Soil pH Values Research Articles

KARAKTERISASI INDIKATOR KESESUAIAN LAHAN KOMODITI NANAS LOKAL (Ananas comosus) KABUPATEN MAJENE

Indonesia boasts a high biodiversity, intricately linked to the various ecosystems within its territories. In Majene Regency, West Sulawesi Province, for instance, there is a unique commodity in the form of pineapple, locally known as 'pondang'. One of the efforts to preserve this unique pineapple commodity is to understand the characteristics of the cultivation land that has sustained it over time. This research aimed to characterize the land in the cultivation areas of Majene's local pineapple as fundamental information for farmers to comprehend the plant growth ecosystem and manage the land optimally. The research utilized purposive random sampling based on the cultivation locations of Majene's local pineapple. Observations revealed that the cultivation land conditions for Majene's local pineapple had an average temperature ranging from 25.65 to 29.75 ºC, rainfall between 1,488.05 and 2,820.50 mm, with humidity ranging from 63.38 to 89.00%. Additionally, soil fertility conditions in the research locations indicated high nutrient retention, as shown by slightly acidic to neutral soil pH values and high Cation Exchange Capacity (CEC), although some available nutrients indicated very low to low soil fertility levels, such as potassium. Soil management significantly influenced nutrient availability, soil salinity, and alkalinity in the research locations.

INDENTIFIKASI KARATERISTIK KIMIA TANAH DAN EVALUASI STATUS KESUBURAN TANAH PADA LAHAN TANAMAN NANAS DI KELURAHAN WALAMBENO WITE KECAMATAN PARIGI KABUPATEN MUNA

Soil fertility provides an overview of the condition of the soil to provide nutrients. As land management is carried out intensively and over a long period of time, a decrease in soil fertility occurs. The research objectives to identify the chemical characteristics of the soil and evaluate the level of fertility of the soil planted with pineapple plants. This research was carried out in Walambeno Wite Village, Parigi District, Muna Regency, Southeast Sulawesi Province. Walambeno Wite Village is one of the central pineapple areas in Muna Regency. Soil samples were taken using the proportional sampling method on land planted with pineapple plants, at a processing layer depth of 0-30 cm. The soil chemical property parameters analyzed in the laboratory are KTK, pH H2O, C organic, N total, P available, K2O and wet saturation. Determination of soil fertility status is guided by the Soil Research Center. The research results show that the chemical characteristics of the soil in pineapple plantations are soil pH values with slightly acidic to neutral state, low to high C-organic, medium total nitrogen, very high P2O5, low to medium K2O, K2O medium to high KTK and high KB. The soil fertility status is low at location 2, medium at location 2, and high at location 3. The factors inhibiting soil fertility at the research site are low levels of C-organic and K2O.

Soil Quality Indicators under Different Smallholder Managed Cropping and Landuse Practices in Abuja, Nigeria

There are limited reports about the impacts of smallholder-managed cropping and land-use practices (CLUPs) on soil quality, especially in developing countries. This study investigates the impact of six different Cropping Land Use Practices (CLUPs) on soil quality parameters in Abuja, Nigeria, focusing on sesame mono-cropping (SM), guinea corn mono-cropping (GCM), yam mono-cropping (YM), maize + yam mixed cropping (MYM), maize mono-cropping (MM), and natural forest (NF). The objectives are to determine Soil Organic Carbon (SOC), Total Nitrogen (TN), and pH values in the six CLUPs and assess differences under various CLUPs and soil depths. The study conducted in the University of Abuja Permanent Site, covers 11,000 hectares and analyzes soil samples from three replicate plots per CLUP, considering topsoil (0-15cm) and subsoil (20-30cm). The results indicate slightly acidic soils with low SOC and TN contents. Significant differences in SOC, TN, and C/N ratio are observed among cropping systems, with mixed cropping (MYM) promoting higher SOC. The C/N ratio is consistently low across CLUPs, indicating accelerated decomposition. While intra-plot soil heterogeneity is low, significant declines in soil quality indicators are noted under cropping systems compared to the natural forest. The study recommends site-specific, sustainable land management practices tailored to each cropping system. Encouraging organic matter additions, such as using animal and farmyard manure, is proposed to enhance soil fertility and reverse degradation trends. The findings contribute to understanding how diverse cropping practices impact soil quality, providing valuable insights for sustainable land management in the Abuja region.

Effects of Soil Properties on Pb, Cd, and Cu Contents in Tobacco Leaves of Longyan, China, and Their Prediction Models.

Longyan City in Fujian Province is one of China's top-quality tobacco-producing areas and plays an essential role in local economic development. To determine the correlation between heavy metal content in tobacco leaves and soil factors, soil physical and chemical properties and heavy metal contents of lead, cadmium, and copper in tobacco leaves were measured and analyzed by the correlation regression method. The content of lead, cadmium, and copper in soil was determined using hydrochloric acid extraction-AAS and graphite furnace atomic absorption spectrometry. Inductively coupled plasma-mass spectrometry was used to determine heavy metal in tobacco leaf. The findings revealed that the average concentrations of lead, cadmium, and copper in the soil were 12.1, 0.092, and 3.88 mg/kg, respectively. In contrast, the average levels of lead, cadmium, and copper in tobacco leaves were 2.33, 4.89, and 4.35 mg/kg, respectively. The cadmium enrichment coefficient of 54.3 was higher than lead and copper, indicating a greater health risk. Soil pH value was negatively correlated with lead content in tobacco leaf, while potassium and phosphorus nutrient levels were negatively correlated with copper content. In contrast, a positive correlation was established between the presence of organic matter with cadmium content in tobacco leaves. The prediction models of lead, cadmium, and copper in tobacco leaves can be expressed by the regression equation corresponding to each heavy metal as follows: YPb=2.33 - 0.005∗ XK+0.007∗XN - 0.271∗XpH+0.065∗XPb (R2 = 0.787), YCd=1.55+0.012∗XOM - 0.014∗XCu+34.6∗XCd (R2 = 0.891), and YCu=4.64 - 0.029∗XP - 0.007∗XK+0.245∗XCu (R2 = 0.724), respectively. The prediction models above provide an effective predictive tool for assessing heavy metal risk in tobacco leaves using soil properties in the study area.

Geçiş İklimi Koşulları Altında Farklı Akarsu Yataklarında Yer Alan Toprakların Verimlilik Özellikleri

This study was conducted to identify and evaluate some of the fertility characteristics of soils in stream beds in Şebinkarahisar district of the Giresun province of Türkiye, which has a transitional climate between semi-arid and humid climate zones. To this end, a total of 48 soil samples, surface (0-30 cm) and subsurface (30-60/61/62/65 cm), were collected from 24 different sampling points on various stream beds. The textures of the surface and subsurface soils taken were determined as CL, SL, SCL, L, C, and LS. pH values of surface soils ranged from 5.84 to 7.98, and the pH values of subsurface soils ranged from 6.06 to 8.05. Lime contents of the soils without salinity problem ranged from 0.00% to 38.30% for surface soils, and from 0.00% to 37.90% for subsurface soils. Organic matter contents varied between 0.32% and 4.16% for surface soils, and between 0.14% and 2.16% for subsurface soils. While the soils were poor in total nitrogen, phosphorus, zinc and manganese, it was determined that the calcium and copper contents were at sufficient levels. Although deficiencies were detected in some soils for potassium, magnesium and iron, they were generally determined to be at sufficient levels. To deal with deficiencies of macro and micro plant nutrients, including deficiency of organic matter, a fertilization planning is recommended that includes barnyard manure, poultry manure, green manure, compost, vermicompost, and various organic fertilizers containing macro and micro elements. Within the scope of the research, climate classifications were also made according to Thornthwaite, De Martonne-Gottman and Erinç methods by had used 48 years (1965-2012) climate data of Şebinkarahisar district. Plant species and varieties to be grown in the study area should be selected from among those suitable to the transitional climate conditions prevailing in the region. It will also be useful to analyze the stream waters in the areas where soil sampling is done.

Impacts of land use/cover and slope on the spatial distribution and ecological risk of trace metals in soils affected by smelting emissions.

The soil contamination around smelting sites shows high spatial heterogeneity. This study investigated the impacts of distance, land use/cover types, land slopes, wind direction, and soil properties on the distribution and ecological risk of trace metals in the soil around a copper smelter. The results demonstrated that the average concentrations of As, Cd, Cu, Pb, and Zn were 248.0, 16.8, 502.4, 885.6, and 250.2 g mg kg-1, respectively, higher than their background values. The hotspots of trace metals were primarily distributed in the soil of smelting production areas, runoff pollution areas, and areas in the dominant wind direction. The concentrations of trace metals decreased with the distance to the smelting production area. An exponential decay regression revealed that, depending on the metal species, the influence distances of smelting emissions on trace metals in soil ranged from 450 to 1000 m. Land use/cover types and land slopes significantly affected trace element concentrations in the soil around the smelter. High concentrations of trace metals were observed in farmland, grassland, and flatland areas. The average concentrations of trace metals in the soil decreased in the order of flat land > gentle slope > steep slope. Soil pH values were significantly positively correlated with Cd, Cu, Pb, Zn, and As, and SOM was significantly positively correlated with Cd, Pb, and Zn in the soil. Trace metals in the soil of the study area posed a significant ecological risk. The primary factors influencing the distribution of ecological risk, as determined by the Ctree analysis, were land slope, soil pH, and distance to the source. These results can support the rapid identification of high-risk sites and facilitate risk prevention and control around smelting sites.

Exploring the spatial distribution and influencing factors of soil PH value of cultivated land in Sichuan Province

Exploring the spatial distribution and influencing factors of soil PH value of cultivated land in Sichuan Province

Substituting readily available nitrogen fertilizer with controlled-release nitrogen fertilizer improves crop yield and nitrogen uptake while mitigating environmental risks: A global meta-analysis

ContextControlled-release nitrogen fertilizer (CRN) is considered as an efficient tool for improving crop total uptake of N (TUN) and crop yield by providing better synchronization of crop N demand, but its effects on crop productivity, greenhouse gases (GHG) emissions and N loss are variable across agroecosystems. Objective and methodsHere, we conducted a meta-analysis by synthesizing 8874 observations from 240 published studies to address the effects of substituting CRN for readily available N fertilizer on crop yield, TUN, profit, GHG emissions, and N loss in rice, maize, wheat, soybean, and rape, with focus on cereals. ResultsOverall, CRN could increase crop productivity (crop yield, 5.1 %; profit, 8.2 %; TUN, 7.1 %) and reduce environmental pollution (GHG emissions, −3.6 % to − 18.6 %; N loss, −32.6 % to −49.1 %). These efficacies varied among crops but showed similar trends in general. The effect of CRN on crop yield was modulated by the N rate and the ratio of CRN. The optimal N rate and CRN ratio to obtain higher crop yields and profits also varied with crops. The CRN efficacies for decreasing GHG emissions and N loss depended on the mean growing season temperature, mean growing season precipitation, background soil total organic carbon content and pH values, the regions, and the CRN ratio and coating materials. A synergy of CRN with other crop management practices, such as mulching and efficient irrigation, was an effective strategy for increasing both crop productivity and environmental benefits. ConclusionsSubstituting readily available nitrogen fertilizer with CRN could produce more food and obtain higher profits with less environmental risk in crops, especially in cereals. ImplicationsThis study provides new insights into the effect of plant-soil-climate-management systems on crop productivity and environmental benefits for Sustainable Development Goals.

The Influence of Intensive Agriculture on Soil Properties and Nutrient Availability in Kauwi and Zombe Wards of Kitui County, Kenya

Soils perform various functions for the purpose of supporting agroecosystems. Numerous agroecosystem support functions rely on the properties of soils. Inappropriate agricultural techniques and land usage have led to a global 12.5% drop in soil health during the previous few decades. Inappropriate cultivation, nutrient mining, and overuse of inorganic chemical treatments are some of the activities that may have degraded soil quality. A study on the influence of intensive agriculture on soil properties and nutrient availability under different cropping systems and locations was done in the years 2018 and 2019 in Kauwi and Zombe Wards of Kitui County, Kenya. Four commonly occurring cropping systems, namely, vegetable, cereal, fruit, and agroforestry, were selected in the two locations. Uncultivated land in the area was considered as control. In total, there were five treatments, which were replicated five times in each of the locations. During the typical long (March, April, May) and short (October, November, December) rainfall seasons, composite soil samples were randomly taken from the cropping systems. Analysis of the results revealed that the influence of cropping systems on locational variation of soil quality parameters varied significantly (p<0.05). Further, the interaction between cropping strategies and locations significantly influenced soil pH and soil organic carbon. In Zombe, the vegetable cropping system registered the lowest soil pH and electrical conductivity values. Similarly, Soil Organic Carbon, Nitrogen, Phosphorus, and Potassium mean values under the vegetable farming system were higher in Zombe compared to Kauwi ward, probably due to the heavy application of fertilisers. Based on the results from the study, farmers in the area should be sensitised to embrace sustainable agricultural practices that promote moderate application of fertilisers to maintain healthy soils

Characterization of the physiological parameters, effective components, and transcriptional profiles of Polygonum multiflorum Thunb. Under pH stress

Polygonum multiflorum Thunb. is a traditional Chinese medicine with extensive distribution and robust adaptability, but comprehensive research on its acid and alkali resistance is presently lacking. This study aimed to analyze the effects of 5 months of continuous pH stress on the physiological and photosynthetic parameters of P. multiflorum, and the content of effective components. Results revealed that pH stress significantly influenced the normal growth, physiological functions, and photosynthetic indicators of P. multiflorum. At soil pH 4.5, the tubers of P. multiflorum exhibited the highest levels of 2,3,5,4′-tetrahydroxy stilbene-2-O-β-d-glucoside (THSG) and total anthraquinones at 5.41% and 0.38%, respectively. However, increased soil pH significantly reduced the content of THSG and total anthraquinones. Reference-free transcriptome analysis was further conducted on P. multiflorum treated at pH 4.5 and 9.5, generating a total of 47,305 unigenes with an N50 of 2118 bp, of which 31,058 (65.65%) were annotated. Additionally, 2472 differentially expressed genes (DEGs) were identified. Among them, 17 DEGs associated with the biosynthesis of THSG and anthraquinones were screened. A comprehensive analysis of differential gene expression and effective component content demonstrated a significant positive correlation between the content of effective components and the 14 DEGs’ expression but a negative correlation with soil pH. This study highlighted the influence of varying soil pH values on the effective component content of P. multiflorum. Specific acidic conditions proved beneficial for the synthesis and accumulation of THSG and total anthraquinones in P. multiflorum, thereby enhancing the quality of the medicinal material.

The effect of exogenous plant growth regulators on elevated Cd phytoremediation by Solanum nigrum L. in contaminated soil.

Maximizing amendment potential is an emphasis in the HM-contaminated field of phytoremediation by hyperaccumulators due to the low bioavailability of HMs in soils and small biomass yields of plants. This study investigated the influence of different types and concentrations of plant growth regulators on Cd phytoremediation by Solanum nigrum in contaminated soil. Our conclusions showed that the shoot Cd extractions (μg plant-1) and the root and shoot biomasses at all the treatments remarkedly increased compared with that of the CK (p < 0.05), while the Cd concentrations at root and aboveground parts by S. nigrum, the extractable Cd concentrations, and pH value of soils did not change significantly compared with the CK (p < 0.05). Furthermore, correlation analysis showed that the shoot Cd phytoaccumulation and the root and aboveground biomasses of S. nigrum were particularly dependent upon the application of CTK and GA3 concentration gradient (p < 0.05). Moreover, some related physicochemical indexes were determined for supervising the growth conditions of plants, and these results pointed out that after exogenous PGRs treatments, the chlorophyll content and antioxidative enzymes POD and SOD activities in vivo of plants clearly advanced, while the H2O2 and MDA contents and CAT apparently declined. These consequence demonstrated that the exogenous PGR addition prominently reinforced the Cd phytoextraction capacity of S. nigrum in contaminated soil by stimulating plant growth and increasing shoot yields.

Mapping soil property variability in oil palm (Elaeis guineensis jacq.) plantationsof Krishna basin of Andhra Pradesh through geospatial technologies

Sixty seven soil samples were collected from oil palm growing regions of NTR District of Andhra Pradesh and were analysed for different soil properties. The data was subjected to descriptive analysis to find out the variability and then to geostatistical analysis to design best fit models having minimal error for developing prediction maps. Highest variation was observed in exch. Mg and the lowest in pH. The mean values of soil pH, EC (dS/m), OC (g/kg), Olsen-P (mg/kg), NH4OAc-K (mg/kg), Exch. Ca (mg/kg), Exch. Mg (mg/kg), CaCl2-S (mg/kg) and HWB (mg/kg) were 7.32 ± 0.08, 0.25 ± 0.02, 0.87 ± 0.03, 101.47 ± 6.95, 566.14 ± 42.97, 4.72 ± 0.24, 2.46 ± 0.27, 60.86 ± 2.6 and 5.98 ± 0.25 respectively in the surface layer (0-20 cm) of the soil. Geostatistical analysis revealed wider spatial variability in surface soil properties and they had circular, spherical, stable and exponential best fit semi variogram models for evaluating dependency. The wide spatial variability of soil properties warrants site specific nutrient management for higher oil palm production. Nutrient distribution maps could be developed through kriging interpolation to interpolate the nutrient levels in unsampled areas.

Implications of tussock degradation for soil properties in Momoge wetland, Northeast China

Carex schmidtii wetland, as a unique landscape in the Momoge National Nature Reserve, has suffered from serious degradation due to climate change and anthropogenic disturbance before 2017 and soil properties of degraded tussock meadows have changed in last 30 years. In the present work, typical (TT), slightly degraded (SLT), severely degraded (SET) and completely degraded (CDT) tussock wetlands based on plant coverage was used to construct the degradation succession so as to study the effects of tussock degradation on soil properties. Soil physicochemical properties, stable isotopes of carbon (δ13C) in plants and soil organic carbon (SOC) were thoroughly investigated in field so as to predict the consequences of tussock degradation. Results showed that soil pH value was decreased with the degree of tussock degradation increased. The SOC, total nitrogen and total phosphorus of SLT had peak values among the four wetlands. The δ13C value in soil and plants demonstrated that the change of SOC during degradation process have no significant relevance with Carex schmidtii. Principal component analysis indicated that the clusters of TT and SLT are different from SET and CDT. Tussock degradation had a significant negative effect on soil properties. The findings can contribute to establishing the evidence for predicting the influences of tussock degradation on soil properties in Momoge wetland.

Investigation of Soil Properties Effect on Crop Yield Performance

Soil nutrient is essential for crop growth. Spatial variability of nutrients will have occurred in numerous scales, between regions, a field, particularly in soil properties. A study was carried out to observe the yield performance in an agricultural plot at Semujuk Jasin, Melaka. Using management zone delineation, the area is divided into fifteen smaller 6.8-meter × 6.8-meter plots. A soil sample from each plot was tested in the laboratory to obtain the soil moisture, organic matter, pH level, Phosphorus, and Manganese content. Using ArcGIS software, the result is interpolated using the Kringging method, mapped, and then compared with the crop value from each. Plot A3 generated the lowest yield with a crop yield value of RM6.8. This plot also has the lowest soil moisture content, which is 6.452%. Plot A1 produces only RM65.2 for crop yield, although it has 21.505% soil moisture content, while plot C1 only produces RM47.4 for crop yield value, although it has a higher soil moisture content of 23.265%. Regarding the soil organic matter content for both plots, plot A1 has only 1.455% organic matter content, while plot C1 has lower soil organic matter content, which is 0.823%. Plot B2, with a low pH value (4.51), shows a poor performance of RM52.6 regarding satisfactory readings on other plots. From the analysis made based on the experiment result, the primary limiting factor affecting crop performance is soil moisture content. Soil pH value and Organic Matter also play an essential role in determining crop performance.

Long-term effects of biochar on soil chemistry, biochemistry, and microbiota: Results from a 10-year field vineyard experiment

Application of biochar to soil has been recommended as a carbon sequestration approach that can also improve soil physical and chemical properties. The addition of biochar to soil can change the physicochemical properties of the soil, leading to a subsequent modification of the microbial community. However, the long-term implications of these changes remain insufficiently elucidated. Here, we examined soil chemical and biochemical properties of the bulk soil and employed next-generation sequencing techniques to analyze the microbiological properties of both bulk and rhizosphere soils after 10 years of biochar application. Specifically, we compared these properties between soil treated with two doses of biochar, i.e., SB and DB, and untreated soil, i.e., CK. After 10 years, biochar application increased the soil organic carbon from 12.7 g.kg−1 in CK to 17.3 and 23.1 g.kg−1, in SB and DB, respectively. Moreover, biochar application led to a slight decrease in soil bulk density, and increased the soil pH value 6.33 in CK to 7.07 in DB. Moreover, our findings revealed a distinct taxonomic signature within bacteria; however, this signature was not observed in terms of diversity. Specifically, we observed an increase in the abundance of oligotrophic bacteria compared to copiotrophic bacteria. The double dose of biochar increased the fungal species richness in the rhizosphere, particularly of Basidiomycota yeasts, from a relative abundance of 9.4 % in the CK soil to 17.0 % in the SB soil and 24.8 % in the DB soil and reduced putative plant pathogens like Phaeoacremonium and Aspergillus. Biochar amendment can significantly improve soil physical, chemical, and biological fertility on the long-term even under intensive viticulture management, with no detectable detrimental effects on microbial diversity and soil functions, and potential of soil organic carbon storage.

Influence of azolla, grass, water hyacinth, and peanut residues in amending soil properties

An incubation experiment was undertaken to evaluate the effects of azolla, grass, water hyacinth, and peanut residues for amending some soil properties. The experiment was laid out in pots comprising 7 treatments, viz. T1: Control, T2: Azolla (Azolla pinnata) @ 100 g/pot, T3: Grass (Phleum pretense) @ 100 g/pot, T4: Water hyacinth (Pontederia crassipes) @100 g/pot, T5: Peanut (Arachis hypogaea) @ 100 g/pot, T6: Azolla @ 50 g/pot + Water hyacinth @ 50 g/pot, and T7: Peanut@ 50 g/pot + Grass @ 50 g/pot. The results revealed that peanut treated soils (T5) played an important role in enhancing soil properties significantly (p &lt; 0.05) and the values of soil organic carbon (SOC), pH, nitrogen, moisture content and cation exchange capacity (CEC) reached at an optimum level to support microbial growth over a year. Biodivers. Conserv. Bioresour. Manag. 2023, 9(2): 57-64

Thallium content in vegetables and derivation of threshold for safe food production in soil: A meta-analysis

Soil thallium (Tl) pollution is a serious environmental problem, and vegetables are the primary pathway for human exposure to Tl. Therefore, it is important to investigate the characteristics of soil Tl uptake by vegetables. In this study, the meta-analysis approach was first applied to explore the relationship between Tl content in vegetables and soil environment, as well as key factors influencing soil physical–chemical properties, and to derive soil thresholds for Tl. The results indicated that various types of vegetables have different capabilities for Tl accumulation. Vegetables from contaminated areas showed high Tl accumulation, and the geomean Tl content in different types of vegetables was in the following order: leafy > root–stalk > solanaceous vegetables. Taro and kale had significantly higher capability to accumulate soil Tl among the 35 species studied, with Tl bioconcentration factor values of 0.060 and 0.133, respectively. Pearson correlation analysis and meta-analysis revealed that the Tl content in vegetables was significantly correlated with soil pH and Tl content in soil. The linear predictive model for Tl accumulation in vegetables based on soil Tl content described the data well, and the fitting coefficient R2 increased with soil pH value. According to potential dietary toxicity, the derived soil Tl thresholds for all, leafy and root–stalk vegetables increased with an increase in soil pH, and were in the range of 1.46–6.72, 1.74–5.26 and 0.92–6.06 mg/kg, respectively. The soil Tl thresholds for kale, lettuce and carrot were in the range of 0.24–4.89, 2.94–3.32 and 3.77–14.43 mg/kg, respectively. Ingestion of kale, beet, sweet potato, potato, taro, pepper, turnip, Chinese cabbage, eggplant and carrot poses potential health risks. The study provides scientific guidance for vegetable production in Tl-contaminated areas and can help with the selection of vegetable species suitable for avoiding the absorption of Tl from contaminated soil.

Relationships between Heavy Metal and Metalloid Contents and Major Soil Characteristics in Soils around the Former Kremikovtsi Metallurgical Plant Following Its Closure in 2009

Soils around the former metallurgical plant Kremikovtsi were subject of continued interest due to the environmental problems resulting from the plant's activities and especially heavy metal pollution. The aim of the present study was to investigate the contamination of the studied soils by metals and metalloids, several years after the closure of the plant (2009) and to relate their concentrations to basic soil parameters, pH, electrical conductivity, cation exchange capacity, clay content and total organic carbon, which will contribute to better assessment of their behaviour and remediation strategies. Total concentrations (aqua-regia) of the elements Al, B, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Zn and As were determined. Elevated levels of the heavy metals Pb, Cd, Zn, and the metalloid arsenic (As) were found at the studied sites. Lead (Pb) exceeded maximum permissible concentrations (MPC), regulated by Bulgarian legislation for arable lands between 2 and 15 times, cadmium (Cd) between 3 and 5 times, arsenic (As) between 3 and 6 times, and zinc (Zn) was higher than MPC in three of the sampled sites. Soil pH values were in significant correlation with EC (R** = 0.805), CEC R** = 0.781), B (R* = 0.638), Cu (R* = 0.669), Fe (R** = 0.766) and Mn (R*** = 0.916) contents. Aluminium, cadmium, lithium and lead concentrations were related to the content of the clay fraction in soil. Positive correlation was obtained in multiple regression models between Pb, Al, Cd, TOC and soil pH, and negative relationship was observed with electrical conductivity (EC). The obtained results showed complex relationships between soil characteristics and the metals and metalloids, which emphasize the need for their simultaneous assessment, remediation and careful use for agricultural purposes.

Responses of non-structural carbohydrates and biomass in plant to heavy metal treatment

The contamination of heavy metals profoundly impacts plant metabolic processes and various physiological indicators, such as non-structural carbohydrates (NSC). However, a comprehensive understanding of how NSC in plants respond to heavy metal treatment and how different experimental setting and plant types affect the response of plant NSC is still lacking. Here, we compiled data of 2084 observations of NSC from 85 published studies and conducted a meta-analysis to investigate the responses of soluble sugars, starch, the ratio of soluble sugar to starch, and total non-structural carbohydrates (TNSC) to heavy metal treatment. Our results showed that, under heavy metal treatment, foliar soluble sugars, foliar TNSC, and the ratio of soluble sugars to starch in both foliage and root increased significantly by 21.6 %, 11.6 %, 55.9 %, and 65.1 %, respectively; and foliar starch, root starch, and root TNSC decreased significantly by 10 %, 23.3 %, and 11 %, respectively; while root soluble sugars remained unchanged. The treatment of heavy metals significantly diminished the biomass of foliage, above-ground, and root by 12.3 %, 29.5 %, and 34.3 %, respectively. The responses of foliar NSC to heavy metal treatment were strongly dependent on leaf habit, the duration and concentration of heavy metal treatment, and soil pH value. The magnitude of the response of NSC to heavy metals increased with the duration and concentration of heavy metal treatment. Furthermore, the types of heavy metals modulated the magnitude of the response of foliar NSC to heavy metal treatment. Overall, our findings provide valuable insights into the responses of plant NSC to heavy metal stress and contribute to a comprehensive understanding of this crucial aspect of plant physiology.

X-Ray Fluorescence Monitoring Metal Content and Nutrient Elements for Predicting Soil Fertility Parameters Based on pH in Ultisol Soil

Soil fertility parameters, including macronutrients, micronutrients, and metal content, are very important for optimizing agricultural and plantation land management. Ultisol is a type of soil that is commonly used as a planting medium for oil palm plantations, rubber, and various types of vegetables. Continuous land use causes variations in nutrient and metal content. This change is also caused by the fertilization process and the characteristics of the plants grown in the area. In this study, an analysis of soil fertility parameters (macronutrients, micronutrients, and metal content) was analyzed using X-Ray Fluorescence (XRF) on Ultisol soil taken from Muara Jambi Regency, Indonesia. This analysis was conducted across land-use areas (Palm, Rubber, Vegetables, and Forest). Subsequently, the obtained measurements were used to model correlations with soil pH values to predict soil fertility parameters. The quantitative results showed that the metal content values were reasonably consistent across all locations regarding metal types and their percentage concentrations. However, locations 1 (T1) and 2 (T2) have higher aluminum (Al) content than locations 3 and 4 and lower magnesium (Mg) content. The modeling, when correlated with pH values, indicated that metal elements correlated 0.938, macronutrients 0.934, and micronutrients 0.767. From these correlations, it can be qualitatively inferred that there is a strong relationship between pH and the presence of metal content, macronutrients, and micronutrients. In the future, this can serve as a model for estimating the presence of soil fertility parameters.