Jian Liu
Forsker
(+47) 464 22 528
jian.liu@nibio.no
Sted
Ås - Bygg O43
Besøksadresse
Oluf Thesens vei 43, 1433 Ås (Varelevering: Elizabeth Stephansens vei 21)
Biografi
I am a soil and water researcher working on agricultural effects on the environment. By combining research approaches of experimentation, modeling and data synthesis, I study drivers and processes controlling nutrient losses from land to water (and air) at soil core to catchment scales and explore mitigation measures to reduce the losses both at source and during transport. I have research experience in Norway, Sweden, Canada, USA and China. While my current research activities can be found on this webpage, my past research experience included: (1) water and nutrient transport from both surface and subsurface pathways, (2) climate and management effects on nutrient losses, (3) management of soil nutrient, fertilizer, manure and biochar, including place-based phosphorus management (variable rate applications), for crop production and environmental protection, (4) effects of crop management, including cover crops and crop residues in combination with tillage, on water and nutrient cycling, (5) drainage and irrigation in paddy and horticulture systems, and (6) field and catchment phosphorus modeling. Through collaborations with other researchers, students and stakeholders in many countries, my research has also involved soil health, crop production, greenhouse gas emissions, and generally sustainable agriculture.
Sammendrag
In agricultural areas dominated by subsurface drainage, leaching of phosphorus (P) from soils is a concern for downstream water quality. Still, the role of chemical processes in subsoils and organic soils in influencing dissolved P leaching needs to be clarified for better predicting the P leaching. In ten mineral and organic soils, we examined a wide range of chemical characteristics including various P pools and sorption–desorption properties at different soil depths and related those characteristics to leaching of dissolved P at the drain depth in an indoor lysimeter experiment. Results showed significant correlations between different P pools (R2-adj = 0.61 to 0.98, p < 0.001) and between sorption capacity measurements (R2-adj = 0.60 to 0.95, p < 0.001). Some organic soils followed the same patterns in P sorption capacity and P lability as sandy soils but some did not, suggesting organic soils differ among themselves possibly due to differences in origin and/or management. Flow-weighted mean concentrations of dissolved reactive P and dissolved organic P depended on both the labile P pools (labile inorganic and organic P pools, respectively) in the topsoil and P sorption and desorption characteristics in the subsoils. Mass-weighted whole-profile degree of P saturation based on the ammonium lactate extraction method (DPS-AL) was an excellent indicator of flow-weighted mean concentration of total dissolved P (FWMC-TDP) (R2-adj = 0.93, p < 0.001). Two profiles, one with organic soils overlaying on sand and the other with sandy soils in all layers, had the greatest FWMC-TDP among all profiles (316 and 230 µg/L versus 33–84 µg/L) due to the same reason, i.e., large labile P pools in the topsoils, low P sorption capacity in the subsoils, and high whole-profile DPS-AL. All results point to the need to include subsoil characteristics for assessing the risks of dissolved P leaching from both mineral and organic soils. Also, the study suggests the need to investigate further the roles of the origin and management of organic matter and organic P in influencing P lability and dissolved organic P (DOP) leaching, as well as the bioavailability of DOP in recipient waters.
Forfattere
Yilai Lou Liangshan Feng Wen Xing Ning Hu Elke Noellemeyer Edith Le Cadre Kazunori Minamikawa Pardon Muchaonyerwa Mohamed A. E. AbdelRahman Erika Flavia Machado Pinheiro Wim de Vries Jian Liu Scott Chang Jizhong Zhou Zhanxiang Sun Weiping Hao Xurong MeiSammendrag
Agriculture, broadly defined to include crop and livestock production, forestry, aquaculture and fishery, represents a key source or sink of greenhouse gas emissions. It is also a vulnerable sector under climate change. The term climate-smart agriculture has been widely used since its inception in 2010, but no clear and unified understanding of its scientific meaning exists. Here, we systematically analyzed the relationship between agriculture and climate change and interpreted the scientific definition of climate-smart agriculture. We believe that climate smart agriculture represents a modern production approach to coordinatively promote food security, climate mitigation benefits and agricultural adaptation to climate change towards the Sustainable Development Goals. In addition, due to the worsening global climate change situation, we expounded on the urgency and major challenges in promoting climate-smart agriculture.
Sammendrag
Agricultural sustainability is threatened by both water deficit and water excess, especially at the presence of extreme meteorological events resulting from climate change. However, there has been lack of demonstrations on management options with long-term values for agricultural adaptation to runoff. Using 20 years of monitoring data (1993–2012) for two experimental fields in the Canadian Prairies as a case study, we quantified the effects of rainfall characteristics, crop type and biomass, and tillage on growing-season runoff generation using regression analyses and thereafter scenario comparisons. With growing-season gross rainfall ranging between 183 and 456 mm, runoff responses varied between 0 and 59 mm. Over the 20-year study period, 70%–74 % of the growing season runoff was generated by rainfall events >100 mm. Compared to high-intensity tillage, long-term conservation tillage reduced both overall runoff and runoff in large events likely by improving water infiltration. Under both tillage methods, growing-season runoff significantly increased with increasing rainfall but decreased with increasing biomass (R2 range: 0.40–0.58; p range: 0.0007–0.02). At the event level, the rainfall-runoff relationship followed a piecewise regression model (Cd ¼ 0.82; p
Forfattere
Jian Liu Faruk Djodjic Barbro Ulén Helena Aronsson Marianne Bechmann Lars Bergström Tore Krogstad Katarina KyllmarSammendrag
Nordic agriculture faces big challenges to reduce phosphorus (P) loss from land to water for improving surface water quality. While understanding the processes controlling P loss and seeking for P mitigation measures, Norwegian and Swedish researchers have substantially benefited from and been inspired by Dr. Andrew Sharpley’s career-long, high-standard P research. Here, we demonstrate how Sharpley and his research have helped theNordic researchers to understand the role of cover crops in cold environmental conditions, best manure P management practices, and ditch processes. His work on critical source area (CSA) identification and site assessment tool development have also greatly inspired our thinking on the targeting of mitigation measures and the contextualizing tools for Nordic climate, landscape, and soils.While reflecting on Sharpley’s legacy, we identify several needs for Norwegian and Swedish P research and management. These include (1) tackling the challenges caused by local/regional unevenness in livestock density and related manure management and farm P surpluses, (2) identifying CSAs of P loss with high erosion risk and high P surplus, (3) obtaining more high-resolution mapping of soils with low P sorption capacity both in the topsoil and subsoil, (4) improving cross-scale understanding of processes and mitigation measures and proper follow-up of applied mitigation measures, and (5) increasing collaborations of researchers with farmers and farmers’ advisory groups and watershed groups by developing high-quality educational courses and extension materials. The needs should be addressed in the context of the challenges and opportunities created by climate change.
Sammendrag
Livestock husbandry has raised enormous environmental concerns around the world, including water quality issues. Yet there is a need to document long-term water quality trends in livestock-intensive regions and reveal the drivers for the trends based on detailed catchment monitoring. Here, we assessed the concentration and load trends of dissolved reactive phosphorus (DRP) in streamwater of a livestock-intensive catchment in southwestern Norway, based on continuous flow measurements and flow-proportional composite water sampling. Precipitation and catchment-level soil P balance were monitored to examine the drivers. At the field level, moreover, the relationship between soil P balance and soil test P (measured using the ammonium lactate extraction method, P-AL) was assessed. Results showed that on average of 20 years 95 % of the P was applied to the catchment during March–August, when 40 % of annual precipitation and 25 % of annual discharge occurred. The low runoff helped reduce P loss following P applications. However, flow-weighted annual mean DRP concentration significantly increased with increasingly cumulative soil P surplus (R2 = 0.55, p = 0.0002). With a mean annual P surplus of 8.8 kg ha−1, the annual mean DRP concentration (range: 49–140 μg L−1; mean: 80 μg L−1) and annual DRP load (range: 0.35–1.46 kg ha−1; mean: 0.65 kg ha−1) significantly increased over the 20-year monitoring period (p = 0.001 and 0.0003, respectively). At the field level, P-AL concentrations were positively correlated with soil P balances (R2 = 0.48, p < 0.0001), confirming the long-term impact of P balances on the risks of P loss. The study highlights the predominant role of long-term P balances in affecting DRP loss in livestock-intensive regions through the effect on soil test P.
Divisjon for miljø og naturressurser
Næringsstoff balanserer og brukseffektivitet for Timebekken nedbørfelt (Nutrient balances and use efficiencies for the Timebekken catchment)
Næringsbalanser påvirker i stor grad risikoen for tap av næringsstoffer fra land til vannmiljøet og bør derfor forstås bedre. Nutrient balances significantly affect the risk of nutrient losses from land to the water environment, and therefore should be better understood.
Divisjon for miljø og naturressurser
Tiltak mot fosfor- og nitrogenavrenning i et endret klima: konflikter og synergier (Mitigation measures for phosphorus and nitrogen under changing climate: conflicts and synergies)
Tiltak for å redusere tap av næringsstoffer er nødvendig, men de virker ikke alltid samtidig eller likt for både N og P, på grunn av forskjellene i deres agronomiske og biogeokjemiske egenskaper og dominerende transportveier. Mitigation measures for reducing nutrient losses are pressingly needed but they do not always work simultaneously or equally for both N and P, due to the differences in their agronomic and biogeochemical characteristics and dominant transport pathways.
Divisjon for miljø og naturressurser
SOILPROM: Modelling pollutant transport across the soil-water-atmosphere continuum, and impacts on ecosystem services
Developing sustainable solutions for soil pollution. Empowering Global Change by Advancing Soil Health with Cutting-Edge Research and Collaborative Efforts.
Divisjon for miljø og naturressurser
ENGAGE: Europe Nutrient Management - Guided Approaches for Greater Export reduction
ENGAGE aims to operationalise a novel vision for the future of multi-scale nutrientexport reduction and associated ecosystem services in national andtransboundary/international river basins in Europe by bringing together robuststakeholder engagement strategies with coupled state-of-the-art computationalhydrology techniques and online interactive use-tailored DS tool approaches that integrate remote sensing, socio-economic, governance, and society-change decisionelements.
Divisjon for matproduksjon og samfunn
ECONUTRI
Innovative concepts and technologies for ECOlogically sustainable NUTRIent management in agriculture aiming to prevent, mitigate and eliminate pollution in soils, water and air
Divisjon for miljø og naturressurser
PATH4MED: Demonstrating innovative pathways addressing water and soil pollution in the Mediterranean Agro-Hydro-System.
Path4Med is a multi-participatory and multidisciplinary project that will pave clear pathways towards zero water and soil pollution in the agro-hydro-system of the Mediterranean sea basin and other European seas through an innovative triple bottom line approach achieving economic, social, and environmental sustainability to ensure human well-being and ecosystems functioning.
Divisjon for matproduksjon og samfunn
Fremtidssatsning - Raffinering av husdyrgjødsel
I områder med mye husdyr oppstår det miljøproblemer i forbindelse med lagring og spredning av gjødsel, og oppsamling av næringsstoffer i jord. Disse problemene må løses raskt. Vi trenger derfor mer kunnskap om miljømessig og økonomisk bærekraftige systemer for gjødselraffinering og -bruk.
Divisjon for miljø og naturressurser
Precilience: Precision climate resilience for agriculture and forestry sectors in the European boreal regions
Precilience will develop precision solutions with farmers, foresters, landowners, and other actors to increase climate resilience in the Nordic-Baltic regions of Denmark, Estonia, Finland, Norway and Sweden.
Divisjon for matproduksjon og samfunn
Agricultural mitigation measures and the value of water quality improvements
Agriculture is one of the main sources of water pollution in Norway, and an important contributor to GHG emissions.
Divisjon for matproduksjon og samfunn
Tiltak i landbruket og verdien av forbedret vannkvalitet
Landbruket er en av de viktigste kildene til vannforurensing i Norge, og samtidig en stor bidragsyter til klimautslipp.