In-situ 13CO2 labeling to trace carbon fluxes in plant-soil-microorganism systems: Review and methodological guideline

The amount of lupin below-ground biomass (BGB), BGB nitrogen (N) content, and utilization of BGB-N by subsequent wheat was estimated from lupins grown in soil columns. Lupin plants were enriched in situ with 15N-labelled urea through a cotton wick inserted through the stem. Of the applied 15N. 92% was recovered in the lupin plant-soil system at maturity: 87% of this 15N was in lupin aboveground biomass and 13% in the soil columns. Total mature lupin dry matter (DM) approximated 11 t/ha, with 3.0 t/ha (27%) of this DM below ground. Total mature lupin N approximated 321 kg/ha, of which 91 kg/ha (28%) resided below ground. In terms of N and DM, BGB was the largest lupin residue component even though only 35% of this was recoverable as root material. About 13% of the BGB-N was in inorganic form at maturity. The net mineralisation of lupin BGB-N after 2 consecutive years of wheat growth was 27%. and wheat assimilated about 74% of this N (i.e. 20% of BGB-N), with equal quantities assimilated in each year. The contribution of lupin BGB-N to the N in wheat tops ranged from 40% for soil columns receiving no fertiliser N to 15-20% for soil columns fertilised with 30 kg N/ha. The net mineralisation of BGB-N and the assimilation of BGB-N by wheat were unaffected by the application of fertiliser N.

Download Full-text

Physical changes in the rhizosphere and their significance for plant-soil interactions

Acta Agronomica Hungarica ◽

10.1556/aagr.48.2000.1.12 ◽

2000 ◽

Vol 48 (1) ◽

pp. 107-112 ◽

Cited By ~ 1

Author(s):

P. Gregory

Keyword(s):

Surface Active Agent ◽

Active Agent ◽

Root Surface ◽

Cone Beam ◽

Non Invasive ◽

Plant Soil ◽

Scanning Time ◽

Surface Active ◽

Physical Changes

The rhizosphere has biological, chemical and physical properties that differ from those of bulk soil and which influence the availability of water and nutrients. Mucilage produced by roots contains a surface active agent which reduces the surface tension around the root. The presence of root cap cells in the mucilage gives it viscoelastic properties which draw soil particles towards the root surface and, together with the increasing viscosity as the soil dries and mucilage dehydrates, facilitates the formation of rhizosheaths.The development of non-invasive imaging allied with computed tomography (CT) has allowed the study of root systems in situ and the observation of root growth. It is now possible to achieve cone beam images in a scanning time of 30 minutes with a resolution of 100 .m. Further developments of this technique should allow changes in bulk density and water content close to the root surface to be observed and quantified.

Download Full-text

Constraining surface carbon fluxes using in situ measurements of carbonyl sulfide and carbon dioxide

Global Biogeochemical Cycles ◽

10.1002/2013gb004644 ◽

2014 ◽

Vol 28 (2) ◽

pp. 161-179 ◽

Cited By ~ 40

Author(s):

M. Berkelhammer ◽

D. Asaf ◽

C. Still ◽

S. Montzka ◽

D. Noone ◽

...

Keyword(s):

Carbon Dioxide ◽

Carbonyl Sulfide ◽

Carbon Fluxes ◽

In Situ Measurements ◽

Surface Carbon

Download Full-text

In situ fate of mineral N in the tree-soil-microorganism system before and after budburst in 20-year-old Quercus petraea (Matt.) Liebl.

Plant and Soil ◽

10.1007/s11104-020-04610-4 ◽

2020 ◽

Vol 455 (1-2) ◽

pp. 425-438

Author(s):

Tania L. Maxwell ◽

Stéphane Bazot ◽

Anne Marmagne ◽

Liliana Pinek ◽

Baptiste Laffont ◽

...

Keyword(s):

Quercus Petraea ◽

Soil Microorganism ◽

Mineral N ◽

Before And After

Download Full-text

The effect of assimilating satellite-derived soil moisture data in SiBCASA on simulated carbon fluxes in Boreal Eurasia

Hydrology and Earth System Sciences ◽

10.5194/hess-20-605-2016 ◽

2016 ◽

Vol 20 (2) ◽

pp. 605-624 ◽

Cited By ~ 9

Author(s):

M. K. van der Molen ◽

R. A. M. de Jeu ◽

W. Wagner ◽

I. R. van der Velde ◽

P. Kolari ◽

...

Keyword(s):

Soil Moisture ◽

Carbon Cycle ◽

Carbon Fluxes ◽

Vegetation Model ◽

Annual Variations ◽

Data Usage ◽

Order Of Magnitude ◽

Active Data ◽

Global Carbon

Abstract. Boreal Eurasia is a region where the interaction between droughts and the carbon cycle may have significant impacts on the global carbon cycle. Yet the region is extremely data sparse with respect to meteorology, soil moisture, and carbon fluxes as compared to e.g. Europe. To better constrain our vegetation model SiBCASA, we increase data usage by assimilating two streams of satellite-derived soil moisture. We study whether the assimilation improved SiBCASA's soil moisture and its effect on the simulated carbon fluxes. By comparing to unique in situ soil moisture observations, we show that the passive microwave soil moisture product did not improve the soil moisture simulated by SiBCASA, but the active data seem promising in some aspects. The match between SiBCASA and ASCAT soil moisture is best in the summer months over low vegetation. Nevertheless, ASCAT failed to detect the major droughts occurring between 2007 and 2013. The performance of ASCAT soil moisture seems to be particularly sensitive to ponding, rather than to biomass. The effect on the simulated carbon fluxes is large, 5–10 % on annual GPP and TER, tens of percent on local NEE, and 2 % on area-integrated NEE, which is the same order of magnitude as the inter-annual variations. Consequently, this study shows that assimilation of satellite-derived soil moisture has potentially large impacts, while at the same time further research is needed to understand under which conditions the satellite-derived soil moisture improves the simulated soil moisture.

Download Full-text

Using Unmanned Aerial Systems (UAS) and Object-Based Image Analysis (OBIA) for Measuring Plant-Soil Feedback Effects on Crop Productivity

Drones ◽

10.3390/drones3030054 ◽

2019 ◽

Vol 3 (3) ◽

pp. 54 ◽

Cited By ~ 3

Author(s):

Rik J. G. Nuijten ◽

Lammert Kooistra ◽

Gerlinde B. De Deyn

Keyword(s):

Image Analysis ◽

Template Matching ◽

Large Scale ◽

Crop Productivity ◽

Unmanned Aerial Systems ◽

Object Based Image Analysis ◽

Plant Soil ◽

Object Based ◽

Soil Feedback

Unmanned aerial system (UAS) acquired high-resolution optical imagery and object-based image analysis (OBIA) techniques have the potential to provide spatial crop productivity information. In general, plant-soil feedback (PSF) field studies are time-consuming and laborious which constrain the scale at which these studies can be performed. Development of non-destructive methodologies is needed to enable research under actual field conditions and at realistic spatial and temporal scales. In this study, the influence of six winter cover crop (WCC) treatments (monocultures Raphanus sativus, Lolium perenne, Trifolium repens, Vicia sativa and two species mixtures) on the productivity of succeeding endive (Cichorium endivia) summer crop was investigated by estimating crop volume. A three-dimensional surface and terrain model were photogrammetrically reconstructed from UAS imagery, acquired on 1 July 2015 in Wageningen, the Netherlands. Multi-resolution image segmentation (MIRS) and template matching algorithms were used in an integrated workflow to detect individual crops (accuracy = 99.8%) and delineate C. endivia crop covered area (accuracy = 85.4%). Mean crop area (R = 0.61) and crop volume (R = 0.71) estimates had strong positive correlations with in situ measured dry biomass. Productivity differences resulting from the WCC treatments were greater for estimated crop volume in comparison to in situ biomass, the legacy of Raphanus was most beneficial for estimated crop volume. The perennial ryegrass L. perenne treatment resulted in a significantly lower production of C. endivia. The developed workflow has potential for PSF studies as well as precision farming due to its flexibility and scalability. Our findings provide insight into the potential of UAS for determining crop productivity on a large scale.

Download Full-text

Terrestrial ecosystem carbon flux estimated using GOSAT and OCO-2 XCO<sub>2</sub> retrievals

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-12067-2019 ◽

2019 ◽

Vol 19 (18) ◽

pp. 12067-12082 ◽

Cited By ~ 5

Author(s):

Hengmao Wang ◽

Fei Jiang ◽

Jun Wang ◽

Weimin Ju ◽

Jing M. Chen

Keyword(s):

Carbon Flux ◽

Carbon Sink ◽

Terrestrial Ecosystem ◽

Carbon Fluxes ◽

Atmospheric Co2 ◽

Total Carbon ◽

Ecosystem Carbon ◽

The Poor ◽

Spatial Coverage

Abstract. In this study, both the Greenhouse Gases Observing Satellite (GOSAT) and the Orbiting Carbon Observatory 2 (OCO-2) XCO2 retrievals produced by the NASA Atmospheric CO2 Observations from Space (ACOS) project (version b7.3) are assimilated within the GEOS-Chem 4D-Var assimilation framework to constrain the terrestrial ecosystem carbon flux during 1 October 2014 to 31 December 2015. One inversion for the comparison, using in situ CO2 observations, and another inversion as a benchmark for the simulated atmospheric CO2 distributions of the real inversions, using global atmospheric CO2 trends and referred to as the poor-man inversion, are also conducted. The estimated global and regional carbon fluxes for 2015 are shown and discussed. CO2 observations from surface flask sites and XCO2 retrievals from Total Carbon Column Observing Network (TCCON) sites are used to evaluate the simulated concentrations with the posterior carbon fluxes. Globally, the terrestrial ecosystem carbon sink (excluding biomass burning emissions) estimated from GOSAT data is stronger than that inferred from OCO-2 data, weaker than the in situ inversion and matches the poor-man inversion the best. Regionally, in most regions, the land sinks inferred from GOSAT data are also stronger than those from OCO-2 data, and in North America, Asia and Europe, the carbon sinks inferred from GOSAT inversion are comparable to those from in situ inversion. For the latitudinal distribution of land sinks, the satellite-based inversions suggest a smaller boreal and tropical sink but larger temperate sinks in both the Northern and Southern Hemisphere than the in situ inversion. However, OCO-2 and GOSAT generally do not agree on which continent contains the smaller or larger sinks. Evaluations using flask and TCCON observations and the comparisons with in situ and poor-man inversions suggest that only GOSAT and the in situ inversions perform better than a poor-man solution. GOSAT data can effectively improve the carbon flux estimates in the Northern Hemisphere, while OCO-2 data, with the specific version used in this study, show only slight improvement. The differences of inferred land fluxes between GOSAT and OCO-2 inversions in different regions are mainly related to the spatial coverage, the data amount and the biases of these two satellite XCO2 retrievals.

Download Full-text