Soil Content Research Articles

Interaction of Te(IV) and Te(VI) with the soil matrix – Sorption and fractionation as a function of soil composition

Tellurium is a technology-critical element (TCE), with relatively limited data on its behavior in the environment, especially the pedosphere. As with other TCEs, its more widespread use, especially in new energy sources, might lead to Te spillage during production or in the eventual waste. Investigation of tellurium's interaction with soil is a necessary step in the research into the physiochemical transformation and determining the mobility of different tellurium species. To broaden the hitherto scarce knowledge of tellurium behavior in the soil environment, selected soluble tellurium compounds were introduced into different types of well-characterized soil (content of fertilizers, organic matrix, clay minerals, Mn, Fe, pH). The study of Te(IV) and Te(VI) sorption indicated that after 7 days the sorption is quantitative and close to 100%. Addition of Fe2O3 to a soil deficient in Mn and Fe increases its sorption potential by about 10 percentage points. Based on fractionation study (0.11 mol L−1 CH3COOH, 0.1 mol L−1 ascorbic acid in oxalate buffer (pH 3), 30% H2O2 at 85 °C followed by 0.5 mol L−1 CH3COONH4), it was shown that the presence of Mn/Fe (oxyhydr)oxides plays an essential role in the mobility of Te, especially Te(VI), regardless of the soil type. In the soil poor in reducible fraction and rich in organic matrix (peat), the organic fraction was responsible for the immobilization of Te, especially Te(IV). Extraction of the mobile fraction after incubation in the presence of DI water (Te extraction: 7–8%), oxalic acid (5–7%) or citric acid (6%) (mimicking rhizosphere activity) indicated that these did not play a significant role in Te retention. Nevertheless, soil modification with biocarbon limited the effect of citrates on Te mobilization. This knowledge is fundamental, i.e. in the context of soil remediation processes and counteracting the migration of Te in the environment from anthropogenic sources (e.g. solar farms).

Ecological factors impacting genetic characteristics and metabolite accumulations of Gastrodia elata

ObjectiveThe investigation of the correlation between ecological factors and the genetic characteristics or metabolites of plants offers valuable insights into the regional causes of genetic and metabolic diversity. Here, Gastrodia elata, a medicinal plant, is employed as a model to explore the environmental factors that influence its genetic characteristics and metabolic accumulations. MethodsA total of 23 G. elata populations from six cultispecies and 11 cultivated regions were selected based on the predictions of the global geographic information system. The genetic characteristics of these populations were evaluated using highly polymorphic simple sequence repeat markers. Additionally, the metabolic accumulations and antioxidant capacity of mature tubers were measured employing colorimetry and high performance liquid chromatography (HPLC). Ecological data of each region were obtained from the WorldClim-global climate database and harmonized world soil database. To assess the influence of ecological factors on the genetic characteristics and metabolic profiles of G. elata, Pearson’s correlation analysis was conducted. ResultsGenetic variation among G. elata populations exceeded that within populations. Genetic diverisity, distance and structure manifested regional and species-specific patterns. Metabolic profiling and antioxidant capacity exhibited regional variations. Notably, the Lueyang region demonstrated that a content range of total polysaccharide, total protein, and phenolic glycosides was 9.34 %−189.67 % higher than the average. Similarly, in the Hubei region, total phenolic content, p-hydroxybenzyl alcohol content, and antioxidant indicators were observed to be higher than the average levels, by 106.57 %, 136.47 % and 12.50 %−91.14 %, respectively. Furthermore, ecological factors had a significant comprehensive impact on G. elata genetic characteristics (r > 0.256 and P<0.05). Multivariate metabolite accumulations in G. elata were influenced by dominant ecological factors. Temperature notably impacted the accumulation of total protein (|r| > 0.528 and P<0.05). Moisture, encompassing precipitation and soil content, significantly affected the production of phenolic glycosides (|r| > 0.503 and P<0.05). ConclusionThe genetic characteristics of G. elata manifested regional and species-specific patterns, with the metabolic accumulations and antioxidant capacity of mature tubers exhibited regional variations. Specifically, multivariate ecological factors comprehensively influenced genetic characteristics. Temperature and moisture played pivotal roles in regulating the accumulations of proteins and phenolic glycosides, respectively. These findings underscore the significant impact of ecological factors on the shaping of G. elata, highlighting their crucial role in enhancing the quality of Chinese medicinal materials.

Temperature and water content estimation in soils of the semi‐arid region of Brazil using finite difference and CFD

AbstractDetermining the temperature and water content of soil, at a given instant or along time, is fundamental to understand several soil‐related phenomena and processes. Evaporation, aeration, chemical‐reaction rates and types, biological processes such as germination and growth of seeds, root development, nutrient and water uptake by roots, and decomposition of organic matter by microbes, are all strongly influenced by soil temperature. On the other hand, infiltration of water through the soil surface allows soil to temporarily store water, making it available for uptake by plants and organisms living in soil. Furthermore, soil water content is closely related to physical and chemical properties of soil, such as oxygen content and demand, which impacts root breathing, microbial activity and soil chemical balance. The accurate evaluation of these two parameters and their interconnection is even relevant in semi‐arid regions, where climate conditions are particularly difficult, such as the north‐eastern zone of Brazil. Thus, the use of computational models and coupled approaches are imperative for rigorous descriptions. This work presents a contribution to estimate soil temperature and water content, by solving the heat transfer equation and the Richards equation, respectively, through finite differences. As input, the model uses the experimental material composition of the soil, the time‐dependent temperature profile at the surface and information about the regional rain regime. Three different numerical approaches were implemented: explicit, simple implicit and the Crank–Nicolson method. The calculations for temperature and water content of the soil obtained with these computational models were compared with the results from Computational Fluid Dynamics (CFD). The relative differences between the numerical methods were less than 0.006% by solving the heat transfer equation and less than 2.75% using the Richards equation. The maximum relative differences within the model, including both a constant and a variable water‐content profile, were 3.28%. The results from the computational model using the CFX tool have maximum relative differences of 0.6%, which contributes to verifying the accuracy of the implemented methods.

Predicting the risk of arsenic accumulation in soil-rice system in Asian monsoon region

Rice is a staple food for a significant portion of the global population. Arsenic (As) accumulated in rice grains influences rice quality which threatens human health. In this study, we used three machine learning models to predict arsenic accumulation in rice based on over 300 surveys. The prediction results of soil arsenic indicate that high-arsenic soil areas are mainly distributed in South and Southeast Asia such as India, China, and Thailand. In addition, higher bioaccumulation factors (BAF), associated with higher temperature, are predominantly observed in eastern India and southern Myanmar. However, arsenic content in soil is relatively lower in these areas. About 5.5 billion population may be threatened by the consumption of high-arsenic rice. It can be concluded that temperatures may influence the BAF except for soil arsenic, and soil physicochemical properties. Further research on the relationship between climate parameters and BAF should be conducted to address and adapt to future climate change. Additionally, understanding the mechanism of arsenic accumulation under different climatic conditions is crucial for developing agricultural technologies to reduce arsenic accumulation in rice.

A nationwide study of heavy metal(loid)s in agricultural soils and the soil-grown black morel Morchella sextelata in China

The accumulation of heavy metal(loid)s (HMs) in soil-grown mushrooms poses potential health risks. Morchella sextelata (black morel) is a typical soil-grown mushroom with a rapidly expanding cultivation area. This study investigated the distribution of arsenic, cadmium, chromium, copper, mercury, nickel, lead, and zinc in 213 pairs of soil and morel samples collected from 29 provincial administrative regions in China, together with the nutritional contents in the morel samples. The HM contents in the arable soils used to cultivate morels were 2.4–33.1 times higher than those in desert soils, while the HM contents in arable-soil morels were 2.9–155.9 times higher than desert morels. The HM contents of morels and their cultivation soils were significantly correlated (0.465 ≤ R ≤ 0.778, P < 0.001). Furthermore, the enrichment factors of most HMs were higher in arable soils than in desert soils (P < 0.05), except Hg. A considerable proportion of the arable soils produced morels with HMs exceeding the risk control standards (RCSs) for food and the health-risk thresholds of dietary intake. In comparison, HMs in morels from desert soils were far below the RCSs and health-risk thresholds. In addition, desert morels contained higher contents of crude proteins, total polysaccharides, and free amino acids (P < 0.001). These findings indicate that growing morels in desert soils is a way of green production that provides mushroom products with improved safety and nutrition.

Contrasting effects of iron oxides on soil organic carbon accumulation in paddy and upland fields under long-term fertilization

Active iron oxides, especially poorly crystalline forms, benefit soil organic carbon (SOC) accumulation via directly bounding and indirectly promoting aggregation. However, it remains unclear on the impacts of active iron oxides on SOC accumulation in paddy and upland soils under long-term fertilization regimes. Here, we attempted to clarify the underlying mechanisms of amorphous (FeO) and organically complexed (FeP) iron oxides mediating SOC accumulation in paddy and upland soils based on two long-term fertilization experiments (both including no fertilization [CK]; chemical nitrogen, phosphorus and potassium [NPK] and NPK plus manure [NPKM] treatments). Results showed that compared to upland soil, Fe-bound organic carbon (Fe-bound OC) content in paddy soil, occupying 21–30% of SOC, was 77% higher on average, due to larger amounts of FeO (+31%) and FeP (+224%). The FeO and FeP were positively related to mean weight diameter (MWD) of soil aggregates across paddy and upland soils. Compared to NPK treatment, NPKM treatment strongly increased FeO (+41%), FeP (+60%) and associated Fe-bound OC (+19%) in paddy soil, and increased FeO (+17%) and FeP (+25%) while decreasing Fe-bound OC (−9%) in upland soil. These combined findings indicated the importance of poorly crystalline iron oxides facilitating Fe-bound OC formation and its contribution to SOC accumulation in paddy soil rather than upland soil. Moreover, long-term manure amendment could enhance SOC accumulation by increasing Fe-bound OC and aggregation stability in paddy soil and enhancing physical protection in upland soil, largely attributed to increased poorly crystalline iron oxides. Overall, these results highlight the potential mechanisms through which active iron oxides regulate SOC accumulation and guide fertilization management in paddy and upland soils.

Distribution of manganese in surface soils and ecological risk assessment: a case study in the Pb-Zn mining and smelting area in the Mitrovica Region, Kosovo

ABSTRACT This study was conducted on the distribution of manganese content in the soils of the city of Mitrovica and its surroundings in Kosovo. A total of 156 topsoil samples were taken in the entire study region (sampling grid of 1.4 × 1.4 km2). The average Mn content of the entire study area is 1600 mg/kg (range 170–17000 mg/kg), which is 4.2 times higher than the EU average and 3.3 times higher than the global average. The spatial distribution maps show that the higher Mn contents occur mainly in soils from Miocene latite as well as quartz-latite and from Triassic volcanic-sedimentary formations in the eastern and north-eastern part of the study area. The lower values were found in the Flysch and Cretaceous flysch outcrops. It was found that the increased Mn contents in soils from this area are mostly of lithogenic origin. The values of the enrichment factor (EF) show that the soils of the entire study area are very highly enriched with Mn (20 < EF < 40). The values of the geo-accumulation index (1< I-geo ≤ 2), show that the soils of the entire study area are moderately contaminated with Mn.

An experimental and theoretical study on the creep behavior of silt soil in the Yellow River flood area of Zhengzhou City

We took the silt soil in the Yellow River flood area of Zhengzhou City as the research object and carried out triaxial shear and triaxial creep tests on silt soil with different moisture contents (8%, 10%, 12%, 14%) to analyze the effect of moisture content on silt soil. In addition, the influence of moisture contents on soil creep characteristics and long-term strength was analyzed. Based on the fractional derivative theory, we established a fractional derivative model that can effectively describe the creep characteristics of silt soil in all stages, and used the Levenberg–Marquardt algorithm to inversely identify the relevant parameters of the fractional derivative creep model. The results show that the shear strengths of silt soil samples with moisture contents of 8%, 10%, 12% and 14% are 294 kPa, 236 kPa, 179 kPa and 161 kPa, respectively. The shear strength of silt soil decreases with increasing moisture content. When the moisture content increases, the cohesion of the silt soil decreases. Under the same deviatoric stress, the higher the moisture content of the silt soil, the greater the deformation will be. The long-term strength of silt soil decreases exponentially with the increase of moisture content. If the moisture content is 12%, the long-term strength loss rate of silt soil is the smallest, with a value of 32.96%. The calculated values of our creep model based on fractional derivatives have a high goodness of fit with the experimental results. This indicates that our model can better simulate the creep characteristics of silt soil. This study can provide a theoretical basis for engineering construction and geological disaster prevention in silt soil areas in the Yellow River flood area.

Identification of key factors and mechanism determining arsenic mobilization in paddy soil-porewater-rice system

Arsenic (As) mobilization in paddy fields poses significant health risks, necessitating a thorough understanding of the controlling factors and mechanisms to safeguard human health. We conducted a comprehensive investigation of the soil-porewater-rice system throughout the rice life cycle, focusing on monitoring arsenic distribution and porewater characteristics in typical paddy field plots. Soil pH ranged from 4.79 to 7.98, while porewater pH was weakly alkaline, varying from 7.2 to 7.47. Total arsenic content in paddy soils ranged from 6.8 to 17.2 mg/kg, with arsenic concentrations in porewater during rice growth ranging from 2.97 to 14.85 μg/L. Specifically, arsenite concentrations in porewater ranged from 0.48 to 7.91 μg/L, and arsenate concentrations ranged from 0.73 to 5.83 μg/L. Through principal component analysis (PCA) and analysis of redox factors, we identified that arsenic concentration in porewater is predominantly influenced by the interplay of reduction and desorption processes, contributing 43.5 % collectively. Specifically, the reductive dissolution of iron oxides associated with organic carbon accounted for 23.3 % of arsenic concentration dynamics in porewater. Additionally, arsenic release from the soil followed a sequence starting with nitrate reduction, followed by ferric ion reduction, and subsequently sulfate reduction. Our findings provide valuable insights into the mechanisms governing arsenic mobilization within the paddy soil-porewater-rice system. These insights could inform strategies for irrigation management aimed at mitigating arsenic toxicity and associated health risks.

The advantage of afforestation using native tree species to enhance soil quality in degraded forest ecosystems

Different vegetation restoration methods have improved soil quality to varying degrees. This study, focused on the forest–grassland–desert transition zone in the Hebei–Inner Mongolia border region, and employed a systematic grid sampling method to establish fixed monitoring plots in the Saihanba Mechanized Forest Farm and the Ulan Buh Grassland. The differences in soil quality evolution across various vegetation restoration methods under the same climatic and soil historical conditions were analyzed, elucidating the roles of these vegetation restoration methods in degraded forest ecosystems, with the aim of providing a reference for ecological restoration under similar land conditions. This study used a grid method to establish sample points in the forest–grassland–desert transitional zone and assessed five methods of vegetation restoration sites: artificial forest composed of native species of Larix principis-rupprechtii (FL), artificial forest composed of exotic Pinus sylvestris var. mongolica (FP), natural secondary broad-leaved forest (FN), open grassland (GO), and enclosed grassland (GC). The differences in soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkaline hydrolysis nitrogen (AN), rapidly available phosphorus (AP) and rapidly available potassium (AK) among the different vegetation restoration sites were compared via variance analysis, and the soil quality index (SQI) was calculated to assess the soil quality at the sample points. The SOC, TN, and AN contents of forest soil were significantly greater than those of grassland, and the TN, TP, AN, AK, and SOC contents of FL, FN, and GC were significantly greater than those of FP and GO. Among them, the TN, TP, and SOC contents were the highest in the FL, reaching 2.74, 0.39, and 47.27 g kg−1, respectively. In terms of ecological stoichiometric characteristics, the average N:P ratio in the study area was 6.68, indicating a serious lack of N in the study area. Among the different types of restoration sites, the effect was stronger in the FP than in the FL, and the TN and AN contents were only 1.48 g kg−1 and 116.69 mg kg−1, respectively. The SQI in the FL was not significantly different from that in the FN or GC, but it was significantly greater than that in the FP and GO. These findings indicate that native tree species restoration in degraded forest ecosystems significantly improved soil quality, while the introduction of exotic tree species for afforestation had a minimal effect on improving soil quality.

Near Infrared Spectroscopy for Rapid Prediction of Soil Organic Carbon Content in Agricultural Soils

Near Infrared Spectroscopy for Rapid Prediction of Soil Organic Carbon Content in Agricultural Soils

Trade-Offs in Plant Functional Traits Driven by Soil Changes under Urban Hardened Surfaces

The large-scale surface hardening has changed the urban environment and affected the normal growth of urban plants. However, it is still unclear how the urban hardened surface affects the functional urban plant traits. To explore whether the urban hardened surface affects the ecological strategies of plants by changing the urban soil properties and reflecting them on the plant traits, we studied the physical and chemical properties and plant functional traits of three different types of hardened surface in Shandong Province, China. Our results showed that the physical and chemical properties (soil bulk density, soil total porosity, capillary porosity, non-capillary porosity, soil moisture content, pH, organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorus, and available potassium) of urban soils showed obvious differences with the increase of hardening strength. In this case, the plant functional traits (branch diameter, branch length, leaf thickness, branch weight, internode length, leaf dry weight, leafing intensity, leaf area, specific leaf area, and leaf dry matter content) were also differentiated to varying degrees. Meanwhile, there was a strong correlation among plant functional traits. Nevertheless, hardened surfaces break the quantitative relationship among functional traits of urban trees. They do not affect their stable correlation: as the hardening intensity gradually increases, its correlation weakens. In addition, plant functional traits have a significant response mechanism to soil physicochemical properties. There was a transformation of plant resource utilization strategy by changing plant functional traits to adapt to the hardened environment. Urban trees exhibit strong and rapid resource-allocation strategies. They are mainly reflected in the reduction of branch diameter, branch weight, leaf dry matter content, leaf area, mass ratio of branches and leaves, and the improvement of leafing intensity and leaf thickness. Overall, there were tight connections among urban soil properties, plant branches, and leaves functional properties. This finding reveals that urban trees can change their functional traits and the plasticity of their trait combinations under the background of hardened urban surface expansion, which is conducive to survival and growth.

The Potential of Providing Chicken Manure in Improving Soil Health in Dry Lands

Despite having a considerable potential area, the optimal utilization of dry land is challenging due to the generally low soil moisture content and fertility of dry land in Indonesia. This is evidenced by the intrinsically low organic matter content in dryland soils. Therefore, this article aims to provide information on the potential application of chicken manure to enhance soil fertility and health or to rehabilitate suboptimal dry lands in Indonesia. The methodology used in this article is qualitative, based on a literature review. One approach to improving the condition of dry land in Indonesia is the application of chicken manure, which acts as a soil conditioner and enhances overall soil fertility and health. The results of the study indicate that using chicken manure on dry land can increase crop production, thereby positively correlating with the profits of dry-land farmers.

Response of oilseed flax to different level of mineral nutrition in the forest-steppe of Western Siberia

The article presents the results of studying the influence of nitrogen and phosphorus fertilizers on the water regime of meadow-chernozem soil, yield and oil content of flax seeds in 2022–2023. on a stationary experiment at the field forage production laboratory of the Federal State Budgetary Institution “Omsk ASC” in the conditions of the southern forest-steppe of the Omsk region. The objects of observation are oilseed flax of the Northern variety and meado-chernozem soil. The scheme of the experiment included the following options: factor A — medium soil availability of mobile phosphorus (50-100 mg/kg according to F.V. Chirikov, background 0), increased (100–120 mg/kg, background I and 140–150 mg/kg, background II), high (150– 200 mg/kg, background III); factor B — phosphorus fertilizer (P0, P60); factor C — nitrogen fertilizer (N0, N30, N60). In this case, nitrogen and phosphorus fertilizers were superimposed on backgrounds of varying soil phosphorus supply. Climatic factors (temperature and precipitation) determined the initial reserve of total moisture in the soil when sowing oil flax, which was at the level of 82% of the lowest moisture capacity in a meter layer and did not depend on the background phosphorus supply. Mineral fertilizers increased crop productivity. Its highest yield was observed against the background of an increased supply of soil with mobile phosphorus (1.71 t/ha) with the pre-sowing application of ammonium nitrate and ammophos. The oil content of flax, on the contrary, decreased when using fertilizers. Its highest indicators (39.5%) were observed against background II when using phosphorus fertilizers.

Soil organic carbon pools as influenced by 21 years of conservation agriculture management practices in Saskatchewan

Soil organic carbon (SOC) content is a key metric of soil quality and limited work has been done to examine the effect of long-term conservation agriculture management practices (CAMP) on SOC pools within western Canadian soils. We assessed the nature and permanence of sequestered SOC within 90 diverse Saskatchewan surface (0–10 cm) agricultural soils before and after 21 years of CAMP. Comparisons were made of total SOC, labile and dynamic SOC fractions (light fraction, water-extractable, and microbial biomass), respirable CO2–C during a 6-week incubation, along with spectroscopic characterization using 13C/12C stable isotope ratio and ATR-FTIR. Among soil climatic zones, the SOC content increased in the semi-arid Brown and Dark Brown soils, ranging from 2.4 to 3.7 Mg C ha−1 (111.4–187.7 kg C ha−1 year−1), but did not change in the subhumid Black, Dark Gray, and Gray soils. Overall, soils having the smallest initial SOC level were most responsive to CAMP and accumulated more SOC. According to the δ13C data, CAMP appeared to reduce annual crop moisture stress, especially within the Brown soil zone. Decreased light fraction and water-extractable SOC contents in Black, Dark Gray, and Gray soils could reflect more intense decomposition and greater surface stratification of crop residues. Brown soils experienced the largest increase in microbial biomass-C content. The CO2–C emissions from the Brown, Dark Brown, and Gray soils under CAMP suggest greater SOC stability in 2018 compared with 1996. The ATR-FTIR data pointed to enhanced SOC persistence, via more stabilized SOC forms and mineral-associated organic C fractions.

Soil silicon availability and silicon uptake by winter wheat in Tokachi district, Hokkaido

ABSTRACT Silicon (Si) is the second most abundant element in soils and is a beneficial element for plant growth, particularly for gramineous plants such as rice, corn, and wheat. In Japan, soil Si availability and its relationship with Si in plants have been mainly focused on paddy soils and rice. Although Si has also been reported to benefit wheat production via enhanced phosphorous uptake and resistance to diseases, there is little study on Si availability in agricultural soils related to wheat production in Japan. The objectives of this study were to (1) assess the soil available Si and its relation to other soil properties in upland fields, (2) evaluate Si concentration and its distribution in winter wheat, (3) clarify the relationship between the soil available Si and the Si concentration in wheat, and (4) identify suitable methods to determine available Si for agricultural soils. Surface soil and wheat samples were collected from 40 growers’ field along four different river terraces including lowland, low terrace, middle terrace, and high terrace of the Tokachi district in 2020 and 2021. Soil available Si was evaluated by three methods using acetate buffer and phosphate buffer solution. The soil available Si contents in agricultural soils varied from field to field considerably, and were remarkably larger in the fields located on the middle and high terraces compared to the lowland and the low terrace, suggesting the effects of soil parent materials and pedogenic factors, particularly volcanic ashes and amorphous clay minerals. The mean Si uptake by winter wheat was 13.4 g m−2 and comparable to N and K uptake and greater than P. Winter wheat mainly stores Si in culms, leaves and husks, and the highest mean concentration of Si in above-ground part of winter wheat was 27.6 g kg−1 in husks. The high Si concentration in the husk may be related to enhancing plant physical protection to preharvest sprouting and fungal diseases. Among three methods, the acetate buffer solution method could be the most promising method to determine soil Si availability in agricultural soils of the studied area.

Effects of Freeze−Thaw Cycles on Available Nitrogen Content in Soils of Different Crops

In order to study the effect of freeze−thaw cycles on the content of available nitrogen in soils of different crops and obtain an in-depth understanding of changes in soil fertility and soil environment in cold regions, a laboratory simulation experiment was conducted with different freeze−thaw times, temperature differences, and periods. The changes in available nitrogen concentrations in the 0–15 cm and 15–30 cm layers of corn, vegetable, and paddy soils were measured by the alkaline-hydrolysis diffusion method. The results were as follows. (1) The freeze−thaw process had significant effects on the available nitrogen content in the three soils. Under the treatment with different numbers of freeze−thaw cycles, the available nitrogen content in the 0–15 cm layers of corn soil, vegetable soil, and paddy soil reached the maximum values at the 8th, 1st, and 3rd freeze−thaw cycle, at 156.92 mg/kg, 479.17 mg/kg and 181.75 mg/kg, respectively; the available nitrogen content decreased slowly after reaching the maximum value. (2) Under the freeze−thaw temperature-difference treatment, the available nitrogen concentration in the 0–15 cm layers of corn soil, vegetable soil, and paddy soil reached the maximum value at a temperature difference of 30 °C, at 147 mg/kg, 476 mg/kg and 172.5 mg/kg, respectively, and the available nitrogen content of the 15–30 cm soil layers changed slightly. (3) Under different freeze−thaw periods, the magnitudes of the changes in soil available nitrogen concentration in 0–15 cm of corn soil and paddy soil were, in descending order, short-term freezing and long-term melting &gt; long-term freezing and long-term melting &gt; short-term freezing and short-term melting &gt; long-term freezing and short-term melting. The soil available nitrogen concentration at different depths in the vegetable soil reached the maximum value under the treatment with long-term freezing and short-term melting. (4) The available nitrogen content of paddy soil under the high-water-content condition was higher than that of paddy soil under the low-water-content condition, and the change in available nitrogen content was more obvious under the high-water-content condition under different freeze−thaw period treatments; the opposite was true for corn soil and vegetable soil. Simulation studies on rapid changes in soil nitrogen content during tests that simulate winter freeze−thaw conditions are important for understanding crop growth, the application of nitrogen fertilizer in spring, and the prevention of surface-water pollution from agricultural runoff.

Efficiency of Fulvic Acid for Improving Physico-Chemical Properties of Albic Black, Gansu Desert and Shahjiang Black Soils

Fulvic acids are a crucial component of soil that influence various chemical, biological, and physical aspects of soils as well as increase nutrient availability. We examined that application of plant-derived liquid (PDL) fulvic acid on three low obstacle, typical Chinese soil can improve the soil fertility and enhance the plant growth and nutrients uptake. The pot experiments were carried out on three different Albic (AL), Irrigated Desert (IR) and Shahjiang Black (SH) soils, the Plant-derived Liquid (PDL) fulvic acid (FA) was applied at rates of 0.50% as well as control applied at 0% along with three replications. The results showed that PDL FA significantly increases the SOC content in three soils highest SOC was detected at SH, however the SOC fractions were significantly decreased in AL, SH and no-significant difference was recorded at IR. Similarly, the soil pH was significantly increased in AL and decreased at IR and SH, however, the electrical conductivity of IR decreased and increased in AL and SH comparing with initial soil pH and electrical conductivity. The results also examine that available nitrogen, phosphorus of AL, IR and SH soils were increased, however, available potassium content was decreased in IR and increased at AL and SH comparing with initial values. The highest Ca and Mg content was observed in SH and organic degree compound were found 26.7% AL, 49.2% IR and 18.2%, SH soil, conversely the organic-inorganic composite was observed lower. This study suggests that the PDL FA significantly increases the nutrient content of AL, IR and SH soils comparing with initial soil properties.

Development of a Chitosan‐Based Food Packaging Film with the Incorporation of Pectin and Silver Nanoparticles for Improved Antibacterial and Physical Properties

AbstractThis research incorporated grapefruit peel‐derived Pectin and Silver nanoparticles (AgNPs) into the Chitosan‐based bio‐packaging film to improve its antibacterial efficacy and physical properties such as moisture content, swelling degree, and biodegradability in soil. Systematic investigations revealed that preservative films made from Chitosan 1.75 wt %, Pectin 0.55 wt %, and AgNP 31 ppm have shown a 17.5‐fold reduction in swelling degree in water compared to Chitosan films. At the same time, the anti‐gram‐positive and anti‐gram‐negative bacteria capacity, the ability to retain moisture, and biodegradability in soil, have been enhanced. Low swelling degrees provided better barrier performance, extending the shelf life of packaged products by preventing the ingress of oxygen, and water vapor; on the other hand, higher moisture content improved the flexibility and handling characteristics of packaging films, making them easier to manipulate during packaging processes. These findings herald a sustainable option for eco‐friendly food packaging, a critical step toward minimizing plastic waste and strengthening food preservation procedures using Chitosan‐based antibacterial films enhanced with natural additives.

Insight into the short-term effects of TiO2 nanoparticles on the cultivation of medicinal plants: Comprehensive analysis of Panax ginseng physiological indicators, soil physicochemical properties and microbiome

To meet societal needs, a large number of medicinal plants are cultivated artificially. However, issues such as diseases and continuous cropping obstacles (CCO) have severely impacted their quality and yield. Exploring and innovating the cultivation technology for medicinal plants is essential to meet their high demand and ensure sustainable development. The role of titanium dioxide nanoparticles (nano-TiO2) in medicinal plant cultivation remains unclear. To advance the application of nanotechnology in this field, a comprehensive exploration of its potential benefits is necessary. In this study, nano-TiO2 was applied to ginseng (Panax ginseng C.A. Meyer) to acquire a holistic comprehension of its impact on ginseng growth, rhizosphere, and ginseng-used soil. Our findings reveal that nano-TiO2 significantly enhances ginseng root activity and has notable effects on antioxidant enzyme systems. The two concentrations of nano-TiO2 markedly influenced the structure and composition of microbial communities in the rhizosphere and ginseng-used soil, including key microorganisms such as Chloroflexi and Acidobacteriota, which are closely involved in soil function. Furthermore, nano-TiO2 altered the competitive and cooperative relationships within microbial networks. Nano-TiO2 application significantly increased soil organic matter (SOM) content in rhizosphere and ginseng-used soils and affected the activities of several important soil enzymes. Environmental factors, such as EC, pH, and soil nutrients, were found to be the main factors influencing the microbial community. In conclusion, our findings illuminate the complex effects of nano-TiO2 on the “plant-microbial-soil” system in the context of ginseng cultivation. This work offers novel strategies for optimizing medicinal plant growth and development, as well as improving cultivated soil by using nanomaterials.