Pub Date : 2025-12-24DOI: 10.1016/j.still.2025.107030
Raissa Schwalbert , Lincon Stefanello , Rai Schwalbert , Luana Garlet , Lucas Dotto , Filipe Nunes , Luciane Tabaldi , Alvaro Berghetti , Gerson Drescher , Gustavo Brunetto , Ignacio Ciampitti , Fernando Nicoloso
Understanding phosphorus (P) starvation effects on uptake, partitioning, and redistribution during the growing season is crucial to monitoring deficiencies in soybean plants. The goals of this study were (i) to evaluate the influence of P availability and soil type on soybean growth, P partitioning, and P redistribution across the plant cycle; (ii) to quantify late-season changes in Pi and Po concentrations in soybean organs and relate them to plant enzymatic activity; and (iii) identify the soybean growth stage where fundamental plant functions are affected by P deficiency and establish plant physiological indicators. Soybean plants were grown under fertilized and unfertilized Oxisol and Alfisol. Organic and inorganic P fractions were determined in roots, stems, petioles, leaves, and pods. Plant growth, P uptake, photosynthetic, and biochemical measurements were performed in V5, R1, R5, and R7 growth stages. The first symptom of P deficiency (V5) was a reduction in leaf area by more than 20 % and 50 % in unfertilized Oxisol and Alfisol, respectively. The photosynthetic rate began to decline at R1, while the plants' ability to process light energy was only affected at R5. In the late season (R7), Pi and Po concentrations decreased by approximately 20 % in plants grown in unfertilized Alfisol, whereas only Pi concentrations declined in plants grown in unfertilized Oxisol. These findings suggest that soybean response mechanisms to P stress vary depending on the stress level and growth stage. However, physiological indicators like leaf area, which are sensitive to short-term P stress, may help detect early-season P deficiency.
{"title":"Phosphorus dynamics in soybean: Partitioning, redistribution, and physiological responses under fertilized and unfertilized tropical soils","authors":"Raissa Schwalbert , Lincon Stefanello , Rai Schwalbert , Luana Garlet , Lucas Dotto , Filipe Nunes , Luciane Tabaldi , Alvaro Berghetti , Gerson Drescher , Gustavo Brunetto , Ignacio Ciampitti , Fernando Nicoloso","doi":"10.1016/j.still.2025.107030","DOIUrl":"10.1016/j.still.2025.107030","url":null,"abstract":"<div><div>Understanding phosphorus (P) starvation effects on uptake, partitioning, and redistribution during the growing season is crucial to monitoring deficiencies in soybean plants. The goals of this study were (i) to evaluate the influence of P availability and soil type on soybean growth, P partitioning, and P redistribution across the plant cycle; (ii) to quantify late-season changes in Pi and Po concentrations in soybean organs and relate them to plant enzymatic activity; and (iii) identify the soybean growth stage where fundamental plant functions are affected by P deficiency and establish plant physiological indicators. Soybean plants were grown under fertilized and unfertilized Oxisol and Alfisol. Organic and inorganic P fractions were determined in roots, stems, petioles, leaves, and pods. Plant growth, P uptake, photosynthetic, and biochemical measurements were performed in V5, R1, R5, and R7 growth stages. The first symptom of P deficiency (V5) was a reduction in leaf area by more than 20 % and 50 % in unfertilized Oxisol and Alfisol, respectively. The photosynthetic rate began to decline at R1, while the plants' ability to process light energy was only affected at R5. In the late season (R7), Pi and Po concentrations decreased by approximately 20 % in plants grown in unfertilized Alfisol, whereas only Pi concentrations declined in plants grown in unfertilized Oxisol. These findings suggest that soybean response mechanisms to P stress vary depending on the stress level and growth stage. However, physiological indicators like leaf area, which are sensitive to short-term P stress, may help detect early-season P deficiency.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107030"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.still.2025.107018
Baishun Liu , Lihua Huang , Fengyi Zhang , Jinghui Cai , Lei Tian , Xiaotong Jiang , Yanping Liang , Ge Zhu , Guangzhi Huang
Soil salinization severely restricts the content of soil nitrogen, resulting in low rice yield in saline-sodic soils. It is well known that soil organic nitrogen (SON) fractions play important roles in nitrogen retention and supply. However, the SON fractions characteristics, and the mechanism of salinization affecting on SON fractions and nitrogen supply have not been clearly elucidated in saline-sodic paddy soils. In this study, 168 paddy soil samples with different salinity and alkalinity were collected to construct a machine learning model and structural equation model (SEM) to describe the characteristics of SON fractions, quantify the influence of soil factors on SON fractions, and elucidate the mechanism of salinization affecting on SON fractions and nitrogen supply. The results showed that the non-hydrolysable nitrogen (NHN) had significantly negative correlation with soil pH, and NHN decreased by 31.6 % in severe saline-sodic soils compared to moderate saline-sodic soils, and by 55.3 % compared to mild saline-sodic soils. The soil organic carbon (SOC) was significantly positively correlated with SON fractions, which explained amino acid nitrogen (AAN) and NHN variation of 13.9 % and 17.7 %, respectively. Among all SON fractions, the NHN showed higher nitrogen supply potential in saline-sodic paddy soils, which explained available nitrogen (AN) variation of 38.0 %. Soil salinization mainly affects the stable SON fractions (mainly NHN) by inhibiting SOC, thereby suppressing the long-term supply of AN and reducing the retention and supply capacity of nitrogen in saline-sodic paddy soils.
{"title":"High pH decreases the contents of stable organic nitrogen fractions and nitrogen supply capacity by inhibiting soil organic carbon in saline-sodic paddy fields","authors":"Baishun Liu , Lihua Huang , Fengyi Zhang , Jinghui Cai , Lei Tian , Xiaotong Jiang , Yanping Liang , Ge Zhu , Guangzhi Huang","doi":"10.1016/j.still.2025.107018","DOIUrl":"10.1016/j.still.2025.107018","url":null,"abstract":"<div><div>Soil salinization severely restricts the content of soil nitrogen, resulting in low rice yield in saline-sodic soils. It is well known that soil organic nitrogen (SON) fractions play important roles in nitrogen retention and supply. However, the SON fractions characteristics, and the mechanism of salinization affecting on SON fractions and nitrogen supply have not been clearly elucidated in saline-sodic paddy soils. In this study, 168 paddy soil samples with different salinity and alkalinity were collected to construct a machine learning model and structural equation model (SEM) to describe the characteristics of SON fractions, quantify the influence of soil factors on SON fractions, and elucidate the mechanism of salinization affecting on SON fractions and nitrogen supply. The results showed that the non-hydrolysable nitrogen (NHN) had significantly negative correlation with soil pH, and NHN decreased by 31.6 % in severe saline-sodic soils compared to moderate saline-sodic soils, and by 55.3 % compared to mild saline-sodic soils. The soil organic carbon (SOC) was significantly positively correlated with SON fractions, which explained amino acid nitrogen (AAN) and NHN variation of 13.9 % and 17.7 %, respectively. Among all SON fractions, the NHN showed higher nitrogen supply potential in saline-sodic paddy soils, which explained available nitrogen (AN) variation of 38.0 %. Soil salinization mainly affects the stable SON fractions (mainly NHN) by inhibiting SOC, thereby suppressing the long-term supply of AN and reducing the retention and supply capacity of nitrogen in saline-sodic paddy soils.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107018"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.still.2025.107038
Yufei Li , Kaiping Zhang , Wucheng Zhao , Yuling Li , Ningning Zhang , Pingxing Wan , Zhongke Zhou , Jianjun Yang , Hongyuan Kan , Feng Zhang
Soil freeze–thaw cycles (FTCs) during the non-growing season influence soil respiration (Rs), yet the effect of widely used plastic film mulch (PFM) on FTCs remains unclear. Based on four years of high-frequency observations in the semi-arid Loess Plateau, we found that PFM shortened the freeze-thaw transition (F-T) period by 59 days per year and extended the freezing period by 42 days per year through reducing the daily soil temperature (ST) range by 2.5 °C during the non-growing season. Although microbial biomass carbon (MBC) decreased during the F-T period compared to the freeze period, increases in dissolved organic carbon (DOC) and the activities of β-glucosidase (BG), cellobiohydrolase (CBH) contributed to higher Rs under both treatments. PFM did not significantly influence Rs (relative to the control) within either period. PFM increased cumulative CO2 emissions by 24 g C m−2 due to the extended freezing period, while reducing emissions by 47 g C m−2 owing to the shortened F-T period. PFM increased Rs by 24 % during the thaw period, causing only an 8 g C m−2 rise. Overall, PFM reduced cumulative CO₂ emissions by 16 %. To investigate the regional effect of PFM on FTCs, we used a process-based model with good performance to simulate the spatiotemporal patterns of FTCs in PFM-applied cropland across northern China. Simulations showed that PFM shorten annual F-T periods by approximately 15 days, especially between 35°N and 45°N. Of the un-mulched cropland in northern China, 7 % showed an increasing F-T duration from 1990 to 2019, a figure which potentially increased to 11 % under PFM, mainly located in Northeast China. During the same period, 16 % of the un-mulched cropland showed a decreasing F-T events, which increase to 19 % under PFM, primarily in the central part of northern China. These results suggest that PFM effectively reduces F-T duration and may mitigate non-growing season Rs.
非生长季节土壤冻融循环影响土壤呼吸，但地膜覆盖对土壤冻融循环的影响尚不清楚。基于4年黄土高原半干旱地区的高频观测，研究发现，在非生长期，PFM使土壤日温度（ST）变化幅度降低2.5℃，使冻融过渡期（F-T）每年缩短59天，冻结期每年延长42天。与冻结期相比，F-T处理期间微生物生物量碳（MBC）减少，但溶解有机碳（DOC）和β-葡萄糖苷酶（BG）、纤维素生物水解酶（CBH）活性的增加均导致Rs升高。在两个时间段内，PFM均未显著影响Rs（相对于对照组）。由于冻结期延长，PFM使累积CO2排放量增加了24 g C m−2，而由于缩短了F-T期，减少了47 g C m−2。在解冻期间，PFM增加了24 %的Rs，仅引起8 g cm−2的上升。总体而言，PFM减少了累积二氧化碳排放量的16% %。为了研究土壤施肥对土壤覆盖度的区域效应，我们采用一个基于过程的模型对中国北方施用土壤覆盖度的时空格局进行了模拟。模拟结果表明，PFM使年F-T周期缩短了约15天，特别是在35°N和45°N之间。1990 - 2019年，中国北方未覆盖的农田中，有7% %的土壤土壤温度持续时间增加，而在土壤保护措施下，这一数字有可能增加到11. %，主要分布在东北地区。同期，16 %的未覆盖农田的F-T事件呈下降趋势，在土壤保护措施下上升至19 %，主要集中在华北中部地区。这些结果表明，PFM可以有效地缩短F-T持续时间，并可能减轻非生长期Rs。
{"title":"Plastic film mulch mitigates soil respiration by reducing the duration of freeze-thaw transition","authors":"Yufei Li , Kaiping Zhang , Wucheng Zhao , Yuling Li , Ningning Zhang , Pingxing Wan , Zhongke Zhou , Jianjun Yang , Hongyuan Kan , Feng Zhang","doi":"10.1016/j.still.2025.107038","DOIUrl":"10.1016/j.still.2025.107038","url":null,"abstract":"<div><div>Soil freeze–thaw cycles (FTCs) during the non-growing season influence soil respiration (R<sub>s</sub>), yet the effect of widely used plastic film mulch (PFM) on FTCs remains unclear. Based on four years of high-frequency observations in the semi-arid Loess Plateau, we found that PFM shortened the freeze-thaw transition (F-T) period by 59 days per year and extended the freezing period by 42 days per year through reducing the daily soil temperature (ST) range by 2.5 °C during the non-growing season. Although microbial biomass carbon (MBC) decreased during the F-T period compared to the freeze period, increases in dissolved organic carbon (DOC) and the activities of β-glucosidase (BG), cellobiohydrolase (CBH) contributed to higher R<sub>s</sub> under both treatments. PFM did not significantly influence R<sub>s</sub> (relative to the control) within either period. PFM increased cumulative CO<sub>2</sub> emissions by 24 g C m<sup>−</sup><sup>2</sup> due to the extended freezing period, while reducing emissions by 47 g C m<sup>−2</sup> owing to the shortened F-T period. PFM increased R<sub>s</sub> by 24 % during the thaw period, causing only an 8 g C m<sup>−</sup><sup>2</sup> rise. Overall, PFM reduced cumulative CO₂ emissions by 16 %. To investigate the regional effect of PFM on FTCs, we used a process-based model with good performance to simulate the spatiotemporal patterns of FTCs in PFM-applied cropland across northern China. Simulations showed that PFM shorten annual F-T periods by approximately 15 days, especially between 35°N and 45°N. Of the un-mulched cropland in northern China, 7 % showed an increasing F-T duration from 1990 to 2019, a figure which potentially increased to 11 % under PFM, mainly located in Northeast China. During the same period, 16 % of the un-mulched cropland showed a decreasing F-T events, which increase to 19 % under PFM, primarily in the central part of northern China. These results suggest that PFM effectively reduces F-T duration and may mitigate non-growing season R<sub>s</sub>.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107038"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.still.2025.107043
Yuhuan Wu , Qianhu Ma , Yanan Liu , Zikui Wang
In semi-arid dryland farming, continuous cultivation of perennial deep-rooted pastures can excessively deplete soil moisture, whereas annual crops underutilize precipitation. We hypothesize that intercropping these two types of plants has great potential for water resource conservation and efficient utilization. A field experiment on wheat-alfalfa strip intercropping was conducted over four seasons from September 2017 to September 2021 to examine root development and water use in three intercrops with wheat-to-alfalfa row ratios of 2:1 (I21), 4:2 (I42), and 8:4 (I84). We observed that wheat roots were primarily distributed within the 0–2 m soil profile, whereas alfalfa roots extended to 5-m-depth. Intercropping reduced vertical penetration while facilitating the lateral extension of wheat roots into alfalfa strips and promoting alfalfa roots distribution laterally below 2-m-depth in the wheat strip. Intercropping also increased root length and surface area of both species. Root plasticity enhanced the complementary use of soil water. Wheat in I21, I42, and I84 absorbed an average of 39.0, 33.1, and 14.7 mm yr−1 of soil water from the alfalfa strip. In the dry year, 2021, alfalfa in I21, I42, and I84 absorbed 19.5, 20.2, and 62.4 mm of soil water from the wheat strip below 2-m-depth. Intercropping increased wheat grain yield by 18.4–22.3 % while maintaining the alfalfa biomass production. The wide-strip pattern, I84, achieved the highest production and water use advantages, averaging 9 % and 13 % respectively, over monocultures, with peaks of 14 % and 31 % in 2021. Our research confirms the feasibility of intercropping shallow- and deep-rooted crops to enhance water use efficiency in semi-arid regions, demonstrating a replicable and scalable approach that can be applied globally.
{"title":"Enhancing water use efficiency and crop production through shallow- and deep-rooted crop strip intercropping in semi-arid regions","authors":"Yuhuan Wu , Qianhu Ma , Yanan Liu , Zikui Wang","doi":"10.1016/j.still.2025.107043","DOIUrl":"10.1016/j.still.2025.107043","url":null,"abstract":"<div><div>In semi-arid dryland farming, continuous cultivation of perennial deep-rooted pastures can excessively deplete soil moisture, whereas annual crops underutilize precipitation. We hypothesize that intercropping these two types of plants has great potential for water resource conservation and efficient utilization. A field experiment on wheat-alfalfa strip intercropping was conducted over four seasons from September 2017 to September 2021 to examine root development and water use in three intercrops with wheat-to-alfalfa row ratios of 2:1 (I21), 4:2 (I42), and 8:4 (I84). We observed that wheat roots were primarily distributed within the 0–2 m soil profile, whereas alfalfa roots extended to 5-m-depth. Intercropping reduced vertical penetration while facilitating the lateral extension of wheat roots into alfalfa strips and promoting alfalfa roots distribution laterally below 2-m-depth in the wheat strip. Intercropping also increased root length and surface area of both species. Root plasticity enhanced the complementary use of soil water. Wheat in I21, I42, and I84 absorbed an average of 39.0, 33.1, and 14.7 mm yr<sup>−1</sup> of soil water from the alfalfa strip. In the dry year, 2021, alfalfa in I21, I42, and I84 absorbed 19.5, 20.2, and 62.4 mm of soil water from the wheat strip below 2-m-depth. Intercropping increased wheat grain yield by 18.4–22.3 % while maintaining the alfalfa biomass production. The wide-strip pattern, I84, achieved the highest production and water use advantages, averaging 9 % and 13 % respectively, over monocultures, with peaks of 14 % and 31 % in 2021. Our research confirms the feasibility of intercropping shallow- and deep-rooted crops to enhance water use efficiency in semi-arid regions, demonstrating a replicable and scalable approach that can be applied globally.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107043"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.still.2025.107034
Tao Zhou , Yajun Geng , Huijie Li , Hongmin Zhang , Hongchen Li , Junming Liu , Shuang Li , Tingting Liu , Jianjun Pan , Bingcheng Si , Angela Lausch
Timely and accurate spatial information on soil properties is essential for addressing global challenges, including climate change, food security, and ecosystem degradation. Despite advances in digital soil mapping (DSM), current approaches remain limited by reliance on optical satellite data and insufficient exploration of synthetic aperture radar (SAR) potential at continental scales. Here, we advance DSM by integrating multi-frequency SAR and optical satellite observations to map four key soil chemical properties—soil organic carbon, pH, extractable potassium, and total nitrogen—across Europe. Eleven scenarios with different data integrations, combined with two machine learners (support vector machine and random forest algorithms) and measurements from the LUCAS 2018 soil module, were employed to construct prediction models. The results confirm that continental-scale DSM is feasible using long-term optical and SAR observations. For all soil properties, C-band Sentinel-1 outperformed L-band PALSAR-1/2, and the integration of multi-frequency SAR data achieved prediction accuracies comparable to or even exceeding those of optical data, with R² improvements of approximately 29 %–87 % compared with using only L-band backscatter bands. The joint use of radar and optical observations produced the best performance, improving predictions of all soil properties compared to using optical data alone, with R² values ranging approximately from 0.31 to 0.60—highest for soil pH and lowest for soil total nitrogen. The relative importance of SAR features in the predictions varied with specific polarization modes and band frequencies, and radar indices were found to be more influential in models than backscatter bands. The generated soil property maps showed spatial patterns consistent with previous efforts based on multi-source environmental data. This study demonstrates that multi-frequency SAR data can both substitute for and complement optical data in DSM, offering new insights and practical directions for future model development.
{"title":"Multi-frequency SAR and optical data integration for continental-scale digital mapping of soil chemical properties across Europe","authors":"Tao Zhou , Yajun Geng , Huijie Li , Hongmin Zhang , Hongchen Li , Junming Liu , Shuang Li , Tingting Liu , Jianjun Pan , Bingcheng Si , Angela Lausch","doi":"10.1016/j.still.2025.107034","DOIUrl":"10.1016/j.still.2025.107034","url":null,"abstract":"<div><div>Timely and accurate spatial information on soil properties is essential for addressing global challenges, including climate change, food security, and ecosystem degradation. Despite advances in digital soil mapping (DSM), current approaches remain limited by reliance on optical satellite data and insufficient exploration of synthetic aperture radar (SAR) potential at continental scales. Here, we advance DSM by integrating multi-frequency SAR and optical satellite observations to map four key soil chemical properties—soil organic carbon, pH, extractable potassium, and total nitrogen—across Europe. Eleven scenarios with different data integrations, combined with two machine learners (support vector machine and random forest algorithms) and measurements from the LUCAS 2018 soil module, were employed to construct prediction models. The results confirm that continental-scale DSM is feasible using long-term optical and SAR observations. For all soil properties, C-band Sentinel-1 outperformed <span>L</span>-band PALSAR-1/2, and the integration of multi-frequency SAR data achieved prediction accuracies comparable to or even exceeding those of optical data, with R² improvements of approximately 29 %–87 % compared with using only <span>L</span>-band backscatter bands. The joint use of radar and optical observations produced the best performance, improving predictions of all soil properties compared to using optical data alone, with R² values ranging approximately from 0.31 to 0.60—highest for soil pH and lowest for soil total nitrogen. The relative importance of SAR features in the predictions varied with specific polarization modes and band frequencies, and radar indices were found to be more influential in models than backscatter bands. The generated soil property maps showed spatial patterns consistent with previous efforts based on multi-source environmental data. This study demonstrates that multi-frequency SAR data can both substitute for and complement optical data in DSM, offering new insights and practical directions for future model development.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107034"},"PeriodicalIF":6.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1016/j.still.2025.107033
Junsheng Lu , Wei Zhang , Xuezhi Liu , Xinyue Zhu , Penghai Su , Tiantian Hu
Incorporating straw or straw-derived biochar is recognized as a promising strategy to enhance soil quality and promote sustainable agricultural development. However, the sustained effects of straw and biochar amendments on crop productivity, greenhouse gas (GHG) emissions and soil multifunctionality remain controversial, largely due to the lack of comparative studies between raw straw and biochar produced from an equivalent amount of straw. To address this issue, a five-year field experiment was conducted with three treatments—CK (no incorporation), SI (continuous raw straw incorporation), and BI (continuous incorporation of biochar derived from an equivalent amount of straw)—to evaluate whether converting raw straw into biochar for soil application provides greater benefits in mitigating GHG emissions and improving soil quality, crop yield, and water productivity. The results showed that both SI and BI significantly improved soil physical (bulk density, porosity, field capacity), chemical (pH, organic carbon, nutrient levels), and biological (microbial biomass carbon and nitrogen) properties, leading to increases in soil ecosystem multifunctionality by 222.8 % and 251.8 %, respectively, compared with CK. Additionally, SI consistently elevated N2O emissions, whereas BI generally reduced N2O emissions relative to CK. Both SI and BI increased CO2 emissions and significantly enhanced crop yield, with SI and BI increasing grain yield by 8.3 % and 25.6 %, and water productivity by 12.2 % and 24.8 %, respectively, in the maize-wheat rotation system compared to CK. As a consequence, SI and BI increased the global warming potential (GWP) by 22.4 % and 6.1 %, respectively, while SI increased greenhouse gas intensity (GHGI) by 12.6 % and BI reduced it by 16.1 %, relative to CK. Notably, continuous incorporation of straw and biochar resulted in a cumulative effect (residual effect + current-season effect) on N2O and CO2 emissions. The residual effect on N2O and CO2 emissions persisted for 3 and 4 years, respectively, under SI, and extended up to 7 years for both gases under BI. Overall, these findings demonstrate that converting straw into biochar for soil incorporation not only enhances soil quality and sustains high crop productivity but also contributes to mitigating GHG emissions. This study highlights the importance of considering long-term dynamics in straw and biochar management and underscores biochar's potential as a sustainable strategy for climate change mitigation.
{"title":"Effects of continuous straw and equivalent straw-derived biochar application on soil multifunctionality, crop productivity, and greenhouse gas emissions","authors":"Junsheng Lu , Wei Zhang , Xuezhi Liu , Xinyue Zhu , Penghai Su , Tiantian Hu","doi":"10.1016/j.still.2025.107033","DOIUrl":"10.1016/j.still.2025.107033","url":null,"abstract":"<div><div>Incorporating straw or straw-derived biochar is recognized as a promising strategy to enhance soil quality and promote sustainable agricultural development. However, the sustained effects of straw and biochar amendments on crop productivity, greenhouse gas (GHG) emissions and soil multifunctionality remain controversial, largely due to the lack of comparative studies between raw straw and biochar produced from an equivalent amount of straw. To address this issue, a five-year field experiment was conducted with three treatments—CK (no incorporation), SI (continuous raw straw incorporation), and BI (continuous incorporation of biochar derived from an equivalent amount of straw)—to evaluate whether converting raw straw into biochar for soil application provides greater benefits in mitigating GHG emissions and improving soil quality, crop yield, and water productivity. The results showed that both SI and BI significantly improved soil physical (bulk density, porosity, field capacity), chemical (pH, organic carbon, nutrient levels), and biological (microbial biomass carbon and nitrogen) properties, leading to increases in soil ecosystem multifunctionality by 222.8 % and 251.8 %, respectively, compared with CK. Additionally, SI consistently elevated N<sub>2</sub>O emissions, whereas BI generally reduced N<sub>2</sub>O emissions relative to CK. Both SI and BI increased CO<sub>2</sub> emissions and significantly enhanced crop yield, with SI and BI increasing grain yield by 8.3 % and 25.6 %, and water productivity by 12.2 % and 24.8 %, respectively, in the maize-wheat rotation system compared to CK. As a consequence, SI and BI increased the global warming potential (GWP) by 22.4 % and 6.1 %, respectively, while SI increased greenhouse gas intensity (GHGI) by 12.6 % and BI reduced it by 16.1 %, relative to CK. Notably, continuous incorporation of straw and biochar resulted in a cumulative effect (residual effect + current-season effect) on N<sub>2</sub>O and CO<sub>2</sub> emissions. The residual effect on N<sub>2</sub>O and CO<sub>2</sub> emissions persisted for 3 and 4 years, respectively, under SI, and extended up to 7 years for both gases under BI. Overall, these findings demonstrate that converting straw into biochar for soil incorporation not only enhances soil quality and sustains high crop productivity but also contributes to mitigating GHG emissions. This study highlights the importance of considering long-term dynamics in straw and biochar management and underscores biochar's potential as a sustainable strategy for climate change mitigation.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107033"},"PeriodicalIF":6.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1016/j.still.2025.107024
Yulu Chen , Li Huang , Shaomin Huang , Tengfei Guo , Shuiqing Zhang , Doudou Guo , Xiao Song , Shijie Ding , Muhammad Mehran , Yongqiang Yang , Ke Yue , Sumiao Su , Mingjian Geng , Huimin Zhang
Dissolved organic carbon (DOC), the most labile fraction of soil organic carbon (SOC), plays a vital role in ecosystem functioning and soil productivity. However, the influence of long-term green manure application on DOC composition and its role in soil aggregate formation and carbon stabilization remains unclear. This study investigated changes in DOC composition and their effects on aggregate stability and carbon sequestration in two rice-green manure rotation trials long-5 years in Jingzhou (JZ) and 36 years in Qiyang (QY), China. Treatments included rice-winter fallow (WF), rice-Chinese milk vetch (MV), rice-oilseed rape (RP), and rice-ryegrass (RG). At the JZ test site, 5-year MV incorporation slightly improved aggregate stability, measured by mean weight diameter (MWD) and geometric mean diameter (GMD), but without significant changes. In contrast, at QY, 36-year MV and RG incorporation significantly enhanced both MWD and GMD. Green manure addition increased SOC and DOC contents and enhanced the molecular complexity of DOC, reflected by higher molecular weight, aromaticity, and humification degree. DOC was primarily derived from plant residues and microbial metabolites, with green manure application enhancing microbial contributions. Fluorescence spectroscopy identified three DOC components: bioavailable, humic-like, and protein-like. While DOC composition at JZ remained largely unchanged after 5 years of MV incorporation, 36 years of MV and RG incorporation at QY facilitated the transformation of protein-like into humic-like components. SOC, humic-like DOC, and the humification index (HIX), were the key drivers of aggregate stability, showing direct positive effects on aggregate MWD. Humic-like DOC indirectly promoted SOC accumulation through increased DOC aromaticity and enhanced humification. Our findings highlight the central role of humic-like DOC in enhancing SOC sequestration and soil aggregate stabilization, underscoring the long-term benefits of green manure in sustainable agriculture.
{"title":"Long-term green manure incorporation increases soil carbon sequestration and improves aggregate stability by changing organic carbon components","authors":"Yulu Chen , Li Huang , Shaomin Huang , Tengfei Guo , Shuiqing Zhang , Doudou Guo , Xiao Song , Shijie Ding , Muhammad Mehran , Yongqiang Yang , Ke Yue , Sumiao Su , Mingjian Geng , Huimin Zhang","doi":"10.1016/j.still.2025.107024","DOIUrl":"10.1016/j.still.2025.107024","url":null,"abstract":"<div><div>Dissolved organic carbon (DOC), the most labile fraction of soil organic carbon (SOC), plays a vital role in ecosystem functioning and soil productivity. However, the influence of long-term green manure application on DOC composition and its role in soil aggregate formation and carbon stabilization remains unclear. This study investigated changes in DOC composition and their effects on aggregate stability and carbon sequestration in two rice-green manure rotation trials long-5 years in Jingzhou (JZ) and 36 years in Qiyang (QY), China. Treatments included rice-winter fallow (WF), rice-Chinese milk vetch (MV), rice-oilseed rape (RP), and rice-ryegrass (RG). At the JZ test site, 5-year MV incorporation slightly improved aggregate stability, measured by mean weight diameter (MWD) and geometric mean diameter (GMD), but without significant changes. In contrast, at QY, 36-year MV and RG incorporation significantly enhanced both MWD and GMD. Green manure addition increased SOC and DOC contents and enhanced the molecular complexity of DOC, reflected by higher molecular weight, aromaticity, and humification degree. DOC was primarily derived from plant residues and microbial metabolites, with green manure application enhancing microbial contributions. Fluorescence spectroscopy identified three DOC components: bioavailable, humic-like, and protein-like. While DOC composition at JZ remained largely unchanged after 5 years of MV incorporation, 36 years of MV and RG incorporation at QY facilitated the transformation of protein-like into humic-like components. SOC, humic-like DOC, and the humification index (HIX), were the key drivers of aggregate stability, showing direct positive effects on aggregate MWD. Humic-like DOC indirectly promoted SOC accumulation through increased DOC aromaticity and enhanced humification. Our findings highlight the central role of humic-like DOC in enhancing SOC sequestration and soil aggregate stabilization, underscoring the long-term benefits of green manure in sustainable agriculture.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107024"},"PeriodicalIF":6.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1016/j.still.2025.107032
Muhammad Masood Azeem , Therese McBeath , Jackie Ouzman , Chris Saunders , Rick Llewellyn
Deep ripping, a tillage practice that loosens compacted soil layers below 30 cm, has gained traction in south-eastern Australia's sandy soils due to recognition of its ability to overcome constraints to crop production and advances in machinery that allow the operation to be deeper and more effective. While it has the potential to improve productivity, deep ripping requires significant investment and exhibits variable effectiveness across locations, seasons, and timeframes. Despite its growing adoption, robust economic assessments of different ripping depths have been limited. This study evaluates the economic performance of deep ripping at varying depths using data from 162 treatment-site-years collected between 2014 and 2021 across on-farm trials in the southern Australian cropping zone (250–400 mm annual rainfall). Cost–benefit analysis combined with Monte Carlo simulations was used to estimate probabilistic outcomes under different scenarios and uncertainty levels. Results show that 73 % of cases yielded a positive net present value (NPV) and benefit–cost ratio (BCR), with NPV outcomes ranging from –$406 to $1218 per hectare. A cumulative grain yield gain of approximately 1 tonne per hectare was generally required to achieve a positive NPV. Ripping to depths between 40 and 60 cm—targeting the layers most restrictive to root exploration—produced higher economic returns than shallower ripping (e.g., 30 cm).
{"title":"Unearthing profits: The impact of ripping depth on cost-benefit dynamics in south-eastern Australia's sandy soils","authors":"Muhammad Masood Azeem , Therese McBeath , Jackie Ouzman , Chris Saunders , Rick Llewellyn","doi":"10.1016/j.still.2025.107032","DOIUrl":"10.1016/j.still.2025.107032","url":null,"abstract":"<div><div>Deep ripping, a tillage practice that loosens compacted soil layers below 30 cm, has gained traction in south-eastern Australia's sandy soils due to recognition of its ability to overcome constraints to crop production and advances in machinery that allow the operation to be deeper and more effective. While it has the potential to improve productivity, deep ripping requires significant investment and exhibits variable effectiveness across locations, seasons, and timeframes. Despite its growing adoption, robust economic assessments of different ripping depths have been limited. This study evaluates the economic performance of deep ripping at varying depths using data from 162 treatment-site-years collected between 2014 and 2021 across on-farm trials in the southern Australian cropping zone (250–400 mm annual rainfall). Cost–benefit analysis combined with Monte Carlo simulations was used to estimate probabilistic outcomes under different scenarios and uncertainty levels. Results show that 73 % of cases yielded a positive net present value (NPV) and benefit–cost ratio (BCR), with NPV outcomes ranging from –$406 to $1218 per hectare. A cumulative grain yield gain of approximately 1 tonne per hectare was generally required to achieve a positive NPV. Ripping to depths between 40 and 60 cm—targeting the layers most restrictive to root exploration—produced higher economic returns than shallower ripping (e.g., 30 cm).</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107032"},"PeriodicalIF":6.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-22DOI: 10.1016/j.still.2025.107026
Zhihua Zhang , Yuhui Guo , Li Li , Honghu Liu , Wenfeng Ding , Wenjian Tang , Jigen Liu
Spoil heaps, resulting from excavation and backfilling at construction sites, are highly susceptible to soil detachment and transport, leading to rill development, while large-scale infrastructure activities continually alter the soil bulk density. However, the mechanisms by which soil bulk density affects rill erosion on spoil heaps remain poorly understood. This study aims to investigate how soil bulk density governs rill morphology and hydraulic parameters on spoil heaps by conducting multiple flume tests under different flow discharges (3, 5, and 7 L min−1), slope gradients (10, 20, and 30°), and soil bulk densities (1.2, 1.5, and 1.8 g cm−3). Close-range digital photogrammetry was utilized to obtain surface elevation information, which was used for constructing a digital elevation model (DEM). The results showed: 1) soil bulk density significantly affected the soil erosion resistance of spoil heaps: as it increased from 1.2 to 1.8 g cm−3, soil erodibility decreased, while critical shear stress increased from 4.17 to 6.47 Pa and critical stream power from 1.23 to 2.13 N m−1 s−1; 2) soil bulk density significantly suppressed rill development as it increased from 1.2 to 1.8 g cm−3, reducing the mean rill density by 19.4 %, the mean rill width-depth ratio by 48.2 %, and the mean rill inclination angle by 30.5 %; 3) rill depth was the best morphological predictor of sediment yield (P < 0.01), and among the four derived morphological indicators, the degree of rill dissection was the optimal predictor of rill erosion and morphology, followed by the rill inclination angle, the rill width-depth ratio, and the rill density. This study would enhance understanding of the complicated interactions between soil bulk density and morphological development on spoil heaps, and provides strategic erosion control plans for their management.
在建筑工地开挖和回填产生的矸石堆极易受到土壤剥离和运输的影响，从而导致了细沟的发展，而大规模的基础设施活动不断改变着土壤的容重。然而，土壤容重影响废土堆上细沟侵蚀的机制仍然知之甚少。本研究旨在通过在不同流量（3、5和7 L min−1）、坡度（10、20和30°）和土壤容重（1.2、1.5和1.8 g cm−3）下进行多次水槽试验，研究土壤容重如何影响矸石堆的细沟形态和水力参数。利用近景数字摄影测量技术获取地表高程信息，用于构建数字高程模型（DEM）。结果表明：1)土壤容重对矸石堆土壤抗侵蚀能力有显著影响，当容重从1.2增大到1.8 g cm−3时，土壤可蚀性降低，临界剪应力从4.17增大到6.47 Pa，临界水流功率从1.23增大到2.13 N m−1 s−1；2)土壤容重从1.2 ~ 1.8 g cm−3显著抑制了细沟的发育，使平均细沟密度降低19.4% %，平均细沟宽深比降低48.2 %，平均细沟倾角降低30.5% %；3)细沟深度是产沙量的最佳形态预测因子（P <； 0.01），在4个衍生形态指标中，细沟解剖程度是细沟侵蚀和形态的最佳预测因子，其次是细沟倾角、细沟宽深比和细沟密度。该研究将有助于进一步认识土壤容重与矸石堆形态发育之间的复杂相互作用，并为矸石堆治理提供战略规划。
{"title":"Effect of construction activities-altered soil bulk density on spoil heap rill erosion and morphological characteristics","authors":"Zhihua Zhang , Yuhui Guo , Li Li , Honghu Liu , Wenfeng Ding , Wenjian Tang , Jigen Liu","doi":"10.1016/j.still.2025.107026","DOIUrl":"10.1016/j.still.2025.107026","url":null,"abstract":"<div><div>Spoil heaps, resulting from excavation and backfilling at construction sites, are highly susceptible to soil detachment and transport, leading to rill development, while large-scale infrastructure activities continually alter the soil bulk density. However, the mechanisms by which soil bulk density affects rill erosion on spoil heaps remain poorly understood. This study aims to investigate how soil bulk density governs rill morphology and hydraulic parameters on spoil heaps by conducting multiple flume tests under different flow discharges (3, 5, and 7 L min<sup>−1</sup>), slope gradients (10, 20, and 30°), and soil bulk densities (1.2, 1.5, and 1.8 g cm<sup>−3</sup>). Close-range digital photogrammetry was utilized to obtain surface elevation information, which was used for constructing a digital elevation model (DEM). The results showed: 1) soil bulk density significantly affected the soil erosion resistance of spoil heaps: as it increased from 1.2 to 1.8 g cm<sup>−3</sup>, soil erodibility decreased, while critical shear stress increased from 4.17 to 6.47 Pa and critical stream power from 1.23 to 2.13 N m<sup>−1</sup> s<sup>−1</sup>; 2) soil bulk density significantly suppressed rill development as it increased from 1.2 to 1.8 g cm<sup>−3</sup>, reducing the mean rill density by 19.4 %, the mean rill width-depth ratio by 48.2 %, and the mean rill inclination angle by 30.5 %; 3) rill depth was the best morphological predictor of sediment yield (<em>P</em> < 0.01), and among the four derived morphological indicators, the degree of rill dissection was the optimal predictor of rill erosion and morphology, followed by the rill inclination angle, the rill width-depth ratio, and the rill density. This study would enhance understanding of the complicated interactions between soil bulk density and morphological development on spoil heaps, and provides strategic erosion control plans for their management.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107026"},"PeriodicalIF":6.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-19DOI: 10.1016/j.still.2025.107027
Wen Zhihao, Zhai Bingnian, Jia Hanzhong, Li Ziyan
Iron-bound organic carbon (Fe-OC) is an important form of soil organic carbon (SOC), and understanding the mechanisms that underlie its formation is crucial for elucidating soil carbon cycling processes. Here, multiple inorganic leaching solutions were used to extract different types of iron minerals from soil under different nitrogen application rates. The results show that fertilization drives the activation of soil iron minerals by regulating root growth and microbial community composition. Iron mineral activation was highest under moderate nitrogen supplementation, but manure application also regulates iron mineral form. EEMs (Excitation-Emission-Matrix Spectra) analysis was also used to determine the molecular structure of Fe-OC, revealing that different types of iron minerals have a significant fractionation effect on organic carbon. To investigate the processes mediating this fractionation, FT-ICR MS (Fourier Transform Ion Cyclotron Resonance Mass Spectrometry) was employed to determine Fe-OC structure. This analysis revealed that fractionation was jointly determined by both iron-mineral and organic-carbon structure. This study reveals the mechanisms by which fertilization of regulates the formation of Fe-OC in temperate soils, improving understanding of the relationship between Fe-OC formation and fractionation.
{"title":"Iron-bound organic-carbon dynamics in a fertilized Agriustoll","authors":"Wen Zhihao, Zhai Bingnian, Jia Hanzhong, Li Ziyan","doi":"10.1016/j.still.2025.107027","DOIUrl":"10.1016/j.still.2025.107027","url":null,"abstract":"<div><div>Iron-bound organic carbon (Fe-OC) is an important form of soil organic carbon (SOC), and understanding the mechanisms that underlie its formation is crucial for elucidating soil carbon cycling processes. Here, multiple inorganic leaching solutions were used to extract different types of iron minerals from soil under different nitrogen application rates. The results show that fertilization drives the activation of soil iron minerals by regulating root growth and microbial community composition. Iron mineral activation was highest under moderate nitrogen supplementation, but manure application also regulates iron mineral form. EEMs (Excitation-Emission-Matrix Spectra) analysis was also used to determine the molecular structure of Fe-OC, revealing that different types of iron minerals have a significant fractionation effect on organic carbon. To investigate the processes mediating this fractionation, FT-ICR MS (Fourier Transform Ion Cyclotron Resonance Mass Spectrometry) was employed to determine Fe-OC structure. This analysis revealed that fractionation was jointly determined by both iron-mineral and organic-carbon structure. This study reveals the mechanisms by which fertilization of regulates the formation of Fe-OC in temperate soils, improving understanding of the relationship between Fe-OC formation and fractionation.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"258 ","pages":"Article 107027"},"PeriodicalIF":6.8,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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