Pub Date : 2024-12-09DOI: 10.1016/j.still.2024.106403
Sandeep Sharma, Paawan Kaur
Fluctuations in soil management practices, temperature and moisture conditions can impact adsorption-desorption and bioavailability of phosphorus (P) in agricultural soils. Therefore, this study investigates P dynamics in straw-managed soils of Punjab collected from five treatments namely (1) conventional tillage (CT) after removal of rice straw (CT-R), (2) Treatment 1 plus biochar amendment at 2 Mg ha−1 (CT+biochar), (3) zero tillage with straw retention as mulch (ZT+RM), (4) CT with straw incorporation (CT+RI) and (5) CT after rice residue burned (CT+RB) after three years from an ongoing experiment in rice-wheat cropping system. The adsorption-desorption of P followed pseudo second order kinetics (R2> 0.99) and Freundlich isotherm (R2> 0.95) for all the treatments and temperatures. Freundlich adsorption capacity (KFads) varied with the physico-chemical soil properties and ranged from 10.9 to 28.5, 14.3–32.2, 18.3–40.2, and 22.5–56.5 μg1−ng−1mLn at 15, 25, 35, and 45 ± 1°C, respectively. The sequential order of P adsorption was as follows: CT+ biochar > CT+RB > ZT+RM > CT+RI > CT-R, irrespective of temperature. Thermodynamic parameters revealed feasible, spontaneous and endothermic process indicative of physio-sorption via. hydrogen bonding as the dominant mechanism in in-situ straw managed soils. The Freundlich desorption coefficient (KFdes) ranged from 54.8 to 85.2, 39.9–60.8, 23.4–37.0, 29.6–45.7 and 19.4–36.7 μg1−ng−1mLn in CT+ biochar, CT+ RB, ZT+RM, CT+RI, CT-R, respectively at studied temperatures and was greater than adsorption in all treatments indicating hysteresis. The desorption sequence was observed as: CT-R > CT+RI > ZT+RM > CT+ RB> CT+ biochar. The greater adsorption and slower desorption of P under in-situ straw managed treatments (CT+biochar, CT+RB and ZT+RM) than CT-R and CT +RI, particularly CT+ biochar compared to CT-R will lead to more P retention in soil matrix thereby preventing eutrophication and deterioration of surface waters.
{"title":"Rice straw management options impact soil phosphorus adsorption-desorption, kinetics and thermodynamics in rice-wheat system of north-western India","authors":"Sandeep Sharma, Paawan Kaur","doi":"10.1016/j.still.2024.106403","DOIUrl":"https://doi.org/10.1016/j.still.2024.106403","url":null,"abstract":"Fluctuations in soil management practices, temperature and moisture conditions can impact adsorption-desorption and bioavailability of phosphorus (P) in agricultural soils. Therefore, this study investigates P dynamics in straw-managed soils of Punjab collected from five treatments namely (1) conventional tillage (CT) after removal of rice straw (CT-R), (2) Treatment 1 plus biochar amendment at 2 Mg ha<ce:sup loc=\"post\">−1</ce:sup> (CT+biochar), (3) zero tillage with straw retention as mulch (ZT+RM), (4) CT with straw incorporation (CT+RI) and (5) CT after rice residue burned (CT+RB) after three years from an ongoing experiment in rice-wheat cropping system. The adsorption-desorption of P followed pseudo second order kinetics (R<ce:sup loc=\"post\">2</ce:sup>> 0.99) and Freundlich isotherm (R<ce:sup loc=\"post\">2</ce:sup>> 0.95) for all the treatments and temperatures. Freundlich adsorption capacity (K<ce:inf loc=\"post\">Fads</ce:inf>) varied with the physico-chemical soil properties and ranged from 10.9 to 28.5, 14.3–32.2, 18.3–40.2, and 22.5–56.5 μg<ce:sup loc=\"post\">1−n</ce:sup>g<ce:sup loc=\"post\">−1</ce:sup>mL<ce:sup loc=\"post\">n</ce:sup> at 15, 25, 35, and 45 ± 1°C, respectively. The sequential order of P adsorption was as follows: CT+ biochar > CT+RB > ZT+RM > CT+RI > CT-R, irrespective of temperature. Thermodynamic parameters revealed feasible, spontaneous and endothermic process indicative of physio-sorption via. hydrogen bonding as the dominant mechanism in <ce:italic>in-situ</ce:italic> straw managed soils. The Freundlich desorption coefficient (<ce:italic>K</ce:italic><ce:inf loc=\"post\"><ce:italic>Fdes</ce:italic></ce:inf>) ranged from 54.8 to 85.2, 39.9–60.8, 23.4–37.0, 29.6–45.7 and 19.4–36.7 μg<ce:sup loc=\"post\">1−n</ce:sup>g<ce:sup loc=\"post\">−1</ce:sup>mL<ce:sup loc=\"post\">n</ce:sup> in CT+ biochar, CT+ RB, ZT+RM, CT+RI, CT-R, respectively at studied temperatures and was greater than adsorption in all treatments indicating hysteresis. The desorption sequence was observed as: CT-R > CT+RI > ZT+RM > CT+ RB> CT+ biochar. The greater adsorption and slower desorption of P under <ce:italic>in-situ</ce:italic> straw managed treatments (CT+biochar, CT+RB and ZT+RM) than CT-R and CT +RI, particularly CT+ biochar compared to CT-R will lead to more P retention in soil matrix thereby preventing eutrophication and deterioration of surface waters.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1016/j.still.2024.106405
Babak Minofar, Nevena Milčić, Josef Maroušek, Beata Gavurová, Anna Maroušková
Biochar application to topsoil has been repeatedly and independently reported to reduce N2O emissions, yet the underlying mechanisms remain poorly understood. This study hypothesizes that biochar enhances the stability and catalytic activity of N2O reductase enzymes in denitrifying bacteria, promoting the conversion of N2O to N2 during denitrification. Interactions between biochar and the N2O reductase enzyme (PsN2OR) from the denitrifying bacterium Pseudomonas stutzeri were investigated through molecular dynamics simulations. The obtained results firstly revealed that biochar stabilizes this periplasmic enzyme in the aqueous solution via hydrophobic and hydrophilic interactions. Specifically, π–π stacking and hydrophobic interactions reduce the thermal fluctuations of hydrophobic amino acids, lowering entropy and improving enzymatic efficiency. Additionally, biochar adsorbs N2O molecules, facilitating their delivery to the active site of the enzyme and enhancing the reaction rate. Deeper understandings of molecular interactions open new pathways in developing biochar-based fertilizers with slower, more economically and more environmentally favorable release of nutrients. This new type of fertilizers creates new opportunities for the biochar market, positioning it as a valuable tool for carbon sequestration and the mitigation of N₂O emissions.
{"title":"Understanding the molecular mechanisms of interactions between biochar and denitrifiers in N₂O emissions reduction: Pathway to more economical and sustainable fertilizers","authors":"Babak Minofar, Nevena Milčić, Josef Maroušek, Beata Gavurová, Anna Maroušková","doi":"10.1016/j.still.2024.106405","DOIUrl":"https://doi.org/10.1016/j.still.2024.106405","url":null,"abstract":"Biochar application to topsoil has been repeatedly and independently reported to reduce N<ce:inf loc=\"post\">2</ce:inf>O emissions, yet the underlying mechanisms remain poorly understood. This study hypothesizes that biochar enhances the stability and catalytic activity of N<ce:inf loc=\"post\">2</ce:inf>O reductase enzymes in denitrifying bacteria, promoting the conversion of N<ce:inf loc=\"post\">2</ce:inf>O to N<ce:inf loc=\"post\">2</ce:inf> during denitrification. Interactions between biochar and the N<ce:inf loc=\"post\">2</ce:inf>O reductase enzyme (PsN<ce:inf loc=\"post\">2</ce:inf>OR) from the denitrifying bacterium <ce:italic>Pseudomonas stutzeri</ce:italic> were investigated through molecular dynamics simulations. The obtained results firstly revealed that biochar stabilizes this periplasmic enzyme in the aqueous solution via hydrophobic and hydrophilic interactions. Specifically, π–π stacking and hydrophobic interactions reduce the thermal fluctuations of hydrophobic amino acids, lowering entropy and improving enzymatic efficiency. Additionally, biochar adsorbs N<ce:inf loc=\"post\">2</ce:inf>O molecules, facilitating their delivery to the active site of the enzyme and enhancing the reaction rate. Deeper understandings of molecular interactions open new pathways in developing biochar-based fertilizers with slower, more economically and more environmentally favorable release of nutrients. This new type of fertilizers creates new opportunities for the biochar market, positioning it as a valuable tool for carbon sequestration and the mitigation of N₂O emissions.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"248 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The shrinkage and swelling phenomenon of clayey soils induces substantial effects on measurement and modeling of soil thermal and hydraulic properties. This study developed a combined heat-pulse and evaporation method for simultaneous measurement of soil deformation, thermal, and hydraulic properties of clayey soils during drying-shrinkage processes. Four clayey soils with different textures and initial bulk densities (ρb) were subjected to evaporative-drying experiments. The results showed that the shrinkage process significantly altered the soil pore structure, water-holding capacity, and hydraulic conductivity. Neglecting the soil volume change during drying led to an underestimation of soil water retention, with maximum biases of 0.05–0.09 cm3 cm−3 in the water content (θ) at the same metric potential, and resulted in errors spanning several orders of magnitude in hydraulic conductivity at the same θ condition. The soil thermal properties, including volumetric heat capacity (C), thermal conductivity (λ), and thermal diffusivity (α), exhibited distinct trends with changing θ and ρb compared to rigid soils. The C showed strong positive linear correlations with the θ, but the slopes were lower than those for rigid soils due to the offsetting effect of increasing ρb. The λ first increased and then decreased with the increasing θ, in contrast to the monotonic increase observed in rigid soils. The α had a strong negative linear relationship with the θ, contrary to the typical positive correlation in rigid soils. Meanwhile, effects of the changing ρb on the thermal properties were opposite than did the variation in θ. The findings highlight the importance of considering soil volume change when characterizing the coupled water-heat transport processes in expansive clayey soils. The developed method provides a useful tool for investigating the complex interactions between soil deformation, thermal and hydraulic properties during drying-wetting cycles.
{"title":"Effects of drying-induced shrinkage on thermal and hydraulic properties of clayey soils","authors":"Zhengchao Tian, Mouhui Zhang, Jiazhou Chen, Thorsten Knappenberger","doi":"10.1016/j.still.2024.106415","DOIUrl":"https://doi.org/10.1016/j.still.2024.106415","url":null,"abstract":"The shrinkage and swelling phenomenon of clayey soils induces substantial effects on measurement and modeling of soil thermal and hydraulic properties. This study developed a combined heat-pulse and evaporation method for simultaneous measurement of soil deformation, thermal, and hydraulic properties of clayey soils during drying-shrinkage processes. Four clayey soils with different textures and initial bulk densities (ρ<ce:inf loc=\"post\">b</ce:inf>) were subjected to evaporative-drying experiments. The results showed that the shrinkage process significantly altered the soil pore structure, water-holding capacity, and hydraulic conductivity. Neglecting the soil volume change during drying led to an underestimation of soil water retention, with maximum biases of 0.05–0.09 cm<ce:sup loc=\"post\">3</ce:sup> cm<ce:sup loc=\"post\">−3</ce:sup> in the water content (θ) at the same metric potential, and resulted in errors spanning several orders of magnitude in hydraulic conductivity at the same θ condition. The soil thermal properties, including volumetric heat capacity (<ce:italic>C</ce:italic>), thermal conductivity (λ), and thermal diffusivity (α), exhibited distinct trends with changing θ and ρ<ce:inf loc=\"post\">b</ce:inf> compared to rigid soils. The <ce:italic>C</ce:italic> showed strong positive linear correlations with the θ, but the slopes were lower than those for rigid soils due to the offsetting effect of increasing ρ<ce:inf loc=\"post\">b</ce:inf>. The λ first increased and then decreased with the increasing θ, in contrast to the monotonic increase observed in rigid soils. The α had a strong negative linear relationship with the θ, contrary to the typical positive correlation in rigid soils. Meanwhile, effects of the changing ρ<ce:inf loc=\"post\">b</ce:inf> on the thermal properties were opposite than did the variation in θ. The findings highlight the importance of considering soil volume change when characterizing the coupled water-heat transport processes in expansive clayey soils. The developed method provides a useful tool for investigating the complex interactions between soil deformation, thermal and hydraulic properties during drying-wetting cycles.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic fertilizer was widely used to enhance the buildup of soil organic carbon (SOC) and microbial necromass C. Iron and aluminum (Fe/Al) oxides serve as critical factors influencing SOC by controlling microbial necromass C. Nevertheless, the alterations and dynamics of microbial necromass C alongside Fe/Al oxides in the presence of organic fertilizer remain poorly elucidated. To evaluate the effect of organic fertilizer substitution for chemical fertilizer on Fe/Al oxides and its relationship to microbial necromass C, a site experiment was initiated in 2010 including three treatments: chemical fertilizer (CF), 50 %CF+ 50 % organic fertilizer (50 % OF), and 100 % organic fertilizer (100 %OF). The data were collected after 4, 8, and 13 years of experiments in 2014, 2018, and 2023, respectively. The results showed that organic fertilizer substitution decreased C loss from microbial mineralization and increased microbial necromass C, and thus contributed to SOC accumulation. With experiment duration, SOC content did not increase from 2018 to 2023 under 100 %OF may be due to C saturation, while microbial necromass still had an increasing trend. In 2023, bacterial and fungal necromass C was increased by 157.4 % and 178.5 % under 50 %OF, and by 230.7 % and 337.8 % under 100 %OF compared with CF, respectively. This suggests that prolonged use of organic fertilizer can enhance the stable SOC. Organic fertilizer increased microbial necromass C mainly through promoting the formation of Fe/Al oxides, and Fe oxides had a more important effect than Al oxides. Overall, we concluded that organic fertilizer substitution increased stable SOC sequestration through the association of microbial necromass C with iron oxides.
{"title":"Organic fertilizer substitution increased soil organic carbon through the association of microbial necromass C with iron oxides","authors":"Yinan Xu, Jing Sheng, Liping Zhang, Guofeng Sun, Jianchu Zheng","doi":"10.1016/j.still.2024.106402","DOIUrl":"https://doi.org/10.1016/j.still.2024.106402","url":null,"abstract":"Organic fertilizer was widely used to enhance the buildup of soil organic carbon (SOC) and microbial necromass C. Iron and aluminum (Fe/Al) oxides serve as critical factors influencing SOC by controlling microbial necromass C. Nevertheless, the alterations and dynamics of microbial necromass C alongside Fe/Al oxides in the presence of organic fertilizer remain poorly elucidated. To evaluate the effect of organic fertilizer substitution for chemical fertilizer on Fe/Al oxides and its relationship to microbial necromass C, a site experiment was initiated in 2010 including three treatments: chemical fertilizer (CF), 50 %CF+ 50 % organic fertilizer (50 % OF), and 100 % organic fertilizer (100 %OF). The data were collected after 4, 8, and 13 years of experiments in 2014, 2018, and 2023, respectively. The results showed that organic fertilizer substitution decreased C loss from microbial mineralization and increased microbial necromass C, and thus contributed to SOC accumulation. With experiment duration, SOC content did not increase from 2018 to 2023 under 100 %OF may be due to C saturation, while microbial necromass still had an increasing trend. In 2023, bacterial and fungal necromass C was increased by 157.4 % and 178.5 % under 50 %OF, and by 230.7 % and 337.8 % under 100 %OF compared with CF, respectively. This suggests that prolonged use of organic fertilizer can enhance the stable SOC. Organic fertilizer increased microbial necromass C mainly through promoting the formation of Fe/Al oxides, and Fe oxides had a more important effect than Al oxides. Overall, we concluded that organic fertilizer substitution increased stable SOC sequestration through the association of microbial necromass C with iron oxides.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-07DOI: 10.1016/j.still.2024.106404
Zhihao Xiong, Ziyi Gao, Jianwei Lu, Yangyang Zhang, Xiaokun Li
Potassium (K) supplementation strategies are required to enhance farm productivity in rice-upland rotations, where intensive cultivation practices often result in K deficiencies. Straw return improves the adsorption of K by increasing the content of soil humic acid in macroaggregates. Iron/aluminium (Fe/Al) oxides promote soil organic carbon storage and aggregate stability by acting as binding agents. However, limited information is available on the effects of Fe/Al oxides on the distribution of aggregate-associated K stocks. A field experiment was performed in the Yangtze River Basin, an area with low K stemming from intensive cultivation, with four fertilization treatments: inorganic nitrogen-phosphorus fertilizer (NP), (NPK), inorganic NP with straw return (NP+St), and inorganic NPK with straw return (NPK+St). Results showed that the straw return (NP+St), K fertilization (NPK) and the combination of both (NPK+St) increased soil exchangeable K content (EK) by 32.6 %, 23.7 % and 53.6 % in the rice season, respectively, and increased by 49.9 %, 25.5 % and 182.0 % in the oilseed rape season, respectively, compared with that of no K addition (NP) treatment. K stocks in macroaggregates accounted for more than 90 % of the total K stocks in all treatments. Straw return and K fertilization increased EK and non-exchangeable K (NEK) stocks in large-macroaggregates (>2 mm) by increasing the aggregate-associated K content and regulating the abundance of aggregate. Redundancy analysis showed that complex iron oxide (Fep) was one of the main factors influencing soil available K. The NP+St and NPK+St treatments increased the proportion of particle size and K stocks by increasing the Fep content in large-macroaggregates. Pearson’s correlation analysis and random forest model analysis indicated that EK and NEK stocks in the large-macroaggregates were positively correlated with K uptake by rice and oilseed rape, which suggested that they were key factors influencing K uptake. Therefore, straw return increased Fep in large-macroaggregates to expand the K stock in soil and K uptake by crops under this field experiment conditions. Our results provided new insights with implications for improving soil K availability by straw return combined with K fertilization.
{"title":"Straw return combined with potassium fertilization improves potassium stocks in large-macroaggregates by increasing complex iron oxide under rice–oilseed rape rotation system","authors":"Zhihao Xiong, Ziyi Gao, Jianwei Lu, Yangyang Zhang, Xiaokun Li","doi":"10.1016/j.still.2024.106404","DOIUrl":"https://doi.org/10.1016/j.still.2024.106404","url":null,"abstract":"Potassium (K) supplementation strategies are required to enhance farm productivity in rice-upland rotations, where intensive cultivation practices often result in K deficiencies. Straw return improves the adsorption of K by increasing the content of soil humic acid in macroaggregates. Iron/aluminium (Fe/Al) oxides promote soil organic carbon storage and aggregate stability by acting as binding agents. However, limited information is available on the effects of Fe/Al oxides on the distribution of aggregate-associated K stocks. A field experiment was performed in the Yangtze River Basin, an area with low K stemming from intensive cultivation, with four fertilization treatments: inorganic nitrogen-phosphorus fertilizer (NP), (NPK), inorganic NP with straw return (NP+St), and inorganic NPK with straw return (NPK+St). Results showed that the straw return (NP+St), K fertilization (NPK) and the combination of both (NPK+St) increased soil exchangeable K content (EK) by 32.6 %, 23.7 % and 53.6 % in the rice season, respectively, and increased by 49.9 %, 25.5 % and 182.0 % in the oilseed rape season, respectively, compared with that of no K addition (NP) treatment. K stocks in macroaggregates accounted for more than 90 % of the total K stocks in all treatments. Straw return and K fertilization increased EK and non-exchangeable K (NEK) stocks in large-macroaggregates (>2 mm) by increasing the aggregate-associated K content and regulating the abundance of aggregate. Redundancy analysis showed that complex iron oxide (Fep) was one of the main factors influencing soil available K. The NP+St and NPK+St treatments increased the proportion of particle size and K stocks by increasing the Fep content in large-macroaggregates. Pearson’s correlation analysis and random forest model analysis indicated that EK and NEK stocks in the large-macroaggregates were positively correlated with K uptake by rice and oilseed rape, which suggested that they were key factors influencing K uptake. Therefore, straw return increased Fep in large-macroaggregates to expand the K stock in soil and K uptake by crops under this field experiment conditions. Our results provided new insights with implications for improving soil K availability by straw return combined with K fertilization.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-06DOI: 10.1016/j.still.2024.106413
P.I.A. Kinnell
There are many soil erosion models and model applications. However, as a general rule, models of rainfall erosion cannot fully model the complexity of the detachment and transport processes involved in soil erosion by rain so that it is crucial that soil erosion models are tested against experimental data. In developing the USLE, the designers recognised that the fundamental ability of a model to predict erosion in croplands began with its ability to account for soil losses from bare fallow areas under natural rainfall. Given this, any event-based model perceived to be a replacement for USLE-based models should be first tested for its ability to account for event soil losses from bare fallow areas under natural rain. Comparisons between the abilities of WEPP, RUSLE2 and the USLE-M to account for event soil loss on bare fallow runoff and soil loss plots leads to questions about the capacity of WEPP to model erosion on areas where some storms produce rills but others do not. One reason for this may lie in the fact that, in WEPP, sediment produced by raindrop-driven erosion is moved by flow-driven sediment transport to the outlet in situations where flow-driven sediment transport in channels does not occur. The modelling approach adopted by the designers of the USLE requires the veracity of any alternative erosion model to be established on bare fallow runoff and soil loss plots before focusing on erosion on vegetated areas.
{"title":"Comparing WEPP with USLE based models: The role of bare fallow runoff and soil loss plots","authors":"P.I.A. Kinnell","doi":"10.1016/j.still.2024.106413","DOIUrl":"https://doi.org/10.1016/j.still.2024.106413","url":null,"abstract":"There are many soil erosion models and model applications. However, as a general rule, models of rainfall erosion cannot fully model the complexity of the detachment and transport processes involved in soil erosion by rain so that it is crucial that soil erosion models are tested against experimental data. In developing the USLE, the designers recognised that the fundamental ability of a model to predict erosion in croplands began with its ability to account for soil losses from bare fallow areas under natural rainfall. Given this, any event-based model perceived to be a replacement for USLE-based models should be first tested for its ability to account for event soil losses from bare fallow areas under natural rain. Comparisons between the abilities of WEPP, RUSLE2 and the USLE-M to account for event soil loss on bare fallow runoff and soil loss plots leads to questions about the capacity of WEPP to model erosion on areas where some storms produce rills but others do not. One reason for this may lie in the fact that, in WEPP, sediment produced by raindrop-driven erosion is moved by flow-driven sediment transport to the outlet in situations where flow-driven sediment transport in channels does not occur. The modelling approach adopted by the designers of the USLE requires the veracity of any alternative erosion model to be established on bare fallow runoff and soil loss plots before focusing on erosion on vegetated areas.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-06DOI: 10.1016/j.still.2024.106386
Zhenyu He, Bo Kang, Leiyu Feng, Yonggao Yin, Jie Yang, Guiqiang Liu, Fusheng Zha
Currently, China is undergoing reforms in its rural land transfer policy. As a traditional agricultural country, the operation and management of small-scale farmland serve as the primary economic source for Chinese farmers. However, small-scale farmland is vulnerable to external influences and lacks sufficient risk-resistance capabilities. Developing a low-cost, long-term improvement model is essential for enhancing small-scale farmland.This paper explores the direct integration of biochar and microbial organic fertilizer into the cultivation process of heavy metal-contaminated farmland. The results indicate that the combined application of biochar and microbial organic fertilizer increased soil fertility by 161 % and enhanced the abundance of the antagonistic Chaetomiaceae by 31.6 %. Geostatistical simulations revealed low variation in soil pH, while fertility and water content exhibited high variability. Furthermore, the partial least squares path model confirmed that biochar and organic fertilizer promote.This study elucidates the improvement mechanisms facilitated by biochar and microbial organic fertilizer, providing valuable insights for the management of small-scale farmland in the context of agricultural reform in China.
{"title":"Evaluation of nutrient spatial distribution and heavy metal pollution improvement in small-scale farmland under the action of biochar and microbial organic fertilizer","authors":"Zhenyu He, Bo Kang, Leiyu Feng, Yonggao Yin, Jie Yang, Guiqiang Liu, Fusheng Zha","doi":"10.1016/j.still.2024.106386","DOIUrl":"https://doi.org/10.1016/j.still.2024.106386","url":null,"abstract":"Currently, China is undergoing reforms in its rural land transfer policy. As a traditional agricultural country, the operation and management of small-scale farmland serve as the primary economic source for Chinese farmers. However, small-scale farmland is vulnerable to external influences and lacks sufficient risk-resistance capabilities. Developing a low-cost, long-term improvement model is essential for enhancing small-scale farmland.This paper explores the direct integration of biochar and microbial organic fertilizer into the cultivation process of heavy metal-contaminated farmland. The results indicate that the combined application of biochar and microbial organic fertilizer increased soil fertility by 161 % and enhanced the abundance of the antagonistic Chaetomiaceae by 31.6 %. Geostatistical simulations revealed low variation in soil pH, while fertility and water content exhibited high variability. Furthermore, the partial least squares path model confirmed that biochar and organic fertilizer promote.This study elucidates the improvement mechanisms facilitated by biochar and microbial organic fertilizer, providing valuable insights for the management of small-scale farmland in the context of agricultural reform in China.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-05DOI: 10.1016/j.still.2024.106399
Wei Dai, Gary Feng, Yanbo Huang, Haile Tewolde, Mark W. Shankle, Johnie N. Jenkins
Knowledge on integrating cover crops and poultry litter effects on soil aggregation and associated carbon remains uncertain. In this study, aggregate size fractions, aggregate stability, and aggregate-associated carbon were examined within the topsoil (0–5 cm depth) across five winter cover crops [no cover crop as a control, cereal rye (Secale cereale L.), winter wheat (Triticum aestivum), hairy vetch (Vicia villosa), and mustard (Brassica rapa) plus cereal rye (mix)] and three fertilizer sources (no fertilizer as a control, recommended inorganic fertilizers, and poultry litter) in a split-plot design in no-till upland Atwood silt loam soil. Results demonstrated that the aggregate size 0.25–0.053 mm was the most dominant, containing the largest soil organic carbon (SOC) stock, and contributing significantly to the bulk SOC in no-till upland Atwood silt loam soil. Among the cover crops, the mustard plus cereal rye cover crop increased SOC stock both in bulk soil (10.0 Mg ha−1) and in the 0.25–0.053 mm aggregates (7.1 Mg ha−1). The corresponding increases for poultry litter were 9.7 and 5.9 Mg ha−1, respectively. The highest values for aggregate stability index, mean weight diameter, and geometric mean diameter (56.8 %, 1.0 mm, and 0.6 mm, respectively) were obtained under winter wheat cover crop, while fractal dimension and soil erodibility factor were highest (2.8 and 0.14, respectively) under no cover crop. Multivariate analysis revealed the > 2 mm aggregates was the most dominant predictor for the stability of soil aggregates, suggesting its pivotal role in affecting soil aggregate stability. Aggregate-associated carbon positively correlated with aggregate stability index. Overall, integrating cover crops such as winter wheat and mustard plus cereal rye, along with poultry litter, can increase the stability of soil aggregates and improve SOC stock, which may further enhance the sequestration potentials of soil carbon and decrease the threat of soil degradation and erosion in agricultural systems.
{"title":"Water-stable soil aggregation and associated carbon in a no-till Atwood silt loam soil with cover crops and poultry litter","authors":"Wei Dai, Gary Feng, Yanbo Huang, Haile Tewolde, Mark W. Shankle, Johnie N. Jenkins","doi":"10.1016/j.still.2024.106399","DOIUrl":"https://doi.org/10.1016/j.still.2024.106399","url":null,"abstract":"Knowledge on integrating cover crops and poultry litter effects on soil aggregation and associated carbon remains uncertain. In this study, aggregate size fractions, aggregate stability, and aggregate-associated carbon were examined within the topsoil (0–5 cm depth) across five winter cover crops [no cover crop as a control, cereal rye (<ce:italic>Secale cereale</ce:italic> L.), winter wheat (<ce:italic>Triticum aestivum</ce:italic>), hairy vetch (<ce:italic>Vicia villosa</ce:italic>), and mustard (<ce:italic>Brassica rapa</ce:italic>) plus cereal rye (mix)] and three fertilizer sources (no fertilizer as a control, recommended inorganic fertilizers, and poultry litter) in a split-plot design in no-till upland Atwood silt loam soil. Results demonstrated that the aggregate size 0.25–0.053 mm was the most dominant, containing the largest soil organic carbon (SOC) stock, and contributing significantly to the bulk SOC in no-till upland Atwood silt loam soil. Among the cover crops, the mustard plus cereal rye cover crop increased SOC stock both in bulk soil (10.0 Mg ha<ce:sup loc=\"post\">−1</ce:sup>) and in the 0.25–0.053 mm aggregates (7.1 Mg ha<ce:sup loc=\"post\">−1</ce:sup>). The corresponding increases for poultry litter were 9.7 and 5.9 Mg ha<ce:sup loc=\"post\">−1</ce:sup>, respectively. The highest values for aggregate stability index, mean weight diameter, and geometric mean diameter (56.8 %, 1.0 mm, and 0.6 mm, respectively) were obtained under winter wheat cover crop, while fractal dimension and soil erodibility factor were highest (2.8 and 0.14, respectively) under no cover crop. Multivariate analysis revealed the > 2 mm aggregates was the most dominant predictor for the stability of soil aggregates, suggesting its pivotal role in affecting soil aggregate stability. Aggregate-associated carbon positively correlated with aggregate stability index. Overall, integrating cover crops such as winter wheat and mustard plus cereal rye, along with poultry litter, can increase the stability of soil aggregates and improve SOC stock, which may further enhance the sequestration potentials of soil carbon and decrease the threat of soil degradation and erosion in agricultural systems.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Northeast China’s primary granary, long-term conventional tillage (CT) has led to significant soil degradation in the high-fertility black soil. Conservation tillage (CS) presents an opportunity to preserve soil quality but may reduce crop yield. The suitability of CT and CS in black soil regions and underlying mechanisms are not clear. This study aimed to investigate the impact of CT and CS on soil quality, crop yield and associated influencing factors at a regional scale. A comprehensive field experiment spanning six sites across the black soil region was conducted to evaluate the effects of rotary tillage (RT, traditional practice), no-tillage (NT, a form of CS), and deep ploughing (DP, representing CT) on maize yield and soil physicochemical properties. Results revealed that NT significantly enhanced total and available soil nutrients, along with soil organic carbon (SOC) content in surface layer (0–20 cm), compared to RT. Conversely, DP improved these soil properties in the subsurface layer (20–40 cm) across various sites. Notably, SOC accumulation rates were higher in warmer than cooler regions under NT. NT also significantly increased soil water content throughout the entire growth season and subsequently decreased soil temperature during the seeding stage, particularly in semi-arid areas. DP slightly increased soil water content and maintained a similar soil temperature compared to RT in both semi-arid and semi-humid areas. Variable partitioning analysis (VPA) highlighted the significant influence of soil bulk density, nutrient contents, and hydrothermal properties on yield variation under NT and DP compared to RT. Under NT, these factors contributed to 77 %, 81 %, and 63 % of yield variation, respectively, while for DP, the contributions were 65 %, −33 %, and 70 %. Our findings suggest that NT effectively preserves soil quality, conserves water, and sequesters carbon in semi-arid areas, leading to optimal maize production. Alternatively, DP with straw incorporation shows more variable yields and promises more positive outcomes in semi-humid areas.
{"title":"A six-site field study on assessing the suitability of conservation and conventional tillage in the black soil region, Northeast China","authors":"Fahui Jiang, Xinhua Peng, Shuihong Yao, Mahbub Ul Islam, Zhongbin Zhang, Baoyu Chen, Yuxian Wang, Nan Wang, Hua Qi, Zhengyu Wang, Xiangwei Gong, Xinwei Xue, Fansheng Meng","doi":"10.1016/j.still.2024.106379","DOIUrl":"https://doi.org/10.1016/j.still.2024.106379","url":null,"abstract":"In Northeast China’s primary granary, long-term conventional tillage (CT) has led to significant soil degradation in the high-fertility black soil. Conservation tillage (CS) presents an opportunity to preserve soil quality but may reduce crop yield. The suitability of CT and CS in black soil regions and underlying mechanisms are not clear. This study aimed to investigate the impact of CT and CS on soil quality, crop yield and associated influencing factors at a regional scale. A comprehensive field experiment spanning six sites across the black soil region was conducted to evaluate the effects of rotary tillage (RT, traditional practice), no-tillage (NT, a form of CS), and deep ploughing (DP, representing CT) on maize yield and soil physicochemical properties. Results revealed that NT significantly enhanced total and available soil nutrients, along with soil organic carbon (SOC) content in surface layer (0–20 cm), compared to RT. Conversely, DP improved these soil properties in the subsurface layer (20–40 cm) across various sites. Notably, SOC accumulation rates were higher in warmer than cooler regions under NT. NT also significantly increased soil water content throughout the entire growth season and subsequently decreased soil temperature during the seeding stage, particularly in semi-arid areas. DP slightly increased soil water content and maintained a similar soil temperature compared to RT in both semi-arid and semi-humid areas. Variable partitioning analysis (VPA) highlighted the significant influence of soil bulk density, nutrient contents, and hydrothermal properties on yield variation under NT and DP compared to RT. Under NT, these factors contributed to 77 %, 81 %, and 63 % of yield variation, respectively, while for DP, the contributions were 65 %, −33 %, and 70 %. Our findings suggest that NT effectively preserves soil quality, conserves water, and sequesters carbon in semi-arid areas, leading to optimal maize production. Alternatively, DP with straw incorporation shows more variable yields and promises more positive outcomes in semi-humid areas.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-05DOI: 10.1016/j.still.2024.106401
Tingfeng He, Huiqing Zhang, Huatao Liu, Liu Enke, Qishuo Ding
Soil compaction caused by the use of farm machinery is a widespread issue. Freeze–thaw cycles can improve the soil structure after compaction; however, the effect decreases as soil depth increases. Herein, we applied freeze–thaw cycle treatments to re-moulded compacted sandy loam soil (bulk density of 1.6 g/cm³) in two water content states (80 % and 30 % field capacities). Artificial perforation was performed to create long, straight pores in soil, which ensured that the soil mass was largely intact and unbroken, leaving the freeze–thaw cycles to complete the structural remediation and monitoring soil structure recovery. We measured the soil temperature, heat flux and thermal properties to explore the mechanisms of soil temperature regulation using artificial pores during freeze–thaw cycles. The pore and aggregate structure parameters before and after the freeze–thaw cycle treatment were measured. Under the freeze–thaw cycle treatment, the temperature in the bottom layer of compacted soil with artificial pores rapidly dropped below 0°C during the third and second cycles under high- and low-water-content conditions, respectively, whereas the temperature of soil without artificial pores decreased during the seventh and fourth cycles at the same water content states. Results indicated that the heat flux during the freezing phase was larger in the soil with artificial pores. However, no significant differences were observed in the thermal parameters, including thermal conductivity, volumetric heat capacity and thermal diffusivity, of soils with and without artificial pores at each water content state. The air-filled porosity, aggregate mean weight diameter and structure coefficient of the surface and bottom layers of the compacted soil columns were generally better in soil with artificial pores than in soil without artificial pores after repeated freeze–thaw cycles. This indicates that the artificial pores facilitated the restoration of compacted soil in the bottom layer during freeze–thaw cycles owing to the rapid drop in soil temperature. We deduced that the artificial long, straight pores in compacted soil created additional soil heat exchange areas in the heat transfer process to increase the rate of heat transfer, thus increasing soil heat exchange and causing the soil temperature of the bottom layer to drop rapidly during repeat freezing and thawing. However, further studies are required to investigate the remediation of artificial pores on compacted soils in fields and the optimal process for creating artificial pores in agricultural settings.
{"title":"Restoration of compacted soils using artificial pores under freeze–thaw conditions","authors":"Tingfeng He, Huiqing Zhang, Huatao Liu, Liu Enke, Qishuo Ding","doi":"10.1016/j.still.2024.106401","DOIUrl":"https://doi.org/10.1016/j.still.2024.106401","url":null,"abstract":"Soil compaction caused by the use of farm machinery is a widespread issue. Freeze<ce:italic>–</ce:italic>thaw cycles can improve the soil structure after compaction; however, the effect decreases as soil depth increases. Herein, we applied freeze–thaw cycle treatments to re-moulded compacted sandy loam soil (bulk density of 1.6 g/cm³) in two water content states (80 % and 30 % field capacities). Artificial perforation was performed to create long, straight pores in soil, which ensured that the soil mass was largely intact and unbroken, leaving the freeze<ce:italic>–</ce:italic>thaw cycles to complete the structural remediation and monitoring soil structure recovery. We measured the soil temperature, heat flux and thermal properties to explore the mechanisms of soil temperature regulation using artificial pores during freeze–thaw cycles. The pore and aggregate structure parameters before and after the freeze–thaw cycle treatment were measured. Under the freeze–thaw cycle treatment, the temperature in the bottom layer of compacted soil with artificial pores rapidly dropped below 0°C during the third and second cycles under high- and low-water-content conditions, respectively, whereas the temperature of soil without artificial pores decreased during the seventh and fourth cycles at the same water content states. Results indicated that the heat flux during the freezing phase was larger in the soil with artificial pores. However, no significant differences were observed in the thermal parameters, including thermal conductivity, volumetric heat capacity and thermal diffusivity, of soils with and without artificial pores at each water content state. The air-filled porosity, aggregate mean weight diameter and structure coefficient of the surface and bottom layers of the compacted soil columns were generally better in soil with artificial pores than in soil without artificial pores after repeated freeze–thaw cycles. This indicates that the artificial pores facilitated the restoration of compacted soil in the bottom layer during freeze–thaw cycles owing to the rapid drop in soil temperature. We deduced that the artificial long, straight pores in compacted soil created additional soil heat exchange areas in the heat transfer process to increase the rate of heat transfer, thus increasing soil heat exchange and causing the soil temperature of the bottom layer to drop rapidly during repeat freezing and thawing. However, further studies are required to investigate the remediation of artificial pores on compacted soils in fields and the optimal process for creating artificial pores in agricultural settings.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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