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.

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172 results:

Balancing the Nitrogen Derived from Sewage Effluent and Fertilizers Applied with Drip Irrigation
Water, Air, & Soil Pollution (2017)
Lijun Guo, Jiusheng Li, Yanfeng Li, Di Xu

Balancing the nitrogen derived from sewage effluent and fertilizers is essential for efficiently utilizing the nitrogen and minimizing the environmental degradations when applying sewage effluent. Pot experiments of maize (Zea mays L.) under drip irrigation were performed using 15N labeled urea to quantify the nitrogen balances of sewage effluent and fertilizers. Field experiments were conducted to confirm the findings of pot experiments. Four nitrogen rates ranging from 0 to 2.64 g/pot (0–210 kg/ha equivalently) for pot experiments and from 0 to 180 kg/ha for field experiments were established applying either secondary sewage effluent (SW) or groundwater (GW). Both pot and field experiments revealed that SW irrigation boosted nitrogen uptake and yield of maize compared to GW irrigation. However, the sewage-derived effects decreased with increasing nitrogen rates. SW irrigation could facilitate the uptake of 15N labeled urea relative to GW irrigation. Nonetheless, the nitrogen containing in effluent possibly had lower uptake effectiveness than the fertilizer urea for maize, suggesting greater potential for nitrogen losses resulting from effluent nitrogen compared to urea nitrogen. The percentage utilization of effluent nitrogen declined from 43 to 34% in 2014 and 48 to 32% in 2015 as nitrogen rates increased from 0 to 2.64 g/pot. Besides, the percentages utilization of total nitrogen (including effluent and fertilizers) under SW irrigation increased from 43 to 55% in 2014 and from 48 to 55% in 2015 when the rates increased from 0 to 1.76 g/pot, and subsequently decreased to 48% in 2014 and 44% in 2015 at the rate of 2.64 g/pot. This result was strengthened by the pattern of nitrogen recovery efficiency observed in the field experiments. Overall results of pot and field experiments recommended an optimal rate of 120 kg/ha for maize under drip irrigation applying SW to maximize nitrogen use efficiency and achieve an acceptably high yield.
Tags: nitrogen , soil , poll , elem

Aged acidic biochar increases nitrogen retention and decreases ammonia volatilization in alkaline bauxite residue sand
Ecological Engineering (2017)
M. Esfandbod, I.R. Phillips, B. Miller, M. Rezaei Rashti, Z.M. Lan, P. Srivastava, B. Singh, C.R. Chen

Bauxite residue sand (BRS) is the primary growth medium for rehabilitating Alcoa’s residue storage areas in south-west Western Australia. Successful revegetation of highly alkaline BRS can be hindered by its low nitrogen (N) use efficiency. Biochar, a carbon (C)-rich material, has been suggested to have the potential to improve water and nutrient retention in soil. However, little is still known about the effect of biochar amendment on N use efficiency in the alkaline BRS environment. This incubation study aimed to evaluate the impact of biochars with different characteristics on N retention and dynamics in BRS. The BRS (pH 9.5 after being pre-treated with 1% gypsum and leached with water) was amended with the acidic biochar (pH 3.86; AC, from wild fire) and alkaline biochars (pH 9.58–10.8; greenwaste, GW; Jarrah, JL; mallee, ML) at a rate of 10%(w/w). The N loss via NH3 volatilization was much lower from the AC treatment (24% of di-ammonia phosphate (DAP)-N added) than the alkaline biochars treatments (76–80% of the DAP-N added). The AC treatment can retain about 73% of N added to BRS, compared with <25% in alkaline biochar treatments. This can be attributed to the acidic nature and the greater NH4+-N sorption capacity arising from the presence of a high density of the oxygen-containing functional groups on the surface of acidic biochar as revealed by the FTIR spectroscopy. These results imply acidic biochar can be used as an effective amendment for increasing N use efficiency by plants growing in alkaline BRS.

Interactive effects of irrigation and nitrogen fertilizer on yield, nitrogen uptake, and recovery of two successive Chinese cabbage crops as assessed using 15N isotope
Scientia Horticulturae (2017)
Na Gao, Yu Liu, Hanqing Wu, Peng Zhang, Na Yu, Yuling Zhang, Hongtao Zou, Qingfeng Fan, Yulong Zhang

The aim of this study was to evaluate the interactive effect of irrigation and nitrogen fertilization on yield, nitrogen (N) uptake, and recovery of two successive Chinese cabbage (Brassica campestris L.) crops and to assess the residue effects of N on the 2nd season crop under greenhouse conditions. 15N-labeled urea was administered to pot-grown Chinese cabbage in the 1st season. The cabbage plants were subjected to three irrigation treatments, 60 (W1), 75 (W2), and 90% (W3) of the soil field capacity, and four N rates, 0 (N0), 0.1 (N1), 0.2 (N2), and 0.3 (N3) g N kg−1 soil. The highest yield, dry matter (DM), N uptake, %Ndff (the percentage of N derived from fertilizer), N recovery rate, and the lowest loss rate were recorded in W3 treatment. N1 treatment had the maximum values for yield, DM, N recovery rate, and the lowest N loss rate. The highest %Ndff was recorded in N2 treatment, with no significant difference observed compared to N3 treatment in the 1st season. In addition, no significant difference among the N rates was observed in the 2nd season. Besides, roots exhibited higher %Ndff values than leaves. Only 5.30–23.00% fertilizer was absorbed by the Chinese cabbage, 56.22–71.29% remained in the soil, and 13.17–37.10% was presumably lost in the 1st season. The recovery rate in the 2nd season was approximately 3.51–17.40%. Therefore, in terms of yield, nitrogen recovery, and environmental impact, W3N1 treatment was recommended as the best combination for Chinese cabbage production and this treatment showed a productive potential in the 2nd season, as well.

Fate of 13C labelled root and shoot residues in soil and anecic earthworm casts: A mesocosm experiment
Geoderma (2017)
A. Vidal, K. Quenea, M. Alexis, T.T. Nguyen Tu, J. Mathieu, V. Vaury, S. Derenne

Earthworms are known to have a major impact on organic matter dynamics in soils. The precise dynamics of carbon incorporation and/or decomposition in soil under the influence of earthworms still need to be investigated. In a mesocosm experiment, the fate of Ryegrass root and shoot litter was monitored in the soil, in the presence and absence of anecic earthworms Lumbricus terrestris L. Residues were13C labelled and deposited onto the soil surface. Incorporation of 13C in surface casts and in the 0–20 and 40–60cm soil layers was monitored 1, 2, 4, 8, 24 and 54weeks after adding labelled litter. Organic carbon content and δ13C values were obtained for all samples, allowing the determination of the percentage of carbon derived from labelled litter (Clab). Roots and shoots were incorporated in the 0–20cm soil layer during the year of experiment, Clab reaching 11.4% of the soil organic carbon after 54weeks. On the contrary, no significant contribution from labelled residues was observed in the 40–60cm layer. Roots decomposed at a slower rate compared to shoots. Litter incorporation was observed in casts from the very first weeks of experiment (Clab from 34.8 to 51.4% after 2weeks). In the soil, a significant effect of earthworms on the Clab was detected after 24weeks. Earthworms accelerated root and shoot decomposition in the soil. They also enhanced, in the presence of shoot residues, the decomposition of the organic matter originally present in the soil. However, after one year, earthworms smoothed the difference between residue types in casts and to a lesser extent in soil, revealing their capacity to enhance the decomposition of both roots and shoots.

How do plants share water sources in a rubber-tea agroforestry system during the pronounced dry season?
Agriculture, Ecosystems & Environment (2017)
Junen Wu, Wenjie Liu, Chunfeng Chen

Extensive cultivation of rubber plantations in Xishuangbanna in southwest (SW) China has resulted in negative hydrological consequences, particularly drought, during the pronounced dry season. Although rubber-tea agroforestry is regarded as the most successful agroforestry system for improving the sustainability of rubber agriculture and environmental conservation, plant water use patterns and their related interactions have rarely been examined in such systems. How do coexisting plants compete and share water under water deficit remains to be explored. Therefore, we used stable isotope (δD and δ18O) methods to determine the spatial water use patterns of both rubber trees and tea trees in a rubber-tea agroforestry system during the pronounced dry season and explored the movement of soil water in this system. The results of the MixSIAR model (a Bayesian mixing model) indicated that tea trees primarily uptake water from the 5–30cm soil layer (40.3%, on average), and rubber trees primarily uptake water from the 30–80cm soil layer (35.3%, on average) and absorb soil water evenly along slopes during the dry season. These results suggest that rubber trees and tea trees have different but complementary water use patterns. We also observed that the soil of the uphill and downhill tea rows contained much more water; however, the collaborative hydraulic redistribution in the studied agroforestry system could redistribute the soil water along the slope and below the ground well. Therefore, soil drought on terraces can be alleviated during the dry season. Our results confirmed that the tea tree is an appropriate crop for intercropping with rubber trees when considering water sharing and water management and provided a practical analysis of water use benefits from a rubber agroforestry system during drought stress.

Nitrification inhibitors mitigate N2O emissions more effectively under straw-induced conditions favoring denitrification
Soil Biology and Biochemistry (2017)
Di Wu, Mehmet Senbayram, Reinhard Well, Nicolas Brüggemann, Birgit Pfeiffer, Nadine Loick, Barbara Stempfhuber, Klaus Dittert, Roland Bol

The application of reactive nitrogen (N) in the form of synthetic/organic fertilizers plays a central role in supporting a larger human population, but also contributes to global warming through the emission of nitrous oxide (N2O). The use of nitrification inhibitors (NIs) has repeatedly been shown to minimize N2O emissions; however, their effectiveness in reducing N2O emissions varies greatly under different environmental conditions. A better understanding of how and to what extent NIs can mitigate fertilizer-related soil-borne N2O emissions under a range of different conditions is required. In the present study, we carried out a soil incubation experiment in a fully automated continuous-flow incubation system under conditions favoring either nitrification- or denitrification-derived N2O emissions. Additionally, the abundance of AOB amoA, and AOA amoA genes was quantified and N2O isotopic signatures were analyzed. We mixed a common NI (PIADIN®) with mineral fertilizer (ammonium sulfate) and examined the N2O mitigation potential of the NI in a fertilized sandy soil (low denitrification potential) and a sandy soil mixed with wheat straw (high denitrification potential) at 70% water holding capacity (WHC). In non-NI treatments, the addition of straw led to a drastic increase of CO2 and N2O emissions compared to the non-straw-amended soils, suggesting stimulated microbial activity and higher denitrification rate. The NI reduced N2O emissions in the straw-amended treatment by 41%, whereas in the treatment without straw this was only 17%. With the combination of N2O isotopic signatures and functional gene abundances, fungal denitrification was considered to be the major process contributing to the higher N2O fluxes specifically in straw-amended soils. Overall, our study indicated that NI can be used as an effective method for mitigating N2O emissions in cropland specifically when the denitrification potential is high, e.g. in moist N-fertilized and straw-amended soils.

Unique photosynthetic phenotypes in Portulaca (Portulacaceae): C3-C4 intermediates and NAD-ME C4 species with Pilosoid-type Kranz anatomy.
Journal of experimental botany (2016)
Elena V Voznesenskaya, Nuria K Koteyeva, Gerald E Edwards, Gilberto Ocampo

Portulacaceae is a family that has considerable diversity in photosynthetic phenotypes. It is one of 19 families of terrestrial plants where species having C4 photosynthesis have been found. Most species in Portulaca are in the alternate-leaved (AL) lineage, which includes one clade (Cryptopetala) with taxa lacking C4 photosynthesis and three clades having C4 species (Oleracea, Umbraticola and Pilosa). All three species in the Cryptopetala clade lack Kranz anatomy, the leaves have C3-like carbon isotope composition and they have low levels of C4 cycle enzymes. Anatomical, biochemical and physiological analyses show they are all C3-C4 intermediates. They have intermediate CO2 compensation points, enrichment of organelles in the centripetal position in bundle sheath (BS) cells, with selective localization of glycine decarboxylase in BS mitochondria. In the three C4 clades there are differences in Kranz anatomy types and form of malic enzyme (ME) reported to function in C4 (NAD-ME versus NADP-ME): Oleracea (Atriplicoid, NAD-ME), Umbraticola (Atriplicoid, NADP-ME) and Pilosa (Pilosoid, NADP-ME). Structural and biochemical analyses were performed on Pilosa clade representatives having Pilosoid-type leaf anatomy with Kranz tissue enclosing individual peripheral vascular bundles and water storage in the center of the leaf. In this clade, all species except P. elatior are NADP-ME-type C4 species with grana-deficient BS chloroplasts and grana-enriched M chloroplasts. Surprisingly, P. elatior has BS chloroplasts enriched in grana and NAD-ME-type photosynthesis. The results suggest photosynthetic phenotypes were probably derived from an ancestor with NADP-ME-type C4, with two independent switches to NAD-ME type.
Tags: carbon , nitrogen , soil , elem

Marginal Calluna populations are more resistant to climate change, but not under high-nitrogen loads
Plant Ecology (2016)
Maren Meyer-Grünefeldt, Kristina Belz, Leonor Calvo, Elena Marcos, Goddert von Oheimb, Werner Härdtle

The dominant plant species of European heathlands Calluna vulgaris is considered vulnerable to drought and enhanced nitrogen (N) loads. However, impacts may vary across the distribution range of Calluna heathlands. We tested the hypothesis that Calluna of southern and eastern marginal populations (MP) are more resistant to drought events than plants of central populations (CP), and that this is mainly due to trait differences such as biomass allocation patterns. Furthermore, we hypothesised that N fertilisation can offset differences in drought susceptibility between CP and MP. We conducted a full-factorial 2-year greenhouse experiment with Calluna plants of CP and MP and quantified growth responses in terms of biomass production, allocation and tissue δ13C signatures. Biomass production, shoot–root ratios and tissue δ13C values of 1-year-old plants were higher for CP than for MP, indicating a higher drought susceptibility of CP. These trait differences were not observed for 2-year-old plants. N fertilisation increased shoot–root ratios of 1- and 2-year-old plants and across populations due to a stimulation of the aboveground biomass allocation. As a consequence, population-related differences in drought susceptibility were offset for N-fertilised plants. We concluded that Calluna plants originating from different populations developed adaptive traits to local climates, which determined their drought sensitivity. However, the higher drought resistance of MP can be attenuated by an N-induced increase in shoot–root ratios. This suggests that analyses on plant growth responses to global change should include multi-factor approaches with a focus on different populations throughout a species’ distribution range.
Tags: carbon , nitrogen , soil , ecol , clim , elem

Establishment of the soil water potential threshold to trigger irrigation of Kyoho grapevines based on berry expansion, photosynthetic rate and photosynthetic product allocation
Australian Journal of Grape and Wine Research (2016)
Y. Lou, Y. Miao, Z. Wang, L. Wang, J. Li, C. Zhang, W. Xu, M. Inoue, S. Wang

rrigation is an important management practice in viticulture. Irrigation scheduling established by previous researchers was based mainly on the irrigation level for optimal berry composition and size at harvest. Because eventual berry size and composition depend on the accumulation of daily growth, a more precise study must be implemented to establish the soil water potential (ψsoil) threshold to trigger irrigation at different development stages of the berry.
Tags: carbon , food , soil , elem

Streptomyces thermoautotrophicus does not fix nitrogen
Scientific Reports (2016)
Drew MacKellar, Lucas Lieber, Jeffrey S. Norman, Anthony Bolger, Cory Tobin, James W. Murray, Mehtap Oksaksin, Roger L. Chang, Tyler J. Ford, Peter Q. Nguyen, Jimmy Woodward, Hugo R. Permingeat, Neel S. Joshi, Pamela A. Silver, Björn Usadel, Alfred W. Rut

Streptomyces thermoautotrophicus UBT1 has been described as a moderately thermophilic chemolithoautotroph with a novel nitrogenase enzyme that is oxygen-insensitive. We have cultured the UBT1 strain, and have isolated two new strains (H1 and P1-2) of very similar phenotypic and genetic characters. These strains show minimal growth on ammonium-free media, and fail to incorporate isotopically labeled N2 gas into biomass in multiple independent assays. The sdn genes previously published as the putative nitrogenase of S. thermoautotrophicus have little similarity to anything found in draft genome sequences, published here, for strains H1 and UBT1, but share >99% nucleotide identity with genes from Hydrogenibacillus schlegelii, a draft genome for which is also presented here. H. schlegelii similarly lacks nitrogenase genes and is a non-diazotroph. We propose reclassification of the species containing strains UBT1, H1, and P1-2 as a non-Streptomycete, non-diazotrophic, facultative chemolithoautotroph and conclude that the existence of the previously proposed oxygen-tolerant nitrogenase is extremely unlikely.