Effect of long-term fertilization on greenhouse gases emission in paddy soils, China

Poster Sessio

The Case Study on Soil Fauna Diversity in Different Ecological System in Shilin NationalPark, Yunnan, China

Predhodno sta bili preučevani razporeditev in raznovrstnost talne favne v vrsti degradiranih ekosistemov v narodnem parku Shilin. Ti ekosistemi vključujejo pet tipov rastlinskega pokrova: 1. naravno grmišče, 2. umetno nasajen cipresov gozd, 3. naravni travnik, 4. drugotni travnik, 5. golo rdečo prst. Na vsakem izmed njih je bila talna favna nabrana s kvadrata velikosti 1 krat 1 m. Živali so bile nabrane ročno ali pa izločene s pomočjo segrevanja. V talni favni so prevladovale acarina, collembola, nematoda, coleoptera in opistopora. Toda razmeroma pogoste so bile tudi skupine enchytraeidae, araneida, lepidoptera in diptera. Indeks raznovrstnosti H je manjši od 1,5 in se močno znižuje vzporedno z degradacijo rastlinstva. V kraških prsteh so med najpogostejšimi parholaspidae. Biomasa trhypochthoniidae in ologamasidae je najbolj zgoščena v naravnem grmišču in kaže veliko občutljivost teh skupin na degradacijo rastlinstva. Razmerje biomase acarina v primerjavi s collembola je v razponu 0.7 do 1.5, kar je veliko odstopanje od podatkov za naravne prsti podobnih geografskih širin, znanih iz literature. Majhna biomasa talne favne in manjša raznovrstnost kažeta, da se habitati v preučevanih prsteh slabšajo in se torej slabša tudi zdravje celega ekosistema. Izsledki tudi kažejo na ranljivost talne favne v prsteh z vidika sonaravnega razvoja parka Shilin.A preliminary study of the distribution and diversity of soil fauna in a sequence of ecosystem degradation in the Shilin National Park, Yunnan, China has been made. The degraded ecologic system includes 5 types of vegetation cover: (1) natural bush; (2) human planted cypress forest; (3)natural grass; (4)secondary grass and (5) bared red earth. A quadrate of 1m×1m in each eco-tessera was sampled for soil fauna collection. The animals were obtained either by picking up or by heat-removing. The soil fauna were dominated by Acarina, Collembola, Nematode, Coleoptera,and Opistopora in these soils. However, Erchytraeidae, Araneida, Lepidoptera and Diptera were also common groups. The diversity index H turned to be less than 1.5, drastically decreasing with the vegetation degradation trend. In the karst soils, Parholaspidae was one of the most populous among the mites. The biomass of Trhypochthoniidae and Ologamasidae was very concentrated in the natural bush ecosystem, showing high sensitivity of mites to vegetation degradation. The biomass ratio of Acarina to Collembola in the studied soils ranged from 0.70 to 1.50, which was in great discrepancy to the results reported of the natural soils at similar latitude. The small soil fauna biomass and less diversity indicated that the studied soil was in a state of deterioration of soil fauna habitats and, in turn, the soil ecosystem health. The results also evidenced that the soil fauna in the karst soil was definitely vulnerable as regarded to the sustainable development of the Shilin Park

Perspectives on studies on soil carbon stocks and the carbon sequestration potential of China

Peer reviewedPostprin

Does metal pollution matter with C retention by rice soil?

Date of Acceptance: 17/07/2015 The research work was supported by the China Natural Science Foundation under a grant number of 40830528 and of 40671180. P.S. is a Royal Scoiety-Wolfson Research Merit Award holder and was supported by additional travel funds from a UK BBSRC China Partnership Award. P.S.’s contribution was supported by the UK-China Sustainable Agriculture Innovation Network (SAIN). D.C. was supported by an additional travel and collaboration funding from the China Ministry of Education under a “111” project.Peer reviewedPublisher PD

Evaluation of four modelling approaches to estimate nitrous oxide emissions in China’s cropland

This work was financially supported by China Natural Science Foundation under a grant number 41501569 and “the Fundamental Research Funds for the Central Universities” under a grant number KJQN201673. This work was also supported by Department of Science and Technology of Jiangsu province under a grant number BK20150684. This work also contributes to the activities of NCircle - a BBSRC-Newton Funded project (BB/N013484/1). The first author thanks the China Scholarship Council (CSC) for funding to support study at University of Aberdeen, UK.Peer reviewedPostprin

Estimating ammonia emissions from cropland in China based on the establishment of agro-region-specific models

ACKNOWLEDGMENTS This work was financially supported by Natural Science Foundation of China under a grant numbers 41877546 and U1612441, and a BBSRC-Newton Funded project (BB/N013484/1). This work also contributes to the activities of Top-notch Academic Programs Project of Jiangsu Higher Education Institution of China (PPZY2015A061), and Program for Student Innovation through Research and Training (1913A22).Peer reviewedPostprin

Re-assessing Nitrous Oxide Emissions from Croplands Across Mainland China

Reliable quantification of nitrous oxide emission is a key to assessing efficiency of use and environmental impacts of N fertilizers in crop production. In this study, N2O emission and yield were quantified with a database of 853 field measurements in 104 reported studies and a regression model was fitted to the associated environmental attributes and management practices from China’s croplands. The fitted emission model explained 48% of the variance in N2O emissions as a function of fertilizer rate, crop type, temperature, soil clay content, and the interaction between N rate and fertilizer type. With all other variables fixed, N2O emissions were lower with rice than with legumes and then other upland crops, lower with organic fertilizers than with mineral fertilizers. We used the subset of the dataset for rice - covering a full range of different typical water regimes, and estimated emissions from China’s rice cultivation to be 31.1 Gg N2O-N per year. The fitted yield model explained 35% of the variance in crop yield as a function of fertilizer rate, temperature, crop type, and soil clay content. Finally, the empirical models for N2O emission and crop yield were coupled to explore the optimum N rates (N rate with minimum N2O emission per unit yield) for combinations of crop and fertilizer types. Consequently, the optimum N application rate ranged between 100 kg N ha−1 and 190 kg N ha−1 respectively with organic and mineral fertilizers, and different crop types. This study therefore improved on existing empirical methods to estimate N2O emissions from China’s croplands and suggests how N rate may be optimized for different crops, fertilizers and site conditions

More microbial manipulation and plant defense than soil fertility for biochar in food production: A field experiment of replanted ginseng with different biochars

The role of biochar–microbe interaction in plant rhizosphere mediating soilborne disease suppression has been poorly understood for plant health in field conditions. Chinese ginseng ( Panax ginseng C. A. Meyer) is widely cultivated in Alfisols across Northeast China, being often stressed severely by pathogenic diseases. In this study, the topsoil of a continuously cropped ginseng farm was amended at 20 t ha − 1, respectively, with manure biochar (PB), wood biochar (WB), and maize residue biochar (MB) in comparison to conventional manure compost (MC). Post-amendment changes in edaphic properties of bulk topsoil and the rhizosphere, in root growth and quality, and disease incidence were examined with field observations and physicochemical, molecular, and biochemical assays. In the 3 years following the amendment, the increases over MC in root biomass were parallel to the overall fertility improvement, being greater with MB and WB than with PB. Differently, the survival rate of ginseng plants increased insignificantly with PB but significantly with WB (14%) and MB (21%), while ginseng root quality was unchanged with WB but improved with PB (32%) and MB (56%). For the rhizosphere at harvest following 3 years of growing, the total content of phenolic acids from root exudate decreased by 56, 35, and 45% with PB, WB, and MB, respectively, over MC. For the rhizosphere microbiome, total fungal and bacterial abundance both was unchanged under WB but significantly increased under MB (by 200 and 38%), respectively, over MC. At the phyla level, abundances of arbuscular mycorrhizal and Bryobacter as potentially beneficial microbes were elevated while those of Fusarium and Ilyonectria as potentially pathogenic microbes were reduced, with WB and MB over MC. Moreover, rhizosphere fungal network complexity was enhanced insignificantly under PB but significantly under WB moderately and MB greatly, over MC. Overall, maize biochar exerted a great impact rather on rhizosphere microbial community composition and networking of functional groups, particularly fungi, and thus plant defense than on soil fertility and root growth