Red Yellow Soil Research Articles

Phosphorus Footprint in the Whole Biowaste-Biochar-Soil-Plant System: Reservation, Replenishment, and Reception.

Two phosphorus (P)-rich biowastes, sewage sludge (SS) and bone dreg (BD), were selected to clarify P footprints among biowaste, biochar, soil, and plants by introducing a novel "3R" concept model. Results showed that pyrolysis resulted in P transformation from an unstable-organic amorphous phase to a stable-inorganic crystalline phase with a P retention rate of 70-90% in biochar (P reservation). In soil, SSBC released more P in acid red soil and alkaline yellow soil than BDBC, while the opposite result appeared in neutral paddy soil. The P released from SSBC formed AlPO4 by combining with Al in soil, whereas P from BDBC transformed into Ca5(PO4)3F(or Cl) in conjunction with Ca in the soil (P replenishment). Various plants exhibited an uptake of approximately 2-6 times more P from biochar-amended soil than from the original soil (P reception). This study can guide the application of biochar in various soil-plant systems for effective nutrient reclamation.

Comprehensive analysis of environmental factors on the quality of tea (Camellia sinensis var. sinensis) fresh leaves

“High mountain, cloud and mist produce high-quality tea”; however, the specific mechanism has not been fully understood. To explore the influence of environmental factors on the quality of tea fresh leaves, we firstly selected the same variety of tea plant growing at different altitudes in Xuan'en County, China. And then, based on the analyses of the physical and chemical properties of the soil where they grew, we comprehensively analyzed the composition and content of volatile and non-volatile substances in these tea fresh leaves harvested from 27 sampling sites. The relative contents of linalool and its oxides I and II, phenylethanol and nerol in paddy soil were higher than those in red soil and yellow soil, but the contents of acids and esters were significantly lower than those in other soils (P < 0.05). Benzoic acid content and palmitic acid content are relatively high in red soil and yellow soil, respectively. The amino acid content of tea fresh leaves produced in paddy soil is significantly lower than that in red soil and yellow soil, while the contents of catechins and flavonol glycosides were significantly higher than that in other soils (P < 0.05). The relative contents of EGCG, ECG and C in paddy soil were significantly higher than those in yellow soil and red soil. The content of alkaloids in red soil is high. With the increase of altitude, the content of amino acids gradually increased, and the catechins content showed a trend of first decreasing and then increasing; the phenolic acid content changes in accordance with catechins with the elevation; the flavonoids content (alcohols) glycosides did not change obviously in each altitude range. These results are helpful for us to fully understand the influence of environmental factors on the quality of fresh tea leaves.

Kajian Uji Kualitas Sumber Air untuk Pemenuhan Kebutuhan Air Bersih di Daerah Rawa yang Berkelanjutan

Siak Regency consists of plains and hills with an average soil composition consisting of podzolic red yellow rocks and alluvium and organosol soil and humus gley in the form of swamps or wet gley. United States Department of Agriculture (USDA) that Podsolic Red Yellow (PMK) soil is a soil formed due to too low temperature and very high rainfall and is an ancient mineral soil type with a reddish or yellowish color. This podzolic soil color indicates relatively low soil productivity due to leaching. While the red and yellow soil colors are caused by rusty iron and lumps of aluminum that decompose and undergo weathering. Clay minerals in this soil are dominated by compounds containing silicon, oxygen, and some metals, which have implications for water quality. The purpose of this research is to test water quality to support the fulfillment of sustainable clean water needs in the Swamp Area in Rempak Village, Siak District, Siak Regency, Riau Provonce. The approach method used is Permenkes No. 492/Menkes/IV/2010.The data needed for this research is to use primary data by taking samples of rainwater, well water, and raw water from the Siak river by researchers directly on March 16, 2022. The main results of the research stated that the quality of rainwater was ranked first to support the policies of the National Development Planning Agency towards a just and prosperous Indonesia in 2045 which has mandated the importance of water security to support strategic sectors, disaster prevention, and improvement of community welfare through construction of rainwater harvesting buildings.

The Responses of Some Doses Fertilizer Bat Guano on The Crop Yield of Hiyung Chili Pepper in The Ultisols

Hiyung chili is a type of chili found in Hiyung Village, Tapin District, South Kalimantan with a spiciness rate of 94,500 ppm. Bat manure is a fertilizer that contains elements of N, P, and K which are important for plant growth and development and are expected to increase nutrient content in the soil. This study aims to determine the effect and the best dosage of bat manure on the growth and yield of Hiyung chili on ultisol. Ultisol is a soil that has low organic matter, yellowish-red soil, acidic soil reaction, low base saturation, high Al content, low nutrient content such as N, P, and K. This study used a single factor CRD consisting of 5 treatment levels, namely k0 = 0 t.ha-1, k1 = 1 t.ha-1, k2 = 2 t.ha-1, k3 = 3 t.ha-1, k4 = 4 t.ha-1. The results of this study showed that giving several doses of bat manure fertilizer significantly affected plant growth, leaf size, fresh fruit weight, cropping, and crop production. The best bat manure doses to increase growth and yield of hiyung chili plants at a dose of 3 t.ha-1

Effect of various types and doses of biochar on hybrid maize growth

Climate change also has an impact on agriculture, especially at Mediterranean red-yellow soil which is characterized with low fertility. The application of biochar is an alternative to increase soil fertility, as well as promoting the growth and yield of maize in red-yellow Mediterranean soil. The study aimed it determining the appropriate type and dose of biochar in red-yellow Mediterranean soil to support the growth of hybrid maize. The study used a factorial Randomized Completely Block Design (RCBD) with two factors. The first factor was the type of biochar which consisted of 3 levels, namely coconut shell biochar (B1), rice husk biochar (B2), and maize cob biochar (B3). The second factor was the dose of biochar which consists of 5 levels, namely 0 ton.ha−1 (D0), 5 ton.ha−1 (D1), 10 ton.ha−1 (D2), 15 ton.ha−1 ( D3), and 20 ton.ha−1 (D4). The analysis of variance (ANOVA) continued with the Duncan’s Multiple Range Test (DMRT) at level 5% were employed for data analysis. The results showed that the application of biochar had a significant effect on the growth of hybrid maize, especially on some observational variables. The application of biochar rice husks significantly affected the stem diameter, leaves number, and dry weight of 7 week after plant (WAP). The dose of 15 tons.ha−1 significantly affected the dry weight of 4 WAP, while the interaction of rice husk biochar with a dose of 15 tons.ha−1 significantly affected the leaves width.

Growth of Deciduous and Evergreen Species in Two Contrasting Temperate Forest Stands in Korea: An Intersite Experiment.

Poor seedling establishment and growth can be a result of the limitation of light and soil resources in the forest understory. Here, we investigate the interacting effects of stand and soil characteristics on the seedling growth of deciduous species (Fraxinus rhynchophylla and Zelkova serrata) and evergreen species (Pinus koraiensis) through a 3-year intersite experiment in two contrasting forest stands. Seedlings were grown in both oak and pine stands using two different soil types, i.e., gray-brown forest soil (GB) and red-yellow forest soil (RY). Soil physicochemical properties, light intensity, tree-seedling height, root-collar diameter (RCD), and biomass growth were analyzed between two stands and/or soil types. Light availability was generally more abundant in the pine stand (mean: 1074.08 lx or 20.25%) than the oak stand (mean: 424.33 lx or 9.20%) throughout the year. The height and RCD growth of fast-growing and deciduous F. rhynchophylla and Z. serrata were higher in the pine than in the oak stand, particularly in GB soil. The growth of the slow-growing and evergreen P. koraiensis was not affected by the forest stand, except for its higher root growth in the oak stand and RY soil. Therefore, abundant light availability can enhance the growth and seedling establishment of F. rhynchophylla and Z. serrata in the pine-stand understory. Contrarily, P. koraiensis may be planted in the understory regardless of light condition, but with a slower growth rate.

ZONING PRONE TO LANDSLIDES THROUGH 3D VISUALIZATION USING GEO CAMERA APPLICATION IN CIKUYA VILLAGE, CULAMEGA DISTRICT, TASIKMALAYA REGENCY

Cikuya Village Culamega District Tasikmalaya District, West Java, landslide prone areas that cause material losses and fatalities. The landslide occurred because Cikuya Village is located in the South Mountain Zone with hilly morphology so that it has a steep slope. Other characteristics cause landslides due to high rainfall intensity, geological conditions, soil types, and land use that are not in accordance with the carrying capacity of the environment. Prevention efforts that can be done by measuring the characteristics of landslide prone and 3D visualization zoning maps using map overlays to produce zoning maps and land suitability using ArcGis 10.5 software and Geo Camera applications The results of this study show the characteristics that cause landslides are high rainfall intensity ranging from 2,203 - 3,054 mm / year, Steep slopes range from 8° - 40°, geological conditions (types of rocks) are divided into two types, namely sedimentary rocks and volcanic rocks, podsolic yellow red soil types that are not good in water escape, as well as land use that is not in accordance with the conditions and carrying capacity of the region. The results of the analysis of assessment, weighting and overlay zoning of disaster-prone areas are divided into three "non-prone" hazardous landslide zones with an area of 7,597 hectares, a "prone" zone with an area of 1,972,147 hectares, and a "very vulnerable" landslide vulnerability zone with an area of 256,968 hectares. Further analysis is that land suitability is divided into three "appropriate" zones with an area of 1,057,391 Hectares, "somewhat appropriate" with an area of 1,080,373 Hectares, and "incompatible" with an area of 98,948 Hectares. It is expected that the results of this study can be a reference for the community in recognizing landslide-prone zone areas in Cikuya Village, Culamega Subdistrict, Tasikmalaya Regency.

An investigation of upland soil fertility from different soil types

Soil type is a vital determinant of soil fertility because of its characteristic biological, chemical, and physical properties. However, the soil fertility of upland soil is probably changed by different agricultural management practices regardless of soil type. This study investigated the features of soil fertility (bacterial biomass, total carbon (TC), and total nitrogen (TN)) in upland fields in Japan. One thousand soil samples from different soil types were collected from upland fields located on 36 prefectures in Japan. The soil fertility was analyzed using the Soil Fertility Index (SOFIX). There were six soil types included in this study: Organic soils (B), Andosols (D), Lowland soils (F), Red-yellow soils (G), Stagnic soils (H), and Brown Forest soils (I). Of these, the soil types D and F occupied the largest percentage of samples. The values of bacterial biomass, TC, and TN varied greatly, regardless of soil type. The soil fertility does not seem to be characterized by the soil type in upland soils in Japan. The correlations between bacterial biomass and TC (r = 0.23, p < 0.01) and bacterial biomass and TN (r = 0.16, p < 0.01) were relatively weak. Conversely, the correlation between TC and TN (r = 0.68, p < 0.01) was moderate. In soil type D, up to 40% of samples had no bacterial biomass detected and 17% possessed a low bacterial biomass. The effect of the soil types may not be a critical factor in soil fertility in the upland fields.

Soil CO2 emission in ‘Tifton 85’ bermudagrass pasture fertilized with liquid pig slurry

The application of liquid pig slurry (LPS) to pastures offers potential as a fertilizer but could have a direct influence on soil CO2 emissions. This study evaluated soil carbon dioxide emissions after successive LPS applications to soils under pasture cultivation. The experiment was carried out on ‘Tifton-85’ bermudagrass pasture cultivated in a red-yellow oxisol soil in the municipality of Lucas do Rio Verde-MT, Brazil. Two treatments were evaluated: the control and an application of 20 m3 ha-1 of LPS after each cut of the pasture. The CO2 emissions from the soil were determined using a high-precision infrared gas analyzer. Soil temperature and soil moisture were determined as were micrometeorological variables. The application of LPS had a significant effect on soil C-CO2 flow. The average flow of C-CO2 from the soil for the control treatment and with the application of LPS was 0.236 g C-CO2 m-2 h-1 and 0.291 g C-CO2 m-2 h-1, respectively. The application of LPS increased the accumulated CO2 emissions from the soil by 23.2%. Soil temperature and moisture are the main factors regulating the process of soil CO2 emission. These factors therefore need to be considered when evaluating the impact of LPS application on greenhouse gas emissions

Aplikasi Limbah Padat Karet Remah Pada Tanah Podsolik Merah Kuning Terhadap Ketersediaan Hara Makro Dan Perbaikan Sifat Fisika Tanah

The chemical properties of Podsolic Red-Yellow soil have pH is very acidic to slightly acidic, low to moderate percentage of C-organic, low to moderate P, and low status of K, Ca, Mg, Na, and other saturation of bases. Also, the physical characteristics of the Red-Yellow Podsolic soil show a distinctive characteristic, as bulk density soil index of 1.30 - 1.50 g.cm-3, with low water absorption. The chemical and physical properties are bad enough to make Red-Yellow Podsolic soil have a low ability to provide macronutrients needed by plants. Organic matter is proven to be able to control nutrient availability in mineral soils. The potentials for organic material that has been completely decomposed is crumb rubber solid waste. The use of crumb rubber solid waste material as organic material is expected to be able to influence the availability of macronutrients and improve the physical characteristics of the Podsolic Red-Yellow soil. This study aims to find differences in the availability of NH4+ NO3-, H2PO4-, K-exchangeable, C-organic and to compare the treatments that produce the best index of soil bulk density, increase the percentage of water content, and determine the soil temperature of Red-Yellow Podsolic with the application of crumb rubber solid waste with difference level, statistical test with through the index of mean difference Tukey’s test on level α 5%. In this research it was concluded that the application of crumb rubber solid waste could increase soil pH, provide levels of NH4+, NO3-, H2PO4, K-exchangeable, C-organic and reduce soil bulk density index, increase water content and soil temperature compared to not using crumb rubber solid waste. PCr3 treatment showed the highest yield at pH, NH4+, H2PO4, C-organic and increased water content, but it was not significantly different than PCr2 treatment, whereas PCr2 was significantly different from PCr3 in providing NO3-, K-exchangeable.

Kết cấu và đa dạng loài cây gỗ của rừng Dầu trên những loại đất khác nhau tại khu vực Nam Cát Tiên, tỉnh Đồng Nai

This paper introduces some characteristics of Dipterocarp forests on different soil types in Nam Cat Tien area, Dong Nai province, Vietnam. The objective of the study was to determine the differences in tree species composition and tree species diversity of Dipterocarp forest on dark brown soil developed from basalt and yellowish red soil developed from clay rock. Tree species composition and diversity of Dipterocarp forests on each soil type was analyzed from three typical sample plots with the size of 0.25 ha. All trees with diameter at breast height (DBH) from 6 cm are listed according to species, DBH, height, basal area and volume. Then determine and compare tree species composition and diversity indicators of Dipterocarp forests on two soil types. Research results have shown that the number of tree species found in Dipterocarp forests on both soil types is 65 species belonging to 54 genera of 31 families; of which the number of families in Dipterocarp forests on dark brown soil (30 families) was more than that of yellowish red soil (25 families). Dipterocarpaceae family is the dominant ecological family; of which Dipterocarpus alatus is dominant species on dark brown soil, while Anisoptera costata is dominant species on yellowish red soil. The number of tree species found in Dipterocarp forests on dark brown soil (58 species) was higher than that of yellowish red soil (47 species). The similarity coefficient for tree species on these two types of soils is 76.2%. The mixed index of Dipterocarp forests on dark brown soil (0.21) was higher than that of yellowish red soil (0.17). The tree species diversity of Dipterocarp forests on soil dark brown soil is higher than the yellowish red soil. The number of precious tree species found on these two soils is 14 species. The number of rare tree species in Dipterocarp forests on dark brown soil (31 species) was higher than that of yellowish red soil (15 species).

Soil Organic Carbon Stabilization on Forested and Deforested Red-yellow Soil under Different Temperature Conditions

Soil Organic Carbon Stabilization on Forested and Deforested Red-yellow Soil under Different Temperature Conditions

Arduino system and ultrasonic sensor for automation of the determination of water infiltration rate in soil

The velocity of water infiltration in soil is important for the design of irrigation systems, drainage, septic tanks, sanitary landfills, dams, channels for water distribution, soil and water management to control erosion and estimate surface runoff. Infiltration tests are generally done with rulers and visual reading, which can lead to errors. The present study therefore aimed to determine the Infiltration Velocity (IV) curves of water in the soil by the concentric ring infiltrometer method, using an Arduino microcontroller and an ultrasonic sensor to measure the lowering of the water depth. For that, in the same infiltration test, four readings in Automatic mode (AT) and four readings in Manual mode (MN) were performed simultaneously, in a red-yellow Argisol type soil, in the Areal Basin, located in the southeastern region of Brazil. municipality of Taubaté, Vale do Paraíba, in the state of São Paulo. Adjustments of kostiakov curves and their equations were made from the data obtained in the field, and the values of R² were determined, as well as the values of Basic Infiltration Velocities (BIV), Accumulated Infiltration (AI) and the Average Percentage Error (APE) of the calculated IS values and those estimated by the equations. The results show that the number of readings in the same test time in Automatic mode (AT) was 2.3 times higher than in the manual (MN). All tests showed that the Red-Yellow Argisol showed a high infiltration speed, and in the pasture area the BIV values were 1.9 times higher than those obtained in the forest area. The R² determination coefficients for all curves are 0.99 in all tests and demonstrate the strong correlation between the data. The APE of the calculated and estimated IS values were low, and the biggest discrepancies that occurred were (APE = 0.30%) in the MN - 4 test and (APE = -0.01%) in the AT - 4. APE of MN mode BIVs for AT was 2.7%. These differences in IS values are reflected in the accumulated infiltration (AI) in the soil over time, and in this study the AI of the ATs tests was on average 4.1mm higher than in the MN tests, which corresponds to a difference of 41m³ ha-1. It was concluded that the use of the Arduino microcontroller with the ultrasonic sensor installed in the ring infiltrometer proved to be efficient in the field measurements and made the determination of the accumulated infiltration and the infiltration speed practical, proving to be an economical and technically viable alternative mainly due to the quantity of possible points to collect for each test and the greater reliability added to the low error values when compared to the manual.

Effects of reducing chemical fertilizer on the quality components of Tieguanyin tea leaves

Fertilizer plays an important role in agricultural development. However, the soil environment of tea gardens has been deteriorated and the growth of tea trees has been hindered by the long-term excessive chemical fertilizer used in tea gardens. To study effects of reducing chemical fertilizer on the quality components of Tieguanyin tea leaves, Tieguanyin tea garden located in yellow-red soil was treated with three consecutive times and five recipes of chemical fertilizer. The results showed that appropriate reduction of chemical fertilizer applied in tea gardens can increase the contents of potassium and organic matter in soil, polyphenols and water extract in tea leaves. Most of the contents reach their peaks in T3 treatment, which compound fertilizer that the contents of NPK are all 15% was 412.50 kg/ha and urea was 206.25 kg/ha applied in the tea gardens, that 55% of the conventional usage by local farmers. At the same time, with the reducing chemical fertilizer applied in tea gardens, the caffeine in tea leaves was significantly decreased. Therefore, T3 treatment can improve the soil environment of tea gardens and the concentration of Oolong tea soup. Besides, it infers that the amount of chemical fertilizer in T3 treatment is a key control point for the quality of tea. The indirect influence coefficients that the chemical fertilizer effects on the contents of tea water extract, free amino acid and caffeine are all at their peaks of 5.249, 4.245 and 8.594 respectively through the changing of the soil nutrient contents. It is benefit for improving the overall quality of Oolong tea.

Physiological and biomass partitioning shifts to water stress under distinct soil types in Populus deltoides saplings

Abstract Aims Although soil environments exist extensive heterogeneity for many plants with a wide range of distribution, researches about effects of soil conditions on plants’ tolerance and adaptation are particularly inadequate. In our study, the aims are to reveal physiological strategies of Populus deltoides against drought stress under different soil conditions and to select the most suitable soil type for P. deltoides plantation. Methods Under controlled conditions, we used P. deltoides as a model species to detect differences in gas exchange rate, antioxidative capacity, nitrogen metabolism and biomass accumulation and partitioning in response to drought stress under three mineral soil types with distinct physicochemical characters, i.e. red soil (RS), yellow soil (YS) and yellow-brown soil (BS). Important Findings Exposure to 25% of field water holding capacity in soil for 3 months had significantly decreased biomass of all organs, photosynthetic rate, enzyme activities related to N assimilation, but increased H2O2, malondialdehyde and content of both NO3− and NH4+, when P. deltoides was planted in both RS and YS. In contrast, under BS, there are slightly negative effects exerted by water deficit on total biomass, gas exchange rate, activities of enzymes related to nitrogen metabolism and membrane damage caused by reactive oxygen species, which can be associated with a consistent increase in superoxide dismutase, peroxidase and catalase, and a higher ratio of root mass to shoot mass. It is concluded that, such higher capacity in tolerance and adaptation against drought stress under BS relative to both RS and YS could be accounted for more sufficient nutrient provision in soil parental materials and better soil aeration conditions which play a vital role in plant acclimation to water shortage. Our study also revealed that, distribution areas of BS might be preferable for cultivation of P. deltoides, when compared with those of RS and YS.

Soil fertility characteristics and their influencing factors in tea plantations of Jiangxi Pro-vince, China

To investigate soil fertility status and characteristics of typical tea plantations, we selec-ted 372 typical tea plantations of 21 areas across Jiangxi Province and analyzed the soil nutrient, spatial data, and their correlations with topography, soil type, elevation and plantation age. The results showed that soil pH, organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus and total potassium of tea plantation in Jiangxi reached 53.9%, 60.1%, 56.1%, 22.9%, 38.5%, 43.7%, 11.1% and 95.5% of indices of high fertility, high efficiency and high yield tea plantation, respectively, with the available phosphorus showing a strong variation. Soil available copper, zinc, iron, manganese and boron reached 76.3%, 74.2%, 96.8%, 73.1% and 0.0% of the first-class standards for soil trace elements, respectively. Tea plantations with highest soil fertility located in central Jiangxi, followed by northeastern and northwestern Jiangxi, and lowest in southern Jiangxi. Soil pH was significantly positively correlated with organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen and total phosphorus but not for total potassium. For different topography, soil fertility was highest in the flat land, followed by the high mountains, and lowest in the mountains and hills. Across different soil types, soil fertility was higher in paddy soil, sandy soil and mountain yellow brown soil, followed by yellow soil, red-yellow soil and purple soil, and lowest in red soil. Soil pH, organic matter and total potassium increased while available phosphorus decreased with altitude. The organic matter, alkaline nitrogen, available phosphorus, total nitrogen and total phosphorus increased, but soil pH decreased with time. In summary, soil fertility of tea plantations in Jiangxi Province was generally good, with high organic matter, total potassium, available copper, zinc, iron and manganese. However, soil was acidic, available phosphorus and total phosphorus content was low, available boron was seriously limited. We suggest increase soil pH and potassium supply in central Jiangxi, increase potassium and nitrogen fertilizer supply in northeastern Jiangxi, increase organic matter and phosphorus fertilizer supply in northwestern Jiangxi, and increase nitrogen, phosphorus and potassium supply combined with organic fertilizers in southern Jiangxi. High mountain tea plantations should enhance available phosphorus and potassium supply. Mountain tea plantations should enhance nitrogen and phosphate supply. Tea plantations with red and yellow soil should increase pH and total potassium supply. Tea plantations with red soil should apply nitrogen, phosphorus and potassium fertilizers combined with organic fertilizers. Tea plantations with yellow soil and mountain yellow brown soil required additional phosphorus supply, and tea plantations with purple soil should increase soil organic matter supply. Tea plantations need to increase dolomite powder, physiological alkaline fertilizers and organic fertilizers to prevent soil acidification.

Study on Exchangeable Cation Determining Base Saturation Percentage of Soil in South China

Base saturation percentage (BSP) is an important soil chemical index in soil fertility and soil taxonomy. However, it is still unclear what exchangeable cation dominates BSP of soil in south China. Therefore, in this study, the data of BSPs and exchangeable H+, Al3+, Ca2+, Mg2+, K+ and Na+ of 109 and 45 horizon samples of 50 and 28 soil species in red soil and yellow soil groups in the Database of Chinese Soil Species were used to explore further the characteristics of BSPs and exchangeable cations as well as the correlation between BSPs and exchangeable cations. The results showed that the concentrations of exchangeable cations in both red soil and yellow soil groups were in an order of Al3+ (4.55 ± 1.47 and 4.22 ± 1.2 cmol(+)/kg) > Ca2+ (0.32 ± 0.21 and 0.36 ± 0.24 cmol(+)/kg) > H+ (0.23 ± 0.13 and 0.19 ± 0.10 cmol(+)/kg) > K+ (0.16 ± 0.09 and 0.16 ± 0.11 cmol(+)/kg) > Mg2+ (0.13 ± 0.09 and 0.11 ± 0.08 cmol(+)/kg) > Na+ (0.08 ± 0.06 and 0.11 ± 0.06 cmol(+)/kg). For red soil group, Al3+ concentration was significantly higher than those of other exchangeable cations, Ca2+ and H+ concentrations were significantly higher than those of K+, Mg2+ and Na+; while for yellow soil group, Ca2+, H+ and K+ concentrations were significantly higher than those of Mg2+ and K+. BSP of red soil group was codetermined by Ca2+, Al3+, Mg2+ and Na+, with the contributions of 33.81%, 19.82% and 14.49%, respectively; while BSP of yellow soil group was codetermined by Al3+, Ca2+, Mg2+, K+ and Na+, with the contributions of 24.91%, 21.55%, 19.91% and 14.21%, respectively. A higher concentration of exchangeable cation does not mean the higher importance of the cation to soil BSP.

Cerium-manganese Modified Biochar Immobilizes Arsenic in Farmland Soils

Loaded cerium and manganese modified biochar (MBC) was prepared by high temperature pyrolysis at 600℃, and three kinds of arsenic (As) contaminated soils were selected for remediation, including red soil, yellow soil, and purple soil with different basic properties. During the soil incubation experiment, the goal of this research was to investigate the influence of MBC as a stabilizer of the mobility of arsenic in these three soils after treated by biochar (BC) and MBC. The results revealed that the application of MBC resulted in a significant decrease of water soluble arsenic content in the three different kinds of soils. With the additional amount increasing, the stabilization efficiency of soil arsenic increased continuously. When the applied amount of MBC ranged from 1% to 10%, the stabilization efficiency of arsenic was in the range of 70%-99%. The corresponding stabilizing efficiencies of the red, yellow, and purple soils were 70.59%-94.72%, 75.24%-98.35%, and 76.53%-99.61%, respectively, after being treated by MBC at 1%-10%. At a higher addition of 10% MBC, the efficiency of stabilization reached 95%. On the contrary, the addition of unmodified biochar caused the activation and dissipation of As in soils. Comparatively speaking, according to the stabilization efficiency, the three soils ranked in this decreasing order:purple soil > yellow soil > red soil. It also illustrated that the addition of MBC into soils led to the conversion of active arsenic to stable ones in soil, indicating the conversion from non-specifically sorbed (F1) and specifically sorbed (F2) to well-crystallized hydrous oxides of Fe and Al (F4) and residual phases (F5), which reduced the mobility of arsenic in these soils. According to the analysis of scanning electron microscopy (SEM) and X-ray diffraction analysis, the immobilization of arsenic by MBC was strongly related to the successful loading of cerium-manganese oxide onto biochar. Therefore, MBC can be used to make suitable amendments to immobilize As in soils for remediation of arsenic-contaminated farmland soils.

Study on the long-term effects of DOM on the adsorption of BPS by biochar.

Bisphenol S (BPS), regarded as a valid alternative to Bisphenol A (BPA), has been found to induce acute toxicity, genotoxicity. In this paper, BPS pollution was repaired by corn straw biochar, and the effect of dissolved organic matter (DOM) on the remediation mechanism was investigated. Different DOMs were obtained by decomposing corn straw in red soil, yellow soil and brown soil. The DOMs were characterized by Elemental analysis, Fourier infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (Uv-vis) spectroscopy, Three-dimensional excitation-emission matrix (3D-EEM). Different kinds of DOMs were added into the biochar adsorption system to determine the optimal pH, optimal dosage, equilibrium adsorption capacity, adsorption kinetics, adsorption isotherms, thermodynamic characteristics, and explore the influence mechanism of DOM on the adsorption of BPS by biochar. The results of the adsorption experiments showed that DOM would suppress the BPS adsorption capacity on biochar. In addition, the DOM, produced by decomposition of corn straw with brown soil, had the strongest inhibitory effect on adsorption, and red soil was the soil with the lowest inhibitory effect on organic pollution removal by biochar.

Ecophysiological responses of Jatropha curcas L. seedlings to simulated acid rain under different soil types

Acid rain is a global environmental problem. Acid rain can affect plants directly by damaging the leaves and indirectly by soil acidifying. Many studies have been conducted to investigate the impacts of acid rain on plant under a single soil type. However, there is little information on the effect of acid rain on plant under different soil types. Jatropha curcas L. is an energy plant widely distributed in acid rain pollution area with various soil types. In this study, we investigated the effects of acid rain (pH2.5, pH3.5, pH4.5, pH5.6) on the growth, physiology, nutrient elements and bacterial community of J. curcas seedlings under different soil types [Red soils (RS), Yellow soils (YS), Yellow-brown soils (YBS), and Purplish soils (PS)]. Acid rain and soil types significantly influence the growth of J. curcas seedlings, and there was a significant interaction between acid rain and soil types. Acid rain (pH 4.5) was beneficial to the growth of J. curcas seedlings, whereas acid rain (pH 2.5 or 3.5) inhibited growth of J. curcas seedlings. The growth of J. curcas seedlings could resist the stress of acid rain by scavenging and detoxification of active oxygen species in leaves. Combined with the increase in relative growth rate of seedlings treated with simulated acid rain at pH 4.5, we inferred that K can stimulate the growth of seedlings. The lower soil pH, cation exchange capacity and base saturation had stronger inhibitory effects on growth of J. curcas seedlings. YBS and PS were beneficial for growth of J. curcas seedlings by higher buffering capacity under acid rain treatments. The phylum Proteobacteria was found to predominate in rhizosphere soils. YBS was favorable to support Proteobacteria growth and reproduction. The redundancy analysis showed that the Cyanobacteria were favorable to growth of J. curcas seedlings.