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:

Arboreal Legume Litter Nutrient Contribution to a Tropical Silvopasture
Agronomy Journal (2016)
Valéria Xavier de Oliveira Apolinário, José Carlos Batista Dubeux, Mário de Andrade Lira, Everardo V. S. B. Sampaio, Silvânia Oliveira de Amorim, Nalígia Gomes de Miranda e Silva, James P. Muir

Legumes contribute to pasture sustainability through symbiotic N2 fixation, which may increase primary productivity and animal performance in low-input systems. Litterfall is the main way of cycling nutrients from tree legumes. We quantified gliricidia [Gliricidia sepium (Jacq.) Kunth ex Walp.] and sabiá (Mimosa caesalpiniifolia Benth) litter deposition, along two 336-d cycles, in a signalgrass (Brachiaria decumbens Stapf.) pasture. Litterfall was produced throughout the year but concentrated in the dry season. Sabiá produced slightly greater (P < 0.0001) litterfall amounts in the two cycles (10,790 kg ha–1) than gliricidia (10,420 kg ha–1) but the overall average N concentration of gliricidia (21.5 g kg–1) was greater than that of sabiá (18.8 g kg–1). Nitrogen amounts cycled through the litter were greater for gliricidia in both cycles (105 and 109 kg N ha–1) than for sabiá (87 and 98 kg N ha–1). The proportions of litter N that were derived from the atmosphere by symbiotic fixation were similar (P ≥ 0.05) in both species (55%) and varied little along the two cycles. Lignin concentration, which influences decomposition, was similar in both species, averaging 238 and 214 g kg–1 in the two cycles for gliricidia and 233 and 246 g kg–1 for sabiá. Greater N concentration, lower C/N ratio and lower lignin concentration indicate that gliricidia litter may have a faster cycling rate than sabiá litter. Sabiá could be a more promising species for soil cover and protection because of its slower litter decomposition rate.

Temperature dependence of CO2 emissions rates and isotopic signature from a calcareous soil
Journal of Arid Environments (2016)
Tiphaine Chevallier, Laurent Cournac, Salwa Hamdi, Tahar Gallali, Martial Bernoux

In the context of climate change, studies have focused on the temperature dependence of soil CO2 emissions. Although calcareous soils cover over 30% of the earth's land surface, few studies have considered calcareous soils where soil inorganic carbon (SIC) makes the analysis of the C fluxes at the soil to air interface more complex. This study tested how temperature could affect the contributions of soil organic carbon (SOC) and SIC to the CO2 emitted from a calcareous soil. The soil pH, CO2 emissions and δ13C signatures of CO2 were measured after soil incubations at 4 temperatures (20 °C, 30 °C, 40 °C and 50 °C). The CO2 emissions and the δ13C signature of the emitted CO2 increased with temperature. The proportion of SIC-derived CO2 in these emissions seemed to be stimulated by temperature. Three processes were discussed: (1) isotopic fractionations, (2) temperature impacts on SIC- and SOC-derived CO2, and (3) isotope exchanges between SIC- and SOC-derived CO2. The use of δ13C signature analysis to determine the contribution of SIC and SOC to the total CO2 emissions from soil is not straightforward. An increase in the SIC signature of emitted CO2 does not directly imply an increase in SIC as a source of CO2.

Temperature sensitivity of soil organic carbon decomposition as affected by long-term fertilization under a soybean based cropping system in a sub-tropical Alfisol
Agriculture, Ecosystems & Environment (2016)
Avijit Ghosh, Ranjan Bhattacharyya, B.S. Dwivedi, M.C. Meena, B.K. Agarwal, P. Mahapatra, D.K. Shahi, R. Salwani, R. Agnihorti

Understanding temperature sensitivity of soil organic carbon (SOC) decomposition from bulk soils and aggregates of long-term fertilized plots is imperative to forecast soil C dynamics. We evaluated the impacts of 43 years of fertilization under a soybean (Glycine max) based cropping system on temperature sensitivity of SOC decomposition (Q10) in an Alfisol. Treatments were: no mineral fertilizer or manure (control), 100% recommended dose of nitrogen (N), N and phosphorus (NP), N, P and potassium (NPK), NPK+lime at 0.4Mgha−1 (NPK+L), 150% recommended NPK (150% NPK), and NPK+farmyard manure (FYM) at 10Mgha−1 (NPK+FYM). Bulk soils as well as macro- and micro-aggregates were incubated for 24days at 25°C and 35°C. Cumulative SOC mineralization (Ct) in the 0–15cm soil layer of bulk soils with NPK+FYM and NPK treated plots were similar but significantly higher than unfertilized control plots. However, both Ct and Q10 values in the NPK+FYM plots were higher than NPK in the 15–30cm soil layer. In the 0–15cm soil layer, NPK+FYM plots had ∼10 and 26% greater Q10 values of macro- and microaggregates than NPK. Activation energies required for bulk soils C mineralization was ∼2 and 3 times higher in NPK+FYM and NPK+L plots, respectively, compared with unfertilized control plots in that layer. Lime along with NPK application increased the activation energy of SOC decomposition. Thus, long-term NPK+FYM and NPK+L applications have great potential for less proportional SOC decomposition than NPK or unfertilized control plots under a temperature rise in these acid soils. However, NPK+FYM management practice is recommended as it has highest SOC accumulation and can have less SOC losses under a temperature rise.

Isoscapes resolve species-specific spatial patterns in plant-plant interactions in an invaded Mediterranean dune ecosystem.
Tree physiology (2016)
Christine Hellmann, Katherine G Rascher, Jens Oldeland, Christiane Werner

Environmental heterogeneity and plant-plant interactions are key factors shaping plant communities. However, the spatial dimension of plant-plant interactions has seldom been addressed in field studies. This is at least partially rooted in a lack of methods that can accurately resolve functional processes in a spatially explicit manner. Isoscapes, that is, spatially explicit representations of stable isotope data, provide a versatile means to trace functional changes on spatial scales, for example, related to N-cycling (foliar δ(15)N) and water use efficiency (WUEi, foliar δ(13)C). In a case study in a nutrient-depleted Mediterranean dune ecosystem, we analysed the spatial impact of the invasive N2-fixing Acacia longifolia on three native species of different functional types using δ(15)N and δ(13)C isoscapes and spatial autocorrelation analyses. Isoscapes revealed strong spatial patterns in δ(15)N and δ(13)C with pronounced species-specific differences, demonstrating distinct spatial ranges of plant-plant interactions. A coniferous tree and an ericaceous dwarf shrub showed significant enrichment in δ(15)N within a range of 5-8 m surrounding the canopy of A. longifolia, indicating input of N originating from symbiotic N2-fixation by the invader. In the dwarf shrub, which was most responsive to invader influence, enrichment in δ(13)C additionally demonstrated spatially explicit changes to WUEi, while a native N2-fixer was unresponsive to the presence of the invader. Furthermore, δ(15)N and δ(13)C isoscapes yielded different patterns, indicating that plant-plant interactions can have distinct spatial distributions and ranges based on the process measured. Additionally, the magnitude of the effect differed between field situations with high and low invasion pressure. This study highlights that the spatial scale must be accounted for when assessing the effects and outcome of species interactions. Functional tracers such as stable isotopes enable us to quantify spatial ranges of plant-plant interactions, providing empirical data that can help to better understand and predict complex species interactions in multifaceted natural environments.
Tags: carbon , nitrogen , soil , elem

Terrestrial biome distribution in the Late Neogene inferred from a black carbon record in the northeastern equatorial Pacific
Scientific Reports (2016)
Donghyun Kim, Yong Il Lee, Kiseong Hyeong, Chan Min Yoo, T. E. Cerling, T. E. Cerling, E. J. Edwards, C. P. Osborne, C. A. Strömberg, S. A. Smith, C. A. Strömberg, F. A. McInerney, W. D. Tidwell, E. M. V. Nambudiri, S. Singh, A. Awasthi, B. Parkash, S. Ku

The appearance and expansion of C4 plants in the Late Cenozoic was a dramatic example of terrestrial ecological change. The fire hypothesis, which suggests fire as a major cause of C4 grassland is gaining support, yet a more detailed relationship between fire and vegetation-type change remains unresolved. We report the content and stable carbon isotope record of black carbon (BC) in a sediment core retrieved from the northeastern equatorial Pacific that covers the past 14.3 million years. The content record of BC suggests the development process of a flammable ecosystem. The stable carbon isotope record of BC reveals the existence of the Late Miocene C4 expansion, the ‘C4 maximum period of burned biomass’ during the Pliocene to Early Pleistocene, and the collapse of the C4 in the Late Pleistocene. Records showing the initial expansion of C4 plants after large fire support the role of fire as a destructive agent of C3-dominated forest, yet the weak relationships between fire and vegetation after initial expansion suggest that environmental advantages for C4 plants were necessary to maintain the development of C4 plants during the late Neogene. Among the various environmental factors, aridity is likely most influential in C4 expansion.
Tags: carbon , soil , geol , elem

Do forests represent a long-term source of contaminated particulate matter in the Fukushima Prefecture?
Journal of Environmental Management (2016)
J. Patrick Laceby, Sylvain Huon, Yuichi Onda, Veronique Vaury, Olivier Evrard

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident resulted in radiocesium fallout contaminating coastal catchments of the Fukushima Prefecture. As the decontamination effort progresses, the potential downstream migration of radiocesium contaminated particulate matter from forests, which cover over 65% of the most contaminated region, requires investigation. Carbon and nitrogen elemental concentrations and stable isotope ratios are thus used to model the relative contributions of forest, cultivated and subsoil sources to deposited particulate matter in three contaminated coastal catchments. Samples were taken from the main identified sources: cultivated (n = 28), forest (n = 46), and subsoils (n = 25). Deposited particulate matter (n = 82) was sampled during four fieldwork campaigns from November 2012 to November 2014. A distribution modelling approach quantified relative source contributions with multiple combinations of element parameters (carbon only, nitrogen only, and four parameters) for two particle size fractions (<63 μm and <2 mm). Although there was significant particle size enrichment for the particulate matter parameters, these differences only resulted in a 6% (SD 3%) mean difference in relative source contributions. Further, the three different modelling approaches only resulted in a 4% (SD 3%) difference between relative source contributions. For each particulate matter sample, six models (i.e. <63 μm and <2 mm from the three modelling approaches) were used to incorporate a broader definition of potential uncertainty into model results. Forest sources were modelled to contribute 17% (SD 10%) of particulate matter indicating they present a long term potential source of radiocesium contaminated material in fallout impacted catchments. Subsoils contributed 45% (SD 26%) of particulate matter and cultivated sources contributed 38% (SD 19%). The reservoir of radiocesium in forested landscapes in the Fukushima region represents a potential long-term source of particulate contaminated matter that will require diligent management for the foreseeable future.
Tags: carbon , nitrogen , soil , poll , elem

Forensic Comparison of Soil Samples
Jisook Min, Kiwook Kim, Sangcheol Heo, Yurim Jang

As a preliminary experiment to test the discriminating ability of forensic soil analysis techniques and obtain area-specific information, soil samples were collected from eight areas near the eastern branch of the National Forensic Service (NFS) located in Gangwondo, an eastern province of South Korea. The soil samples were collected from five spots within each sample area using a small-scale (1 m2) soil sampling technique; for each of these five spots, two samples were collected from two places in each spot, (i) one from the surface and (ii) another from 30 cm below the surface. For each sample, the color of the sample with particle size in the range 53–500 μm and the major constituents were determined using a spectrophotometer and X-ray fluorescence spectrometer (XRF), respectively. The carbon content and carbon isotope ratio of the part of the sample of particle size below 53 μm were measured using an element analyzer-isotope ratio mass spectrometer (EA-IRMS). The canonical discriminant and XRF analyses showed an excellent color discriminating ability of 87.5 % and 88.8 %, respectively, with respect to the major constituents. The EA-IRMS results showed that the soils obtained from a 30-cm depth below the surface were generally more enriched in δ13C (0/00) than the surface soils, and that the surface soils contained a higher carbon amount (%). The canonical discriminant analysis confirmed 100 % discriminating ability when all three soil characteristics (i.e., color, composition, and content) were used in the analysis. Out of the two functions obtained from the analysis, Function 1 exhibited greater potential for explaining the SiO2, Fe2O3, and TiO2; thus, Area 6 and 7 could be more easily differentiated than the other areas using this function. Function 2 exhibited greater potential for explaining color factor b* (δ13C and C content), and could more efficiently differentiate Area 2 and 5. However, different results were obtained within the same area based on the soil depth. Therefore, when performing a comparative sampling analysis in forensic science, due care should be taken to prevent the mixing of adjacent soils from various depths. Better results can be achieved by collecting soil samples from different spots within the same area.

Linking rhizospheric CH4 oxidation and net CH4 emissions in an arctic wetland based on 13CH4 labeling of mesocosms
Plant and Soil (2016)
Cecilie Skov Nielsen, Anders Michelsen, Per Ambus, T. K. K. Chamindu Deepagoda, Bo Elberling

Aims Poorly drained arctic ecosystems are potential large emitters of methane (CH4) due to their high soil organic carbon content and low oxygen availability. In wetlands, aerenchymatous plants transport CH4 from the soil to the atmosphere, but concurrently transport O2 to the rhizosphere, which may lead to oxidation of CH4. The importance of the latter process is largely unknown for arctic plant species and ecosystems. Here, we aim to quantify the subsurface oxidation of CH4 in a waterlogged arctic ecosystem dominated by Carex aquatilis ssp. stans and Eriophorum angustifolium, and evaluate the overall effect of these plants on the CH4 budget. Methods A mesocosms study was established based on the upper 20 cm of an organic soil profile with intact plants retrieved from a peatland in West Greenland (69°N). We measured dissolved concentrations and emissions of 13CO2 and 13CH4 from mesocosms during three weeks after addition of 13C-enriched CH4 below the mesocosm. Results Most of the recovered 13C label (>98 %) escaped the ecosystem as CH4, while less than 2 % was oxidized to 13CO2. Conclusions It is concluded that aerenchymatous plants control the overall CH4 emissions but, as a transport system for oxygen, are too inefficient to markedly reduce CH4 emissions.

Sensitivity of soil carbon fractions and their specific stabilization mechanisms to extreme soil warming in a subarctic grassland
Global Change Biology (2016)
Christopher Poeplau, Thomas Kätterer, Niki I. W. Leblans, Bjarni D. Sigurdsson

Terrestrial carbon cycle feedbacks to global warming are major uncertainties in climate models. For in-depth understanding of changes in soil organic carbon (SOC) after soil warming, long-term responses of SOC stabilization mechanisms such as aggregation, organo-mineral interactions and chemical recalcitrance need to be addressed. This study investigated the effect of 6 years of geothermal soil warming on different SOC fractions in an unmanaged grassland in Iceland. Along an extreme warming gradient of +0 to ~+40 °C, we isolated five fractions of SOC that varied conceptually in turnover rate from active to passive in the following order: particulate organic matter (POM), dissolved organic carbon (DOC), SOC in sand and stable aggregates (SA), SOC in silt and clay (SC-rSOC) and resistant SOC (rSOC). Soil warming of 0.6 °C increased bulk SOC by 22 ± 43% (0–10 cm soil layer) and 27 ± 54% (20–30 cm), while further warming led to exponential SOC depletion of up to 79 ± 14% (0–10 cm) and 74 ± 8% (20–30) in the most warmed plots (~+40 °C). Only the SA fraction was more sensitive than the bulk soil, with 93 ± 6% (0–10 cm) and 86 ± 13% (20–30 cm) SOC losses and the highest relative enrichment in 13C as an indicator for the degree of decomposition (+1.6 ± 1.5‰ in 0–10 cm and +1.3 ± 0.8‰ in 20–30 cm). The SA fraction mass also declined along the warming gradient, while the SC fraction mass increased. This was explained by deactivation of aggregate-binding mechanisms. There was no difference between the responses of SC-rSOC (slow-cycling) and rSOC (passive) to warming, and 13C enrichment in rSOC was equal to that in bulk soil. We concluded that the sensitivity of SOC to warming was not a function of age or chemical recalcitrance, but triggered by changes in biophysical stabilization mechanisms, such as aggregation.
Tags: carbon , soil , clim , elem

Short-term and seasonal soil nitrogen dynamics and recovery by bermudagrass irrigated with 15N labelled swine lagoon effluent
Plant and Soil (2016)
Jiuquan Zhang, Jac J. Varco, Ardeshir Adeli

Aim Rapid and efficient utilization of swine (Sus scrofa domestucus) lagoon effluent nitrogen (N) by crops is necessary to minimize N losses and environmental pollution. The objective of this study was to determine the dynamics and fate of effluent N applied to bermudagrass (Cynodon dactylon (L.) pers.) using 15N tracer technology as influenced by irrigation date. Methods Anaerobic swine lagoon effluent was labeled with enriched (15NH4)2SO4 and applied to an acid silty clay soil. Microplots (1 × 1 m) were established for each irrigation event (main plots) and soil was sampled and bermudagrass was harvested on day 0, 1, 2, 3, 7, and 14 (subplots) following irrigation. Soil sampling coincided with harvests to monitor effluent derived 15N transformations. Results Application in July when bermudagrass growth was most active resulted in a plant 15N recovery of 59 %. Crop recoveries for June and September irrigation events were equal at 33 %. Nitrification of effluent NH4+-N occurred rapidly within 24 h to 48 h following application. Rapid losses of effluent 15N within 1 d suggest a high probability for NH3 volatilization, while losses following rainfall and high soil moisture content in June infer denitrification was most active. Lack of 15N detection in the 30 to 60 cm soil depth indicated a low probability of leaching losses, while unaccounted for 15N was 45, 5, and 30 % for irrigation events in June, July, and September, respectively. Conclusion Bermudagrass recovery, dynamics and fate of effluent N applied to an acid soil varied with environmental conditions affecting crop growth and N uptake and soil N transformations.
Tags: nitrogen , soil , poll , elem