2026-03-27
Manuel Sampériz Sarvisé, Asunción Usón Murillo
While within-plot soil variability strongly influences crop development and agronomic management efficiency, practical and transferable methods for characterizing this variability remain limited. This study proposes a remote sensing framework to assess soil-driven crop heterogeneity using Normalized Difference Vegetation Index (NVDI)-derived parameters and phenological analysis. Crop dynamics were monitored using Sentinel-2 imagery to identify key phenological stages (start of season, maximum development, and senescence), while high-resolution PlanetScope imagery was used to analyze within-plot spatial variability. NDVI dispersion metrics were used as proxies for spatial variability in crop development across soil units and under homogeneous management conditions to isolate soil effects. Results showed that NDVI standard deviation effectively captured spatial heterogeneity in crop development, revealing greater variability in Glacis Slope soils compared with the more homogeneous Platform unit. Crop senescence emerged as the most informative stage for detecting soil-driven variability, while emergence patterns were influenced by sowing dates and early establishment conditions. Analyses under homogeneous management confirmed that soil properties controlling soil moisture dynamics govern spatial variability in crop response. The proposed methodology provides a robust, low-cost, and transferable approach for identifying within-plot variability and supports precision agriculture by enabling site-specific management decisions based on satellite-derived indicators.
DOI: 10.3389/sjss.2026.146942026-01-26
Cristian Vasilică Secu, Radu Gabriel Pîrnău
The pedodiversity concept integrates diversity indices and GIS techniques to assess the spatial heterogeneity of soils. This study proposes using pedodiversity indices for Romania’s geographic regions and relief units to evaluate their connectivity. Keeping the map scale, the soil type-subtypes vector was simplified to soil types. Aggregation reduced the number of polygons from two taxonomic categories only for certain taxa (variable taxa), while constant taxa remained unchanged. Low connectivity in parts of the Southern and Eastern Carpathians and the Western Plain suggests the presence of numerous subtypes within soil assemblages, whereas arid regions (e.g., Dobrogea Plateau), characterized by lower taxonomic variability, display strong connectivity. The connectivity index ranks landform units as follows: plains < plateaus < Carpathians < Subcarpathians, differing from the geographic regions hierarchy. Among the indicators tested, the connectivity index exerts the strongest influence on spatial ranking, while the diversity index proves less decisive.
DOI: 10.3389/sjss.2026.156642026-01-14
Rafael Hernández Maqueda, Fernando Del Moral
Intensive greenhouse cultivation, characterized by high agrochemical inputs and minimal organic amendments, maximizes crop productivity but often leads to soil degradation and environmental harm, notably through nitrate leaching and increased nitrous oxide (N2O) emissions. To reduce agricultural inputs that may lead to soil degradation, this study evaluates an alternative fertilization strategy based in ecological intensification (EI). Specifically, a management system incorporating horticultural crop residues and organic amendments—with limited use of inorganic fertilizers—was compared to a conventional fertilization system (C) over a six-year period. Soil quality was assessed using physical and chemical indicators alongside microbial gene abundance (16s, ITS) and genes related to denitrification processes (nirK, nirS, nosZ1, and nosZ2) measured by Real-Time PCR. The EI system enhanced soil organic matter and soil structure by enhancing macroporosity and aggregate stability. However, it also increased the risk of salinization. Fungal abundance and the key denitrification genes (nosZ1 and nosZ2) were significantly higher under EI management. The fungal-to-bacterial ratio approached, but did not reach, statistical significance, and the nos/nir gene ratio—an indirect indicator of N2O emission potential—remained similar between treatments. These findings suggest a complex interaction between soil quality and denitrifier community dynamics that warrants further investigation, particularly to assess potential N2O emissions.
DOI: 10.3389/sjss.2025.151842025-11-27
Yonggang Huang, Hongri Zhang, Xinzhong Wang, Yuexing Wu, Xianliang Tan, Kang Xiong
This study systematically analyzed the influence mechanism of the ratio of organic fertilizer (OF), slow-release fertilizer (SRF), and rice straw (RS) on the crack ratio and root content of expansive soil through Box-Behnken experimental design (BBD) and quadratic polynomial regression model. The results show that RS has the greatest contribution to fissure suppression. For every 0.1% increase in its content, the crack ratio decreases by 0.204% (p 10%) significantly increases the crack ratio by exacerbating the non-uniformity of drying shrinkage (β = 0.132, p 12%), drainage measures need to be combined to control the risk of salinization. This study provides a quantitative ratio design and risk control basis for the improvement of expansive soil with agricultural waste.
DOI: 10.3389/sjss.2025.149982025-10-02
Paula Madejón, Lisa Ciadamidaro, Michel Chalot, Carmen M. Navarro-Fernández, Laura L. de Sosa, Engracia Madejón
Ecological restoration of mine dumps poses a significant global challenge. This study explores the viability of plant growth in the soils of the Riotinto mine, where high concentration of trace elements hinders vegetation establishment. Greenhouse experiments were conducted using 5 poplar hybrids (PA148, PA149, PA152, PA153 and the parental P10) and two herbaceous species, Brassica juncea L. and Lablab purpureus, grown in both contaminated and uncontaminated soils. The contaminated soil (RT) had an initial acidic pH of 3.07, which required the addition of a sugar lime amendment (SL), to reduce the availability of cationic trace elements. Poplar hybrids were grown for 3 months in both uncontaminated (C) and amended (RT + A) soils, while the herbaceous species were grown for 1 month in C, RT, and RT + A soils. Soil parameters, including pH, organic matter (OM), and both pseudototal and available trace element concentrations (extracted using 0.01 M CaCl2), were analyzed. Plant biomass, trace element accumulation, and nutritional content in aerial tissues were also assessed. All poplar hybrids survived, with P152 and P153 demonstrating the highest survival rates and significant accumulation of trace elements, particularly Cd, Pb and Zn, in their leaves under RT + A soil conditions. B. juncea showed very limited growth compared to the other species, although it accumulated the highest concentration of trace elements. In contrast, L. purpureus demonstrated successful germination and growth in RT soil, showing strong tolerance to both acidity and contamination while maintaining the lowest levels of trace elements in its aerial tissues. These results highlight the importance of selecting appropriate plant species and soil amendments tailored to site-specific conditions and remediation goals.
DOI: 10.3389/sjss.2025.145552025-09-25
Weina Zhang, Dongzhi Xu, Han Wang, Bingshen Jiang, Changli Liang, Minzhi Huang, Zilong Chen, Xinmin Zhang, Dong Su, Mingfu Yu, Junhe Liu
The North China Plain (NCP), a major maize production region in China, faces critical challenges of P overuse under intensive farming, leading to soil P accumulation, leaching risks, and threats to groundwater quality and P resource sustainability. This study employed a parameter-calibrated APSIM model (v7.9) to simulate long-term effects (2007–2017) of eight P application rates (0–300 kg P2O5 ha−1) on maize growth, P utilization, and soil P dynamics using field trial data from Quzhou Country (36.9°N, 115.0°E), Hebei Province, China. Results demonstrated that 71 kg P2O5 ha−1 optimized maize productivity, achieving mean aboveground biomass and grain yields of 17.5 t ha−1 and 9.3 t ha−1, respectively, with a P use efficiency (PUE) of 17%. Continuous P fertilization induced progressive accumulation of labile P (32 mg/kg under 75 kg P2O5 ha−1 application rate vs. 40.8 mg/kg under 100 kg P2O5 ha-1 application rate in 2017) and stable inorganic P pools, with P100 exceeding the environmental threshold (39.9 mg/kg) for calcareous soils. Post-cessation simulations (22 years) revealed that legacy P from 11-year P75 applications sustained maize yields at 8–10 t ha−1 for 12–13 years, despite labile P decreasing from 32.3 to 15.8 mg/kg. Model analysis highlighted limitations in APSIM’s current P module, which prioritizes adsorption-desorption over precipitation-dissolution mechanisms critical for calcareous soils. These findings provide a theoretical foundation for P reduction strategies in NCP maize systems.
DOI: 10.3389/sjss.2025.147182025-09-18
Asunción Usón Murillo, Jesús Betrán Aso, Manuel Sampériz Sarvisé
In the context of the FAO Global Soil Partnership, the Spanish Society of Soil Science (Sociedad Española de la Ciencia del Suelo, SECS), the University of Zaragoza and the Agroenvironmental Laboratory of the Government of Aragon promoted initiatives for the harmonization of soil analysis methods in Spain. These included the development of an inventory of laboratories and the organization of proficiency tests of soil analytical results. The first test, carried out in 2019, showed significant discrepancies among laboratories, which led to methodological improvements for the second test in 2021. Twenty-six laboratories participated in the latter test, evaluating soil fertility parameters (organic matter, assimilable phosphorus, potassium and magnesium) and textural fractions (clay and sand). The analyses, carried out in triplicate, were evaluated using robust statistics and Zscore. The 2021 results showed that sample ‘HUERTO’ had a higher percentage of satisfactory results than “BIPEA,” mainly due to its greater standard deviation. The assessment identified problems arising from differences in analytical methods, especially for organic matter. A comparison of the two exercises revealed that, out of 17 laboratories analyzed, 10 improved their overall performance, 3 maintained it and 4 deteriorated. A positive trend was observed for assimilable phosphorus and magnesium, parameters that achieved satisfactory overall ratings, while sand and organic matter content showed more problematic results. Despite the improvements observed, only five out of the seventeen laboratories achieved an overall satisfactory rating, which underlines the need to regularly maintain and strengthen these proficiency tests. These results are particularly relevant within the context of the CAP Strategic Plan, which requires reliable data on the state of agricultural soils. This exercise has proven to be an effective tool for encouraging continuous improvement in the analytical quality of soil laboratories, contributing to the sustainable governance of soil resources.
DOI: 10.3389/sjss.2025.148382025-09-18
Said Al-Ismaily, Aminat Umarova, Johan Bouma
Soil science stands at a critical juncture, facing both mounting global environmental crises and transformative possibilities in education. This study advocates a bold re-envisioning of soil science pedagogy, aimed at cultivating the inter- and transdisciplinary competencies essential for achieving the 2030 Sustainable Development Goals (SDGs). Drawing on in-depth case studies from Sultan Qaboos University (Oman) and Moscow State University (Russia), along with global stakeholder insights and integrative frameworks, such as Soil Security, One Health, and the Pedometrics Challenge, we propose a future-facing curriculum focused on sustainability, systems thinking, and real-world engagement. This study showcases pedagogical innovations—including inquiry-based learning, SDG-aligned outcomes, debate-based reasoning, and community-engaged research—that foster core skills in transdisciplinary problem-solving. Supported by empirical findings and curriculum analysis, this study demonstrates that reframing soil-science education around ecosystem services and natural capital can empower students to become solution-oriented professionals. Ultimately, we call for a global curricular reform that positions soil education as a dynamic catalyst for sustainability transformation rather than as a technical subdiscipline.
DOI: 10.3389/sjss.2025.151732025-09-17
Omid Sharifi, Sepideh Behroozeh, Samira Behroozeh
The study of land use change dynamics in developing countries is particularly important, as it contributes to sustainable land management and the more efficient use of natural resources. Southern Iran, which includes the provinces of Bushehr, Fars, Kerman, Sistan and Baluchestan, and Hormozgan, provides a valuable case study due to its diverse land uses and varying climatic conditions. It is hypothesized that land use changes between 2000 and 2022 in this region have significantly impacted the trends of soil temperature (ST) and soil volumetric water content (SWV), especially in areas where natural covers such as forests and shrublands have been converted to agricultural or barren lands. Trend analysis using the Mann-Kendall Z test and Sen’s slope estimator revealed a negative trend in ST across 62.60% of the study area, encompassing most parts of Sistan and Baluchestan, Kerman, Hormozgan, and southeastern Fars. In these regions, soil volumetric water content showed a positive and statistically significant trend. It can be attributed to an increase in sudden and intense rainfall and seasonal precipitation patterns. In 34.79% of the study area, an increasing trend in ST was observed, particularly in Bushehr and sporadically in parts of Fars Province. Similarly, the trend analysis of soil climate variables across different land uses indicated that soil volumetric water content increased by 85.36% in barren lands and by 66.36% in grasslands. In contrast, negative trends were found in forests (94.85%), shrublands (72.79%), and agricultural lands (82.24%). The main reason for this declining trend is the conversion of forests and shrublands to agricultural land. The trend of ST showed a decrease of 69.23% in barren land use, 94.85% in forest use, and 56.73% in grassland use. In these land uses, trees and dense vegetation block direct sunlight, which helps keep ST lower in these areas. In contrast, an increasing trend was observed in shrublands (63.48%) and agricultural lands (82%). Given the rapid pace of land use change, forecasting and analyzing satellite imagery represents a valuable approach for supporting environmental management strategies. Such forecasts provide deeper insights into potential future changes and inform proactive measures to mitigate their adverse impacts.
DOI: 10.3389/sjss.2025.148062025-07-30
Mohamed Mdaini, Eva Lloret, Nadhem Brahim, Najet Shimi, Raúl Zornoza
The soil microbiome, crucial for nutrient cycling and soil health, has been extensively studied in topsoil, yet the subsoil microbiome remains relatively unexamined despite its potential contributions to agroecosystem functionality. This research aimed to bridge this knowledge gap by investigating the interconnections between soil properties and the microbial communities residing in the topsoil and the subsoil of irrigated orchards under a semiarid Mediterranean climate. We collected soil samples from two depths, topsoil (0–10 cm) and subsoil (30–50 cm), noting elevated salinity levels in the topsoil due to irrigation practices. Utilizing high-throughput 16S rRNA gene and ITS1 region amplicon sequencing, we characterized the bacterial and fungal communities across these two depths. Our findings indicated that soil pH (higher in subsoil), electrical conductivity (higher in topsoil) and soil organic carbon (higher in topsoil) were the primary physicochemical drivers of microbial community composition shifts between top- and subsoil. Genera such as Rhizobium, Skermanella, Microvirga and Rubrobacter (bacteria) and Aspergillus, Gibellulopsis, Alternaria, Preussia and Monocillium (fungi) were identified as key genera more abundant in the topsoil, while MB-A2-108, Streptomyces and Bacillus (bacteria), and Mortierella, Fusarium, Necosmospora, Chaetomium and Emericellopsis (fungi), were key genera more abundant in the subsoil, associated with key studied soil properties. So they can be considered as key microorganisms contributing to soil processes in the topsoil and the subsoil. Our study gives insights about how soil bacterial and fungal communities respond differently to changes in the soil physicochemical properties across topsoil and subsoil, with salinity as important driver, reflecting the crucial need to develop a better understanding of how environmental changes impact soil properties and the microbiome throughout the soil profile.
DOI: 10.3389/sjss.2025.145372025-07-29
Antonio Aguirre-Arcos, Irene Ortiz-Bernad, Juana Nieto Carricondo, Antonio M. Lallena, Marino Pedro Reyes-Martín, Álvaro Ávila-Pérez, Emilia Fernández-Ondoño
Olive trees are widely cultivated crops, especially in Mediterranean countries, which requires new practices to maintain productivity, optimize resource use and improve the quality of the environment. Integrated production seeks to achieve these objectives, but this requires rapid and effective methods to plan crop nutrition. Sap extracted using a modified Scholander chamber could provide an accurate method for determining the nutritional status of olive trees. To verify this, two trials were conducted in integrated production systems in southern Spain over two periods of time (2018–1019 and 2022–2024). The trials were carried out in five farms in the provinces of Jaén, Granada and Seville, comparing the nutrient concentrations in sap, leaves and soil from Picual and Hojiblanca olive trees. In the first period (2018–2019), critical times when nutrient flux in the sap increased were identified as spring, early fall, winter, and the first half of July. These periods were selected for sampling in the second period (2022–2024). Sap, leaves and soil were analyzed, determining macro- and micronutrients, pH and electrical conductivity. In the first trial, monthly sampling was successful, although in autumn 2022, a very dry year, little sap was extracted. From April 2023 onwards, the amount of sap recovered, which demonstrated the sensitivity of sap extraction to climatic variations and the phenological state of the olive tree. Soil analyses showed pH from 7.9 to 8.5 and electrical conductivity from 1.1 to 5.9 dS m−1. Nutrient concentrations in leaf were higher than in soil and in soil higher or equal than in sap, except for K, the most abundant element in sap, with concentrations exceeding those in soil. Concentrations of Fe, Cu, Mn and Zn increased in 2022 compared to 2018, possibly due to climatic differences. Sap analysis can complement leaf and soil analyses for a more balanced fertilisation in olive orchards.
DOI: 10.3389/sjss.2025.142332025-04-07
Martin H. Gerzabek, Rosa M. Poch, Daniela Álvarez, Leon Ploszczanski, Franz Zehetner
Galápagos has very diverse soil resources. In a recent study, we found vastly different pedogenic development on lava vs. scoria along a hydroclimatic gradient on Santa Cruz Island (800 m elevation difference; precipitation ranging from 100 to 1,600 mm a−1). On the more porous scoria deposits, soils consistently developed towards deeper and more weathered profiles with increasing humidity, while on the lavas, soil development did not follow a consistent elevational pattern. The micromorphological investigations show an increasing degree of primary mineral weathering with increasing altitude and humidity, which was more pronounced in the profiles on scoria than on lava. The greater weathering on scoria is likely due to higher inter-particle porosity and therefore larger surface area exposed to weathering. In the arid climate zone, the soil on scoria was very shallow and the primary minerals hardly weathered, whereas the soil on lava showed a greater profile thickness and a noticeable weathering of primary minerals. Unlike the relatively homogeneous scoria deposits, the lavas show irregular flow patterns with large rock outcrop sections and small depression patches, in which soils with higher available water capacity have formed. In a previous study, we also found strongly elevated phosphorus levels in these soil patches in the arid zone. Bolstered by electron microscopy and microanalyses we show evidence that these possibly originate from tortoise nesting activities. Our results point to a complex interplay of parent material, geomorphology, climate and also the activities of the Galápagos giant tortoises in shaping the soil-scape of this unique ecosystem.
DOI: 10.3389/sjss.2025.14219