Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Understanding sulfur dynamics in soil ecosystems: applications of sulfur-oxidizing bacteria– a review 1 15 3730 10.47176/dlsr.02.01.1034 EN Hossein Besharati Agricultural Research, Education and Extension Organization, (AREEO), Soil and Water Research Institute, Karaj, Iran Maryam Samani Department of Soil Science, University of Zanjan, Zanjan, Iran Ahmad Asgharzadeh Agricultural Research, Education and Extension Organization, (AREEO), Soil and Water Research Institute, Karaj, Iran Journal Article 2025 04 06 Sulfur (S) is an essential element for plants, playing a crucial role in various biochemical processes that are vital for their health.. Insufficient sulfur in the soil can profoundly affect plant health and crop yield. Agriculture commonly relies on sulfur fertilizers containing either sulfate or elemental sulfur (So) as a sulfur source. However, So, being more cost-effective and less prone to leaching than sulfate (SO4-2) is favored, but, So must undergo oxidation to sulfate before plants can readily utilize it, a process largely facilitated by soil microorganisms. The environmental conditions affecting microorganism populations and activities significantly influence So oxidation. Sulfur-oxidizing bacteria (SOB) are instrumental in sulfur cycling within soil ecosystems, impacting their availability and transformation. This review delves into the intricate connections among S dynamics, SOB, soil improvement, and plant nutrition. It explores how plants obtain and employ S, stressing its significance in protein synthesis, enzyme activation, and secondary metabolites production. Additionally, the review scrutinizes SOB's role in mediating S oxidation, which influences soil pH, nutrient availability, and plant-microorganism interactions. Moreover, it discusses the potential of SOB as biofertilizers to enhance sulfur availability and bolster plant growth. Various strategies for leveraging the beneficial effects of SOB in sustainable agriculture are examined, such as microbial inoculation. The review also addresses the environmental implications of sulfur cycling, emphasizing the importance of maintaining balanced sulfur levels in soil ecosystems to mitigate environmental pollution and optimize agricultural productivity. In conclusion, this review offers valuable insights into the dynamic relationship between sulfur, SOB, soil fertility, and plant nutrition. It underscores the potential applications of this understanding in sustainable agriculture and ecosystem management, emphasizing the necessity of sulfur management for fostering agricultural productivity and environmental sustainability.

https://dlsr.iut.ac.ir/article_3730_d8c24ca8f23c562a5600876ca2a550ce.pdf

Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Maize response to sulfur and thiobacillus inoculation in calcareous soils 17 22 3731 10.47176/dlsr.02.01.1025 EN Hosein Besharati Soil and Water Research Institute, Agricultural Research, Education and Extension Organizatio, Karaj, Iran Mahmoud Solhi Agricultural Research Center, Agricultural Research, Education and Extension Organizatio, Isfahan, Iran Abdolhossein Ziaeian Agricultural Research Center, Agricultural Research, Education and Extension Organizatio, Kerman, Iran Arash Sabbah Agricultural Research Center, Agricultural Research, Education and Extension Organizatio, Kerman, Iran Journal Article 2023 11 11 Calcareous soils are widely distributed in the arid and semi-arid regions, where most agricultural soils in Iran, due to climatic conditions and geological formations, are calcareous and have a high pH. In such soils, some nutrients like phosphorus, are fixed and utilizing acid-forming substances may increase the availability of this element. Sulfur is considered to be the most affordable acid-producing material and is a byproduct of gas and oil refineries with an annual production of more than two million tons in Iran. In this research, the effects of bentonite-sulfur produced by a new process were tested on maize silage (Single Cross 704 cultivar) on agricultural soil research farms at three sites (Isfahan, Shiraz, and Jiroft) using a factorial experiment. For this purpose, 0, 0.5, 1, and 2 t ha-1 of the elemental sulfur as well as 0, 65, and 100% of recommended phosphorus were applied. Application of elemental sulfur was combined with the inoculation of Thiobacillus bacteria (1 kg per 50 kg of elemental sulfur). Results indicated that sulfur, phosphorus, and their co-application brought about significant increases in maize shoot dry and fresh weights only at Shiraz site. Sulfur application enhanced the shoot uptakes of zinc and iron at Shiraz and Jiroft sites. The highest Fe uptake was observed with application of 2,000 kg ha-1 of sulfur. No significant effects were, however, detected on shoot phosphorus uptake at any of the study sites. Elemental sulfur was observed to have a limited effect on soil nutrient availability and plant growth because of the high buffering capacity of the studied sites calcareous soils, counteracting the acidification of sulfur oxidation.

https://dlsr.iut.ac.ir/article_3731_7ec3b3cf674f4f1d23e9d30c89426cce.pdf

Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Integrated crop and hydraulic modeling for precision irrigation: parameter estimation and sensitivity analysis (a review) 23 47 3732 10.47176/dlsr.02.01.1045 EN Meisam Rezaei Soil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran 0000-0003-3044-4625 Kambiz Bazargan Soil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran Karim Shahbazi Soil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran 0000-0001-7994-2559 Meysam Cheraghi Soil and Water Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran 0000-0001-6605-3007 Journal Article 2025 08 20 Sustainable agriculture demands innovative strategies to optimize water use amid growing climatic uncertainties, resource limitations, and to bolster the resilience of farming systems worldwide in the face of climate change. This review provides a critical synthesis of state-of-the-art modeling approaches that integrate crop growth dynamics with soil hydraulic processes to support precision irrigation management. Emphasizing the vadose zone's central role as the critical interface governing soil-plant-water interactions, the paper examines a suite of widely used, process-based crop models (e.g., WOFOST, CERES, AquaCrop, DSSAT, APSIM) alongside specialized hydrological models (e.g., HYDRUS, SWAP, SWAT). It highlights their synergistic capability to simulate the complex, nonlinear feedback between root water uptake, soil moisture dynamics, evapotranspiration, and solute transport, which is fundamental for predicting crop water requirements and responses to irrigation. The primary challenge for this approach is the accurate determination of often unknown or highly variable soil hydraulic and crop parameters. This review demonstrated that 1) Advanced inverse modeling techniques provide a powerful alternative to direct measurements by using optimization algorithms to estimate critical parameters from field data. 2) Sensitivity analysis (both local and global) is indispensable for evaluating model robustness, identifying influential parameters, and mitigating calibration issues like equifinality. 3) Well-calibrated, integrated models enable a robust, physically sound framework for generating site-specific irrigation schedules, moving beyond traditional homogeneous management. We also identify key challenges, including data scarcity and computational demands. To address these, we advocate for the future development of quasi-3D hybrid modeling platforms that leverage high-resolution data from easily available resources, laboratories, remote sensing, and IoT networks. This integrative approach holds significant promise for advancing next-generation precision irrigation, enhancing water use efficiency, and strengthening global agricultural resilience.

https://dlsr.iut.ac.ir/article_3732_ee23e7ad9b473ad072d57aaa9b2a5222.pdf

Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Nano/microplastics in agricultural soils and their impacts on physiology, morphology, and plant health 49 64 3733 10.47176/dlsr.02.01.1044 EN Maryam Haghighi Department of Horticulture, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran Journal Article 2025 08 03 Nowaday, plastic contamination is one of the most pressing environmental challenges. With annual production exceeding 360 million tons, plastics have infiltrated into various parts of ecosystem and are alarmingly prevalent in gardens, agricultural fields, and soils of industrial zones worldwide. Over time, these larger plastic particles degrade into smaller fragments, including microplastics (MPs) and nanoplastics (NPs). Among these, NPs pose the most significant threat due to their diminutive size, allowing them to be absorbed by living organisms and subsequently move into the food chain and leading to potential bioaccumulation. This review article aims to synthesize current knowledge on the impact of micro and nanoplastics (MNPs) on soil health, plant physiology, and human health by identifying key themes and knowledge gaps in the literature. Recent studies have highlighted the detrimental effects of MNPs on soil health, revealing that agricultural practices, such as utilizing plastic mulch and synthetic fertilizers, have contributed to the elevated MNP concentrations in soils worldwide. The uptake of MNPs by plants can alter their physiological and morphological characteristics, as well as their gene expression profiles, leading to unpredictable consequences for plant health, growth, and productivity. These contaminants can be absorbed directly into plant tissues or adhere to root surfaces, raising concerns about the potential transfer of MNPs into the food supply. The implications for human health are profound, as the consumption of contaminated crops may lead to adverse health effects, including endocrine disruption and inflammatory responses. While the impact of traditional soil pollutants, such as heavy metals, has been extensively studied, the emerging risks posed by plastic contaminants require urgent attention. This review contributes to existing literature by broadening our understanding of MNPs and their effects, ultimately aiming to safeguard both plant and human health despite escalating environmental plastic contamination.

https://dlsr.iut.ac.ir/article_3733_64d52e08cc03e6090bc1ef30b73ccb85.pdf

Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 A data-driven approach to predict soil hydraulic conductivity: GMDH compared with ANN and multiple regression 65 79 3734 10.47176/dlsr.02.01.1047 EN Mehdi Rahmati 1 Department of Soil Science and Engineering, Faculty of Agriculture, University of Maragheh, Maragheh, Iran, 2 Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences: Agrosphere (IBG-3), Jülich, Germany 0000-0001-5547-6442 Journal Article 2025 09 27 Accurate estimation of saturated hydraulic conductivity (Ks) is essential for soil and water management, yet the reliability of the pedotransfer functions (PTFs) is often overlooked.Tthis study compares the predictive performance and the robustness of field estimates of Ks obtained by three types of PTFs: Multiple Regression (MR), Artificial Neural Networks (ANN) and the Group Method of Data Handling (GMDH) developed using 134 soil samples collected in north-western Iran, which is a region with semi-arid conditions and mixed agricultural uses whereas the dataset encompasses a wide range of structural and textural variationsto Ks prediction. In addition to traditional soil properties soil moisture deficit compared to the optimum value at the time of sampling, θd, was used as a proxy indicator of soil structural condition. Model precision was evaluated using Root Mean Square Error (RMSE) and the Nash–Sutcliffe efficiency; reliability was determined through repeated data splitting. Even though ANN provided good accuracy for the training set, its performance for the validation set was inconsistence. MR produced consistent, albeit limited performances over both the training and validation subsets. Conversely, GMDH appears to strike a good compromise between prediction accuracy, reliability, parsimony of the predictor set, and texture versus structure variables. The results point to the importance of including structural measures such as θd in PTF development and provide a basis for considering model repeatability a long with accuracy. In general, the results indicate that GMDH is a robust and feasible technique to develop accurate PTFs for Ks predictions with limited amount of data.

https://dlsr.iut.ac.ir/article_3734_9d752cb08ef466fc480fba981cfa44a1.pdf

Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Prediction of soil potassium forms using physicochemical properties and exchangeable potassium: II. Influence of soil properties on potassium distribution 81 88 3735 10.47176/dlsr.02.01.1043 EN Manoochehr Gholipoor Deparment of Soil Science, College of Agriculture, Shahrood University of Technology, 3619995161, Shahrood, Iran 0000-0001-9229-4744 Journal Article 2025 07 30 A quantitative understanding of the factors regulating potassium (K) distribution in soils is essential for optimizing nutrient management in agricultural systems, as K availability directly influences crop productivity and soil health. To systematically evaluate the drivers of K dynamics, a suite of artificial neural networks, coupled with Deep Learning Important FeaTures (DeepLIFT) attribution analysis, was employed to quantitatively assess the relative influence of key soil properties, including clay, silt, and sand content, pH, organic carbon (OC), cation exchange capacity (CEC), and electrical conductivity (EC), on four distinct K pools: water-soluble K, non-exchangeable K, fixed K, and total K. Additionally, the study investigated the association of soil initial water-soluble K and fertilizer K application rate with the fixation of K fertilizer to elucidate the relationship between them. Key findings revealed divergent drivers across K fractions, highlighting the complexity of K dynamics in soils. CEC emerged as the dominant factor influencing water-soluble K variability (+22.43%), underscoring its role in regulating K mobility. Clay content exhibited contrasting effects, positively influencing non-exchangeable K (+13.42%), total K (+20.59%), and fixed K (+13.81%), while negatively impacting water-soluble K (-14.38%). EC was the primary determinant of non-exchangeable K (+34.27%), suggesting salinity’s role in K retention. In contrast, pH showed a strong association with fixed K (+26.58%), reflecting its influence on interlayer trapping within 2:1 clay minerals. To bridge predictive modeling and practical applications, a genetic algorithm was integrated into an open-source, user-friendly Excel-based tool. This tool enables farmers and agronomists to optimize soil conditions for maximizing the sum of water-soluble and exchangeable K (plant-available K), thereby supporting precision nutrient management. By elucidating soil-specific K dynamics and providing actionable insights, this research advances sustainable K stewardship. The tool is accessible for download at: https://drive.shahroodut.ac.ir/index.php/s/fayE0zUH16TQe2M

https://dlsr.iut.ac.ir/article_3735_dc0c398086fee58f9d64e1e47aa4e586.pdf