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North Campus Open Space (NCOS) is a large-scale restored habitat in the historic Devereaux slough in Goleta, California. Forty-four plywood cover boards measuring 3’ x 4’ were dispersed across NCOS in four distinct habitats (grassland, woodland, coast sage scrubland, and marshland). For over 4 years, researchers have tracked the presence of animals under these coverboards, mostly small rodents and herpetofauna, following the area’s habitat restoration. Patterns of their distribution are increasingly understood as surveys continue; however, little is known about the patterns of invertebrate distribution and the factors influencing them. Invertebrates provide essential ecosystem functions as they break down organic matter, recycling nutrients back into the ecosystem, and they can serve as insightful bioindicators of ecosystem health. Previous studies documented that in agricultural systems, mean annual precipitation and soil pH are the largest predictors of soil invertebrate richness. In this study, we test whether these variables accurately predict patterns of invertebrate richness in a restored ecosystem. We focused on two diverse macroinvertebrate taxa, Coleoptera (beetles) and Arachnida (spiders). By collecting, curating, and identifying beetles and spiders under each coverboard we were able to establish what species reside in the various habitats. We took measurements of the soil pH under each board as well as the humidity in the interspace between the soil and the board as a proxy for mean annual precipitation. Our preliminary data suggest that soil pH and relative humidity partially contribute to the distribution of macroinvertebrates within habitats. However, other factors such as cohabitation, soil type, adjacent vegetation, or other factors involved in nutrient cycling, could have larger effects on the distribution patterns of these taxa.This poster was presented at the UCSB undergraduate research colloquium 2024.

BACKGROUND: Pseudostellaria heterophylla, known for its significant bioactive ingredients, offers potential health benefits. Amounts of bioactive compounds of the tuberous root of cultivated Pseudostellaria heterophylla are sensitive to environmental conditions. We selected 22 sampling sites in Guizhou Province, China, a primary Pseudostellaria heterophylla planting area. We analyzed polysaccharides, water‐soluble extractives, total ash and inorganic elements (Fe, Mn, Zn, Mg and Ca) in Radix Pseudostellariae, and pH, organic carbon (OC), available nitrogen (AN), available phosphorus (AP), available potassium (AK) and inorganic elements in the soil. RESULTS: Our study revealed a substantial presence of polysaccharides (85.00–181.00 mg g−1), water‐soluble extractives (47.52–57.63%) and total ash (1.87–3.39%) in Radix Pseudostellariae. Polysaccharides and total ash showed no sensitivity to soil pH. Radix Pseudostellariae collected from soil with pH > 7 exhibited slightly higher levels of water‐soluble extractives, Mg and Ca than that from soil with pH < 5. Conversely, soil with a pH less than 5 had higher OC, AN, AP and AK contents. Water‐soluble extractives in Radix Pseudostellariae were negatively correlated with soil pH but positively correlated with OC and AN. CONCLUSION: The results imply that the sequestration of soil nutrients over long‐term Pseudostellaria heterophylla cultivation could negatively impact the accumulation of some bioactive ingredients in Radix Pseudostellariae. This study has a profound implication for enhancing the quality of Radix Pseudostellariae of artificially cultivated Pseudostellaria heterophylla. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduction: Soil acidification imperils soil health and hinders the agricultural sustainability. As being more tolerant than bacteria to soil acidification, so it would be more meaningful for agricultural management and crop yield to characterize fungal community in acidic soils and manifest its key drivers. Method: This study investigated the composition and diversity of fungal communities and its key driving factors by collecting 90 soil samples from the acidic region of Jiaodong Peninsula China, spanning 3 × 104 km2. Results: The results indicated that most soil pH values ranged from 5.01 to 6.42, and the exchangeable acidity (EA) content raised significantly (p < 0.01) along with soil acidic degree increasing. However, no significant differences were found in fungal community diversity and composition among various soil samples, which were all predominantly habited with the phyla of Ascomycota and Basidiomycota. Results of the linear discriminant analysis effect size (LEfSe) analysis revealed that saprophytic fungi were biomarkers of the slightly acidic soil (pH 6.0–6.5), including Nectriaceae, Thielavia, Nectria, Haematonectria , and unclassified Microascaceae , while plant pathogenic fungi, such as Didymellaceae, were biomarkers of the soils pH < 5.5. Similarly, the FUNGuild results also indicated that saprophytic fungi and pathogenic fungi were the dominant functional guilds in the investigated acidic soils, accounting for 66% of the total fungal communities. Redundancy analysis (RDA) revealed that soil pH as well as nitrate nitrogen ( NO 3 − -N) and total nitrogen (TN) significantly associated with fungal community at the phylum level, whilst soil pH was the only factor significantly linked to individual fungal classes (p < 0.01 or 0.05). The further Mantel test analysis and structural equation modeling (SEM) suggested that, in contrast to the negative and directive driving of soil pH on fungal communities' variation, the specific plant pathogenic fungi, Gibberella and Didymellaceae, were significantly and positively associated with soil acidic characteristics (p < 0.05). Discussion: These findings highlighted that, in addition to modulating the variation of soil fungal community, soil acidification might prime some plant pathogens development. So that, more attentions should be focused on impact of soil acidification on fungal ecology, as well as plant pathogenic fungi. [ABSTRACT FROM AUTHOR]

This study determined the nutrient composition of horse manure and examined the agronomic implications of applying it to pastureland. Horse manure and wood shavings bedding mix obtained from diverse equine operations was sampled from 20 truckloads (~150 m3). Manure was applied once at 817 m3 ha−1 onto replicated bovine pasture plots and compared for forage yield, soil fertility levels and weeds species, with unamended plots over a five-year period. On average, the manure had a carbon to nitrogen (C:N) ratio of 32, mean 72% moisture content, and concentrations (g kg−1 dry weight) 17.5 nitrogen (N), 3.4 phosphorus (P), 13 potassium (K), 8.8 calcium (Ca), 3.7 magnesium (Mg), and 2 sulfur (S). Manure application increased soil test levels of P, K, Ca, and zinc (Zn), soil pH, organic matter content, pasture forage yields and clover biomass. Horse manure application increased Horsenettle (Solanum carolinense L.) biomass, while dandelion (Taraxacum officinale F. H. Wigg.), catchweed bedstraw (Galium aparine L.), and broadleaf plantain (Plantago major) biomass decreased. Except for increasing the amount of horsenettle on pastureland, findings demonstrate that horse manure is a valuable agronomic resource when applied to a low fertility soil. [ABSTRACT FROM AUTHOR]

To improve cotton yield in salinized arid fields, excess salt is removed and phosphorus content is increased. Adjusting phosphate fertilizer timing with water and fertilizer reduces phosphorus binding with calcium ions. Salt removal precedes phosphate application, enhancing soil phosphorus availability and promoting better growth. However, the optimal time for delaying phosphate fertilizer drip irrigation remains unclear. Therefore, this study evaluated the total salt, soil available phosphorus, and cotton yield under the condition of delayed phosphate fertilizer application. We conducted a field experiment using a completely randomized design to adjust the timing of phosphatic fertilizer application and apply the same amount of pure phosphorus. Specifically, "t" was defined as the total duration of one irrigation cycle, and the starting points for phosphorus application were as follows: T1, 1 h; T2, 1 h + 1/3 t h; T3, 1 h + 2/3 t h; CK, 1/3 t h. These values represent the duration of salt leaching through irrigation in each treatment. Phosphate fertilizer was applied to the soil after salt washing was complete. The results revealed that the T2 treatment exhibited the highest SPAD value (64.53), which was 11.46% and 15.48% higher than that of the T1 and T3 treatments. The 0–20 and 20–40 cm soil layers under the T2 treatment had the highest pH values of 9.12 and 9.37, representing increases of 1.93%, 1.21%, 4.50%, and 1.38% compared with T1 and T3 treatments, respectively (p < 0.05). At the bud stage, the Olsen-P in the T2 treatment was 82.86% and 26.53% higher than that in the T1 and T3 treatments, respectively (p < 0.05). The T2 treatment achieved the highest yield of 6492.09 kg/hm2, which was 31.47%, 31.53%, and 2.77% higher than that of T1, T3, and CK. Overall, the T2 treatment increased cotton yield and reduced the adsorption of calcium ions to available phosphorus in salinized soil. This study provides an effective technical approach for the sustainable development of salinized cotton fields in Xinjiang. [ABSTRACT FROM AUTHOR]

Soil acidity has negative effects on both plants and soil. Furthermore, liming is the most common and effective management practice used to neutralize the acid produced in the soil and the problems associated with soil acidification. The study evaluated whether liming impacts wheat growth, yield, nutritional status basis exchangeable, and their related soil acidity indices. A greenhouse experiment was performed under a completely randomized arrangement, with four lime application rates equivalent to (0, 4.0, 8.0, and 12.0 Mg ha−1). The results showed that all yield components significantly increased with increasing lime addition rate. The grain yield, shoot and root dry weight, and plant and spike height improved quadratically (R2 = 0.909, 0.950, 0.976, 0.902, and 0.891, respectively). Additionally, the lime rate influenced P and Mg concentrations in the shoot, and the concentrations of Cu and Zn. With increasing lime rate, the soil exchangeable Ca and Mg concentrations increased quadratically (R2 = 0.969 and 0.984), while the soil exchangeable K and Al concentrations decreased significantly. The pH of the soil solution increased linearly (R2 = 0.994) with the lime addition rate. Liming significantly reduced the exchangeable Al3+ and Al + H in the soil. Finally, liming improves wheat yield in acid soil by reducing the negative effects of Al and H by increasing soil pH, Ca2+, and Mg2+ concentration, consequently improving root growth and resulting in wheat yield. Liming increased the grain yield by 188.7, 198.2, and 322.8% following the increase of lime rate, if compared to the control. Furthermore, lime enhances plant resilience by raising pH and improving soil nutrient availability and the root system. [ABSTRACT FROM AUTHOR]

Soil salinization is a type of soil degradation phenomenon caused by the gradual accumulation of salt in soil due to natural processes or improper irrigation practices. Understanding the spatial variations of salinization is the basis for salinized land management and resource utilization. Taking Yinbei Plain irrigation area of Ningxia as the research area, 154 sampling points were set up and soil samples were collected at depths from 0–100 cm in six layers to determine the pH value and total salt content of the soil. Then geostatistics and GIS were used to study the spatial variations of soil pH and total salt content in the irrigation area. The results show three important aspects of this system. (1) The soil in the study area is alkaline soil with pH values ranging from 8.18 to 10.22, and the pH increases with increasing soil depth. The pH values of soil at 0–10 cm are significantly higher than at depths of 10–20 cm and 20–80 cm (P<0.05). The variation coefficients of the soil pH value in each layer are less than 10%, which is characterized as weak variability. The total salt content of soil decreases with increasing soil depth, ranging from 0.24 to 14.95 g kg–1. The total salt content of soil in the surface layer at 0–10 cm was significantly higher than in the lower soil layers (P<0.05). The coefficient of variation of total salt content showed moderate variability except at depths of 10–20 cm and 80–100 cm. Other layers have variabilities of more than 100%, indicating strong variability. (2) The semi-variance function fitting of pH and total salt showed that the soil pH value in each soil layer depth block base ratio ranged from 28.1% to 61.2%, which indicates a medium spatial correlation, and the spatial variability was mainly influenced by the joint action of human activities and natural factors. The total salt block base ratio of each soil layer ranged from 5.5% to 13.3%, which indicates strong spatial autocorrelation. The variation among soil samples is mainly caused by natural structural factors such as parent material, topography, soil and groundwater level. (3) Kriging interpolation was used to obtain the spatial distribution of soil pH values and total salt contents in the study area, and the results showed that the overall pH distribution was high on the eastern and western sides and low in the middle. The total salt distribution was patchy and uneven, and the saline soil was mainly distributed in the surface layer. As the depth increased, the total salt content declined, and the proportions of saline soil and severely salinized soil decreased. In the whole study area, mild salinized soil was the main category, the total salt content increased from south to north, and the profile characteristics of total salt content were mainly surface clustering. This study investigated the distribution and spatial heterogeneity of soil salinization in the Yinbei Irrigation Area, and provides theoretical guidance for the formulation of soil salinization control measures in this area. [ABSTRACT FROM AUTHOR]

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The growing use of tungsten (W) in industrial applications has made it a critical element in modern production processes. This increasing demand is also contributing to the element's wider dispersion in the environment, including in soil. In addition to mining areas, it is necessary to evaluate the possible environmental effects of tungsten even in non-contaminated areas. The mobility and bioavailability of W in soil are essentially determined by the sorption processes that regulate its distribution between the liquid and solid phases of the soil. In this study, the effect of different land uses—natural, agricultural, and urban—on the sorption of W in soils of the same geographical area was addressed. The results showed that the maximum sorption can be found in natural soils, with a value of 528 mg/kg, while for agricultural and urban soils, the mean values are 486 and 392 mg/kg, respectively. Anthropic interventions seem to reduce this capacity in agricultural soils by about 8%, probably due to agronomic practices, and by even more, 26%, in urban soils, where the use of different materials can modify the original characteristics of the soils. These results show that variations in some of the main characteristics of soils, such as pH and organic matter content, also derived from different land uses, influence the sorptive properties of the soils. [ABSTRACT FROM AUTHOR]

This meta-analysis studied the impact of conventional versus organic farming practices on soil organic carbon (SOC) concentrations and mass storage. We aimed to understand the carbon dynamics associated with adopting organic agricultural practices by reviewing and synthesizing data from 1950 to 2023. We analyzed data from 64 experimental field comparisons that involved SOC concentration and mass storage measurements, covering a wide range of studies selected for soil depth analyses, carbon concentration measurements, and comparative methods between conventional and organic systems. Our results indicated a significant increase in SOC under organic agriculture. An analysis of the response ratios (LnRR) for SOC concentration showed variability, with a 95% confidence interval of 0.089–0.149. Similarly, the analysis of carbon storage data indicated a 95% confidence interval of LnRR of 0.053–0.205. These increases in SOC concentration and mass storage reflect the variable but statistically positive impact of organic farming on SOC. Fine soil textures demonstrated the highest mean LnRR for both SOC concentration (0.163) and mass storage (0.173), suggesting the role of soil texture in mediating the effects of organic agriculture on SOC dynamics. Furthermore, there was a significant negative correlation between soil pH and SOC mass storage, with a regression coefficient of −0.174 (p < 0.039). Although a slight positive correlation was observed between temperature and SOC mass storage as LnRR, other environmental factors likely play a critical role in SOC dynamics. These findings emphasize the complexity of SOC dynamics and the significant impact of organic agriculture on increasing SOC concentrations and mass storage. This study broadly contributes to the debate in sustainable agriculture by providing quantitative evidence of the role and benefits of organic agriculture on climate change mitigation. The results also emphasize the importance of adopting organic farming practices for broadly enhancing ecosystems' resilience and long-term food security. [ABSTRACT FROM AUTHOR]

Wet tropical forests play an important role in the global carbon (C) cycle, but given current rates of land‐use change, nitrogen (N) and phosphorus (P) limitation could reduce productivity in regenerating forests in this biome. Whereas the strong controls of climate and parent material over forest recovery are well known, the influence of vegetation can be difficult to determine. We addressed species‐specific differences in plant traits and their relationships to ecosystem properties and processes, relevant to N and P supply to regenerating vegetation in experimental plantations in a single site in lowland wet forest in Costa Rica. Single‐tree species were planted in a randomized block design, such that climate, soil (an Oxisol), and land‐use history were similar for all species. In years 15–25 of the experiment, we measured traits regarding N and P acquisition and use in four native, broad‐leaved, evergreen tree species, including differential effects on soil pH, in conjunction with biomass and soil stocks and fluxes of N and P. Carbon biomass stocks increased significantly with increasing soil pH (p = 0.0184, previously reported) as did biomass P stocks (p = 0.0011). Despite large soil N pools, biomass P stocks were weakly dependent on traits associated with N acquisition and use (N2 fixation and leaf C:N, p < 0.09). Mass‐balance budgets indicated that soil organic matter (SOM) could supply the N and P accumulated in biomass via the process of SOM mineralization. Secondary soil P pools were weakly correlated with biomass C and P stocks (R = 0.47, p = 0.08) and were large enough to have supplied sufficient P in these rapidly growing plantations, suggesting that alteration of soil pH provided a mechanism for liberation of soil P occluded in organo‐mineral soil complexes and thus supply P for plant uptake. These results highlight the importance of considering species' effect on soil pH for restoration projects in highly weathered soils. This study demonstrates mechanisms by which individual species can alter P availability, and thus productivity and C cycling in regenerating humid tropical forests, and the importance of including traits into global models of element cycling. [ABSTRACT FROM AUTHOR]

Microbial carbon (C) use efficiency (CUE) describes the proportion of organic C used by microorganisms for anabolic processes, which increases with soil organic C (SOC) content on a global scale. However, it is unclear whether a similar relationship exists during natural vegetation restoration in terrestrial ecosystems. Here, we investigated the patterns of CUE along a 160‐year vegetation restoration chronosequence (from farmland to climax forest) estimated by stoichiometric modeling; additionally, we examined the relationship between CUE and SOC content and combined these results with a meta‐analysis. The combination indicated that vegetation restoration decreased CUE from 0.35 to 0.28. Surprisingly, SOC content increased with decreasing CUE during vegetation restoration because forest soils have low pH values and high microbial phosphorus limitations compared to early ecosystems, implying that climax forests may not sequester as much soil C as expected. The shift in soil pH was the most important predictor of CUE compared to climate, plant, and microbial factors. CUE changes were directly induced by soil pH and not by the pH‐induced microbial community. Alkaline soil acidification tended to decrease CUE. This first large‐scale estimate of the relationship between CUE and SOC during natural restoration highlights the need to strengthen C sink management in mature forests to sustain their C sequestration potential. [ABSTRACT FROM AUTHOR]

Reducing water input and promoting water productivity in rice field under alternate wetting and drying irrigation (AWD), instead of continuous flooding (CF), are vital due to increasing irrigation water scarcity. However, it is also important to understand how methane (CH4) and nitrous oxide (N2O) emissions and global warming potential (GWPCH4+N2O$$ {\mathrm{GWP}}_{{\mathrm{CH}}_4+{\mathrm{N}}_2\mathrm{O}} $$ of CH4 and N2O) respond to AWD under the influence of various factors. Here, we conducted a meta‐analysis to investigate the impact of AWD on CH4 and N2O emissions and GWPCH4+N2O$$ {\mathrm{GWP}}_{{\mathrm{CH}}_4+{\mathrm{N}}_2\mathrm{O}} $$, and its modification by climate conditions, soil properties, and management practices. Overall, compared to CF, AWD significantly reduced CH4 emissions by 51.6% and GWPCH4+N2O$$ {\mathrm{GWP}}_{{\mathrm{CH}}_4+{\mathrm{N}}_2\mathrm{O}} $$ by 46.9%, while increased N2O emissions by 44.0%. The effect of AWD on CH4 emissions was significantly modified by soil drying level, the number of drying events, mean annual precipitation (MAP), soil organic carbon content (SOC), growth cycle, and nitrogen fertilizer (N) application. Regarding N2O emissions, mean annual temperature (MAT), elevation, soil texture, and soil pH had significant impacts on the AWD effect. Consequently, the GWPCH4+N2O$$ {\mathrm{GWP}}_{{\mathrm{CH}}_4+{\mathrm{N}}_2\mathrm{O}} $$ under AWD was altered by soil drying level, soil pH, and growth cycle. Additionally, we found that MAP or MAT can be used to accurately assess the changes of global or national CH4 and N2O emissions under mild AWD. Moreover, increasing SOC, but not N application, is a potential strategy to further reduce CH4 emissions under (mild) AWD, since no difference was found between application of 60–120 and > 120 kg N ha−1. Furthermore, the soil pH can serve as an indicator to assess the reduction of GWPCH4+N2O$$ {\mathrm{GWP}}_{{\mathrm{CH}}_4+{\mathrm{N}}_2\mathrm{O}} $$ under (mild) AWD as indicated by a significant linear correlation between them. These findings can provide valuable data support for accurate evaluation of non‐CO2 greenhouse gas emissions reduction in rice fields under large‐scale promotion of AWD in the future. [ABSTRACT FROM AUTHOR]

Soil plays a critical role in nutrient availability, microbial activity, and fertility in agriculture. However, the effects of agroclimatic conditions on soil pH are not well understood, particularly in the Horro Guduru Zone of Ethiopia. This study aimed to investigate the soil pH under extremely wet and dry conditions across 3 shared socioeconomic pathway (SSP) scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Baseline agroclimatic data (1981–2010) and future projections (2041–2070) were obtained from the European Commission Climate Change Services. Soil pH data at a 250 m resolution were extracted from the FAO-UNESCO global soil map. Missing values, multicollinearity, and outliers were addressed before modeling. Predictive models, including neural networks, generalized regression, and bootstrap forests, were validated, with the generalized regression model showing the best performance. The results indicate that soil pH decreases under consecutive dry‒wet conditions and increases with increasing maximum day temperatures across all scenarios. Soil pH is significantly influenced by the number of consecutive dry days, consecutive wet days, and maximum day temperature. The SSP1-2.6 and SSP2-4.5 scenarios resulted in improved pH levels, whereas SSP5-8.5 led to a decrease in soil pH, averaging 5.79 and decreasing to 5.54. These findings suggest that under SSP5-8.5, soil health and farming productivity may be compromised. This study emphasizes the need to adjust soil management practices based on prevailing climatic conditions to ensure soil health and agricultural sustainability. [ABSTRACT FROM AUTHOR]

The manual addition of lime to soil, in addition to tree planting and fertilization have been the dominant strategy described in restoration protocols for ecosystems damaged by acid rain and metal contamination. Investigations on aerial-limed soils in inaccessible lands are limited. The objective of this study was to assess the effects of aerial liming on soil pH, organic matter, microbial biomass, and enzymatic activities, and aboveground plant population quality in metal-contaminated lands in northern Ontario, Canada. Soil samples were collected from three sites around the City of Greater Sudbury with each pair being composed of a reclaimed (areal-limed) site and an adjacent undisturbed (unlimed) area. Soil physico-chemistry, microbial biomass (assessed by Phospholipid fatty acid analysis) and enzymatic activities were analyzed. Soil pH was higher in limed sites compared to unlimed at recently restored sites (Baby Lake and Wahnapitae) but not at the oldest reclaimed site (HWY 80 N). Organic matter was higher in limed areas compared to the unlimed reference site only at most recently reclaimed site at Baby Lake. Aboveground plant population health was visibly improved in limed sites compared to unlimed areas. Metal concentrations of iron (Fe) and arsenic (As), total microbial biomasses, gram-negative bacterial, fungal, and eukaryotic biomasses were all significantly increased in the limed soils compared to the unlimed samples. The same trend was observed for the activities of three of the enzymes tested, β-N-acetylglucosaminidase (BG), aryl sulfatase (AS), and glycine aminopeptidase (GAP). Interestingly, strong positive correlations between the levels of soil organic matter, microbial biomasses, and NAGase and ALP activities were observed. Although expensive, aerial liming is effective in restoring inaccessible sites impacted by smelting operations where other methods cannot easily be used. [ABSTRACT FROM AUTHOR]

Soil respiration is an important pathway of carbon release from the terrestrial biosphere to the atmosphere, which plays a key role in ecosystem carbon cycling. However, the response and mechanism of soil respiration to nitrogen and phosphorus addition in legume plants are still unclear. Here, a pot experiment planted with soybean (Glycine max (L.) Merr.) was conducted to investigate the effects of nitrogen (N) and phosphorus (P) addition on soil respiration. Four treatments were designed: control, N addition, P addition, and both N and P addition. Soil respiration was measured twice a month from June to September in 2022. Our results showed that nutrient addition treatments presented significantly negative effects on soil respiration. In particular, nitrogen addition not only directly affected soil respiration, but also indirectly impacted soil respiration by altering soil nitrate nitrogen content. Elevated soil nitrate nitrogen content could inhibit soybean root nodule number and reduce biomass allocation to roots, thereby decreasing soil respiration. Furthermore, phosphorus addition and nitrogen–phosphorus co-addition strongly inhibited soybean nodulation by changing soil pH value, thus inhibiting soil respiration of soybean. The findings provide baseline information for optimizing nutrient management in legume crops. [ABSTRACT FROM AUTHOR]

Accurate soil pH and soil organic carbon (SOC) estimations are vital for sustainable agriculture, as pH affects nutrient availability, and SOC is crucial for soil health and fertility. Hyperspectral imaging provides a faster, non-destructive, and economical alternative to standard soil testing. The study utilizes imaging spectroscopic data from the Africa Soil Information Service (AfSIS) and Land Use and Coverage Area Frame Survey (LUCAS-2009) hyperspectral datasets, capturing spatially distributed spectral information. Machine learning (ML) approaches using high-dimensional spectral bands can be computationally expensive, while those using spectral indices are typically limited to multispectral data. This study addresses these challenges by comparing soil pH and SOC prediction using ML models, with both existing spectral indices and individual hyperspectral bands as input features. Results demonstrate that hyperspectral bands outperform existing indices in predictive accuracy, with R 2 values ranging from 0.8 to 0.94 for both soil pH and SOC. To further enhance prediction performance, this study proposes novel spectral indices-soil pH index (SPI) and soil organic carbon index (SOCI)-specifically designed for hyperspectral data using principal component analysis (PCA) and artificial neural networks (ANN). The proposed SPI and SOCI indices address multicollinearity issues and high dimensionality in raw spectral bands, significantly improving predictive accuracy. The SPI and SOCI indices achieve R 2 values of 0.86 for AfSIS soil pH, 0.945 for LUCAS-2009 soil pH, 0.952 for AfSIS SOC, and 0.963 for LUCAS-2009 SOC. These results show that the proposed spectral indices provide a practical solution for precision agriculture, enhancing soil pH and SOC estimations. [ABSTRACT FROM AUTHOR]

This research aimed to use the cause-and-effect diagram (model) as a method to describe the 15 main factors (for example, awareness, knowledge and motivation of farmers, farmers income, institutional and financial support, condition of the natural environment, healthiness of the population, etc.) leading to soil acidification, their impact on soil health and ecosystem functions, and how soil liming serves as a remedial measure. The cause-and-effect model was developed based on questionnaire studies as a part of the project 'Opportunities and Barriers to the Use of Soil Liming for Improving the Economic Efficiency of Agricultural Production and Reducing Eutrophication of Surface Waters' in 2022–2023. The results showed that the effects of soil acidification and liming as well as their interrelationships are multifaceted and affect agricultural production economics, agricultural land and crop prices, environmental health and biodiversity, as well as soil productivity and food security. The causes of this situation can be attributed to social, technological–logistical–technical, and economic factors. To change the existing situation, it is necessary to take effective steps to motivate farmers to lime their soils. The most effective would be (1) offering training courses for farmers to discuss the benefits that a farmer can achieve by maintaining optimum soil pH levels while growing a specific crop species; (2) implementing liming payment programs that will be more attractive and motivating from the farmers' perspective; and (3) linking agri-environmental payments to the necessity of systematic testing of soil pH levels and maintaining optimal pH levels under specific crops species. [ABSTRACT FROM AUTHOR]

Soil pH, governed by the relative concentrations of hydrogen () and hydroxyl () ions, is a key factor affecting the chemical, physical, and biological properties of soils. Most soils in Türkiye are alkaline due to calcareous parent material and climatic influences, which restricts the availability of essential nutrients to plants. Sulphur applications are widely employed to reduce soil pH and increase nutrient bioavailability. The use of Sulphur for the amelioration of alkaline soils will continue to be a crucial strategy for enhancing agricultural sustainability in the future. This study investigates the effects of different Sulphur sources on the pH of sandy and clay-loam texture soils. This study investigates the effects of different Sulphur sources on the pH of sandy and clay loam textured soils. The soil samples used in the research were taken from Pınarbaşı and Melikgazi districts of Kayseri province, and soil samples were taken from both regions from a depth of 30 cm and from 20 randomly determined different points. Sulphur applications were applied at rates of (0, 0.02, 0.04 g 100 g-1) (X: powdered Sulphur ) and (0, 0.044, 0.088 g 100 g-1) (Y: granular Sulphur ) based on weight for clay-loam and sandy textured soils, respectively. Samples taken on days 0, 15, 30, 60, 90, 180, and 360 post-applications showed that the impact of Sulphur applications on soil pH change was significant across all treatments (p

Abstract Plant growth-promoting microorganisms can enhance sulfur uptake and boost crop production. This study was conducted to evaluate the changes in physiology, metabolism, and yield of chickpeas following the application of sulfur and two microbial consortia: (1) Thiobacillus sp., Bacillus subtilis, Paraburkholderia fungorum, and Paenibacillus sp.; and (2) Enterobacter sp. and Pseudomonas sp. The soil amendment involving a combination of sulfur and sulfur-oxidizing bacteria (SOB) in any quantity had positive effects on the availability of phosphorus, nitrogen, and potassium in the soil. A combination of 90% sulfur with Enterobacter sp. and Pseudomonas sp. resulted in a decrease in soil pH after harvesting in both years. Both years showed a strong correlation between soil pH and soil macronutrient concentration. In both years, the maximum grain yield was achieved through a combination of increased sulfur levels and SOB. The results reveal that sulfur application and SOB can increase nutrient availability, nutrient uptake, and yield of chickpea growth in calcareous soils.

Identification of the most appropriate chemically extractable pool for evaluating Cd and Pb availability remains elusive, hindering accurate assessment on environmental risks and effectiveness of remediation strategies. This study evaluated the feasibility of European Community Bureau of Reference (BCR) sequential extraction, Ca(NO 3) 2 extraction, and water extraction on assessing Cd and Pb availability in agricultural soil amended with slaked lime, magnesium hydroxide, corn stover biochar, and calcium dihydrogen phosphate. Moreover, the enriched isotope tracing technique (112Cd and 206Pb) was employed to evaluate the aging process of newly introduced Cd and Pb within 56 days' incubation. Results demonstrated that extractable pools by BCR and Ca(NO 3) 2 extraction were little impacted by amendments and showed little correlation with soil pH. This is notable because soil pH is closely linked to metal availability, indicating these extraction methods may not adequately reflect metal availability. Conversely, water-soluble concentrations of Cd and Pb were markedly influenced by amendments and exhibited strong correlations with pH (Pearson's r : -0.908 to -0.825, P < 0.001), suggesting water extraction as a more sensitive approach. Furthermore, newly introduced metals underwent a more evident aging process as demonstrated by acid-soluble and water-soluble pools. Additionally, water-soluble concentrations of essential metals were impacted by soil amendments, raising caution on their potential effects on plant growth. These findings suggest water extraction as a promising and attractive method to evaluate Cd and Pb availability, which will help provide assessment guidance for environmental risks caused by heavy metals and develop efficient remediation strategies. [ABSTRACT FROM AUTHOR]

The study investigated the impact of abiotic factors on the yield of harvested mangoes before and after Science and Technology (S&T) interventions in five municipalities, namely: President Quirino, Sultan Kudarat, Tulunan, North Cotabato, Tantangan, South Cotabato, Malungon, Sarangani Province, and General Santos City. The study used the simple linear regression model Y=BX + a to determine the extent to which there was a linear. relationship between a dependent variable and one or more independent variables. In simple linear regression, a single independent variable, ie, rainfall or temperature, was used to predict the value of a dependent variable, the yield of mangoes per hectare during the first and second cycle productions of farmer-cooperators in four provinces, namely: Sultan Kudarat, North Cotabato, South Cotabato and General Santos/Sarangani. The results. indicated that the General Santos/Sarangani Province obtained the highest yield in terms of baseline yield after two years of interventions. The derived regression model for rainfall (mm), temperature (°C), relative humidity (%), and soil pH was unable to predict the yield of mangoes in all provinces studied during the second production cycle of the farmer-cooperators. Conversely, the regression model for temperature (°C) and relative humidity (%) statistically predicted the yield of mangoes (t ha") of farmer-cooperators in Sultan Kudarat during the first cycle of production. Additionally, rainfall (mm), temperature (°C), and relative humidity had linear relationships with the yield of mangoes per hectare. However, soil pH showed fluctuating, curvilinear relationships with the yield of mangoes per hectare. Additionally, rainfall (mm), temperature (°C), relative humidity (%), and soil pH did not show significant relationships with the yield of mangoes per hectare.

Abstract Background Microbial contributions to soil organic carbon formation have received increasing attention, and microbial carbon use efficiency is positively correlated with soil organic carbon storage. Mainbody This work reviews the impact on microbial carbon use efficiency from six constraints, including plant community composition and diversity, soil pH, substrate quality, nutrient availability and stoichiometric ratios, soil texture and aggregates, water and thermal constraints, and external nutrient inputs. In general, the response of microbial carbon use efficiency showed large uncertainty to above constraints, including positive-, negative-, or non-correlation. However, some factors are biased, more likely to promote or inhibit carbon use efficiency. For example, external nutrient input (N, P, K, Ca) tended to promote carbon use efficiency, while climate warming showed more negative influence. Conclusion Further, overwhelming works focused on single constraint, we suggest the importance to consider the synergistic influence of multiple environmental variables on microbial carbon use efficiency, special for the regulation mechanism of biological-environmental interactions.

While soil pH is known to be a key driver of plant species composition, we still have a poor understanding of the quantification of the responses of leaf traits to different soil types, especially in highly sensitive alpine environments susceptible to global environmental changes. By combining traditional and modern geometric morphometrics we aimed to bridge the existing gap and determine whether certain leaf traits reliably separate evergreen Dryas octopetala populations residing in the subalpine-alpine zone of the Kazbegi region, in the eastern part of the Central Great Caucasus in Georgia. To achieve this aim, three populations of D. octopetala were analysed through traditional and, for the first time, modern geometric morphometrics. Both methods revealed congruent results indicating significant differences in leaf shape and size in locations with similar climatic conditions but different soil pH environments (acid vs neutral to slightly alkaline) thus suggesting that D. octopetala exhibits stronger leaf morphological plasticity (wider and larger leaves vs narrower and smaller leaves) to respond to changes in the soil pH gradient. In addition, modern geometric morphometrics, with its high degree of precision as an accessible and inexpensive method, could be advantageous for researchers and scientists seeking to gain a deeper understanding of plant species’ unique responses to varying environmental conditions.