Nele Meyer, Jacqueline Kaldun, Andrei Rodionov, Wulf Amelung, Eva Lehndorff
Background
Microaggregates are suspected to protect soil organic carbon (SOC) from microbial decay, but its residence time is not well understood.
Aims
We aimed at unraveling the relevance of microaggregates for C storage and testing the hypothesis that C in the interior of aggregates is older, compared to the exterior.
Methods
We sampled soil under C3 vegetation and at a site where cropping shifted to C4 vegetation 36 years ago. We isolated free and macroaggregate-occluded size fractions (250–53 µm) by wet sieving and ultrasound, manually isolated aggregates therefrom, and analyzed whether vegetation-related differences in δ13C could be traced at the interior and exterior of microaggregate cross-sections using elemental and laser ablation-isotope ratio mass spectrometry.
Results
Size fraction weights comprised <5% of microaggregates. Based on a source partitioning approach including C3- and C4-derived C, we found mean residence times of SOC in occluded and free microaggregates of 62 and 105 years, respectively. Thus, C storage was longer than that in size fractions (35 years) and bulk soil (58 years). The small-scale variability of δ13C within aggregate cross-sections was considerable, both in C3 and C4 soil, yet without significant (p = 0.46) differences between interior and exterior locations.
Conclusions
We conclude that microaggregates do not persist in an intact form in such a long-term that systematic differences in δ13C patterns between exterior and interior parts can develop.
人们怀疑微团聚体能保护土壤有机碳（SOC）不被微生物腐烂，但对其停留时间却不甚了解。
{"title":"Turnover of soil microaggregate-protected carbon and the challenge of microscale analyses","authors":"Nele Meyer, Jacqueline Kaldun, Andrei Rodionov, Wulf Amelung, Eva Lehndorff","doi":"10.1002/jpln.202300154","DOIUrl":"10.1002/jpln.202300154","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Microaggregates are suspected to protect soil organic carbon (SOC) from microbial decay, but its residence time is not well understood.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>We aimed at unraveling the relevance of microaggregates for C storage and testing the hypothesis that C in the interior of aggregates is older, compared to the exterior.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We sampled soil under C3 vegetation and at a site where cropping shifted to C4 vegetation 36 years ago. We isolated free and macroaggregate-occluded size fractions (250–53 µm) by wet sieving and ultrasound, manually isolated aggregates therefrom, and analyzed whether vegetation-related differences in δ<sup>13</sup>C could be traced at the interior and exterior of microaggregate cross-sections using elemental and laser ablation-isotope ratio mass spectrometry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Size fraction weights comprised <5% of microaggregates. Based on a source partitioning approach including C3- and C4-derived C, we found mean residence times of SOC in occluded and free microaggregates of 62 and 105 years, respectively. Thus, C storage was longer than that in size fractions (35 years) and bulk soil (58 years). The small-scale variability of δ<sup>13</sup>C within aggregate cross-sections was considerable, both in C3 and C4 soil, yet without significant (<i>p</i> = 0.46) differences between interior and exterior locations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We conclude that microaggregates do not persist in an intact form in such a long-term that systematic differences in δ<sup>13</sup>C patterns between exterior and interior parts can develop.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 1","pages":"143-152"},"PeriodicalIF":2.5,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139498737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pramod Rathor, Vianne Rouleau, Linda Yuya Gorim, Guanqun Chen, Malinda S. Thilakarathna
Background
The application of synthetic chemical inputs in current agricultural practices has significantly increased crop production, but their use has caused severe negative consequences on the environment. Humalite is an organic soil amendment that is rich in humic acid and found in large deposits in southern Alberta, Canada. Humic products can enhance nutrient uptake and assimilation in plants by reducing nutrient losses and enhancing bioavailability in the soil.
Aim
Here, we evaluated the effects of different humalite rates in the presence of nitrogen, phosphorus, potassium (NPK) at recommended rates on soil nitrogen availability, wheat growth, grain yield, seed nutritional quality, and nitrogen use efficiency (NUE) under controlled environmental conditions.
Methods
A series of studies were conducted by applying five different rates of humalite (0, 200, 400, 800, and 1600 kg ha−1) with NPK at recommended rates. Soil nitrogen availability and shoot and root growth parameters were recorded at flowering stage. NUE was calculated based on the grain yield at maturity stage.
Results
Plants grown in the presence of humalite augmented root morphological parameters (root length, volume, and surface area), plant biomass (shoot and root), and nutrient uptake (N, P, K, and S) compared to the plants supplied with recommended fertilizer alone. Furthermore, humalite application significantly increased grain yield (14%–19%), seed protein content (23%–30%), and NUE (14%–60%) compared to the fertilizer application alone.
Conclusion
These findings suggest that humalite can be used as an organic soil amendment to reduce synthetic fertilizer application and improve plant growth and yield while enhancing fertilizer use efficiency.
{"title":"Humalite enhances the growth, grain yield, and protein content of wheat by improving soil nitrogen availability and nutrient uptake","authors":"Pramod Rathor, Vianne Rouleau, Linda Yuya Gorim, Guanqun Chen, Malinda S. Thilakarathna","doi":"10.1002/jpln.202300280","DOIUrl":"10.1002/jpln.202300280","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The application of synthetic chemical inputs in current agricultural practices has significantly increased crop production, but their use has caused severe negative consequences on the environment. Humalite is an organic soil amendment that is rich in humic acid and found in large deposits in southern Alberta, Canada. Humic products can enhance nutrient uptake and assimilation in plants by reducing nutrient losses and enhancing bioavailability in the soil.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>Here, we evaluated the effects of different humalite rates in the presence of nitrogen, phosphorus, potassium (NPK) at recommended rates on soil nitrogen availability, wheat growth, grain yield, seed nutritional quality, and nitrogen use efficiency (NUE) under controlled environmental conditions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A series of studies were conducted by applying five different rates of humalite (0, 200, 400, 800, and 1600 kg ha<sup>−1</sup>) with NPK at recommended rates. Soil nitrogen availability and shoot and root growth parameters were recorded at flowering stage. NUE was calculated based on the grain yield at maturity stage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Plants grown in the presence of humalite augmented root morphological parameters (root length, volume, and surface area), plant biomass (shoot and root), and nutrient uptake (N, P, K, and S) compared to the plants supplied with recommended fertilizer alone. Furthermore, humalite application significantly increased grain yield (14%–19%), seed protein content (23%–30%), and NUE (14%–60%) compared to the fertilizer application alone.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>These findings suggest that humalite can be used as an organic soil amendment to reduce synthetic fertilizer application and improve plant growth and yield while enhancing fertilizer use efficiency.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 2","pages":"247-259"},"PeriodicalIF":2.5,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300280","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139498738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon storage and turnover in soils depend on the interplay of soil architecture, microbial activities, and soil organic matter (SOM) dynamics. For a fundamental understanding of the mechanisms that drive these processes, not only the exploitation of advanced experimental techniques down to the nanoscale is necessary but also spatially explicit and dynamic image-based modeling at the pore scale.
Aim
We present a modeling approach that is capable of transferring microscale information into macroscale simulations at the profile scale. This enables the prediction of future developments of carbon fluxes and the impact of changes in the environmental conditions linking scales.
Method
We consider a mathematical model for CO2 transport across soil profiles (macroscale), which is informed by a pore-scale (microscale) model for C turnover. It allows for the dynamic, self-organized re-arrangement of solid building units, aggregates and particulate organic matter (POM) based on surface interactions, realized by a cellular automaton method, and explicitly takes spatial effects on POM turnover such as occlusion into account. We further include the macroscopic environmental conditions water saturation, POM content, and oxygen concentration.
Results
The coupled simulations of macroscopic transport and pore-scale carbon and aggregate turnover reveal the complex, nonlinear interplay of the underlying processes. Limitations by diffusive transport, oxygen availability, texture-dependent occlusion and turnover of OM drive CO2 production and carbon storage.
Conclusions
This emphasizes the need for such micro–macro models exchanging information on different scales to investigate and quantify the effects of structural changes, variations in environmental conditions, or degradation processes on carbon turnover.
{"title":"Coupling scales in process-based soil organic carbon modeling including dynamic aggregation","authors":"Simon Zech, Alexander Prechtel, Nadja Ray","doi":"10.1002/jpln.202300080","DOIUrl":"10.1002/jpln.202300080","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Carbon storage and turnover in soils depend on the interplay of soil architecture, microbial activities, and soil organic matter (SOM) dynamics. For a fundamental understanding of the mechanisms that drive these processes, not only the exploitation of advanced experimental techniques down to the nanoscale is necessary but also spatially explicit and dynamic image-based modeling at the pore scale.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>We present a modeling approach that is capable of transferring microscale information into macroscale simulations at the profile scale. This enables the prediction of future developments of carbon fluxes and the impact of changes in the environmental conditions linking scales.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>We consider a mathematical model for CO<sub>2</sub> transport across soil profiles (macroscale), which is informed by a pore-scale (microscale) model for C turnover. It allows for the dynamic, self-organized re-arrangement of solid building units, aggregates and particulate organic matter (POM) based on surface interactions, realized by a cellular automaton method, and explicitly takes spatial effects on POM turnover such as occlusion into account. We further include the macroscopic environmental conditions water saturation, POM content, and oxygen concentration.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The coupled simulations of macroscopic transport and pore-scale carbon and aggregate turnover reveal the complex, nonlinear interplay of the underlying processes. Limitations by diffusive transport, oxygen availability, texture-dependent occlusion and turnover of OM drive CO<sub>2</sub> production and carbon storage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This emphasizes the need for such micro–macro models exchanging information on different scales to investigate and quantify the effects of structural changes, variations in environmental conditions, or degradation processes on carbon turnover.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 1","pages":"130-142"},"PeriodicalIF":2.5,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139498991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Steffen A. Schweizer, Michaela Aehnelt, Franziska Bucka, Kai Uwe Totsche, Ingrid Kögel-Knabner
Background
Our understanding of C storage in soils lacks insights investigating organic matter (OM) depletion, often studied in bare fallow systems. The content of coarse rock fragments is often excluded, whereas it may affect C storage.
Aims
We aim to contribute to a better understanding of the impact of bare fallow on C storage mechanisms in the soil as influenced by its coarse rock fragment contents. We investigated whether bare fallow induced a depletion of C in OM fractions and analyzed to which extent this affected soil aggregate size distribution and the C loading of the clay-sized fraction.
Methods
A comparison of 14 years bare fallow management with adjacent cropped soils located in Selhausen (Germany) provided a gradient of coarse rock fragments of 34%–71%, from which sites with three different fine earth (FE) contents were compared. Across the FE gradient, we isolated particulate OM and mineral-associated OM fractions, obtained microaggregate and macroaggregate size fractions, and quantified the C loading.
Results
Bare fallow management induced an OM depletion at lower contents of FE. There, the management influence was more concentrated onto less FE volume. The contribution of both particulate and mineral-associated OM fractions to the C in the low-FE soils decreased. The C loading increased under bare fallow, compared to cropped soil. In the low-FE soil, we also found less macroaggregates, whereas the C content decreased in some microaggregate size fractions.
Conclusions
A high content of coarse rock fragments can enhance OM depletion decreasing mineral-associated and particulate C under bare fallow.
{"title":"Impact of bare fallow management on soil carbon storage and aggregates across a rock fragment gradient","authors":"Steffen A. Schweizer, Michaela Aehnelt, Franziska Bucka, Kai Uwe Totsche, Ingrid Kögel-Knabner","doi":"10.1002/jpln.202300156","DOIUrl":"10.1002/jpln.202300156","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Our understanding of C storage in soils lacks insights investigating organic matter (OM) depletion, often studied in bare fallow systems. The content of coarse rock fragments is often excluded, whereas it may affect C storage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>We aim to contribute to a better understanding of the impact of bare fallow on C storage mechanisms in the soil as influenced by its coarse rock fragment contents. We investigated whether bare fallow induced a depletion of C in OM fractions and analyzed to which extent this affected soil aggregate size distribution and the C loading of the clay-sized fraction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A comparison of 14 years bare fallow management with adjacent cropped soils located in Selhausen (Germany) provided a gradient of coarse rock fragments of 34%–71%, from which sites with three different fine earth (FE) contents were compared. Across the FE gradient, we isolated particulate OM and mineral-associated OM fractions, obtained microaggregate and macroaggregate size fractions, and quantified the C loading.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Bare fallow management induced an OM depletion at lower contents of FE. There, the management influence was more concentrated onto less FE volume. The contribution of both particulate and mineral-associated OM fractions to the C in the low-FE soils decreased. The C loading increased under bare fallow, compared to cropped soil. In the low-FE soil, we also found less macroaggregates, whereas the C content decreased in some microaggregate size fractions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>A high content of coarse rock fragments can enhance OM depletion decreasing mineral-associated and particulate C under bare fallow.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 1","pages":"118-129"},"PeriodicalIF":2.5,"publicationDate":"2024-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300156","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139477126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to “Biogeochemical limitations of carbon stabilization in forest subsoils”","authors":"","doi":"10.1002/jpln.202470016","DOIUrl":"10.1002/jpln.202470016","url":null,"abstract":"<p>J.PlantNutr.SoilSci.2022;185:35–43. https://doi.org/10.1002/jpln.202100295</p><p>Figure 2 has been published without complete axis labeling. The correct figure is published below.</p><p>We apologize for this error.</p>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 1","pages":"153"},"PeriodicalIF":2.5,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202470016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139064958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chanda Mutale-joan, Farid Rachidi, Najib El Mernissi, Abderrahim Aasfar, Hicham El Hadi, Laila Sbabou, Karim Lyamlouli, Hicham El Arroussi
Background
Phosphorus (P) fertilizers, made from rock phosphate, increase crop yields. However, rock phosphate is a finite resource, stressing the need for more P-efficient crops.
Aims
This study aims to exploit P-adaptive traits that enhance P-acquisition and P-use efficiency in crops, as a potential sustainable P-use management method in agricultural settings.
Methods
This study investigates the biostimulant effects of Aphanothece sp. extracts (ApE) on P absorption efficiency traits of tomato plants supplied with triple super phosphate fertilizer (0.3, 0.6, and 1.2 mM Pi).
Results
ApE extracts exhibited significant effects on P uptake, Lycopersicum esculentum high-affinity phosphate transporter (LePT) genes, chlorophyll, and lipid contents, compared with control plants. ApE significantly enhanced leaf LePT4 in ApE-treated plants supplied with 0.3 mM Pi, and root LePT2 in ApE-treated plants supplied with 0.6 mM Pi. According to principal component analysis, P concentration in roots (root Pi) was closely associated with root dry weight (DW), root LePT2, and leaf LePT4. The phytohormone, gibberellin gibberellic acid 4, slightly correlated with root Pi, LePT2 (0.18), LePT4 (0.28), and more with root (0.72) and shoot DW (0.60), whereas abscisic acid correlated with chlorophyll content (0.60), LePT2 (0.50), and LePT4 (0.49), and slightly with root Pi (0.22). Gas chromatography–mass spectrometry analysis also showed that the application of ApE to plants stimulated the biosynthesis of several metabolites. The metabolic pathway analysis using MetaboAnalyst revealed that ApE treatment induced the unsaturated fatty acid, steroid, cutin, suberin, and wax biosynthesis pathways.
Conclusions
ApE application to tomato plants stimulated P uptake by roots through enhanced expression of high-affinity P transporters (root LePT2 and leaf LePT4), positively correlated with root DW and root Pi. The study also suggests that algal extracts stimulate plant growth through improved P uptake and modulate the plant's metabolic pathways that favor crop performance in tomato plants under normal Pi conditions.
由磷矿石制成的磷（P）肥料可以提高作物产量。然而，磷矿石是一种有限的资源，因此需要更多的节磷作物。
{"title":"Metabolic and transcriptomic effects of Aphanothece sp. biostimulant on tomato plant growth and phosphorus acquisition","authors":"Chanda Mutale-joan, Farid Rachidi, Najib El Mernissi, Abderrahim Aasfar, Hicham El Hadi, Laila Sbabou, Karim Lyamlouli, Hicham El Arroussi","doi":"10.1002/jpln.202300369","DOIUrl":"10.1002/jpln.202300369","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Phosphorus (P) fertilizers, made from rock phosphate, increase crop yields. However, rock phosphate is a finite resource, stressing the need for more P-efficient crops.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>This study aims to exploit P-adaptive traits that enhance P-acquisition and P-use efficiency in crops, as a potential sustainable P-use management method in agricultural settings.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study investigates the biostimulant effects of <i>Aphanothece</i> sp. extracts (ApE) on P absorption efficiency traits of tomato plants supplied with triple super phosphate fertilizer (0.3, 0.6, and 1.2 mM Pi).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>ApE extracts exhibited significant effects on P uptake, <i>Lycopersicum esculentum</i> high-affinity phosphate transporter (LePT) genes, chlorophyll, and lipid contents, compared with control plants. ApE significantly enhanced leaf LePT4 in ApE-treated plants supplied with 0.3 mM Pi, and root <i>LePT2</i> in ApE-treated plants supplied with 0.6 mM Pi. According to principal component analysis, P concentration in roots (root Pi) was closely associated with root dry weight (DW), root <i>LePT2</i>, and leaf <i>LePT4</i>. The phytohormone, gibberellin gibberellic acid 4, slightly correlated with root Pi, <i>LePT2</i> (0.18), <i>LePT4</i> (0.28), and more with root (0.72) and shoot DW (0.60), whereas abscisic acid correlated with chlorophyll content (0.60), <i>LePT2</i> (0.50), and <i>LePT4</i> (0.49), and slightly with root Pi (0.22). Gas chromatography–mass spectrometry analysis also showed that the application of ApE to plants stimulated the biosynthesis of several metabolites. The metabolic pathway analysis using MetaboAnalyst revealed that ApE treatment induced the unsaturated fatty acid, steroid, cutin, suberin, and wax biosynthesis pathways.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>ApE application to tomato plants stimulated P uptake by roots through enhanced expression of high-affinity P transporters (root <i>LePT2</i> and leaf <i>LePT4</i>), positively correlated with root DW and root Pi. The study also suggests that algal extracts stimulate plant growth through improved P uptake and modulate the plant's metabolic pathways that favor crop performance in tomato plants under normal Pi conditions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 2","pages":"233-246"},"PeriodicalIF":2.5,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139036582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrea Mock, Mariko Ingold, Prem Jose Vazhacharickal, Suman Kumar Sourav, Klaus Dittert, Andreas Buerkert
Background
In a long-term rotation experiment (2016–2022) with different nitrogen (N) fertilizer levels in subtropical South-India, crop yields of low N plots were unexpectedly high. We therefore hypothesized that in the absence of mineral N application, these yields are largely due to N inputs by N2 fixation in the component crops. To assess the diazotrophic N2-fixation of lablab (Lablab purpureus L. Sweet) and possible associative N2-fixation of finger millet (Eleusine coracana L. Gaertn), a controlled experiment was conducted during the 2021 monsoon season within the above-mentioned long-term field study. Two approaches were used to estimate the quantity of N derived from the atmosphere (Ndfa): the dilution method using a 15N-labeled fertilizer and the natural abundance method.
Method
For the 15N dilution method irrigated maize (Zea maize L.), finger millet and lablab were labeled with two split applications of 10% 15N fertilizer (50:50 15N-urea and 15N-ammonium sulfate) amounting to a total of 15 kg N ha−1. Maize was selected as the non-fixing reference plant to estimate diazotrophic N2-fixation. The entire aboveground biomass of the labeled plants was harvested at maturity and analyzed for total DM, N concentration, and the 15N isotope ratio.
Results
N2 fixation efficiency for lablab was 52%–69% depending on the calculation method, corresponding to 40–53 kg N ha−1. For finger millet, the natural abundance method resulted in an estimated N2-fixation of 5 kg N ha−1, which was suggested by the results of the dilution method whereby the reference plant maize was only poorly labeled.
Conclusion
Labeling of maize might have been diluted due to unexpected associative N2-fixation or N-uptake from unlabeled deep soil N pools. The data underline the importance of symbiotic N2-fixation in crop rotation systems of South-India.
在亚热带南印度进行的不同氮肥水平的长期轮作试验（2016-2022 年）中，低氮地块的作物产量出乎意料地高。因此，我们假设，在不施用矿质氮的情况下，这些产量主要归功于成分作物的氮固定。为了评估马铃薯（Lablab purpureus L. Sweet）的重氮固定氮和指粟（Eleusine coracana L. Gaertn）可能的关联固定氮，我们在上述长期田间研究的范围内，于 2021 年季风季节进行了一次对照实验。采用了两种方法来估算从大气中获取的氮量（Ndfa）：使用 15N 标记肥料的稀释法和自然丰度法。
{"title":"Nitrogen fixation of lablab and finger millet in South-India","authors":"Andrea Mock, Mariko Ingold, Prem Jose Vazhacharickal, Suman Kumar Sourav, Klaus Dittert, Andreas Buerkert","doi":"10.1002/jpln.202300319","DOIUrl":"10.1002/jpln.202300319","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>In a long-term rotation experiment (2016–2022) with different nitrogen (N) fertilizer levels in subtropical South-India, crop yields of low N plots were unexpectedly high. We therefore hypothesized that in the absence of mineral N application, these yields are largely due to N inputs by N<sub>2</sub> fixation in the component crops. To assess the diazotrophic N<sub>2</sub>-fixation of lablab (<i>Lablab purpureus</i> L. Sweet) and possible associative N<sub>2</sub>-fixation of finger millet (<i>Eleusine coracana</i> L. Gaertn), a controlled experiment was conducted during the 2021 monsoon season within the above-mentioned long-term field study. Two approaches were used to estimate the quantity of N derived from the atmosphere (Ndfa): the dilution method using a <sup>15</sup>N-labeled fertilizer and the natural abundance method.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>For the <sup>15</sup>N dilution method irrigated maize (<i>Zea maize</i> L.), finger millet and lablab were labeled with two split applications of 10% <sup>15</sup>N fertilizer (50:50 <sup>15</sup>N-urea and <sup>15</sup>N-ammonium sulfate) amounting to a total of 15 kg N ha<sup>−1</sup>. Maize was selected as the non-fixing reference plant to estimate diazotrophic N<sub>2</sub>-fixation. The entire aboveground biomass of the labeled plants was harvested at maturity and analyzed for total DM, N concentration, and the <sup>15</sup>N isotope ratio.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>N<sub>2</sub> fixation efficiency for lablab was 52%–69% depending on the calculation method, corresponding to 40–53 kg N ha<sup>−1</sup>. For finger millet, the natural abundance method resulted in an estimated N<sub>2</sub>-fixation of 5 kg N ha<sup>−1</sup>, which was suggested by the results of the dilution method whereby the reference plant maize was only poorly labeled.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Labeling of maize might have been diluted due to unexpected associative N<sub>2</sub>-fixation or N-uptake from unlabeled deep soil N pools. The data underline the importance of symbiotic N<sub>2</sub>-fixation in crop rotation systems of South-India.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 2","pages":"225-232"},"PeriodicalIF":2.5,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Svenja Roosch, Vincent J. M. N. L. Felde, Daniel Uteau, Stephan Peth
Background
Soil stability is often evaluated using either mechanical or hydraulic stress. The few studies that use both approaches suggest that these two types of stability behave differently.
Aims
Our aim was to explore the mechanisms of aggregate stability regarding mechanical and water stability at the macro- and microscale, among other things, the effect of differing pore structure and soil organic matter content.
Methods
Samples were taken from two adjacent plots that were expected to differ in stability due to land use, that is, cropped versus bare fallow (BF). The stability of dry-separated macroaggregates (8–16 mm) and microaggregates (53–250 µm) was determined via wet sieving and unconfined uniaxial compression tests. To explore the mechanisms of stability, 3D pore characteristics were analyzed with microtomography scans. Furthermore, the contents of carbon and exchangeable polyvalent cations as well as contact angles were determined.
Results
Water stability of macroaggregates was much higher in the cropped plot (geometric mean diameter 0.65–2.37 mm [cropped] vs. 0.31–0.56 mm [BF]), while mechanical stability was very similar (median work 17.3 [cropped] and 17.5 N mm [BF]). The two size fractions behaved similarly regarding both types of stability, with more pronounced differences in macroaggregates. Several soil characteristics, like carbon, exchangeable calcium, and higher connectivity of pores to the aggregate exterior, contributed to water stability. Regarding mechanical stability, the destabilizing effect of lower carbon content and exchangeable calcium in the BF plot was counterbalanced by a lower porosity.
Conclusions
Mechanical and water stability behaved differently in the two plots due to the different deformation mechanisms.
{"title":"Exploring the mechanisms of diverging mechanical and water stability in macro- and microaggregates","authors":"Svenja Roosch, Vincent J. M. N. L. Felde, Daniel Uteau, Stephan Peth","doi":"10.1002/jpln.202300245","DOIUrl":"10.1002/jpln.202300245","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Soil stability is often evaluated using either mechanical or hydraulic stress. The few studies that use both approaches suggest that these two types of stability behave differently.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>Our aim was to explore the mechanisms of aggregate stability regarding mechanical and water stability at the macro- and microscale, among other things, the effect of differing pore structure and soil organic matter content.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Samples were taken from two adjacent plots that were expected to differ in stability due to land use, that is, cropped versus bare fallow (BF). The stability of dry-separated macroaggregates (8–16 mm) and microaggregates (53–250 µm) was determined via wet sieving and unconfined uniaxial compression tests. To explore the mechanisms of stability, 3D pore characteristics were analyzed with microtomography scans. Furthermore, the contents of carbon and exchangeable polyvalent cations as well as contact angles were determined.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Water stability of macroaggregates was much higher in the cropped plot (geometric mean diameter 0.65–2.37 mm [cropped] vs. 0.31–0.56 mm [BF]), while mechanical stability was very similar (median work 17.3 [cropped] and 17.5 N mm [BF]). The two size fractions behaved similarly regarding both types of stability, with more pronounced differences in macroaggregates. Several soil characteristics, like carbon, exchangeable calcium, and higher connectivity of pores to the aggregate exterior, contributed to water stability. Regarding mechanical stability, the destabilizing effect of lower carbon content and exchangeable calcium in the BF plot was counterbalanced by a lower porosity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Mechanical and water stability behaved differently in the two plots due to the different deformation mechanisms.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 1","pages":"104-117"},"PeriodicalIF":2.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300245","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138573099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peter Hartmann, Lelde Jansone, Lucas Mahlau, Martin Maier, Verena Lang, Heike Puhlmann
Background
Forest liming is a common practice in many German forests, which aims primarily at improving soil chemical properties that have been negatively impacted by acid rain. Effects on physical functions have not yet been studied widely.
Aims
The hypothesis of this study is that chemical changes after liming lead to changes in the physical properties of the humus layer and mineral soil.
Methods
We studied soil physical characteristics (water retention characteristics, air and water permeabilities, and conductivities) of limed and adjacent control plots of sandy to loamy, acidified soils under spruce and beech-dominated stands.
Results
We found differences between limed and control plots, especially in the humus layer and mineral top soil. Here, air capacity values (representing air-filled macropores at −6 kPa) have experienced an increase, while available water capacities (representing the sum of dewatered mesopores between −6 and −1500 kPa) were reduced to a variable extent. These changes in pore size distributions affected gas diffusion as well as gas permeability positively. Unsaturated hydraulic conductivity was not affected. Below the top mineral soil, a tendency to a reduced macroporosity and gas permeability was observed, but no clear changes were detected.
Conclusions
Small but significant changes of soil physical properties and functions in the humus layer and top mineral soil are discussed to be an indirect effect of forest liming. Liming improves pH and nutrient availability, which in turn should have stimulated activity and abundance of soil fauna, especially earthworms. Where observed, their activity could explain the observed changes in soil physical properties. We believe that effects below the top soil might be due to mobilization and translocation of soil particles and a clogging of pores, but these depths were only studied at three plots. Compared to common liming practices, however, the investigated sites are characterized by significantly higher lime applications. The effects on practice liming areas in forestry praxis are therefore likely to be smaller than in this study.
{"title":"Liming leads to changes in the physical properties of acidified forest soils","authors":"Peter Hartmann, Lelde Jansone, Lucas Mahlau, Martin Maier, Verena Lang, Heike Puhlmann","doi":"10.1002/jpln.202300055","DOIUrl":"10.1002/jpln.202300055","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Forest liming is a common practice in many German forests, which aims primarily at improving soil chemical properties that have been negatively impacted by acid rain. Effects on physical functions have not yet been studied widely.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>The hypothesis of this study is that chemical changes after liming lead to changes in the physical properties of the humus layer and mineral soil.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We studied soil physical characteristics (water retention characteristics, air and water permeabilities, and conductivities) of limed and adjacent control plots of sandy to loamy, acidified soils under spruce and beech-dominated stands.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found differences between limed and control plots, especially in the humus layer and mineral top soil. Here, air capacity values (representing air-filled macropores at −6 kPa) have experienced an increase, while available water capacities (representing the sum of dewatered mesopores between −6 and −1500 kPa) were reduced to a variable extent. These changes in pore size distributions affected gas diffusion as well as gas permeability positively. Unsaturated hydraulic conductivity was not affected. Below the top mineral soil, a tendency to a reduced macroporosity and gas permeability was observed, but no clear changes were detected.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Small but significant changes of soil physical properties and functions in the humus layer and top mineral soil are discussed to be an indirect effect of forest liming. Liming improves pH and nutrient availability, which in turn should have stimulated activity and abundance of soil fauna, especially earthworms. Where observed, their activity could explain the observed changes in soil physical properties. We believe that effects below the top soil might be due to mobilization and translocation of soil particles and a clogging of pores, but these depths were only studied at three plots. Compared to common liming practices, however, the investigated sites are characterized by significantly higher lime applications. The effects on practice liming areas in forestry praxis are therefore likely to be smaller than in this study.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 2","pages":"195-204"},"PeriodicalIF":2.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138573112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Shi, Owen Fenton, S. M. Ashekuzzaman, K. Daly, J. J. Leahy, N. Khalaf, K. Chojnacka, C. Numviyimana, J. Warchoł, M. G. Healy
Background
Struvite, biochar and ash products (collectively known as STRUBIAS) derived from different waste streams are used as fertilisers in agriculture. Raw dairy processing sludge (DPS) shows promise as bio-based fertilisers, but secondary STRUBIAS-derived products need further testing as fertilisers.
Aims
The objective of this study was to calculate the phosphorus mineral fertiliser equivalency (P-MFE) for some STRUBIAS products derived from DPS.
Methods
Ryegrass (Lolium perenne L.) and wheat (Triticum aestivum) pot trials were used to determine the P-MFE using the apparent P recovery (APR) method for Fe-DPS and DPS-derived struvites (Struvite 1–4), hydrochars (HC1–3) and ash.
Results
The tested STRUBIAS products can be divided into two groups: (1) a range of products that can (i.e. Struvite 1–3) and (2) cannot (i.e., Struvite 4, HC1–3, ash and Fe-DPS) be considered fertilisers. In the first group, the P-MFE ranged from 66.8% to 76.7% for ryegrass and from 77.9% to 93.5% for spring wheat grain. In the second group, the P-MFE ranged from 7.8% to 58.3% for ryegrass and from −34.5% to −151.3% for spring wheat grain. The negative agronomic effects of some products for wheat grain (struvite and HC) in this study were mainly caused by high Fe content, which could be overcome by improved treatment processes.
Conclusions
Future policy and research must be aware that not all the DPS-derived STRUBIAS products are suitable as fertilisers and therefore need to be tested individually.
{"title":"Phosphorus fertiliser equivalent value of dairy processing sludge-derived STRUBIAS products using ryegrass (Lolium perenne L.) and spring wheat (Triticum aestivum)","authors":"W. Shi, Owen Fenton, S. M. Ashekuzzaman, K. Daly, J. J. Leahy, N. Khalaf, K. Chojnacka, C. Numviyimana, J. Warchoł, M. G. Healy","doi":"10.1002/jpln.202300164","DOIUrl":"10.1002/jpln.202300164","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Struvite, biochar and ash products (collectively known as STRUBIAS) derived from different waste streams are used as fertilisers in agriculture. Raw dairy processing sludge (DPS) shows promise as bio-based fertilisers, but secondary STRUBIAS-derived products need further testing as fertilisers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>The objective of this study was to calculate the phosphorus mineral fertiliser equivalency (P-MFE) for some STRUBIAS products derived from DPS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Ryegrass (<i>Lolium perenne L</i>.) and wheat (<i>Triticum aestivum</i>) pot trials were used to determine the P-MFE using the apparent P recovery (APR) method for Fe-DPS and DPS-derived struvites (Struvite 1–4), hydrochars (HC1–3) and ash.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The tested STRUBIAS products can be divided into two groups: (1) a range of products that can (<i>i.e</i>. Struvite 1–3) and (2) cannot (i.e., Struvite 4, HC1–3, ash and Fe-DPS) be considered fertilisers. In the first group, the P-MFE ranged from 66.8% to 76.7% for ryegrass and from 77.9% to 93.5% for spring wheat grain. In the second group, the P-MFE ranged from 7.8% to 58.3% for ryegrass and from −34.5% to −151.3% for spring wheat grain. The negative agronomic effects of some products for wheat grain (struvite and HC) in this study were mainly caused by high Fe content, which could be overcome by improved treatment processes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Future policy and research must be aware that not all the DPS-derived STRUBIAS products are suitable as fertilisers and therefore need to be tested individually.</p>\u0000 </section>\u0000 </div>","PeriodicalId":16802,"journal":{"name":"Journal of Plant Nutrition and Soil Science","volume":"187 2","pages":"215-224"},"PeriodicalIF":2.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jpln.202300164","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138573114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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