their respective SPARQL endpoints.A comparative study of the LOD KOS collected from terminology services Linked Open Vocabularies(LOV)and BioPortal was also performed.Findings:The study proposes a set of Functional,Impactful and Transformable(FIT)metrics for LOD KOS as value vocabularies.The FAIR principles,with additional recommendations,are presented for LOD KOS as open data.Research limitations:The metrics need to be further tested and aligned with the best practices and international standards of both open data and various types of KOS.Practical implications:Assessment performed with FAIR and FIT metrics support the creation and delivery of user-friendly,discoverable and interoperable LOD KOS datasets which can be used for innovative applications,act as a knowledge base,become a foundation of semantic analysis and entity extractions and enhance research in science and the humanities.Originality/value:Our research provides best practice guidelines for LOD KOS as value vocabularies.

Reforming of Wiener Index

Based on distance matrixW, the novel topological indexW F is defined by the matricesX, W, L, asW F=WXL. WhereX is a row matrix, which expresses the bonding characteristics between adjacent atoms;L is a column matrix expressing the characteristic of vertexes in molecules;W is a distance matrix, which expresses the chemical environment of the atoms in the molecule. the properties, the chemical environments and the interaction of the vertexes in a molecule are taken into account in this definition. Hence the application of the indexW F to multiple bonds and heteroatomcontaining organic systems or inorganic systems is possible. Good correlation coefficients are achieved not only in the prediction of the standard formation enthalpy of methyl halides, titanium halides, but also the retention index of gas chromatography of the hydrocarbons. Key words distance matrix - Wiener index - QSPR - organic systems - inorganic systems CLC number O 651 Foundation item: Supported by the National Natural Science Foundation of China (20177018) and the Educational Bureau Foundation of Hubei (2003B001)Biography: Huang Yun-ping (1963-), female, Professor, research direction: biophysical chemistry

Diclofop-methyl affects microbial rhizosphere community and induces systemic acquired resistance in rice

Diclofop-methyl（DM）,a widely used herbicide in food crops,may partly contaminate the soil surface of natural ecosystems in agricultural area and exert toxic effects at low dose to nontarget plants.Even though rhizosphere microorganisms strongly interact with root cells,little is known regarding their potential modulating effect on herbicide toxicity in plants.Here we exposed rice seedlings（Xiushui 63） to 100 μg/L DM for 2 to 8 days and studied the effects of DM on rice rhizosphere microorganisms,rice systemic acquired resistance（SAR） and rice-microorganisms interactions.The results of metagenomic 16 S rDNA Illumina tags show that DM increases bacterial biomass and affects their community structure in the rice rhizosphere.After DM treatment,the relative abundance of the bacterium genera Massilia and Anderseniella increased the most relative to the control.In parallel,malate and oxalate exudation by rice roots increased,potentially acting as a carbon source for several rhizosphere bacteria.Transcriptomic analyses suggest that DM induced SAR in rice seedlings through the salicylic acid（but not the jasmonic acid） signal pathway.This response to DM stress conferred resistance to infection by a pathogenic bacterium,but was not influenced by the presence of bacteria in the rhizosphere since SAR transcripts did not change significantly in xenic and axenic plant roots exposed to DM.The present study provides new insights on the response of rice and its associated microorganisms to DM stress.

Exposing vocabularies for soil as Linked Open Data

Standards to describe soil properties are well established,with many ISO specifications and a few international thesauri available for specific applications.Besides,in recent years,the European directive on "Infrastructure for Spatial Information in the European Community(INSPIRE)"has brought together most of the existing standards into a well defined model.However,the adoption of these standards so far has not reached the level of semantic interoperability,defined in the paper,which would facilitate the building of data services that reuse and combine data from different sources.This paper reviews standards for describing soil data and reports on the work done within the EC funded agINFRA project to apply Linked Data technologies to existing standards and data in order to improve the interoperability of soil datasets.The main result of this work is twofold.First,an RDF vocabulary for soil concepts based on the UML INSPIRE model was published.Second,a KOS(Knowledge Organization System)for soil data was published and mapped to existing relevant KOS,based on the analysis of the SISI database of the CREA of Italy.This work also has a methodological value,in that it proposes and applies a methodology to standardize metadata used in local scientific databases,a very common situation in the scientific domain.Finally,this work aims at contributing towards a wider adoption of the INSPIRE directive,by providing an RDF version of it.