European Journal of Soil Science最新文献

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.

Saline-sodic paddy soils in the Songnen Plain suffer from nitrogen loss due to nitrification. The purpose of the study is to explore soil saline improvement and nitrification mitigation effects of polyaspartic calcium (PASP-Ca) by evaluating changes of soil quality, nitrification, and microbial communities. Four PASP-Ca application treatments (additions of 0, 500, 1000, and 1500 kg hm⁻²) were studied in an experiment in saline-sodic paddy soils of the Songnen Plain, China. Results showed that PASP-Ca application significantly decreased soil pH, electrical conductivity (EC), and water-soluble salt ions, and significantly increased soil total carbon (TC), total nitrogen (TN), urease activity (UA), and sucrase activity (SA). PASP-Ca application significantly slowed down soil nitrification, which was manifested in a significant increase in ammonium nitrogen ($��{\mathrm{NH}}_4^{+}�-�N�$) and a significant decrease in nitrate nitrogen ($��{\mathrm{NO}}_3^{-}�-�N�$) and ammonia monooxygenase activity (AMO). The composition and distribution of soil nitrifying microbial communities were affected by soil salinity, nutrient, and enzyme activities. Ammonia-oxidizing bacteria (AOB) plays an important role in the nitrification process of saline-sodic paddy soils, while PASP-Ca application significantly inhibited nitrification by suppressing AOB amoA gene abundance. This study shows that PASP-Ca, as an effective amendment, can improve soil salinization and slow down nitrification, which has an important role and significance in improving nitrogen utilization and reducing nitrogen loss of saline-sodic soils.

The bacterial communities that harbour the pyrroloquinoline quinone gene (pqqC-harbouring bacteria communities) play a pivotal role in the mobilization of inorganic phosphorus (Pi). However, there is limited knowledge regarding the connection between soil pqqC-harbouring bacterial communities and Pi fractions, as well as the factors that can regulate them, particularly under different fertilization strategies in the agricultural soil. High-throughput sequencing was used to investigate the pqqC-harbouring communities from the wheat (Triticum aestivum L.)–sweet potato (Ipomoea batatas L.) season in a 9-year field experiment, including without fertilization (control), nitrogen (N) and potassium (K) fertilization (NK), NPK fertilization (NPK) and the combined application of chemical NPK and organic fertilizer (NPKM), and to explore their relationships with Pi fractions and their regulatory factors. Long-term N fertilization and crop type substantially changed the community composition of pqqC-harbouring bacteria but had no effect on their diversity. In two crop seasons, long-term N fertilization significantly increased the content and proportion of moderately labile Pi (aluminium- and iron-bound P) and available P (AP) and significantly decreased the proportion of recalcitrant Pi (calcium-bound P) compared with the control. Specifically, AP increased by 79%–778%, Fe-P by 64%–88%, and Al-P by 71%–308%, while Ca-P decreased by 10%–59%. N fertilization increased the relative abundance of Micromonospora, which was significantly positively correlated with moderately labile Pi and AP. Moreover, the relative abundance of some Streptomyces increased by 391% in the sweet potato season, and they were positively correlated with AP. Structural equation modelling revealed that the interplay between the pqqC-harbouring community composition and Pi mobilization was mainly governed by pH, underscoring the role of pH in shaping the communities of Pi-mobilizing microbes and their effect on Pi mobilization processes. This study emphasized how N fertilization and crops reshape Pi-mobilizing microbial communities, which in turn affects Pi mobilization and P availability. Overall, these findings offer valuable insights into optimizing P cycles and availability through N fertilization strategies.

Biological invasion is one of the major challenges to changing ecosystems worldwide. Red fire ants are a prime example of invasive soil animals. However, the impacts of their invasion on the native soil animal communities are still poorly understood. Here, we investigated how the biomass and diversity of soil microarthropods (incl., Collembola and Acari) vary between areas affected by red fire ants at different degrees (i.e., OA, occurrence area, 0–20 m from the nest; PCA, prevention and control area, 20–50 m; POA, potential occurrence area, 50–100 m). We also tested whether the potential effects of ant invasion on other animals are associated with changes in soil properties in the invaded areas. Our results showed a decline of 64% in species richness, 74% in density, and 72% in biomass of microarthropods in OA in comparison with POA. This reduction was mainly driven by the decrease of Acari, while no reduction in Collembola biomass was observed. Despite soil properties being significantly different between ant-impacted areas, structural equation models indicated that the direct association of invasion with microarthropod communities is stronger than the indirect association mediated by soil properties. Therefore, we consider that direct biological interaction is more likely the major mechanism behind the observed changes in microarthropod communities. The effects of red fire ants were different among taxonomic and functional groups, with litter-dwelling Collembola, Oribatida, and Mesostigmata (Acari) affected more negatively than soil-dwelling and surface-dwelling Collembola. Further, red fire ants affected the turnover component of beta-diversity (i.e., replacement of species) for both Collembola and Acari. However, the impact on the nestedness component, which is related to species local extinction and population decline, was only detected for Acari. Our study shows that red fire ant invasion is associated with the depletion of soil microarthropod community, and especially highlights that Acari are more vulnerable to this invasion compared to Collembola. The divergent response between different taxonomic and functional groups of microarthropods and the consequent shift in microarthropod communities may have important significance to soil ecological functioning in the impacted areas.

The literature regarding how rill longitudinal profile (concave and convex) affects soil loss and flow resistance is still lacking. The only analysis available in the literature for rills is limited by the fact that measurements were performed for a unique mean slope value s_p (18%). In this article, further rill measurements were conducted on a plot with s_p = 15% and complex profile shapes and were used to widen the knowledge about the influence of longitudinal profile shape on rill scour, eroded volume, and flow resistance. The findings highlighted that the concave profile has a homogeneous spatial distribution of moderate scours, whereas the scours in the convex one are deeper and more confined, but they are not placed after the slope change as found for s_p = 18%. The mean scour depth, which accounts for the discharge and profile shape effects, is not (concave) or is weakly (convex) related to the flow discharge. The concave profile determined a reduction of approximately 57% of the total eroded volume when compared with the convex profile shape, confirming that a concave hillslope limits erosive phenomena. Finally, the flow resistance equation guaranteed a precise estimation of the Darcy–Weisbach friction factor.