Abstract: Film mulching and gravel mulching are effective methods for increasing crop yields in Northwest China but exacerbate soil organic carbon (SOC) mineralization, while manure amendment is a viable method for offsetting carbon (C) losses from mulching. SOC stability is a key factor in determining the nutrient supply capacity of soil, as it affects the C sources available to microorganisms. However, the synergistic effects of film mulching with manure amendment on SOC stability and crop nutrient uptake are still unclear. Thus, four treatments of no mulching (CK), gravel mulching (GM), film mulching (FM) and film mulching with manure amendment (FCM) were established on the Loess Plateau. The experiments investigated nitrogen (N), phosphorus (P), potassium (K) uptake in the plant and grain, SOC, labile organic C fractions (LOCFs), stability-based organic C fractions (SOCFs) and C management index (CMI) in 2019 and 2020. The results indicated that FM and FCM treatments significantly improved crop dry matter accumulation in both years compared with that of the control, and the FCM treatment significantly increased the two-year NPK average of plants to 44.9%, 50.7%, and 54.5%, and significantly increased the two-year NPK average of grain to 46.7%, 58.2%, and 30.4%. The FCM treatment significantly increased all LOCFs, namely water solution C (WSC), hot-water extractable C (HWC), permanganate oxidizable C (POXC) and particulate organic C (POC) in the topsoil (0-20 cm) in both years, and the fractions of active C pool (AP) in SOCFs, namely very labile C (CVL) and labile C (CL), were significantly increased, which suggested the FCM treatment significantly decreased the C stability of topsoil. The results of CMI confirmed this. The sensitivity index indicated that among all SOC fractions, POC (21.5-72.9%) and less labile C (CLL) (20.8-483.8%) were the most sensitive fractions of LOCFs and SOCFs compared with SOC (1.93-35.8%). The random forest analysis showed that most labile C fractions and CMI had significant contributions to crop N, P and K uptake, especially POXC to crop N uptake, CMI to crop P uptake, and AP to crop K uptake. And the quantitative relationships were determined by linear regression analysis. The study concluded the FCM treatment synergistically enhanced SOC lability, crop NPK uptake, and labile C fractions (especially POXC, AP) and CMI serve as robust indicators for guiding precision nutrient management in semi-arid croplands.

Abstract: In Eritrea, conventional agriculture is the main stay for most of the population for livelihood where crop productivity is very low, and food insecurity and poverty are common. Though initiatives are being taken to promote the agricultural sector in the country, soil resources are not addressed. Soil studies are very limited, and the country lacks digital soil mapping. Thus, the study aims to develop robust soil organic carbon (SOC) prediction model/s for the western lowland soils where most of the agricultural activities of the country are carried out. We employed MLR, PLS, Cubist, RF, GB and XGB algorisms, and regressed multiple soil, climatic, Landsat 8 (L8) bands and spectral indices against SOC (n=178) through machine learning. The SOC modelling was done in 3 steps with 25, 14, and 06 independent environmental variables to identify the main SOC driver variables. Models performances were evaluated using the RMSE, R2, and RPD metrics. The SOC content in the study area was low with an average of 0.44%, which needs effective soil carbon improvement planning. The accuracies of all the tested models were good enough in all the three steps. The PLS model with 14 input variables gave the highest accuracy (RMSE = 0.1128%, R2 = 0.8268, RPD = 2.4393), and RF model with 06 input variables recorded the lowest (0.1435%, 0.7032, 1.9173). MLR and XGB models improved but GB model worsened with dimensionality reduction. PLS, Cubist, and RF models gave better results with 14 input variables. According to the RPD category, the PLS, XGB, and Cubist models were very good, and RF was good in all the three steps. MLR improved from good to very good but GB deteriorated from very good to good. Rainfall was the most important variable for SOC spatial variability prediction in the study area. Temperature, Green and SWIR2 Landsat 8 bands, NDSI, BR2, Sand, and MSAVI2 also had good capacity to predict the SOC spatial variability. We conclude that all the developed models have good predictive accuracies to be employed in short-mid-long-term planning and monitoring of soil fertility and productivity improvements, ecosystem restoration, and climate-change mitigation action. The study, being the first of its kind in the country, has laid the foundation for digital soil mapping (DSM) and management in the country, and more detailed SOC modelling studies are advised with more soil samples in the study area and other parts of the country for better results.

Abstract: Soil organisms serve as reliable indicators of soil quality, particularly when linked to key ecological processes. This study investigated the role of glomalin-related soil protein (GRSP) as a key factor in soil aggregation and organic carbon storage in irrigated and rainfed systems, with a focus on pig slurry fertigation. Two GRSP fractions—easily extractable (EE-GRSP) and total (T-GRSP)—were evaluated across three soil depths (0–10 cm, 10–20 cm, and 20–30 cm) in both management systems. Soil physical, chemical, and microbiological properties were analyzed, including enzyme activity and microbial diversity, with microbial community structure characterized via e-DNA sequencing. Results showed that the irrigated system exhibited a 66% higher T-GRSP concentration compared to the rainfed system, contributing 3.1% to total soil carbon, while the rainfed system contributed 1.1%. Significant correlations were observed between GRSP fractions, nutrient availability, microbial enzyme activities, and e-DNA–derived microbial profiles—especially in the topsoil layer. These findings suggest that glomalin, particularly in systems employing organic practices such as pig slurry fertigation, is a robust indicator of soil quality with potential applications in sustainable land management.

Abstract: Wetland restoration has led to land-use changes of coastal zone and also effected on soil nutrient distribution and dynamics. To characterize the differences of typical biogenic elements (C, N and P) distribution and trends of soil induced by wetland restoration policy, we studied two intervention strategies which covered woodland or cropland converted into wetland from four wetland use conditions (ash grove (AG), permanent wetland (PW), wheat field (WF) and seasonal wetland (SW)) in the Yellow River Delta (YRD). The results demonstrated that conversion to permanent wetland showed a more or less significant increase in concentrations and stoichiometric ratios of soil C, N and P, while reclamation of seasonal wetland increased soil N and soil P and the ratio of soil N:P (RNP). We observed the mean soil C concentrations of PW and SW increased by 31.1% and 6.3% in the 0-50cm soil profile separately, compared to their former wetland use, confirming powerful C sequestration of coastal wetlands. PW after 25 years of conversion of woodland to wetland showed an increase in soil C:N (RCN, 25.7%) and C:P (RCP, 30.0%) and SW after 12 years of returning cropland to wetland showed an increase by 17.6% in RCN throughout the soil profile, while similar differences of soil in top 5 cm layers turned out to be even apparent in the studied four wetland use conditions, suggesting the varying of different wetland intervention strategies and implementation period. The underlying changes in nutrient distribution and stoichiometric ratio dynamics are mainly due to C sequestration of wetland and N/P fertilization of reclamation. This brings new insights and helps to increase the knowledge the long-term effect of wetland restoration on soil nutrient distribution and trends in YRD. Understanding these effects can provide sensible policymaking for the conservation and management of coastal wetlands, which is helpful to realize ecological functionality of coastal wetland and achieve carbon neutrality in China.

Abstract: Liming is a common practice for improving the quality of soils affected by acidity, due to climate change, acid rain, nitrate leaching, and oxidation of sulphide minerals. This study aimed not only to assess the efficiency of fine and coarse lime application at 3 t/ha and 6 t/ha doses in mitigating soil acidity, but also to determine which of the options has a stronger impact on improving subsoil characteristics. Over a period of two years, several key parameters were monitored: pH, exchangeable base cations (Caexch, Mgexch, and Kexch), and Alexch. In the topsoil, the highest increase in pH was observed 6 months after the ap-plication of 3 t/ha fine lime, while in the subsoil, only a modest increase was noted. The highest values of exchangeable base cations in the topsoil were: Caexch = 9.06 cmol/kg soil; Mgexch = 1.15 cmol/kg soil; Kexch = 0.360 cmol/kg soil. These were recorded 24 months after applying 6 t/ha of fine aglime, and were higher than those obtained in the subsoil. While in topsoil Alexch reached 0 at T3, in subsoil, the largest decrease was 38% at T3. The release rate of ca Ca and its mobility depend on the particle size and dose of aglime, playing an important role in alleviating aluminium toxicity.

Abstract: Superabsorbent Polymers (SAPs) have been increasingly studied for their potential to enhance soil water holding capacity and reduce irrigation needs, particularly in water-scarce agricultural regions. The objective of this study is to maximize water holding capacity and minimize water irrigation by evaluating the effectiveness of SAPs on Soil Texture, Water Holding Capacity, and pH Content under controlled treatments in Purok Kabelen. The researchers conducted experiments using different SAPs and water treatments by analyzing their effects through ANOVA, Regression Analysis, and Sensitivity Analysis. Findings from the study indicate that SAPs application significantly influences soil physical characteristics. The ANOVA results showed that SAPs had a statistically significant effect on soil texture, water holding capacity, and pH content, with F-values of 309.254, 1309.8, and 401989, respectively (p < 0.05). Regression analysis further confirmed a strong correlation between SAPs application and increased water retention, as well as changes in soil pH. Specifically, the highest water holding capacity of 82.74% was achieved at a 10g SAP: 200mL water per 500g soil treatment by marking a 34.9% increase from the control. Soil texture analysis revealed a rise in clay content from 37% to 83.9%, and soil pH shifted from 6.27 (moderately acidic) to 7.83 (slightly alkaline). The sensitivity analysis examines the effects of Superabsorbent Polymer (SAP) and water on soil texture, Water Holding Capacity (WHC), and pH. SAP applications significantly altered soil texture, with sand content decreasing by up to 83.01% at 5g SAP and silt content dropping by 74.13% at 40g SAP. In contrast, clay content increased, peaking at 126.76% at 5g SAP before stabilizing. Water Holding Capacity improved by 34.87% at 10g SAP, with smaller gains beyond 20g SAP. pH content increased by 24.88% at 80g SAP, shifting the soil toward alkalinity. However, excessive SAPs application beyond the optimal level did not yield proportionate improvements in water holding capacity. This study aligns with the United Nations Sustainable Development Goals (SDGs), particularly Sustainable Development Goal 12 (SDG 12): Responsible Consumption and Production and Sustainable Development Goal 15 (SDG 15): Life on Land. By improving irrigation efficiency, and reducing excessive water use, this study promotes responsible resource management and supports sustainable land practices in agriculture.

Abstract: In western Jilin Province, China, the presence of soda saline-alkali soil poses a significant threat to the rice seedlings raising due to its harsh soil properties. The scarcity of suitable seedling-raising soil resources has become increasingly pronounced. A short-term soil improvement experiment was conducted using the original saline-alkali soil sourced from the rice-growing region of Jilin Province, followed by the rice seedlings raising test in the improved soil to identify an effective soil improvement strategy. Four distinct treatments were established: no amendment (JCK), gypsum and straw (JCW), gypsum, straw, and sulfuric acid (JCWH), and gypsum, straw, and chemical fertilizer (JCWF). The effects of these amendment treatments on soil physicochemical properties (pH, EC, exchangeable sodium, total alkalinity) ，as well as soil organic carbon and its components (SOC, HAC, and FAC)were evaluated. The results indicated that, compared to the control, all amendment treatments effectively reduced the average soil pH by 0.53 to 0.79 units and decreased exchangeable sodium by 56.7% to 74.8%. Furthermore, the average soil SOC, HAC, and FAC increased by 48.3%, 89.4%, and 56.0%, respectively. Among the treatments, JCWH proved to be the most effective. After two years of improvement, the rice seedlings in the JCWH treatment soil exhibited the highest dry weight and plant height, surpassing those grown in the farmer's seedling-raising soil.

Abstract: Irish potato (Solanum tuberosum) is a critical crop for food security and economic growth in Tsangano and Angónia districts, central Mozambique. Challenges like inconsistent yields and variable quality are often linked to suboptimal soil conditions, and limit production. This study aimed to classify and evaluate the suitability of soils for potato cultivation, filling gaps in detailed soil assessments for sustainable agriculture. Using combined pedological approach and laboratory soil analysis, four pedons TSA-P01 and TSA-P02 in Tsangano, and ANGO-P01 and ANGO-P02 in Angónia were analyzed for bulk density, texture, pH, organic carbon, and nutrient content. The pedons were very deep (> 150 cm) and had textures ranging from sandy clay loam to sandy loam. TSA-P02 had the lowest bulk density (0.78 Mg m-3) and the highest available water capacity (182.0 mm m-1). Soil pH ranged from 5.6 to 7.9, indicating neutral to slightly acidic conditions. Nutrient analysis revealed low total nitrogen (0.12 - 0.22%), varying soil organic carbon (0.16 - 2.73%), and cation exchange capacity (10.1 - 11.33 cmol(+) kg-1). Pedons TSA-P01, ANGO-P1, and ANGO-P02 were characterized by eluviation and illuviation as dominant pedogenic processes while in pedon TSA-P02 shrinking and swelling were the pedo-genic processes. Weathering indices identified ANGO-P01 as the most highly weathered, while TSA-P02 was the least weathered and had better fertility indicators. According to USDA Taxonomy, the soils were classified as Ultisols, Vertisols, and Alfisols, corresponding to Acrisols, Alisols, Vertisols, and Luvisols in the WRB for Soil Resources. All studied soils were marginally suitable for potato production (S3f) due to dominant fertility constraints but with varying minor limitations in climate, topography, and soil physical properties. The findings hence recommended targeted soil fertility management to enhance productivity and sustainability in potato cultivation.

Abstract: Agriculture is increasingly challenged by soil nutrient depletion, climate variability, and resource inefficiency. Advanced technologies have to be incorporated into agriculture and this makes the present assessment of the possible revolution the AI and ML in developing the crop and fertilizer recommendation systems relevant. Drawing from global research and case studies, multiple methodologies are combined including the neural network, a decision tree, as well as complex ensemble models of Random Forest and XGBoost, which can determine the optimality of soil nutrient management and crop selection, while simultaneously ensuring balance between environmental sustainability and economic productivity through tailored recommendations based on soil properties that are detailed on nitrogen (N), phosphorus (P), potassium (K), and pH levels. Some of the existing gaps in pre-existing research, like limited adaptability to localized agricultural conditions, open avenues for future interdisciplinary innovations. Reviewing the book underlines how AI-driven insights can change traditional farming practices toward enabling sustainable agricultural systems that harmonize with the dynamics of nature.

Abstract:

Sustainable fertilization using local resources like manure is crucial for soil health. This study evaluated the potential of guinea pig manure to replace mineral fertilizers in hard yellow maize (hybrid INIA 619) under Peruvian coastal conditions. A split-plot design tested four doses of guinea pig manure (0, 2, 5, 10 t⋅ha⁻¹) and four levels of mineral fertilization (0%, 50%, 75%, 100%). The study assessed plant height, ear characteristics, yield, and nutritional quality parameters. The results indicated that 100% mineral fertilization led to the highest plant height (229.67 cm) and grain weight (141.8 g). Yields of 9.19 and 9.08 t⋅ha⁻¹ were achieved with 5 and 10 t⋅ha⁻¹ of manure, while 50% mineral fertilization gave 8.8 t⋅ha⁻¹, similar to the full dose (8.7 t⋅ha⁻¹). Protein content was highest with 10 t⋅ha⁻¹ of manure combined with mineral fertilization. However, no significant differences were found between the 50%, 75%, and 100% mineral fertilizer doses. In conclusion, applying guinea pig manure improved nutrient use efficiency, yield, and grain protein quality in maize, reducing the need for mineral fertilizers by up to 50%. This provides a sustainable fertilization strategy for agricultural systems.

Abstract: Andisols are highly productive soils generated from the progressive weathering of volcanic products. This study evaluates Andisols from two volcanic zones of central and southwestern Colombia to compare the soil characteristics and to determine the influence of volcanic products on soil components in the region. For this, 54 sites were sampled within the volcanic fields: the Tapias-Guacaica (TGMVF) and the Guamuez-Sibundoy (GSMVF) monogenetic volcanic fields. The sampling included a range of systems, such as secondary forests, pines and blackberry crops, cut grass and paddock. Subsequently, analysis of variance was performed for statistically evaluated cells, cluster analysis and principal component analysis. Results indicate that the TGMVF soils exhibit a neutral pH, good cation exchange capacity, structural stability, macroporosity, adequate water and nutrient drainage, but difficulty in retention. In contrast, the GSMVF soils exhibit elevated levels of organic matter, carbon, nitrogen, phosphorus, microporosity, mesoporosity, efficient water and nutrient mobility, and fixation. Based on these parameters, the variance analysis showed two and three distinctive groups for the TGMVF and GSMVF, respectively. It is proposed that the behavior of the physicochemical variables, mainly Pr, ρa, ρr, CEC and SS, can be affected by external forces such as animal trampling, and internal forces such as soil wetting and drying cycles, especially in the paddock system of both volcanic fields. Overall, the physicochemical variation of soils has been influenced by factors such as geological time, soil management, vegetation, climate, topography and parent material. These results establish the basis for promoting appropriate agricultural practices in the fields.

Abstract: The comparison of equally important prerequisites of viticulture development (climatope and edaphotope) for its two historical regions has shown that both in the antique era and nowadays less favorable conditions of temperate climate (riskier in terms of frost danger) and poorer biogeochemical properties of soils and rocks in the steppe region compared to the conditions of the sub-Mediterranean region had a decisive influence on the volume and quality of wine products. This is supported by historical sources on local consumption of produced wine and imports of higher quality wine from Sub-Mediterranean vineyards (Tauric Chersonesos). Both regions of the Western Crimea are characterized by active bioaccumulation of iron, copper and manganese in the humus horizon of soils, which create a specific regional geochemical background with the prospect of approaching the ecological threshold of danger during long-term viticulture. The specific features of modern agricultural technology of viticulture lead to high concentrations of elements such as copper, vanadium, chromium and nickel, which can exceed the MPC levels 20-25 years after the vineyard is planted, earlier than other elements. This makes it possible to identify this list of heavy metals as a priority in the agroecological monitoring system for vineyard lands and sets the task of adjusting current agricultural technologies for sustainable viticultural practices in the specific soil and climatic conditions. The authors see prospects for further studies not only in improving methods for assessment of components of a wine terroir, especially biogeochemical parameters of soils and vine plants in a particular geographical area, but also in the technology for obtaining coupled integral estimates both in relation to edaphotope (stagnant environment (soil, parent and underlying rock) transformed by anthropogenic activity) and main products of viticulture and wine materials.

Abstract: Soil health is a critical determinant of agricultural productivity and environmental sustainability. Traditional assessment methods often fail to provide a comprehensive understanding of soil microbial communities and their functions. This study addresses this challenge by employing metagenomic techniques to assess the functionality of soil microbiomes in Russian black soil, renowned for its high fertility. We utilized shotgun metagenomic sequencing to analyze soil samples from Western Siberia subjected to different degrees of agro-soil disturbance. We identified functional genes involved in carbon (accA, argG, acsA, mphE, miaB), phosphorus (phoB, ppa, pstB, pnp, phnJ), and nitrogen (queC, amiF, pyrG, guaA, guaB, napA) metabolic pathways and associated with changes in microbial diversity in general and higher representation of certain bacterial species - Bradyrhizobium spp. Results demonstrated significant differences in microbial composition and functional potential between tillage treatments. No-Till technology and conventional tillage practices promoted beneficial microbial communities and enhanced soil health compared to long-term fallow soil. This work underscores the potential of metagenomic analysis in providing a comprehensive understanding of soil health, marking a significant advancement in the field.

Abstract: Rocky desertification is a form of land degradation occurring in tropical and subtropical regions, characterized by the destruction of vegetation and soil erosion caused by natural or anthropogenic factors, resulting in extensive areas of exposed bedrock. Field tests were conducted in three townships—Bolin, Longlai, and Longlei—within Fengshan County, Guangxi Zhuang Autonomous Region, China, to evaluate the effects of various fertilizers (compound fertilizers, slow-release fertilizers, and bio-organic fertilizers) on soil fertility, enzyme activity, bacterial diversity, and the growth performance of Mahonia fortunei (Lindl.) Fedde, aiming for ecological restoration and economic development. The findings indicated that the use of bio-organic fertilizers significantly enhanced soil fertility and enzyme activities, specifically urease, sucrase, and acid phosphatase, followed by slow-release fertilizers, and subsequently compound fertilizers. In comparison to the use of compound fertilizers, bio-organic fertilizers can enhance the organic matter content by 30.4%, 15.73%, and 21.83%, and the total nitrogen content by 19.4, 3.82, and 2.66 g/kg in the Bolin, Longlai, and Longlei regions, respectively. In the Bolin and Longlai regions, the utilization of bio-organic fertilizer yielded the maximum total phosphorus concentration, surpassing compound fertilizer by 85.45% and 53.37%, respectively. In the Longlei region, the total phosphorus concentration in the soil was about equivalent to that of compound fertilizer and bio-organic fertilizer, measuring 1.107 and 1.113 g/kg, respectively. Furthermore, the soil's available nitrogen, phosphorous, and potassium reached their peak levels when bio-organic fertilizers were applied. Urease activity increased by 181.82%, 29.29%, and 25.83%, while sucrase activity rose by 201.52%, 33.13%, and 26.22%, respectively, compared to the administration of compound fertilizer. The activity of acid phosphatase increased by 27.85%, 25.59%, and 40.49%, individually, when compared to the application of compound fertilizer. Unlike compound fertilizer, bio-organic fertilizer improved the diversity and abundance of beneficial soil microorganisms while promoting the growth of Mahonia fortunei (Lindl.) Fedde. In Bolin, Longlai, and Longlei, the concentrations of Boron (B), Copper (Cu), Zinc (Zn), and Iron (Fe) in the soil peaked with the application of slow-release fertilizers. Specifically, the Cu content increased by 151.65%, 69.97%, and 24.51%, respectively, in comparison to the use of compound fertilizers; the levels of these micronutrient elements were more comparable when bio-organic fertilizers and compound fertilizers were utilized. In the Longlei region, the use of slow-release fertilizers resulted in Mahonia fortunei (Lindl.) Fedde achieving a maximum plant height and ground diameter of 3.62 cm and 4.5 cm, respectively, surpassing the measurements obtained with compound fertilizer by 9.04% and 18.42%. This research illustrated the application of bio-organic fertilizer and slow-release formulations. Fertilizer significantly contributed to the amelioration of rocky desertification and the enhancement of vegetation, thereby offering a more effective solution for the restoration of rocky desertification flora, particularly for the cultivation of understorey cash crops.

Abstract:

Vegetation restorations are crucial strategies for combating land degradation, yet their mechanisms on improving soil quality, especially from perspective of soil fertility, remain far from clear. Sparse trees in semi-arid savanna grasslands (i.e., climate communities) offer a provoking reference for vegetation restoration. Here, taking advantage of Ulmus macrocarpa Hance fertile islands of the savanna ecosystem in the Daqinggou National Nature Reserve, this study aimed to investigate the vertical and horizontal distribution patterns of soil physicochemical properties and DOC fluorescence spectral characteristics. Results showed that soil organic carbon (SOC) and DOC were significantly decreased with both the increasing distance from tree and increasing soil depth. Horizontal and vertical treatments significantly enhanced fluorescence intensities of DOC. Additionally, the soil under canopy exhibited slightly richer concentrations of NH4+–N, NO3––N, TN, and TP at topsoil compared with deep soils. The SOC, TN, TP, NH4+–N, and NO3––N showed significantly positive relationships with the DOC. The study provides evidence that trees can form fertile island effects and enhance soil nutrients and DOC. These results are vital for guiding vegetation restoration degraded ecosystem in semi-arid area.

Abstract: Studying the spatial variation patterns and influencing factors of soil organic matter (SOM) in hilly and basin areas is of great significance for guiding agricultural production practices. This study takes Lanxi City as an example and comprehensively considers soil formation factors such as climate, vegetation, and terrain. Based on the genetic algorithm, 47 environmental variables are combined and optimized to construct a random forest (RF) model and an improved version—a random forest model based on genetic algorithm variable combination optimization (RF-GA). At the same time, the SHAP interpretation method is used to quantitatively analyze the spatial distribution characteristics of the SOM content and further identify the main driving factors. Compared with the ordinary Kriging (OK) and random forest (RF) methods, the random forest model (RF-GA) based on genetic algorithm variable combination optimization demonstrates a significantly improved prediction accuracy (R² = 0.49; RMSE = 3.49 g·kg⁻¹), with an MAE = 3.019 and LCCC = 0.67. Among the three models, the R² of the RF-GA model increases by 87.84% and 56.29%. The model prediction results indicate that the SOM content in the study area ranges from 12.11 to 31.38 g · kg ⁻¹, showing spatial distribution characteristics of a higher content in mountainous areas and a lower content in plains. A further SHAP analysis shows that terrain, climate, and biological factors are key environmental factors affecting the spatial differentiation of the SOM, with the CNBL and DEM playing particularly significant roles. By regulating moisture, erosion deposition, vegetation distribution, and microclimate conditions, they significantly affect the spatial distribution of the SOM. In summary, the RF-GA and its interpretable prediction model constructed in this study not only effectively reveal the spatial and driving mechanisms of SOM in hilly and basin areas but also provide a solid theoretical basis and practical guidance for accurate mapping, the formulation of sustainable utilization strategies for soil resources, and ensuring national food security.

Abstract: This study looked at the impact of planting year differences on vegetation and soil parameters in Pinus sylvestris plantation forests in northern Mongolia. Tujiin nars region has three study sites: 18- to 20-year-old plantation forests planted in 2003, 2004, and 2005, as well as natural regeneration stand, natural forest, and steppe area. Three plots with distinct plantation stand types were constructed at each location to investigate changes in vegetation and soil attributes. Species richness, total coverage, and biomass accumulation were significantly higher in the oldest plantation (2003). This is consistent with the results, where BBS (2003 plantation) had the highest species richness (32 species), plant coverage (58.5%), and above-ground biomass (1159.6 g m2). Soil pH across plantations, with steppe and forest edge soils being alkaline and plantation soils slightly acidic. This matches the results, where soil pH ranged from 6.52 to 7.41, with plantations being slightly acidic. Available nitrogen (3.16 mg kg-1), soil organic carbon (10.1 g kg-1), and carbon stock (9.16 Mg ha-1) were higher in top soil and decreased by depth of profile and differed in plantations by year-of-planting. Furthermore, the change in understory vegetation was significantly correlated with soil moisture, fertility, and species composition was driven by over story density and crown parameters.

Abstract: This paper assesses the thermodynamic stability of clay minerals in the upper organo-mineral horizon of podzolic soil, as well as in the rhizosphere of Norway spruce (Picea abies (L.) H. Karst.) and Norway maple (Acer platanoides L.). Moreover, it determines the impact of soil organic matter on thermodynamic stability of clay minerals. Calculations of ΔGf and the saturation index (SI) for clay minerals in laboratory experiments simulating soil conditions without soil moisture outflow allowed us to find out that the thermodynamic stability of clay minerals decreased in the series: kaolinite &gt; illite &gt; vermiculite &gt; chlorite. The spruce rhizosphere contained kaolinite, vermiculite and illite in the lowest thermodynamic stability, while the soil under maple showed the highest thermodynamic stability of clay minerals due to the differences in the properties of soil organic matter in the rhizospheres of different tree species. Laboratory experiments on the sorption of soil humic acid (HA) on clay minerals demonstrated that sorbed HA decreased the thermodynamic stability of biotite and increased the thermodynamic stability of kaolinite and muscovite. Thermodynamic stability of clay minerals decreased with increased proportion of sorbed thermolabile organic matter.

Abstract:

Quantifying the rates of soil evolution greatly benefits our understanding of soil formation and management, especially in the context of strong anthropogenic activities and climate change. This study investigated soil evolution in an artificial oasis region with a reclamation history of more than 50 years, and critical soil properties were measured at 77 sites. A total of 462 soil samples were collected down to a depth of 1 m. A total of seven critical soil properties were analysed, and four (i.e., soil organic carbon (SOC), total phosphorus (TP), pH, and ammonium nitrogen (NH₄⁺)), which were not closely correlated with each other, were selected for further investigation. Through comparison with desert soils, this investigation found that semicentennial cultivation resulted in significant changes in soil properties, with strong vertical variations, including increases in the C, N and P contents and decreases in pH throughout the whole profile. The temperature, clay content, evaporation rate between the topsoil and subsoil, low vegetation cover, cotton lateral roots, irrigation and fertilization played crucial roles in promoting SOC decomposition and reducing soil alkalinity, thereby contributing to rapid soil evolution. Thus, reclaimed desert soil was scientifically confirmed to be suitable for agricultural use, which will ease the food production crisis, protect the environment, and promote soil evolution. Furthermore, three-dimensional digital soil mapping was performed to investigate the effects of long-term cultivation on the distributions of soil properties at unvisited sites. The soil depth functions were separately fitted to model the vertical variation in the soil properties, including the exponential function, power function, logarithmic function and cubic polynomial function, and the parameters were extrapolated to unvisited sites via the quantile regression forest (QRF), boosted regression tree and multiple linear regression techniques. The QRF technique yielded the best performance for SOC (R²= 0.78 and RMSE = 0.62), TP (R² = 0.79 and RMSE = 0.12), pH (R² = 0.78 and RMSE = 0.10) and NH₄⁺ (R² = 0.71 and RMSE = 0.38). The results showed that depth function coupled with machine learning methods can predict the spatial distribution of soil properties in arid areas efficiently and accurately. These research conclusions will lead to more effective targeted measures and guarantees for local agricultural development and food security.

Abstract: A key objective of contemporary agriculture is to restore biodiversity, preserve ecosystem health, reduce the effects of climate change, and produce safe and healthy foods. Maintaining high soil fertility while reducing greenhouse gas emissions requires a precise assessment of how fertilization and crop rotation affect the carbon and nitrogen cycles in agroecosystems. In the context of a long-term fertilizer experiment on Luvic Chernozem, a monitoring of chemical and microbiological soil properties and CO2 emission was carried out. The fertilization treatments that have been continuously applied for 64 years under four-crop (wheat, barley, corn, and beans) rotation are N, P, K, NP, NK, PK, NPK, and 0. The highest organic carbon content was observed in the treatments NPK (1.42%) and NP (1.43%), and the lowest in the control (1.05%). The constant application of nitrogen as single fertilizer led to lower SOC values (1.22%). On average, CO2 emissions were the most intensive in NP (66.34 kg ha-1 day-1), NPK (67.82 kg ha-1 day-1) and PK (60.16 kg ha-1 day-1) treatments. The nitrogen fertilizer application most significantly alters soil properties including pH, EC, and SOC, which alters the environment for soil microbial development and influences the number and composition of soil microbial communities.