Soil Dynamics
    Fertilizer Application
    Plant Physiology

Soil, Plant & Fertilizer

The performance of a particular plant or an entire crop is highly dependent on the fertility of the soil it is growing in. Soil fertility is a multi-faceted analysis of elemental concentrations and biological activity. To get a complete picture of soil fertility, concentrations of carbon, nitrogen, and sulfur, as well as the differentiation of carbon into total organic or total inorganic carbon (TOC or TIC) fractions, are all relevant parameters. Improving soil health by fertilization requires accurate measurements of a wide range of soils and fertilizers. Elementar’s wide range of multi- and single-element analyzers provide individualized solutions to even the most challenging problems.

Soil C:N ratio

The carbon and nitrogen content of soil is directly related to its ability to support healthy plant growth. The vario MAX cube is specially suited to soil analysis. Capable of measuring up to 5 g of soil means that sample inhomogeneity is not an issue. Automated ash removal reduces maintenance requirements and increases productivity. A unique purge-and-trap gas separation system means that even C:N ratios of 7000:1 are perfectly resolved. Additional options, such as using argon as the carrier gas and measuring sulfur or TOC, make the vario MAX cube a versatile, robust solution for soil elemental analysis.

Nitrogen in Fertilizer

The rapid MAX N exceed is ideal for determining the nitrogen content in fertilizer. With sample sizes up to 5 grams of inorganic or 1 gram of organic material, sample preparation in many cases is as easy as weighing the sample into the reusable steel crucibles.

Sulfur in Fertilizer

With the reduction of external sulfur sources, maintaining proper sulfur levels in soil by fertilization is becoming more important. The vario MACRO cube is the world’s only macro sample (up to 1 g) analyzer capable of measuring carbon, hydrogen, nitrogen, and sulfur all in one sample. The wide dynamic range of the thermal conductivity detector enables the accurate determination of sulfur from a fraction of a percent up to 100 % with just one calibration range. Whether interested in just sulfur or any combination of CHNS, the vario MACRO cube provides timely, reliable results with little maintenance, saving you time and money.

Carbon fractions

The total organic carbon (TOC) analysis provides essential information about microbiological activity and organic matter to characterize and evaluate soil and sediment. Soils can also contain a large amount of biologically inaccessible inorganic carbon (TIC), typically in the form of carbonates. Elemental carbon (ROC) is a further common source of carbon, which is also not bio-available. Separately measuring this third carbon fraction can give a much more accurate determination of bio-available, and thus environmentally relevant, TOC compared to acidification method. The revolutionary soli TOC cube measures these three carbon fractions in soils and other solids in a single sample without the need for corrosive acids, providing reliable results with minimal user input.

Soil & plant science publications using our instruments

Our customers use our instruments to do some amazing research in the soil & plant science application field. To show you how they perform their research and how they use our IRMS instruments, we have collected a range of peer-reviewed publications which cite our products. You can find the citations below and then follow the links to the publishing journal should you wish to download the publication.

If you would like to investigate our available citations in more detail, or email the citation list to yourself or your colleagues then take a look at our full citation database.

172 results:

Biodegradability of algal-derived organic matter in a large artificial lake by using stable isotope tracers.
Environmental science and pollution research international (2016)
Yeonjung Lee, Bomi Lee, Jin Hur, Jun-Oh Min, Sun-Yong Ha, Kongtae Ra, Kyung-Tae Kim, Kyung-Hoon Shin

In order to understand the biodegradability of algal-derived organic matter, biodegradation experiments were conducted with (13)C and (15)N-labeled natural phytoplankton and periphytic algal populations in experimental conditions for 60 days. Qualitative changes in the dissolved organic matter were also determined using parallel factor analysis and the stable carbon isotopic composition of the hydrophobic dissolved organic matter through the experimental period. Although algal-derived organic matter is considered to be easily biodegradable, the initial amounts of total organic carbon newly produced by phytoplankton and periphytic algae remained approximately 16 and 44 % after 60 days, respectively, and about 22 and 43 % of newly produced particulate nitrogen remained. Further, the dissolved organic carbon derived from both algal populations increased significantly after 60 days. Although the dissolved organic matter gradually became refractory, the contributions of the algal-derived organic matter to the dissolved organic matter and hydrophobic dissolved organic matter increased. Our laboratory experimental results suggest that algal-derived organic matter produced by phytoplankton and periphytic algae could contribute significantly to the non-biodegradable organic matter through microbial transformations.
Tags: carbon , nitrogen , soil , ecol , poll , elem

Carbon and hydrogen isotopic effects of stomatal density in Arabidopsis thaliana
Geochimica et Cosmochimica Acta (2016)
Hyejung Lee, Sarah J. Feakins, Leonel da S.L. Sternberg

Stomata are key gateways mediating carbon uptake and water loss from plants. Varied stomatal densities in fossil leaves raise the possibility that isotope effects associated with the openness of exchange may have mediated plant wax biomarker isotopic proxies for paleovegetation and paleoclimate in the geological record. Here we use Arabidopsis thaliana, a widely used model organism, to provide the first controlled tests of stomatal density on carbon and hydrogen isotopic compositions of cuticular waxes. Laboratory grown wildtype and mutants with suppressed and overexpressed stomatal densities allow us to directly test the isotope effects of stomatal densities independent of most other environmental or biological variables. Direct hydrogen isotope (H/D) measurements of plant waters and plant wax n-alkanes allow us to directly constrain the isotopic effects of leaf water isotopic enrichment via transpiration and biosynthetic fractionations, which together determine the net fractionation between irrigation water and n-alkane hydrogen isotopic composition. We also measure carbon isotopic fractionations of n-alkanes and bulk leaf tissue associated with different stomatal densities. We find offsets of +15‰ for δD and −3‰ for δ13C for the overexpressed mutant compared to the suppressed mutant. Since the range of stomatal densities expressed is comparable to that found in extant plants and the Cenozoic fossil record, the results allow us to consider the magnitude of isotope effects that may be incurred by these plant adaptive responses. This study highlights the potential of genetic mutants to isolate individual isotope effects and add to our fundamental understanding of how genetics and physiology influence plant biochemicals including plant wax biomarkers.
Tags: carbon , hydrogen , soil , gashead , gaschrom

Trophic transfer of nano-TiO2 in a paddy microcosm: A comparison of single-dose versus sequential multi-dose exposures.
Environmental pollution (Barking, Essex : 1987) (2016)
Jung In Kim, Hyung-Geun Park, Kwang-Hyeon Chang, D H Nam, Min-Kyeong Yeo

In the present study, replicated paddy microcosm systems were used to investigate the environmental fate and trophic transfer of titanium nanoparticles (NPs) over a period of 14 days. Most TiO2 NPs immediately settled down in the sediment, and high accumulations of nano TiO2 in the sandy loam sediment and biofilm were observed. The test organisms (quillworts, water dropworts, duckweeds, biofilms, river snails, and Chinese muddy loaches) and environmental media (freshwater, sandy loam sediment) were exposed to sequential low doses (2 mg/L at 1 h, 4 days, and 9 days) or a single high-dose (6 mg/L) of TiO2 NPs. The bioconcentration factors (BCFs) of nano-TiO2 in biofilms, quillworts, duckweeds, and Chinese muddy loaches were higher in the sequential multi-dose group than in the single-dose group. Chinese muddy loaches showed higher bioaccumulation factors (BAFs) over their prey than river snails. The difference in the carbon isotope ratios between Chinese muddy loaches and river snails was less than 2‰, and an approximately 4‰ difference in the stable nitrogen isotope ratio was observed in the two aquatic predators from their major prey (e.g., biofilms or particulate organic matter). The trophic levels between biofilms and river snails and between biofilms and Chinese muddy loaches were 2.8 and 2.4 levels, respectively. These results indicate that these two predators consumed biofilm and other alternative preys at a higher level than biofilm. Although the trophic transfer rates of TiO2 are generally low, relatively higher biomagnification factors (BMFs) were found in Chinese muddy loaches (0.04-0.05) than in river snails (0.01-0.02). These results suggest that TiO2 NPs show greater movement in the sediment than in the water and that TiO2 NPs can be retained through aquatic food chains more after a sequential low-dose exposure than after a single high-dose exposure.

Root rather than leaf litter input drives soil carbon sequestration after afforestation on a marginal cropland
Forest Ecology and Management (2016)
Ya-Lin Hu, De-Hui Zeng, Xiang-Qing Ma, Scott X. Chang

Afforestation on croplands has been proposed as a means to mitigate the increasing emission of anthropogenic CO2. However, the relative contribution of above- and belowground litter input on soil organic carbon (SOC) sequestration following afforestation is not fully understood. We used a 270-day laboratory incubation experiment to examine the impact of litter type (i.e., leaf vs. fine root litter) of a poplar tree (Populus simonii Carr., C3 plant) on soil respiration and the turnover of new vs. old soil C in surface (0–10cm) and subsurface mineral soils (40–50cm) collected from a marginal cropland planted to maize (Zea mays L., C4 plant) in a semi-arid region in northeast China. Our results showed that fine root rather than leaf litter addition helps to sequester SOC even though soil microbial respiration rates were stimulated by both leaf and fine root litter input. Neither leaf nor fine root litter addition stimulated mineralization of old soil C across the two soil layers, but more new C was incorporated into the soil with fine root addition as compared with leaf litter addition. Moreover, the subsurface soil had greater potential to sequester SOC as compared to the surface soil. Our results suggest that root rather than leaf litter input drives soil carbon sequestration on the marginal soil, especially in the subsurface soil, and planting deep-rooted trees with large belowground biomass production could be used to increase SOC sequestration in marginal croplands.

Deforestation for oil palm alters the fundamental balance of the soil N cycle
Soil Biology and Biochemistry (2016)
R. Liz Hamilton, Mark Trimmer, Chris Bradley, Gilles Pinay

Expansion of commercial agriculture in equatorial regions has significant implications for regional nitrogen (N) budgets. Here we investigate changes in N availability and turnover in Southeast Asia following the replacement of tropical forest with oil palm plantations along a chronosequence of oil palm maturity (3-months to 15-year-old stands) and secondary to primary forest succession in Sabah, Malaysian Borneo. Ten sites were sampled during March and April 2012 and rates of gross ammonium (NH4+) and nitrate (NO3-) production (mineralisation and nitrification) and consumption (n = 8), potential denitrification and "anaerobic ammonium oxidation" ("anammox") (n = 12) were determined using 15N isotope additions to soil cores and slurries respectively. Gross mineralisation rates (0.05-3.08 g N m-2 d-1) remained unchanged in oil palm relative to forests. However, a significant reduction in gross nitrification (0.04-2.31 g N m-2 d-1) and an increase in NH4+ immobilisation disrupt the pathway to nitrogen gas (N2) production substantially reducing (by > 90%) rates of denitrification and "anammox" in recently planted oil palm relative to primary forest. Potential nitrous oxide (N2O) emissions were greater than potential N2 production and remained unchanged across the chronosequence indicating a potentially increased ratio of N2O:N2 emission when soils were first disturbed. These results are an important precursor to studies that could yield improved estimates of regional N turnover and loss in Southeast Asia which will have global implications for N biogeochemical cycling.

Origin and availability of organic matter leading to arsenic mobilisation in aquifers of the Red River Delta, Vietnam
Applied Geochemistry (2016)
Elisabeth Eiche, Michael Berg, Sarah-Madeleine Hönig, Thomas Neumann, Vi Mai Lan, Thi Kim Trang Pham, Hung Viet Pham

Groundwater arsenic (As) concentrations in the Red River Delta (Vietnam) are often patchy and related to the microbially induced reduction of Fe oxy-hydroxides. In this study, we explored the influence of the origin, composition and availability of natural organic matter on the hydrochemical variability in the aquifers of Van Phuc. Carbon isotope signatures (δ13Corg) and C/N ratios were assessed in combination with lithology, geochemistry, hydrochemistry, hydrology and the distribution of specific biomarkers. The elationship of C/N ratios and δ13Corg distinguished four groups of sediment types that differ in their organic carbon sources. This includes organic carbon originating predominantly from vascular C3 plants (C/N: 15.4–21.0, δ13Corg: −28.6 to −26.7‰), C4 plants (C/N: 10.6; δ13Corg: −14.8‰), freshwater derived particulate organic carbon (C/N: ≤8; δ13Corg:≤−24‰) as well as mixtures incorporating both sources. At the high As sites, we found particulate organic carbon (POC) being 1–2‰ less depleted in δ13Corg than at low As sites. More importantly, however, our assessment shows that, the availability of organic matter has to be considered decisive with regard to groundwater As contamination. Fine-grained clayey sediments overlaying sands generally protect organic matter from substantial degradation and its leaching into an adjacent aquifer. However, at the sites that are high in dissolved As in Van Phuc, sediment layers rich in organic matter are hydraulically connected to the underlying aquifer. Here, soluble organic matter seeping into the aquifer can induce and/or enhance reducing conditions, thereby mobilising As from Fe oxy-hydroxides. Our study shows that both the clay content as well as the origin of organic matter are largely controlled by the depositional environment of the sediments.

Relict soil evidence for profound quaternary aridification of the Atacama Desert, Chile
Geoderma (2016)
Angela Ebeling, Erik Oerter, J.W. Valley, Ronald Amundson

A relict soil on a late Tertiary/early Quaternary gravelly alluvial fan in the southern Atacama Desert was studied to determine if evidence of Quaternary climate change was evident in the profile. Stratigraphic relations of soil morphological features indicated that the initial phase of soil development was extensive chemical weathering with the loss of Si, Na, etc. and the formation of secondary clay. This was then followed by a prolonged period of carbonate accumulation that has discontinuously impregnated the earlier formed argillic horizons. The carbonate accumulation occurred both as fine-grained accumulations that engulfed and expanded the gravelly soil matrix, and as carbonate that formed dense and continuous coatings on gravel bottoms. Overlying the carbonate is a Holocene calcareous sand unit. Stable C and O isotope profiles of the disseminated carbonate show that this material appears to have formed under conditions of low to modest plant cover and significant soil water evaporation, very similar to soils presently found at higher latitudes and altitudes in modern Argentina. Seven transects of the carbonate laminations on the gravels at 10-μm scale reveal that all show a nearly 4‰ increase in δ13C values with time over distances of approximately 150mm, and variable δ18O values. The shift in C isotope values, which is unlikely to be due to significant changes in C3 vs. C4 vegetation, reflects a profound and prolonged aridification with a corresponding lowering of plant density and soil respiration. The precise beginning of the aridification is unknown due to a lack of carbonate dating methods amenable to the time frame involved. When all changes are considered, this remarkable soil indicates that local rainfall declined from somewhere between 500 to 1000mm y−1 in the late Tertiary/early Quaternary, to the present climate of about 25mm y−1. Future work will focus on developing more precise geochronological controls, but this initial study reveals the enormous potential that carbonate-bearing relict soils have for understanding climate change.
Tags: carbon , oxygen , soil , geol , mulitcarb

Effects of biocontrol with an atyid shrimp (Caridina denticulata) and a bagrid catfish (Pseudobagrus fulvidraco) on toxic cyanobacteria bloom (Microcystis aeruginosa) in a eutrophic agricultural reservoir
Paddy and Water Environment (2016)
Min-Seob Kim, Yeonjung Lee, Seongjin Hong, Soon-Jin Hwang, Baik-Ho Kim, Kwang-Guk An, Young-Seuk Park, Sang-Kyu Park, Han-Yong Um, Kyung-Hoon Shin

The biocontrol effects of Caridina denticulata, an atyid shrimp, on toxic cyanobacterial bloom (Microcystis aeruginosa) were evaluated in a mesocosm study with stable isotope tracers (13C and 15N) in a eutrophic agricultural reservoir. The accumulated assimilation (at.%) of M. aeruginosa into C. denticulata was increased, causing a significant reduction in the concentration of Chlorophyll-a. The ingestion rate of M. aeruginosa by C. denticulata was influenced by predation pressure exerted by bagrid catfish Pseudobagrus fulvidraco and was dependent on biomass ratio. C. denticulata affected zooplankton density, species composition, and ingestion rate, demonstrating that the number of small-sized cladocerans (Bosmina coregoni and Bosmina longispina) increased because they grazed M. aeruginosa for a food source. This study suggests that C. denticulata and P. fulvidraco can be feasible material to control a nuisance M. aeruginosa bloom in eutrophic agricultural reservoir.
Tags: carbon , nitrogen , soil , ecol , poll , elem

Dynamics of PAHs and derived organic compounds in a soil-plant mesocosm spiked with 13C-phenanthrene
Chemosphere (2016)
Johanne Cennerazzo, Alexis de Junet, Jean-Nicolas Audinot, Corinne Leyval

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous and persistent soil pollutants. Their fate and the influence of the plant rhizosphere on their dynamics has been extensively studied, but studies mainly focused on their dissipation rate. We conducted a plant-soil mesocosm experiment to study the fate and distribution of PAHs or derived compounds in the extractable fraction, the residual soil, the shoot biomass and the root biomass. The experiment was conducted for 21 days using ryegrass and a forest soil spiked with 13C-labeled phenanthrene (PHE), using combined IRMS and NanoSIMS for analyses. Almost 90% of the initial extractable PHE content was dissipated within 3 weeks, but no rhizospheric effect was highlighted on PHE dissipation. More than 40% of 13C-PHE was still in the soil at the end of the experiment, but not as PHE or PAH-derived compounds. Therefore it was under the form of new compounds (metabolites) and/or had been incorporated into the microbial biomass. About 0.36% of the initial 13C-PHE was recovered in the root and shoot tissues, representing similar 13C enrichment (E13C) as in the soil (E13C ≈ 0.04 at.%). Using NanoSIMS, 13C was also localized at the microscale in the roots and their close environment. Global 13C enrichment confirmed the results obtained by IRMS. Some hotspots of 13C enrichment were found, with a high 32S/12C14N ratio. Comparing the ratios, sizes and shapes of these hotspots suggested that they could be bacteria.
Tags: carbon , soil , poll , elem , gaschrom

The main nitrate transporter of the dinoflagellate Lingulodinium polyedrum is constitutively expressed and not responsible for daily variations in nitrate uptake rates
Harmful Algae (2016)
Steve Dagenais Bellefeuille, David Morse

Dinoflagellates are unicellular eukaryotes capable of forming spectacular harmful algal blooms (HABs). Eutrophication of coastal waters by fertilizer runoff, nitrate in particular, has contributed to recent increases in the frequency, magnitude and geographic extent of HABs. Although physiological nitrate uptake and assimilation in dinoflagellates have often been measured in the field and in the laboratory, no molecular components involved in nitrate transport have yet been reported. This study reports the first identification and characterization of dinoflagellate nitrate transporters, found in the transcriptome of the bloom-forming Lingulodinium polyedrum. Of the 23 putative transporters found by BLAST searches, only members of the nitrate transporter 2 (NRT2) family contained all key amino acids known to be essential for nitrate transport. The dinoflagellate NRT2 sequences have 12 predicted transmembrane domains, as do the NRT2 sequences of bacteria, plants and fungi. The NRT2 sequences in Lingulodinium appear to have two different evolutionary origins, as determined by phylogenetic analyses. The most expressed transcript of all putative nitrate transporters was determined by RNA-Seq to be LpNRT2.1. An antibody raised against this transporter showed that the same amount of protein was found at different times over the light dark cycle and with different sources of N. Finally, global nitrate uptake was assessed using a 15N tracer, which showed that the process was not under circadian-control as previously suggested, but simply light-regulated.