Search Results (2,519)

Nitrogen leaching from land and farms is a major global issue that pollutes water, damages ecosystems, and accelerates climate change. This review synthesizes evidence from the literature on how interactions among landscape characteristics, sources of nitrogen input, and temporal dynamics shape leaching vulnerability. It identifies conditions under which nitrogen is most likely to be transported through soil systems into aquatic environments. This review reveals that leaching vulnerability is strongly conditioned by soil hydraulic properties and topographic position. Coarse-textured upland soils exhibit substantially greater nitrate mobilization than finer-textured, hydrologically buffered lowland soils. Fertilizer formulation and application timing further modulate loss potential, with late-season mineral nitrogen inputs disproportionately contributing to subsurface export relative to demand-synchronized applications. Most of the nitrogen leaching occurs outside the active growing period, when vegetative uptake is suppressed and drainage intensity is highest. Farmers can lower nitrate runoff by using targeted fertilization, cover crops, and nitrification inhibitors, while landscape-scale features like controlled drainage and vegetative buffers provide additional downstream filtration. The effectiveness of regulatory approaches is amplified when aligned with economic incentives and regionally calibrated nutrient thresholds. Advances in high-resolution observation platforms and process-based predictive tools offer new capacity for anticipatory management, although widespread deployment is limited by financial and institutional constraints. Collectively, these insights support the development of more targeted and sustainable nitrogen management strategies. Full article

As human space exploration advances towards establishing sustainable Martian habitats, achieving autonomous food production is a critical requirement. The potato (Solanum tuberosum L.), with its notable environmental resilience and nutritional efficiency, is a prime candidate crop. This study develops a conceptual framework for Martian potato cultivation by systematically analyzing the profound disparities between Martian conditions and plant physiology. We identify and evaluate seven fundamental challenges: atmospheric composition, extreme temperatures, water scarcity, soil properties, nutrient deficiencies, absent microbiota, and radiation/gravity effects. To address these challenges, we propose a phased, testable roadmap comprising four stages: (I) screening and bio-engineering of multi-stress-tolerant potato genotypes; (II) phased domestication via Earth-based analog experiments to define adaptability thresholds; (III) deployment of a controlled cultivation module within a Martian habitat, integrating targeted technological interventions; and (IV) conceptual exploration of extra-habitat agricultural potential. The primary contribution of this work is a structured set of hypotheses and key performance indicators for each stage, translating visionary goals into a defined research agenda to guide future empirical work in extraterrestrial agronomy. Full article

This research addresses the challenge of assessing ecosystem services, ecosystem condition, and agricultural externalities in a Latin American socio-ecological context, where primary production is both a major economic activity and a pressure on ecosystems. In Uruguay, the intensification of agriculture and livestock farming has raised concerns about nutrient-related externalities affecting water and soil quality. Although the System of Environmental and Economic Accounting (SEEA)—Ecosystem Accounting framework is used for better ecosystem management, it does not explicitly represent externalities. Using the Santa Lucía sub-basin in Uruguay (supplying water to 60% of the population) as a case study, this research combines the Soil and Water Assessment (SWAT) Tool with ecosystem accounting principles to assess ecosystem services, ecosystem condition, and externalities. Model outputs are used to compile partial ecosystem accounts in physical terms, integrating spatially explicit indicators. Results show that nutrient losses to surface waters, interpreted as agricultural externalities, are predominantly driven by diffuse sources associated with croplands and dairy systems and shaped by hydrological connectivity. Despite data and model-related uncertainties, the approach supports hotspot identification and the spatial targeting of interventions and provides the basis for future monetary assessment, illustrating how hydrological modeling can complement ecosystem accounting in data-scarce contexts. Full article

The enhanced performance of electrokinetics (EK) on the cadmium (Cd) dissociation, redistribution, and phytoremediation of Cd-contaminated agricultural soil has been investigated based on the application of an electric field in different dimensions (1D, 2D, 3D). In electrokinetic–assisted phytoremediation (EKPR), unlike the uniform pH change observed in 1D treatment, more soil points (P1–P9) under 2D/3D electric fields were exposed to the influence of the anode (or cathode during polarity switching). Sedum plumbizincicola mitigates EK-induced soil acidification and alkalization, particularly anode acidification under high voltage (10–20 V). Studies reveal that EK promotes Cd dissolution into soil pore water, with a 227.82% maximum increase in the anode region under EK2 treatment of 10 V voltage, facilitating Cd phytoextraction. Periodically reversed DC electric fields enhanced Sedum plumbizincicola height more significantly than biomass, with no conspicuous regional differences. Overall, EKPR (voltage of 5–10 V) can effectively promote soil Cd phytoremediation due to the synergistic effect of direct interface action and indirect influence of the electric field to improve the Cd speciation evolution, dissociation, and bioavailability at the soil–water interface. The appropriate electric field arrangement and voltage were 2D treatment (EKPR2) and 5 V for S. plumbizincicola, respectively. In this case, the average Cd removal rate was as high as 50.23%, and the biomass and Cd accumulation increased by 16.59% and 29.31%. This suggests that plant growth constitutes the pivotal stage driving Cd accumulation and ultimately achieving Cd removal from soil, which is the key to enhancing remediation efficiency. Meanwhile, the configuration and intensity regulation of electric fields, as core elements ensuring the enhanced efficacy of electrokinetic–assisted phytoremediation (EKPR), can indirectly affect plant growth and Cd accumulation processes by modulating intermediate variables such as soil pH, nutrient status, and heavy metal speciation evolution. Full article

Selenium contamination in arid agricultural basins remains a key ecological concern, yet the Wister Unit of the Imperial Wildlife Area has received comparatively little hydrochemical study. This investigation provides the most integrated assessment to date of selenium, salinity, nitrate, stable water isotopes (δ²H and δ¹⁸O), and selected redox-sensitive trace elements within the Wister Unit and its contributing open agricultural drains, with the goal of identifying controls on selenium concentrations and mobility. Water samples from open agricultural drains, shallow groundwater tile drains, canal project water, and tailwater return flow were analyzed for Total Dissolved Solids (TDS), major ions, nutrients, selenium, and stable water isotopes. A subset of samples was anlayzed for iron, manganese, and vanadium. Overall, 71% of open drain and tile drain samples collected in this study exceeded the U.S. Environmental Protection Agency aquatic-life criterion of 5 µg/L, indicating persistent ecological risk. All waters plotted along an evaporation trajectory originating from imported Colorado River irrigation water; however, isotopic enrichment did not scale directly with salinity. Pure evaporation models predicted much lower TDS values than observed, and the most evaporated samples were not the most saline or selenium-rich. These results demonstrate that simple soil water evaporation alone cannot explain the data. Instead, the broad isotopic range at similar salinities reflects a secondary process in which salts that accumulated in soils during dry or average years are later mobilized and flushed during periods of surplus water and heavy irrigation. Low dissolved iron, manganese, and vanadium concentrations in a subset of water samples indicate predominantly oxidizing conditions, under which selenium behaves conservatively during salt leaching, producing a strong correlation with TDS. Selenium levels measured in Wister Unit are generally lower than those reported in nearby areas during the 1990s–2000s, implying changes in salt accumulation, hydrologic routing, or agricultural practices. These results refine the conceptual model for the Wister Unit and motivate future work on selenium speciation, nitrate isotope tracing, time series monitoring, and soil-salt interactions. Full article

This study addresses the issue of missing basic data and insufficient accuracy in predicting runoff and non-point-source pollution in the Heilongjiang region of China using the Soil and Water Assessment Tool (SWAT) model. Based on the China Ground Climate Data Daily Dataset (V3.0) and SPAW soil characteristic calculation formula, and assisted by the Python V3.0 language for data processing and computation, new high-precision weather generators and soil attribute databases suitable for the Heilongjiang region of China were established. The weather generator is based on daily data and contains detailed meteorological parameters such as temperature, humidity, wind speed, rainfall, etc., used to characterize the periodic changes in meteorological elements. And the differences and fluctuations outside this change curve were also retained in the basic construction of the weather generator. The soil database covers various parameters, such as soil type, texture, structure, nutrient content, organic matter content, etc., enabling the SWAT model to better simulate hydrological and pollutant transport processes in the soil. Additionally, point-source input data, including various industrial and domestic wastewater discharge situations, were collected and organized to improve data quality. Furthermore, a series of agricultural management measures were developed based on the use of fertilizers and pesticides for simulation, providing an important basis for analyzing non-point-source pollution using the SWAT model. By comparing the different results of the simulation using optimized databases, it is shown that the above work improved the simulation accuracy of the SWAT model in predicting runoff and pollution load in Heilongjiang, China. The NSE of runoff simulation increased from 0.923 to 0.988, and the NSE of ammonia nitrogen and CBOD simulation increased from 0.852 and 0.758 to 0.930 and 0.902, respectively. It is expected that these efforts will provide strong data support for subsequent research and provide a theoretical basis for government decision-makers to build scientifically rigorous and effective pollution control strategies. Full article

While deep fertilization improves crop yields and fertilizer use efficiency, it alters crop growth and soil nutrient/moisture distribution, driving nitrous oxide (N₂O) emissions—a potent greenhouse gas. However, conflicting evidence and the unknown effects of varying fertilizer placement depths in mechanized direct-seeded winter rapeseed fields leave the critical trade-off between productivity and emissions mitigation poorly understood. A 2-year field experiment (2019–2021) was conducted in the Yangtze River basin, China. The static closed chamber technique combined with gas chromatography was utilized to investigate the impacts of fertilizer placement depths (5 cm, 10 cm, and 15 cm, designated as D5, D10, and D15, respectively) on soil N₂O emissions, with a no-fertilization treatment serving as the control. Results demonstrated that N₂O fluxes under all treatments exhibited a rapid decline during the early growth stages of rapeseed, subsequently stabilizing at low levels; these dynamics were partially linked to soil temperature and soil water content (SWC). Specifically, N₂O flux showed a significant but moderate exponential response to soil temperature and a weak quadratic trend with SWC. As fertilization depth increased, the richness and diversity of AOA, AOB, and nirK communities showed a numerical decline (p > 0.05). N₂O emissions under D5 were on average 8.7% higher than D10 (p > 0.05), but were significantly 18.0% higher than D15 (p < 0.05). Yield-scaled N₂O emissions under D10 were reduced by 12.7% and 22.3% relative to D5 and D15, respectively. Compared with D10 and D15, the N₂O emission factor increased by 12.9% and 29.0% under D5, respectively (p < 0.05). The net ecosystem economic budget under D10 was 6.5% and 48.6% greater than that of D5 and D15, respectively. Considering crop yield, production costs, and carbon emission, a fertilizer placement depth of 10 cm is recommended as optimal. These findings offer valuable insights for mitigating N₂O emissions and informing rational fertilization strategies in rapeseed cultivation. Full article

Climate change is steadily reshaping hydrological regimes, and one of its clearest consequences is the growing disruption of the biogeochemical pathways that govern water quality across river basins. More frequent high-intensity rainfall events, prolonged dry spells, and shifts in seasonal runoff patterns are altering the timing and magnitude of nutrient, organic matter, sediment, and contaminant fluxes. These pulses of material often originate from short-lived episodes of enhanced connectivity between soils, groundwater, and surface waters, making water-quality responses more variable and harder to anticipate than in previous decades. This review describes the ecohydrological mechanisms underlying these changes, focusing on threshold behaviors, the functioning of transitional zones such as riparian corridors and floodplains, and the cumulative effects of legacy pollution. We also discuss the capacity of nature-based solutions (NbS) to buffer climatic pressures. Although NbS can improve retention and moderate peak flows, their performance proves highly sensitive to hydrological variability and landscape context. In the final part, we describe tools that can strengthen adaptive water-quality management, including high-frequency monitoring, event-focused early-warning systems, and modeling approaches that integrate hydrology with biogeochemical processing. This article addresses ecohydrological pathways for water quality under climate change and presents nature-based solutions for regulating pollutant flows within a general framework. Data from North America and Europe, among other areas, are used as primary examples. However, it is important to remember that the issues and proposed solutions vary depending on landscape conditions and climatic zones, which vary across the globe. This article provides an overview of the most common solutions. Full article

Subsoiling is a highly effective deep tillage method used to mitigate soil compaction in orchard rows, a condition frequently resulting from repeated passes of agricultural machinery. This compaction can reduce water infiltration into deeper soil layers, leading to excessive surface water stagnation and a subsequent reduction in soil fertility. Subsoiling restores the structure of compacted soil by creating a vertical cut and lifting the ground without inverting the soil layers. This action promotes stable soil porosity and enhanced drainage, effectively eliminating the plough sole, and consequently improving root growth and nutrient absorption. Despite its benefits, subsoiling is an energy-intensive practice. Vibrating subsoilers can significantly reduce the high traction force required by conventional subsoilers, thereby enabling the use of smaller, less powerful tractors. This study investigated the performance of a single-shank subsoiler equipped with an innovative oscillating working tool, focusing on its dynamic-energy requirements, tillage quality, and the whole-body vibrations (WBV) transmitted to the tractor driver. Comparative tests were conducted in a compacted poplar grove using two 4WD tractors of different power and mass, with the subsoiler’s oscillating tool alternately activated and deactivated. The results demonstrated that the oscillating tool reduced draft force, traction power requirement, fuel consumption, and tractor slip, while maintaining tillage efficiency, displacing a greater mass of soil. However, a comparison of the measured vibrations indicated that their level reached a hazardous condition for the driver of the lower-power, lower-mass tractor when the oscillating tool was active. Full article

Maximizing the agricultural output on inherently infertile land and minimizing the environmental cost remain central research imperatives. Albic black soil typifies such infertility. Conventional practice relies on fertilization and straw incorporation, but the albic layer’s impermeability funnels applied nutrients into adjacent aquatic systems. Therefore, this study developed deep placement fertilization by lodging fertilizer directly within the albic layer to block hydrologic loss. The feasibility of mechanization was first validated in pot experiments. Soybeans were allocated to six treatments simulating fertilizer placement at different soil depths: control (C), control and fertilizer (CF), surface soil mixing (SM), surface soil mixing and fertilizer (SMF), plow pan soil mixing (PM), and plow pan soil mixing and fertilizer (PMF). The treatments used 20 cm tillage, and the data were collected after 15, 25, and 35 days and at harvest. Integrative transcriptomic, proteomic, metabolomic, and soil microbiome profiling revealed that fertilizer positioned at 25 cm in the albic layer increased yield, restructured the rhizobiont community and promoted arbuscular mycorrhizal fungal colonization. Among the fertilizer treatments, CF had the best growth, and SMF was inhibited by a nutrient shortage. SMF and PMF lost water faster than CF. Abscisic acid (ABA) conveyed the subterranean fertilization signal to the leaf. The enrichment of Vicinamibacterales, Xanthobacteraceae, and Glomeromycota in soil lowered the ABA content in the roots, which upregulated thymidine kinase and peroxidase upon arrival in the leaf, increasing yield. These findings provide a transferable benchmark for any parent material exhibiting poor hydraulic conductivity. Full article

The rapid rise in atmospheric CO₂ necessitates strategies for mitigation and valorization. Microalgae offer potential through simultaneous CO₂ capture and production of high-value biomolecules. Five Chlorophyta strains (A–E: Micractinium sp., Chlamydomonas sp., Micractinium sp., Chlorococcum sp., and Chlorella vulgaris) were isolated from temperate waters and soils and tested for growth and biochemical responses under controlled nitrogen availability (low: 0.346 g L⁻¹ nitrate; high: 0.6 g L⁻¹ nitrate + ammonia), carbon supply (low: 0.04% CO₂; high: 4% CO₂), and cultivation systems (batch reactors, fermenters, and varied illumination). Over 14 days, maximum dry biomass was achieved in batch cultivation with CO₂ sparging, low nitrogen, and continuous light, ranging from 1.47 g L⁻¹ (strain A) to 2.67 g L⁻¹ (strain D). Biomass composition varied: proteins, 25–45%; carbohydrates, 20–35%; and lipids, 18–28%. Nitrogen limitation promoted lipid accumulation (e.g., strain D: +40%) with concurrent protein decline (−25%). Chlorophyll a/b displayed strain-specific plasticity; high CO₂ generally increased chlorophyll, while nitrogen stress reduced it up to 50%. Overall, this study demonstrates that locally adapted Chlorophyta strains can achieve high biomass productivity under CO₂ enrichment while allowing for flexible redirection of carbon flux toward lipids, carbohydrates, or pigments through nutrient management. Among the tested isolates, strains D and E emerged as the most promising candidates for integrated CO₂ sequestration and biomass production, while strains B, C, and D showed strong potential for biodiesel feedstock; strain A for carbohydrate valorization; and strain E for chlorophyll extraction. Future research should focus on scale-up validation in pilot photobioreactors under continuous operation, optimization of two-stage cultivation strategies for lipid production, integration with industrial CO₂ point sources, and strain improvement using modern genomics-assisted breeding and genome-editing technologies. These efforts will support the translation of regional microalgal resources into scalable carbon-capture and bioproduct platforms. Full article

The root system provides the interface between the plant and the soil that is responsible for water and nutrient uptake and transport. We hypothesized that almond trees in the commercial production environment could adjust their root acquisitive traits with distance vertically and horizontally from driplines as adaptive responses to within-orchard reductions in irrigation and nitrogen inputs. We compared the responses of root acquisitive traits under four years of treatments ranging from +W+N (15 ML ha⁻¹ water and 300 kg ha⁻¹ nitrogen per season) to −W−N (10.5 ML ha⁻¹ water and 160 kg ha⁻¹ nitrogen per season, with −W involving a 30% reduction in irrigation and −N involving a 46% reduction in nitrogen). Roots (<3 mm) were sampled through soil coring in the winters of 2017, 2018, and 2019. Root sampling was conducted along the vertical gradient and along the horizonal gradient (0 cm, 80 cm, and 240 cm from the dripline). Four years of treatments highlighted that the data variation was driven mainly by the difference between the +W and −W treatments (along PC1). Further, the difference between −W−N (combined resource reduction) and the other three treatments (+W+N, +W−N, and −W+N) contributed to the data variation (along PC2). Also, the temporal dynamics of treatment effects over 2017, 2018, and 2019 suggested a temporally strengthened +W−N effect to increase root biomass, average root diameter, specific root surface area (SRA), and specific root length (SRL) at deeper soil depths and at greater soil distances from driplines. These findings on the spatial and temporal plasticity of traits representing root resource acquisition capabilities highlighted the important role of root systems in maintaining crop productivity under reduced irrigation and nitrogen inputs. Full article

This study aimed to explore the effect of doubled CO₂ concentration (d[CO₂]) on the modulation of root morphological structure, leaf potassium (K)/sodium (Na) ratio, and nutrient stoichiometry, as well as water use efficiency (WUE) of a C₄ maize (Zea mays L.) in response to soil drought and salinity. C₄ maize was grown in two atmospheric CO₂ concentrations of 400 and 800 ppm (a[CO₂] and d[CO₂]), subjected to two soil water regimes (well-watered and drought stress) and two soil salinity levels (0 and 100 mM NaCl pot⁻¹ (non-salt and salt stress)). The results indicated that soil drought increased maize root tissue density and specific root length. Both d[CO₂] and salt stress reduced leaf phosphorus (P) and K concentrations; conversely, drought stress enhanced leaf nitrogen (N) and K concentrations. The lower specific leaf area, but greater specific leaf N and N/K under soil drought, was amplified by salt stress. In contrast, d[CO₂] promoted leaf carbon (C)/N and C/K. Notably, d[CO₂] combined with soil drought enhanced leaf K/Na under salt stress. Moreover, d[CO₂] ameliorated the adverse impacts of soil drought and salinity on root morphology in terms of enlarged root length and root surface area, contributing to superior leaf C, N, and K use efficiency and consequently improved C₄ maize plant dry mass and WUE. These findings would provide essential knowledge to elevate salt tolerance and achieve optimal nutrient homeostasis and WUE in C₄ maize, adapting to future drier and more saline soils under a CO₂-enriched scenario. Full article

The global population faces increasing demands for sustainable initiatives due to industrialized agriculture. To meet the demand for protein-rich foods, innovative practices must be implemented. Conventional agricultural systems face significant challenges, including soil degradation, biodiversity loss, nutrient depletion, air pollution, and degraded water quality. Additionally, conventional agriculture affects the environment due to unsustainable farming practices utilizing chemical fertilizers, pesticides, and herbicides. These practices contribute to the accumulation of greenhouse gases and carbon emissions, which negatively affect air and water quality. Agricultural yield is declining, reducing the availability of foods, and further increasing food insecurity through increased costs. Microalgae, a unicellular organism with adaptive capabilities for carbon sequestration, offers a beneficial shift from conventional agriculture. Microalgae provide low-impact environmental alternatives to the agricultural sector, promote energy conservation, and synthesize health-promoting biomolecules, such as antioxidants, pigments, essential fatty acids, polysaccharides, and protein. This review evaluates the potentials of microalgal biomass for sustainable food applications, highlighting its role in strengthening microalgae as a biorefinery and alleviating the environmental and ecological burdens of traditional farming. Full article

To elucidate the effects of different plantation types on understory vegetation and soil properties in the Mu Us Sandy Land, this study investigated five plantation types: Pinus sylvestris var. mongolica Litv. pure forest, P. sylvestris var. mongolica-Salix psammophila C. Wang and Ch. Y. Yang mixed forest, Salix matsudana Koidz. pure forest, Amorpha fruticosa L. pure forest, and A. fruticosa-S. psammophila mixed forest, using bare sandy land as a control. Through quadrat survey and stratified soil sampling, we assessed the understory plant diversity, soil characteristics, and their interrelationships. The results showed the following: (1) A total of 11 understory plant species, belonging to 11 genera and five families, were recorded, predominantly shrubs from Asteraceae and Fabaceae, and perennial herbs. The S. matsudana pure forest exhibited the highest understory plant diversity, with Shannon and Margalef indices (1.72 and 1.87, respectively) significantly higher than other stands. (2) Soil nutrients varied significantly with forest type. The mixed forest of A. fruticosa and S. psammophila notably improved the contents of soil total nitrogen and organic matter, whereas the soil total phosphorus content was generally low in all stands. (3) Spearman correlation analysis revealed the differential responses of diversity indices to soil factors: the Simpson dominance index was significantly negatively correlated with 10~20 cm soil water content (SWC) (r = −0.9, p < 0.05), and significantly positively correlated with 20~40 cm total phosphorus (TP) (r = 0.9, p < 0.05), with no significant correlations with other soil factors (TN, TK, OM, pH); the Shannon diversity index was highly significantly negatively correlated with 0~10 cm SWC (r = −0.97, p < 0.01), and no significant correlations with other soil factors (TN, TK, TP, OM, pH); the Pielou evenness index was significantly positively correlated with 0~10 cm pH (r = 0.9, p < 0.05) and positively correlated with 20~40 cm pH (r = 0.8) (not statistically significant); by contrast, the Margalef richness index showed no significant correlations with all measured soil physicochemical factors. This study demonstrates that S. matsudana pure forest is more conducive to the development of understory plant diversity, and that soil factors exert a stronger regulatory effect on community structure (evenness and dominance) than on species richness in this arid sandy ecosystem. Full article