The DOI matches its Crossref record; 26 of the 26 references it cites were found in a registry or an index; 1 of the 27 sources its claims cite were checked for support.
Biochars and the plant-soil interface
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Written from the paper’s full text.
TL;DR
This editorial argues that biochar effects on crop growth remain unpredictable because biochar and soil properties vary widely and mechanistic understanding of the biochar-soil-plant interface is limited. It introduces a special issue showing that roots and microorganisms respond to biochar particles and pore-scale environments, with pH and mycorrhizal interactions as key examples.
Key findings
- Biochar effects on crop yield remain inconsistent, sometimes increasing and sometimes decreasing yield, due to widely varying biochar properties, variable soil properties, and differing environmental plant requirements.
- The paper emphasizes three-way biochar-soil-root interactions and spatial heterogeneity: biochar particles may have pH 9.2, surrounding soil pH 4.2, and a 2 % w/w biochar mixture pH 5.9, so the average pH may not reflect the microenvironment roots actually experience.
- Special-issue findings include significantly increased maize root systems after 4 Mg ha⁻¹ maize-cob biochar on deeply weathered Zambian soils, with increased root-shoot ratio; decreased Arabidopsis root hair abundance with alkaline biochar extracts regardless of inorganic P addition; and greater mycorrhizal abundance within biochar than in surrounding soil, with biochar-induced mycorrhizae increasing P uptake from soil rather than from biochar.
- Responses were often non-linear: plant-water relations or disease suppression improved at intermediate biochar rates of 0.5–1.5 % w/w and decreased beyond that; pH correction was important for increasing biological N fixation and influencing heavy metal uptake by plants.
Methods
- This is an editorial/special-issue introduction that synthesizes and discusses included studies rather than presenting primary experimental research.
- No primary data collection, sample, or statistical analysis is described; reported examples and numbers are drawn from cited special-issue papers and prior literature.
- The paper calls for spatially explicit investigation of the biochar-soil-plant interface at scales relevant to root and microbial interactions.
Limitations
- Stated in the paper: there is a distinct lack of mechanistic insight into how properties shared by many biochars affect plant growth, and causal relationships are particularly difficult to discern.
- Stated in the paper: quantitative evidence on whether more or fewer roots and microorganisms grow in biochar particles is virtually non-existent, and reasons for preferential growth near or in biochar pores remain unclear.
- Evident from the text: as an editorial/special-issue introduction, it does not present new primary data or a systematic review methodology, so its conclusions rely on selected cited studies and conceptual synthesis.
Model-written summary. Check it against the paper before relying on it.
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Claims the paper makes
19 Not checked yet · 19 Own interpretation · 1 Partly supported · accuracy not yet measured
None of the sources cited for this claim have been checked yet.
In the paper
“To a large extent, this is a result of widely varying biochar properties (Enders et al. 2012;Schimmelpfennig and Glaser 2012) as well as of variable soil properties and environmental plant requirements.”
§ Biochars and the plant-soil interface > Introduction
What the sources say
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For example, biochars may affect growth of roots or mycorrhizae in the soil and thereby the extent to which the plant takes up water or nutrients from the soil surrounding the biochar particles that is not directly influenced by the added biochar.”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Further, the roots, root hairs, and mycorrhizal hyphae that grow in the pores or on the surfaces of biochar particles may be exposed to a chemical and physical and biological environment that is very different from the soil environment surrounding it.”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Roots can explore biochar pores directly.
- Rests on an assumption: Biochars are particulate in nature.
In the paper
“Even though roots and microorganisms growing on and in biochar particles have been visualized for some time (Ogawa 1994), quantitative evidence of whether there are more or less roots and microorganisms growing in biochar particles is virtually non-existent (Lehmann et al. 2011).”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
What the sources say
- Not checked yetcites Lehmann et al. 2011 source
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“Even though our knowledge has considerably advanced, the effects of biochars on crop growth still appear unpredictable, with in some instances increasing while in others decreasing yield responses (Liu et al. 2013;Jeffery et al. 2015a).”
§ Biochars and the plant-soil interface > Introduction
What the sources say
- Not checked yetcites Liu et al. 2013 source
- Not checked yetcites Jeffery et al. 2015a
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It also illustrates the large environmental changes that roots (and by extension also microorganisms) may be exposed to in the vicinity of biochar particles; these changes are not limited to pH but may also include changes in electric conductivity (and thereby osmotic potential), concentrations of specific salts (including nutrients and heavy metals) or organic compounds and many other factors.”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In addition, biochars may influence how plants interact with the soil surrounding the biochar particles (Fig. 1b, hashed arrows).”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These can be bidirectional and encompass many different effects; these may include but are not limited to changes in pH, metabolizable organic substances, signaling molecules, plant nutrients and toxins, water, and soil biota (Fig. 1b, solid arrows).”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“This observation differed from those obtained by pot studies, where mostly reductions in root-shoot ratios were found (Lehmann et al. 2011).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Lehmann et al. 2011 source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Causal relationships appear to be particularly difficult to discern in such cases.”
§ Biochars and the plant-soil interface > b) (a)
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: unclear — It is unclear whether it could be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Therefore, the mechanisms of interactions still remain a challenge to predict the effects of different biochars.”
§ Biochars and the plant-soil interface > b) (a)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“Possibly only observations of specific organisms and their abundance generates mechanistic insights into biochar effects on plant-microbe interactions, as shown here with pathogen responses (Jaiswal et al. 2015;Mehari et al. 2015).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Jaiswal et al. 2015
- Not checked yetcites Mehari et al. 2015
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“An experiment with Arabidopsis seedlings (Graber et al. 2015) revealed that root hair abundance decreased in the presence of alkaline extracts of the studied biochar, regardless of whether or not inorganic P was added.”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Graber et al. 2015
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Interestingly, adding a greater amount of biochars often did not lead to a linear increase in plant responses.”
§ Biochars and the plant-soil interface > b) (a)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Relating the effects of biochars on plant growth to observations in the bulk soil blurs causal relationships.”
§ Biochars and the plant-soil interface > The way forward
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: unclear — It is unclear whether it could be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Soil pH effects were also a major contributor to the way in which biochars influenced heavy metal uptake by plants (Rees et al. 2015).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Rees et al. 2015
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“The authors could not resolve whether the added biochar increased the root system which enabled more nutrients to be taken up to increase crop growth; or whether the added biochar increased nutrient availability in the soil directly which improved both below and above ground crop growth.”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Abiven et al. 2015
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Indications for specific effects of organic substances found in biochars on pathogens could not be substantiated (Jaiswal et al. 2015).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Jaiswal et al. 2015
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“The size of maize root systems significantly increased after 4 Mg ha -1 of biochar (produced from maize cobs) were added to various deeply weathered soils in Zambia (Abiven et al. 2015).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Abiven et al. 2015
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Fig. 2 Illustration of the strong pH gradient that plant roots may need to overcome, depending on their proximity to a biochar particle.”
§ Biochars and the plant-soil interface > The way forward
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 13
- Probably not a substantial claim. 8
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Some biochars may increase crop yield, whereas others may decrease yield for reasons that are readily explainable using known responses of crops to for example altered pH or salt contents (Van Zwieten et al. 2010;Rajkovich et al. 2012) and short-term N limitation in N deficient soil (Clough et al. 2013).”
§ Biochars and the plant-soil interface > Introduction
What the sources say
- Not checked yetcites Van Zwieten et al. 2010 source
- Not checked yetcites Rajkovich et al. 2012 source
- Partly supportedcites Clough et al. 2013 sourceExperimental — accuracy not yet measured
Section 5 reports that some biochars can immobilise soil nitrogen in the short term, supporting the proposed nitrogen-limitation mechanism. Section 3 says crop-yield responses vary, but the passages do not establish that short-term nitrogen limitation decreases yield specifically in nitrogen-deficient soils. The pH and salt explanations are attached to the other citations in the citing sentence. (LLM, conf=0.82)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This interaction may also occur in reverse when alkaline biochars increase the pH of an acid soil; this may in turn enhance photosynthesis and could alter the way plants explore the pores of biochar particles.”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“However, because roots can explore biochar pores directly and the biochars are particulate in nature, the spatial arrangement of the biochar-soil-plant interface warrants recognition.”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
plain- Asserted: passes — The authors put it forward as true.
- Checkable: fails — It may be too vague to check against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may be too vague to check against evidence.
- Rests on an assumption: Roots can explore biochar pores directly.
- Rests on an assumption: Biochars are particulate in nature.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In most conceptual models (and most experiments), the plant is thought to interact with a mixture of biochar and soil (Fig. 1a), when in fact there could in many instances be important three-way interactions between biochar particles, soil, and plant roots (Fig. 1b).”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“However, this average pH does not reflect the pH environment the roots are actually exposed to, which could be higher or lower than the composite pH and depend on the proximity to the biochar particles (Fig. 2).”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“For example, the pH of the biochar particles (9.2) may be much higher than that of the surrounding soil (4.2) and the mixture of 2 % w/w biochar may show an intermediate pH (5.9) (Fig. 2).”
§ Biochars and the plant-soil interface > The biochar-soil-plant interface
What the sources say
- Not checked yetcites Van Zwieten et al. 2010 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The need for recognizing the wide variety of biochars with often diametrically opposing characteristics in terms of physical and chemical properties has been amply stated (Novak et al. 2009).”
§ Biochars and the plant-soil interface > The way forward
What the sources say
- Not checked yetcites Novak et al. 2009
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
None of the sources cited for this claim have been checked yet.
In the paper
“Rather, plant-water relations (Haider et al. 2015) or disease suppression (Jaiswal et al. 2015) improved by what these studies considered to be intermediate biochar application rates of 0.5-1.5 % w/w and decreased beyond that.”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Haider et al. 2015
- Not checked yetcites Jaiswal et al. 2015
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The authors were not only able to show that the root architecture was markedly influenced by the biochar additions but also that the root-shoot ratio increased.”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Abiven et al. 2015
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The importance of pH correction in overall effects of biochars on plant performance is often observed and was also important for increasing biological N fixation in a field setting (Van Zwieten et al. 2015).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Van Zwieten et al. 2015
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The reasons for such a preference of microorganisms or roots to grow near biochar particles or even in their pores remain unclear: are these related to nutrients, water or pH (which was excluded as an explanation in the paper by Vanek and Lehmann 2015), and if not, what other reasons may exist?”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Vanek and Lehmann 2015
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“In the study by Wang et al. (2015), the bacterial community structure was not affected by additions of biochar in the presence of plants (that on their own showed a major imprint on community structure), and even without plants was only minimally influenced by additions of biochar.”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Wang et al. 2015
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Soil minerals interacting with biochar particles may create a different interface than exposed biochar surfaces and may warrant separate consideration.”
§ Biochars and the plant-soil interface > The way forward
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“The spatial distribution of microorganisms may be especially revealing, as with the observed greater mycorrhizal abundance within the biochar than in the surrounding soil (Vanek and Lehmann 2015) that confirms earlier visual analyses (Lehmann et al. 2011).”
§ Biochars and the plant-soil interface > b) (a)
What the sources say
- Not checked yetcites Vanek and Lehmann 2015
- Not checked yetcites Lehmann et al. 2011 source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The argument for including appropriate experimental controls in research on biochars that go beyond a no-biochar treatment has also been made (Jeffery et al. 2015b) but appropriate experimental designs are only slowly implemented.”
§ Biochars and the plant-soil interface > The way forward
What the sources say
- Not checked yetcites Jeffery et al. 2015b
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Conversely, investigating the plant-soil interface in a spatially-explicit manner by observing the contribution that areas within and around biochars make brings critical mechanisms into focus.”
§ Biochars and the plant-soil interface > The way forward
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: fails — It may be too vague to check against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may be too vague to check against evidence.
- Rests on an assumption: Emergent evidence shows that processes occur on surfaces of biochar particles and in their pore spaces that are relevant to plant growth.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In most cases, we will face significant methodological hurdles to examine for instance the pH around and in those pores of biochars that root hairs or mycorrhizal hyphae experience.”
§ Biochars and the plant-soil interface > The way forward
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It is tempting to interpret such results with an optimum response to the target effect, but it is equally possible (and given the multitude of effects of different biochars on plant-soil interactions even more likely) that cause and effect are not always discernable, with negative effects emerging at high application rates.”
§ Biochars and the plant-soil interface > b) (a)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This finding shows that root growth may be influenced independent of large changes in nutrient availability (without any observed changes in aeration, pH, moisture), possibly by plant perception of its environment.”
§ Biochars and the plant-soil interface > b) (a)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper relies on this without support.
There is a distinct lack of mechanistic insight into how properties shared by many biochars affect plant growth.
“However, we also observe a distinct lack of mechanistic insight into how properties that are shared by many biochars affect plant growth.”
The paper relies on this without support.
Biochars are known to alter many soil properties (pH, bulk density, soil aggregation, water holding capacity, nutrient availability, organic carbon availability).
“Biochars are known to alter in many instances a wide variety of soil properties, such as pH, bulk density, soil aggregation, water holding capacity, nutrient availability and organic carbon availability.”
The paper relies on this without support.
Roots can explore biochar pores directly.
“because roots can explore biochar pores directly”
The paper relies on this without support.
Biochars are particulate in nature.
“the biochars are particulate in nature”
The paper relies on this without support.
The distribution of biochar particles and thereby its influence on soil properties is not homogeneous on a fine scale.
“In addition, the distribution of biochar particles and thereby its influence on soil properties, is not homogeneous on a fine scale.”
The paper relies on this without support.
Even less is known about the reasons why roots or microorganisms would prefer the biochar spaces, beyond well-known effects of nutrients, water or metabolizable carbon as energy sources.
“Even less is known about the reasons why roots or microorganisms would prefer the biochar spaces, beyond well-known effects of nutrients, water or metabolizable carbon as energy sources.”
The paper relies on this without support.
Emergent evidence shows that processes occur on surfaces of biochar particles and in their pore spaces that are relevant to plant growth.
“Even less recognized is the topic of this special issue: the emergent evidence shows that processes occur on surfaces of biochar particles and in their pore spaces that are relevant to plant growth.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In the citing paper
“In this connection, the application of biochar to soils has been shown to achieve the net carbon gain in soils while also serving for increased plant biomass production by enhancing the nutrient supply to plants and increasing nutrient and water use efficiencies (NUE and WUE) by plants (Kookana et al., 2011; Lehmann et al., 2015; Minasny et al., 2017).”
From A review on biochar modulated soil condition improvements and nutrient dynamics concerning crop yields: Pathways to climate change mitigation and global food security (2019) · cites this paper as Lehmann et al., 2015
Citations
Cites
Biochar effects on soil biota – A review
Lehmann, J., Rillig, M. C., Thies, J., Masiello, C. A., Hockaday, W. C., & Crowley, D. (2011) · Soil Biology and Biochemistry · doi:10.1016/j.soilbio.2011.04.022 · Cited by 5,074
Self-citationBiochar for Environmental Management: Science, Technology and Implementation
(2015) · doi:10.4324/9780203762264 · Cited by 2,280 · cited 3×
“Even though our knowledge has considerably advanced, the effects of biochars on crop growth still appear unpredictable, with in some instances increasing while in others decreasing yield responses (Liu et al. 2013; Jeffery et al. 2015a).”
BackgroundSelf-citationVan Zwieten, L., Kimber, S., Morris, S., Chan, K. Y., Downie, A., Rust, J., Joseph, S., & Cowie, A. (2010) · Plant and Soil · doi:10.1007/s11104-009-0050-x · Cited by 1,916
Microbial hotspots and hot moments in soil: Concept & review
Kuzyakov, Y., & Blagodatskaya, E. (2015) · Soil Biology and Biochemistry · doi:10.1016/j.soilbio.2015.01.025 · Cited by 1,872
Self-citationBiochar for environmental management: an introduction
Arbestain, M. C., Amonette, J. E., Singh, B., Wang, T., & Schmidt, H. P. (2015) · Routledge eBooks · doi:10.4324/9780203762264-8 · Cited by 1,276
A Review of Biochar and Soil Nitrogen Dynamics
Clough, T., Condron, L., Kammann, C., & Müller, C. (2013) · Agronomy · doi:10.3390/agronomy3020275 · Cited by 969 · cited 2×
“…may increase crop yield, whereas others may decrease yield for reasons that are readily explainable using known responses of crops to for example altered pH or salt contents (Van Zwieten et al. 2010; Rajkovich et al. 2012) and short-termN limitation in N deficient soil (Clough et al. 2013).”
Background(2009) · Cited by 884
Rajkovich, S., Enders, A., Hanley, K., Hyland, C., Zimmerman, A. R., & Lehmann, J. (2012) · Biology and Fertility of Soils · doi:10.1007/s00374-011-0624-7 · Cited by 872
Self-citationLiu, X., Zhang, A., Ji, C., Joseph, S., Bian, R., Li, L., Pan, G., & Paz-Ferreiro, J. (2013) · Plant and Soil · doi:10.1007/s11104-013-1806-x · Cited by 793
Self-citationOne Step Forward toward Characterization: Some Important Material Properties to Distinguish Biochars
Schimmelpfennig, S., & Glaser, B. (2012) · Journal of Environmental Quality · doi:10.2134/jeq2011.0146 · Cited by 518
Cited by
Sorted by citations
Patel, M., Kumar, R., Kishor, K., Mlsna, T., Pittman, C. U., & Mohan, D. (2019) · Chemical Reviews · doi:10.1021/acs.chemrev.8b00299 · Cited by 2,654
Response of microbial communities to biochar-amended soils: a critical review
Palansooriya, K. N., Wong, J. T. F., Hashimoto, Y., Huang, L., Rinklebe, J., Chang, S. X., Bolan, N., Wang, H., & Ok, Y. S. (2019) · Biochar · doi:10.1007/s42773-019-00009-2 · Cited by 875
Self-citationXiong, X., Yu, I. K. M., Cao, L., Tsang, D. C. W., Zhang, S., & Ok, Y. S. (2017) · Bioresource Technology · doi:10.1016/j.biortech.2017.06.163 · Cited by 532
Self-citationRizwan, M., Ali, S., Qayyum, M. F., Ibrahim, M., Zia-ur-Rehman, M., Abbas, T., & Ok, Y. S. (2016) · Environmental Science and Pollution Research · doi:10.1007/s11356-015-5697-7 · Cited by 497
Self-citationPurakayastha, T. J., Bera, T., Bhaduri, D., Sarkar, B., Mandal, S., Wade, P., Kumari, S., Biswas, S., Menon, M., Pathak, H., et al. (2019) · Chemosphere · doi:10.1016/j.chemosphere.2019.03.170 · Cited by 379
Metadata
- Authors
- Lehmann, J., Kuzyakov, Y., Pan, G., & Ok, Y. S.
- Affiliations
- Cornell University (US)
- University of Göttingen (DE)
- Nanjing Agricultural University (CN)
- Kangwon National University (KR)
- Corresponding author
- Lehmann, Johannes
- Venue
- Plant and Soil
- Published
- 2015-09-08
- Volume
- 395
- Issue
- 1-2
- Pages
- 1-5
- ISSN
- 0032-079X (ISSN-L)
- 1573-5036
- OpenAlex
- W2128207984
- Semantic Scholar
- 2911c82f6cfe752d9c9ebc3a9d643b467abec946
- Cited by
- 214
- References
- 26
- Citations by year
- 2026: 12 · 2025: 25 · 2024: 22 · 2023: 27 · 2022: 18 · 2021: 25 · 2020: 20 · 2019: 21 · 2018: 18 · 2017: 14 · 2016: 11 · 2015: 1
- FWCI
- 20.13
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- www.springer.com/tdm (tdm)
- Locations
- Plant and Soil (publishedVersion)
- GRO (submittedVersion, cc-by)
- Topics
- Life Sciences › Agricultural and Biological Sciences › Soil Science › Soil Carbon and Nitrogen Dynamics
- Life Sciences › Agricultural and Biological Sciences › Plant Science › Plant-Microbe Interactions and Immunity
- Life Sciences › Agricultural and Biological Sciences › Soil Science › Agricultural Science and Fertilization
- Keywords
- biochar, soil-plant interface, rhizosphere interactions, crop yield, biochar properties, soil amendment, nitrogen limitation, soil pH, salt stress, plant growth mechanisms
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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