European Journal of Soil Science最新文献

Yuan, C., Z. Sun, and J. Li. 2023. Plant Residues Do Not Have an Immediate Impact on Soil Bacterial Community Composition and Abundance. European Journal of Soil Science 74, e13365.

In Correspondence on the first page, the text ‘Sun Yet-sen University’ was incorrect. This should have read: ‘Sun Yat-sen University’.

We apologise for this error.

Multispectral imaging satellites such as Sentinel-2 are considered a possible tool to assist in the mapping of soil organic carbon (SOC) using images of bare soil. However, the reported results are variable. The measured reflectance of the soil surface is not only related to SOC but also to several other environmental and edaphic factors. Soil texture is one such factor that strongly affects soil reflectance. Depending on the spatial correlation with SOC, the influence of soil texture may improve or hinder the estimation of SOC from spectral data. This study aimed to investigate these influences using local models at 34 sites in different pedo-climatic zones across 10 European countries. The study sites were individual agricultural fields or a few fields in close proximity. For each site, local models to predict SOC and the clay particle size fraction were developed using the Sentinel-2 temporal mosaics of bare soil images. Overall, predicting SOC and clay was difficult, and prediction performances with a ratio of performance to deviation (RPD) > 1.5 were observed at 8 and 12 of the 34 sites for SOC and clay, respectively. A general relationship between SOC prediction performance and the correlation of SOC and clay in soil was evident but explained only a small part of the large variability we observed in SOC prediction performance across the sites. Adding information on soil texture as additional predictors improved SOC prediction on average, but the additional benefit varied strongly between the sites. The average relative importance of the different Sentinel-2 bands in the SOC and clay models indicated that spectral information in the red and far-red regions of the visible spectrum was more important for SOC prediction than for clay prediction. The opposite was true for the region around 2200 nm, which was more important in the clay models.

Vegetated blue carbon environments have the potential to sequester large amounts of carbon due to their high productivity and typically saturated, anaerobic soils that promote carbon accumulation. Despite this, and the coupling of Fe–S–C cycling processes, the influence of iron (Fe) in acid sulfate soils (ASSs) on carbon sequestration in blue carbon environments has yet to be systematically explored. To address this knowledge gap, this review provides an overview linking the current state of blue carbon studies with the influence of Fe on soil organic carbon (SOC), as well as the potential influence ASSs have on carbon sequestration. A systematic literature review on SOC stock in blue carbon studies using the Web of Science database yielded 1477 results. Studies that investigated the drivers of carbon accumulation in blue carbon studies were restricted to vegetation species/structure and geomorphic setting, and few focused on soil properties and type. Iron both protects and enhances SOC decomposition depending on its redox state. Under oxic conditions, Fe oxyhydroxides can protect SOC via adsorption, co-precipitation and by acting as a cement in soil aggregates. Iron can also increase SOC decomposition under oxic conditions due to Fenton reactions. However, under anoxic conditions, SOC mineralisation can also occur as Fe acts as an electron transporter in dissimilatory reductions. ASSs contain a range of Fe minerals, but the oxidation of Fe sulfides can result in soil acidification (pH < 4) and subsequent impacts, such as a decline in vegetation health, poor water quality and infrastructure damage. Therefore, potential SOC protection by Fe under oxic conditions may come at the cost of soil acidification in ASSs, while maintaining anoxic conditions prevents acidification but may enhance SOC decomposition. Future studies on the influence of ASSs on Fe–S–C cycling and carbon sequestration in blue carbon environments are important, particularly for ‘hotspots’ such as Australia.

A prevalent strategy to mitigate the negative impacts of soil compaction or sealing on urban trees involves installing aeration tubes, aeration holes or near surface aeration horizons to enhance gas exchange between the soil air and the atmosphere. Despite their widespread use, there is currently no scientific evidence confirming their effectiveness. In this study, gas exchange between the atmosphere and soils that were aerated using different methods was modelled and evaluated in the laboratory and in the field. Both the laboratory and field measurements could be modelled well with the simulation model. The research showed that the effectiveness of aeration tubes and holes is highly dependent on the air-filled porosity of the soil. The more gas exchange can take place via the soil pores, the lesser the influence of the aeration equipment. Thus, the use of aeration tubes is not necessary when using tree substrates in unsealed tree pits but could mitigate disturbances in soil aeration in compacted and fine-grained soils with low air capacity. However, modelling shows that the effect of aeration tubes and holes is less than expected and that near-surface aeration layers are generally more effective than vertical aeration systems. With the help of the modelling of gas exchange as presented here, it is possible to optimise the level of aeration of the soil depending on the existing degree of compaction and/or the planned surface sealing.

Rice grown in California constitutes 20% of total U.S. rice production and is typically grown in a continuous rice monoculture system. In recent years, growers have been forced to fallow their lands often due to winter droughts leading to water restrictions or spring rains leading to prevented planting. Increased soil aeration due to fallowing creates knowledge gaps in soil nitrogen (N) availability. A two-year field study was conducted to evaluate differences in crop N uptake between rice cultivation following a fallow season, fallow rice (FR) and continuous rice (CR) systems. Crop uptake of soil N (N uptake_soil) and fertiliser N (N uptake_fertilizer) were quantified using ¹⁵N-enriched ammonium sulfate applied in microplots as a preplant (150 kg N ha⁻¹) or topdress (30 kg N ha⁻¹) application. In both seasons when N was applied as a preplant fertiliser, the FR treatment had a higher grain yield than did the CR treatment, with yield differences of 2.3 Mg ha⁻¹ in 2021 (p < 0.05) and 1.7 Mg ha⁻¹ in 2022 (p < 0.05). Examining the sources of crop N uptake for preplant applied N, on average, N uptake_soil in the FR treatment was 16.7 kg N ha⁻¹ higher than the CR treatment at maturity (p < 0.05). In contrast, N uptake_fertilizer was similar between treatments. Additionally, comparable soil and crop fertiliser N recoveries in CR and FR preplant N suggested that the pathways and magnitudes of fertiliser N losses were similar in both systems. These results indicate that N uptake_soil was primarily responsible for lower N uptake in CR. Similar results were found when N was applied as a topdress, where FR had increased N uptake_soil in both years. We further investigated the reason for lower rates of N uptake_soil in CR. Soil phenols, which have been documented to accumulate in continuously flooded rice systems and stabilise soil N, were quantified in the field study. Complementing the rigorous field study, a regional survey study that incorporated nine paired fields was conducted to quantify regional phenol levels. In both the field and the regional survey studies, soil phenols were higher in CR than in FR fields. Together, higher phenol levels and lower N uptake_soil in CR provide mechanistic evidence that the introduction of a season-long fallow to continuous rice systems enhances soil N availability by reducing organic substrate recalcitrance. Future work should identify the duration needed for soil phenol accumulation to impair soil N cycling under continuous rice cultivation, as well as any roles of soil microbial populations in these soil N cycling patterns.