European Journal of Soil Science最新文献

When sulfidic soils become drained, oxidation of pyrite can cause acidification and formation of iron (Fe) oxyhydroxy sulfate phases such as jarosite. Remediation via re-establishment of reducing conditions requires submergence and addition of biodegradable organic carbon (OC) to stimulate activity of reducing bacteria. Addition of straw-derived dissolved organic carbon (DOC) has been shown to induce rapid microbial reduction in sandy sulfuric (pH <4) soils. In clayey sulfuric soil, DOC may be less efficient because of limited availability for microbes due to its sorption to reactive minerals. We tested the possible effect of sorption on the remediative potential of straw-derived DOC using a set of incubation and sorption experiments, and used solid-state ¹³C-NMR spectroscopy for the chemical characterization of OC. The tested materials were a clayey, jarosite-containing sulfuric soil (pH 3), and artificial model soils composed of synthesized jarosite either mixed with quartz powder or quartz powder + clay minerals. The results showed that addition of DOC from wheat straw induces reduction conditions varying with soil sorptivity. For the model soils, DOC sorption was little, and DOC additions of 0.8 mg OC g⁻¹ were sufficient to achieve permanently reducing conditions and an increase in pH to >6.0. In the natural sulfuric soil, much higher DOC additions were needed (1.8 mg OC g⁻¹) to facilitate continuous reducing conditions, but pH increased only to values no higher than 5.0–5.5. The natural soil revealed strong sorption of added DOC. Sorption preferentially reduced the proportion of proteins, while the proportion of lignin components, which can hardly be used by microorganisms under reducing conditions, remained relatively high in solution. Thus, high DOC additions were required to overcome the sorption-induced limitations in OC availability. The results suggest that wheat straw-derived DOC is a promising approach also for remediation of clayey sulfuric soils; however, OC additions need to be adjusted to compensate for possible sorption.

The temperature sensitivity (Q₁₀) of soil organic C (SOC) decomposition is an important parameter to predict C dynamics under climate change. Given that SOC is mainly protected by aggregates and minerals, differentiating the Q₁₀ of the two C fractions helps to explain bulk soil C dynamics. In the present study, we collected agricultural soils from adjacent paddy and upland areas in mid-temperate (Mollisols) and subtropic (Ultisols) regions of China. We employed density fractionation to separate aggregate-protected and free mineral-associated C fractions of soil samples and determined the Q₁₀ of SOC and the two C fractions at 15 and 25°C incubated conditions. Results showed that the Q₁₀ of SOC for Mollisols were lower than that for Ultisols, with an exception of aggregates in upland soils. Aggregate-protected C had lower Q₁₀ than free mineral-associated C, except in the upland Mollisols. The Q₁₀ of SOC was negatively correlated with the proportion of C protected in aggregates, whereas it was positively correlated with the proportions of mass or C of free minerals. Given that the mass and C proportion of aggregates in bulk soils of Mollisols were 271% and 80% higher than of Ultisols, respectively, the SOC of Mollisols exhibited lower Q₁₀ than Ultisols. Therefore, stronger soil aggregation and higher proportion of aggregate-protected C contributed to the lower temperature sensitivity of SOC in Mollisols. Consequently, agricultural practices aimed at promoting soil aggregation will alleviate SOC loss under future global warming scenarios.

Asif, S. K. M. D., & Debnath, A. (2024). Adsorption kinetics of organic phosphates on goethite and aluminium oxide: The equation used to describe the reaction. European Journal of Soil Science, 75(4), e13545. 10.1111/ejss.13545

The name of the first author was originally published as ‘S.K. M.D. Asif’, in both the author byline and the Author Contributions section. The correct name of this author should be SK. MD. Asif

We sincerely apologize for this error.

Whether farmers should consider the role of arbuscular mycorrhizal fungi (AMF) in agriculture is a hotly debated topic. We aimed to investigate the role of indigenous AMF in reducing nitrogen (N) loss from paddy fields via runoff, leaching, NH₃ volatilization, and N₂O emission. We conducted a pot experiment employing a mycorrhiza-defective rice mutant (non-mycorrhizal) as the control, grown in soil containing indigenous AMF. The corresponding AMF treatment used the progenitor of this mutant with the same soil. The plants were fertilized with nitrogen, phosphorus and potassium 6 weeks after sowing. The root colonization was 23% in mycorrhizal rice, and no typical AMF structures were observed in the roots of non-mycorrhizal rice. Our findings indicated that the mycorrhizal system exhibited lower N concentrations of runoff and leachate further compounded by reduced fluxes of N₂O and NH₃. This led to 14% decrease (mycorrhizal rice 111 kg N ha⁻¹; the non-mycorrhizal rice: 129 kg N ha⁻¹) in cumulative N loss within 3 days post-fertilization. While this AMF effect was consistent across the four tested N loss pathways, differences were observed between NH₄⁺-N and NO₃⁻-N in the runoff pathway. Notably, our results revealed no evidence of trade-offs in AMF effect on N loss among the tested pathways. Additionally, mycorrhizal rice had larger shoots and roots than their non-mycorrhizal counterparts. Our study underscores the potential benefits of indigenous AMF in paddy fields for mitigating water pollution and reducing greenhouse gas emission.

Converting monocultures to mixed plantations has been emphasized to improve ecosystem productivity and services. However, the impact of tree species identity on phosphorus (P) bioavailability in acidic soils in subtropical China, where P is relatively scarce, is not fully understood. This study explored the changes in soil biologically-based P fractions and the effect of mineral and microbial properties on P transformation after mixing five broadleaved trees (Bretschneidera sinensis, Manglietia conifera, Cercidiphyllum japonicum, Michelia maudiae and Camellia oleifera) individually with coniferous trees (Pinus massoniana). The results showed that most mixed plantations significantly increased pH and citric acid and decreased exchangeable Fe³⁺ and Al³⁺ and the activation of Fe and Al oxides compared with monospecific plantations, which significantly reduced P precipitation and adsorption. Mixed planting significantly increased phosphatase activity and altered the community composition of P-mobilizing bacteria carrying phoD and pqqC genes, which contributed to organic P mineralization and inorganic P (Pi) desorption. Mixed planting increased microbial biomass and the relative rate of microbial biomass P turnover. Labile organic P (Enzyme-P) was a potentially significant source of soluble Pi (CaCl₂-P) among the biologically-based P fractions, plus microbial biomass P. Overall, introducing broadleaved species, especially in species (e.g. Cercidiphyllum japonicum, Michelia maudiae and Camellia oleifera) with relatively high litter quality and belowground secretions (e.g. citric acid, phosphatase), significantly increased the solubilization of recalcitrant Pi (HCl-P), desorption of chemisorbed Pi (Citrate-P) and accumulation and mineralization of Enzyme-P, thereby increasing the available P pools. Redundancy analysis demonstrated that P fractions were mainly driven by phosphatases, exchangeable cations, floor fresh litter lignin/N and citric acid. Altogether, we highlight the importance of choosing tree species mixtures that have synergistic or complementary effects when constructing mixed plantations in order to alleviate soil P limitations.

Vineyard soils are often of inherently poor quality with low organic carbon content. Management can improve soil properties and thus soil fertility. In European wine-growing regions, a broad range of inter-row management strategies evolved based on specific local site conditions and the varying effects of management intensities on soil, water balance, yield and grape quality. Accordingly, there is a need to investigate the effects of locally common cover crop management strategies and tillage intensity on soil organic carbon content and soil physical parameters. In this study, we investigated the impact of the most common inter-row management practices in Austria, France, Romania and Spain. In all countries, we compared paired sites. Each site with cover crops and inter-row management of low intensity was compared with one site with (temporarily) bare soil and high management intensity. All studied sites with cover crops and low management intensity, except those in Spain, had higher organic carbon contents than the paired more intensively managed vineyards. However, the highly water-limited Spanish vineyards with temporary cover crops had lower organic carbon contents than the paired sites with bare soil. Sites with more organic carbon had better results for bulk density, percolation stability (PS), hydraulic conductivity and available soil water, with soil hydraulic parameters being less pronounced than others. Country comparison of inter-row weed control systems showed that PS was particularly low in sampled vineyards in Romania and Spain, where weed control is based on intensive mechanical tillage. Alternating management systems with tillage every second inter-row showed a decrease in soil structure compared with permanent green cover. Thus, inter-row management with cover crops and reduced tillage increases soil organic carbon content and improves soil structure compared with bare soil management. If local constraints, such as water scarcity, do not allow year-round planting, alternating inter-row management with several years of alternating periods may be an option to mitigate those adverse effects. However, negative impact on the soil structure occurs with the very first tillage operation, whereas negative effects on the carbon balance only appear after long-term use of tillage.

When considering ecosystem services in line with relevant Sustainable Development Goals, the proposed logical sequence of the ten pedometric challenges can form a framework defining effective contributions by the soil science discipline to the sustainability challenge facing society. Defining relatively simple, but scientifically sound, indicators and thresholds for ecosystem services can be the basis for a transparent regulatory system justifying payment for ecosystem services provided to society. The current serious lack of trust between the policy and farming arenas can and should be restored by scientists and farmers working jointly in Living Labs, aiming to become Lighthouses, to be part of Communites of Practice (CoP). A Living Lab case study is reviewed showing that much know-how is already available to define indicators and innovative cutting-edge methodology adds attractive new opportunities for rapid and relatively cheap characterizations. Field work remains essential and just routinely applying standard techniques fed by existing databases may lead to poor results. Research on indicator-thresholds has a high priority. In the case study, the important soil fertility indicator was based on the current procedure of field sampling and fertilization recommendations by specialized agencies, that is already followed by 85% of farmers. This could be expanded by including indicators for other ecosystem services thereby contributing substantially to the societal sustainability debate. Soil health plays a key role when contributing to all ecosystem services. Showing this with specific examples in a Living Lab/Lighthouse and CoP context is the best way to promote the profession which is needed to justify current major funding. Not only cutting-edge research can contribute to defining indicators and thresholds. A hundred years of research has produced many valuable insights and methodologies that can be applied as well. The: ‘better’ can be the enemy of the: ‘good’. The sustainable development challenge is highly urgent: there is no time to lose.

Non-steady-state chambers are widely employed for quantifying soil emissions of CO₂, CH₄, and N₂O. Automated non-steady-state (a-NSS) soil chambers, when coupled with online gas analysers, offer the ability to capture high-frequency measurements of greenhouse gas (GHG) fluxes. While these sampling systems provide valuable insights into GHG emissions, they present post-measurement challenges, including the management of extensive datasets, intricate flux calculations, and considerations for temporal upscaling. In this study, a computationally efficient algorithm was developed to compute instantaneous fluxes and estimate diel flux patterns using continuous, high-resolution data obtained from an a-NSS sampling system. Applied to a 38-day dataset, the algorithm captured concurrent field measurements of CO₂, CH₄, and N₂O fluxes. The automated sampling system enables the acquisition of high-frequency data, allowing the detection of episodic gas flux events. By using shape-constrained additive models, a median percentage deviation (bias) of −1.031 and −4.340% was achieved for CO₂ and N₂O fluxes, respectively. Simpson's rule allowed for efficient upscale from instantaneous to diel flux values. As a result, the proposed algorithm can rapidly and simultaneously calculate CO₂, CH₄, and N₂O fluxes, providing both instantaneous and diel values directly from raw, high-temporal-resolution data. These advancements significantly contribute to the field of GHG flux measurement, enhancing both the efficiency and accuracy of calculations for a-NSS soil chambers and deepening our understanding of GHG emissions and their temporal dynamics.

Agricultural practices and meteorological conditions affect soil structure and soil hydraulic properties. However, their temporal evolution is rarely studied, and even less in the field. Thus, their dynamics are rarely taken into account in models, often leading to inconsistent results and poor decision making. In this study, the temporal evolution of water retention properties and soil structure was monitored over a 3-year period under several contrasting production systems. Soil Water Retention Curves (SWRCs) obtained directly in the field (with soil water content and potential sensors) were compared with theoretical SWRCs predicted by pedotransfer functions (PTFs) and laboratory SWRCs measured on undisturbed samples. Bulk densities were measured every 2 months. Results indicate a high degree of variability in SWRCs over time and between production systems. The results suggest that variations in the soil water retention behaviour can be induced by crop differentiation, weed control, crop residue management, compaction during harvest, or the introduction of temporary grassland. Contrasting climatic conditions between 2021 (water excess), 2022 (severe drought) and 2023 (intermediate) provided a unique opportunity to study the resilience of the crop systems to extreme climatic conditions. Different soil drying dynamics were observed and some agricultural practices were identified as influencing the soil water retention behaviour for at least 2 years. Comparison of SWRCs showed that the theoretical curves obtained from PTFs are not a good representation of the field SWRCs, especially for less conventional agricultural practices. The laboratory curves are closer with similar trends. However, these SWRCs are not optimal for investigating the temporal evolution of water retention properties. This research also shows that agricultural practices and crops can be levers for contributing to greater food resilience against future climatic conditions. Therefore, to assess the relevance of production systems for tomorrow's needs, studies should focus on the impact of multi-cropping systems on water retention dynamics in the field.

Soil water conservation in dryland agriculture mainly depends on precipitation. We chose 35 long-term experiments and analysed the data by using meta-analysis to check how fallow management methods affect soil water storage of dryland winter wheat planting (SWS), precipitation storage efficiency (PSE), crop yield and water use efficiency (WUE). No-tillage (NT), compared to conventional tillage (CT) in the fallow period, increased PSE, SWS, grain yield and WUE by 32.9%, 27.1%, 30.5% and 22.6%, respectively. Reduced tillage (RT) and subsoil tillage (ST) increased PSE by 15.2% and 11.7%, SWS by 17.4% and 15.0% and grain yield by 15.5 and 13.8%, respectively, but these had a non-significant effect on WUE. The conservation tillage methods interacted significantly with the residue management and fallow mulching practices. Compared to CT, the conservation tillage methods with fallow mulching increased PSE, SWS, grain yield and WUE, but the growing of cover crops (designated as biological mulching) decreased PSE, SWS and grain yield by 17.3%, 13.0% and 32.0%, and had a non-significant impact on WUE. Under the condition of straw mulching, NT increased PSE, SWS, grain yield and WUE by 43.7%, 38.1%, 40.6% and 42.9%, respectively, compared to CT. NT and RT increased the PSE, SWS and WUE, under normal mean annual precipitation (MAP), however, ST increased these observations under wet MAP, compared to CT. The effects of tillage methods varied with soil texture, and they were highly interrelated with water conservation, wheat yield and water use. We conclude that compared to conventional tillage, the conservation tillage methods increased soil water conservation during the fallow period, which increased wheat yield and water use. Moreover, NT with or without residue retention increased the fallow water conservation and wheat yield. Crop residues should be retained while applying RT and ST to grow winter wheat in dryland regions.