Red Earth Research Articles

The Application of Computed Tomography to Study the Soil Porosity of Mountain Red Earth

Mountain red soil, as a special type of soil in the South, has received widespread attention for its soil erosion problems. Its pore structure restricts water infiltration, thereby affecting the occurrence and development of soil erosion. In order to systematically obtain the distribution characteristics of the pore structure within the surface mountain red soil, this paper uses non-destructive CT detection technology to scan the soil column samples taken from the typical mountain red soil distribution area in Chenggong District, Kunming City, Yunnan Province. Image processing technology is applied to CT slices, and ImageJ (1.46r) software is used to obtain the distribution characteristics of pores within the soil column, including pore sizes and the number of pores at each depth, the proportion of pore area, roundness, and box-counting dimension. The results show that with the increase in depth, the proportion of pore area decreases linearly from the maximum value of 52.25% at the top to the minimum value of 2.02% at the bottom; the roundness of pores fluctuates between 0.8 and 0.9, overall increasing; the total number of pores generally first increases then decreases, and small pores are predominant, with the least number of large pores in the topsoil layer; the box-counting dimension shows a gradual linear decrease, with a maximum value of 1.7980 and a minimum value of 0.9878. The number of pores affects both roundness and the box-counting dimension, and the proportion of pore area also affects the box-counting dimension. There is a negative correlation between roundness and the box-counting dimension. The 3D visualization reconstruction of pores shows that most are interconnected, with the pore size significantly reducing with increasing depth. The quantitative analysis of parameters and 3D visualization reveal, to some extent, the impact of pore structure on the occurrence and development of soil erosion in mountain red soil. These research findings form the foundation for studying soil erosion in this region and provide a basis for systematically understanding its processes and mechanisms.

Prothioconazole Stress Reduces Bacterial Richness and Alters Enzyme Activity in Soybean Rhizosphere.

Prothioconazole (PTC) is currently a popular triazole fungicide. In recent years, as the use of PTC has increased, there has been growing concern about its environmental and toxicological effects. Here, we studied the effect of PTC on the growth of soybean plants and further analyzed the enzyme activity and microbial community of rhizosphere soil after PTC treatment through 16S rRNA gene high-throughput sequencing and fungal ITS. Changes in structural diversity and species richness were measured using Simpson's diversity index, Shannon's diversity index and the Chao1 and ACE algorithms. The statistical t-test was applied to test whether the index values were significantly different between the two groups. The results showed that the contents of malondialdehyde (MDA) and H2O2 increased after the recommended dose of PTC, indicating that PTC has a strong toxic effect on plant growth, thus affecting the healthy growth of plants. In the presence of PTC, the species richness of fungi and bacteria decreased in all three soil types (black soil, yellow earth and red earth), and the community structure also changed significantly (the p-values were all less than 0.05). Proteobacteria, Actinomycetota, Bacteroidota and Acidobacteriota were the main bacteria, and the abundance of Acidobacteriota and Chloroflexi increased. The dominant fungal communities were Ascomycota and Mortierellomycota. The increased abundance of potentially beneficial microorganisms, such as Sphingomonadaceae, suggested that plants may be resistant to PTC stress by recruiting beneficial microorganisms. PICRUSt analysis showed that the metabolism-related functions and membrane transport pathway of rhizosphere bacterial community were inhibited after PTC stress. Spearman correlation analysis revealed a weak correlation between key fungal taxa and rhizosphere variables in the presence of PTC. Therefore, compared with those in the fungal community, the bacterial community was more likely to help plants resist PTC stress, indicating that these key fungal groups may indirectly help soybean growth under PTC stress by affecting the bacterial community.

Employing SHlNO_Glaze technology using local materials and applying it to high-temperature clays

This research is concerned with studying (SHlNO_Glaze technology using local materials), which consists of five chapters: The first chapter included a presentation of the research problem to find out what variables the technique causes when added to the surface of pottery? While the importance of the research came to increase scientific knowledge, in addition to the scarcity of its use, which makes it surrounded by a kind of mystery about the extent of its color and texture transformations, while the research aims to reveal the technical effects resulting in ceramic glass. The limits of the research include the addition of red earth and potassium feldspar. Calcium feldspar and soda ash, in addition to colored oxides, are high-temperature clays (1250 degrees Celsius). While the second chapter contained the theoretical framework and previous studies, this chapter reviewed the clays and their uses, as well as the types of clays found in their locations. It reviewed the structure of the glass and its compatibility with the pottery body and the classification of the glass in terms of chemical composition and maturation temperatures. This chapter also reviewed the coloring oxides through which it was identified. The researcher studied the oxides of copper, cobalt, iron, and tin, which determine the color and texture. This chapter also reviewed the techniques of special effects in porcelain glass, the firing atmospheres, and the types of reduction. The third chapter included the selection of materials added to the glass mixture based on colored oxides, which are considered the most common coloring oxides for potters, which are copper oxide (CuO), cobalt oxide (CoO), tin oxide (zn), and iron oxide (feo). In the golden ratios to the glass mixture, while fixing the ratios of the glass mixture and limiting the variable only to the chino, as it was applied to kaolin clay, the number of glazed models reached (12) models. As for the fourth chapter, it included the research sample, and the number of samples reached (12) samples representing the majority of the research population. They were reviewed with percentages and temperatures and were discussed according to each sample and its variable. The fifth chapter included conclusions, including :Adding recommendations, suggestions, sources, appendices, and a summary in English.

Effect of natural ageing on germination and seedling growth of Palmyrah (Borassus flabellifer) seeds

Experiments were conducted to evaluate the seed longevity period of Palmyrah. The matured fruit branches were selected based on yellow tinge in the stylar region. After manually removing the fruit exocarp and mesocarp, the uniform size seeds were shade dried for fourteen days and stored in ambient condition. The seeds were sown in raised nursery beds containing nursery mixture of red earth, sand and farmyard manure in a ratio of 2:1:1. The experiment was conducted in a randomized block design with three replications of 50 seeds each, sown at monthly intervals up to 18 months. The germination percentage was recorded at 15 days interval till the completion of germination. One year after sowing, the results revealed that fresh seed recorded highest germination of 78.67% followed by one month of stored seed (63.33%), two months of stored seed (53.33%) and nil germination was observed beyond five months of stored seed.

Sorption and attenuation of petroleum VOCs in five unsaturated soils: Microcosms and column experiments

The fate of volatile organic compounds (VOC) vapors in the unsaturated zone is the basis for evaluating the natural attenuation potential and vapor intrusion risk. Microcosm and column experiments were conducted to study the effects chemical speciation and soil types/properties on the fate of petroleum VOCs in unsaturated zone. The biodegradation and total attenuation rates of the seven VOCs obtained by microcosm experiments in black soil and yellow earth were also generally higher than those in floodplain soil, lateritic red earth, and quartz sand. The VOC vapors in floodplain soil, lateritic red earth, and quartz sand showed slow total attenuation rates (<0.3 d−1). N-pentane, methylcyclopentane, and methylcyclohexane showed lower biodegradation rates than octane and three monoaromatic hydrocarbons. Volatilization into the atmosphere and biodegradation are two important natural attenuation paths for VOCs in unsaturated soil columns. The volatilization loss fractions of different volatile hydrocarbons in all five unsaturated soils were generally in the order: n-pentane (93.5%–97.8%) > methylcyclopentane (77.2%–85.5%) > methylcyclohexane (53.5%–69.2%) > benzene (17.1%–73.3%) > toluene (0–45.7%) > octane (1.9%–34.2%) > m-xylene (0–5.7%). The fractions by volatilization into the atmosphere of all seven hydrocarbons in quartz sand, lateritic red earth, and floodplain soil were close and higher compared to the yellow earth and black soil. Overall, this study illustrated the important roles chemical speciation and soil properties in determining the vapor-phase transport and natural attenuation of VOCs in the unsaturated zone.

Assessment of the Swelling Behavior of NaOH-Contaminated Red Earth in the Visakhapatnam Region of India Using X-ray Diffraction Analysis

Research on the impact of alkali contamination on the swelling behavior of red earth in the Visakhapatnam region has been notably limited. Therefore, this study aims to investigate the effects of alkali (NaOH) contamination on the swelling characteristics of the region’s red earth. The red earth of this region was found to be a well-graded sandy soil with 81% sand and 18% fines. X-ray diffraction studies showed that this region’s red earth mainly consists of quartz, kaolinite, and hematite. The soil is inherently non-swelling. However, the free swell tests showed considerable swell under contamination of NaOH solutions of various normalities (0.05, 0.1, 1, 2, and 4N). One-dimensional consolidation tests have shown that the swell increased with the concentration of the NaOH solution and with the duration of the interaction. Red earth exhibited 'an equilibrium swelling' of 5.6, 10, 15, 17, and 20% when contaminated with 0.05, 0.1, 1, 2, and 4N NaOH solutions, respectively. XRD studies revealed that the red earth sample contaminated with even 0.05N NaOH solution and cured for 56 days exhibited the formation of zeolites analcime and natrolite. Silicate minerals like paragonite and ussingite were also formed along with the zeolites. N-A-S-H compounds, hydrosodalites, and zeolites like super hydrated natrolite, zeolite SSZ16, and zeolite ZK-14 were formed at higher normalities of NaOH after a curing period of 56 days, which caused increased swell. The research demonstrated that the formation of zeolites resulting from the alkali contamination led to swelling in the red earth.

Sustainability Analysis of Landfill Cover System Constructed Using Recycled Waste Materials by Life Cycle Assessment

The sustainability of using industrial by-products for the construction of landfill cover was determined using Life Cycle Assessment (LCA). LCA was carried out on four materials: sand- bentonite mix, red earth- bentonite mix (amended soil), Waste Foundry Sand (WFS)- Bentonite mix, and WFS- marine clay mix. The former two are commonly used cover soils and the latter two are alternative materials proposed. Environmental impacts based on the extraction of resources, processing, transportation to the site, and site preparation were considered using the ‘cradle to site’ approach. Analysis was carried out in OpenLCA software using the ReCiPe (H) Midpoint method of impact assessment. Required data for analysis was taken from the Ecoinvent database supplemented with inputs from a field survey. The use of WFS in landfill cover systems was found to be sustainable using LCA studies when compared to conventional materials.

Revealing Juan de Oviedo y de la Bandera’s Artworks: The Case of the Polychrome of a Stone-Carved Sculpture from the Madre de Dios Convent Façade in Seville

The entrance of the Madre de Dios convent in Seville was carved in stone by Juan de Oviedo y de la Bandera, an important sculptor who made great artistic productions, highlighting his carvings in wood and stone. Several studies have been carried out on the carvings in wood, but no interest has been paid by experts to the carving pieces in stone. In this work, this polychrome made on stone around 1590 was studied for the first time. Micro-samples were taken and studied using micro-analytical techniques (optical microscopy, SEM-EDX, colourimetry, XRD, FTIR, and Raman spectroscopy). The pigments (smalt, atacamite, malachite, copper resinate, cinnabar, red earth, yellow ochre, carbon, and bone black) and the consolidation product (acrylic resin, very possibly Paraloid B72) were characterized. The experimental study indicated that the polychrome was applied on a layer of white lead (cerussite and hydrocerussite) that was laid on the substrate stone, constituted by calcarenite. This study also includes a comprehensive discussion on the use of these materials and techniques in other artworks within Seville’s cultural heritage.

Adsorption-desorption of Atrazine with 9 Agricultural Soils in China.

In this work, the characteristics and mechanisms for atrazine adsorption-desorption with 9 types of soils were investigated with batch equilibrium studies, elemental analyses, infrared spectroscopy, and UV‒visible spectroscopy. The atrazine sorption data for the 9 soils showed better fits with the Freundlich model than the Langmuir model, except with Red earth in Jiangxi (REJ) The results showed that the adsorption capacity was positively correlated with the organic matter (OM) content and negatively correlated with cation-exchange capacity (CEC) and pH. UV‒visible spectroscopy showed that dissolved organic matter (DOM) in the soil enhanced atrazine adsorption, but the adsorption on different DOM fractions was quite different. In addition, the infrared spectra revealed differences in the functional groups of soils and these functional groups may drive the adsorption process via hydrogen bonding and coordination with the -NH2 groups in atrazine.

Can corn straw and its pyrolytic biochar be used to mitigate the toxicity of CuO NPs to wheat seedlings?

In order to understand whether corn straw (CS) and straw-derived biochar (CB) can be used as soil amendments to alleviate soil contaminated with metal oxide nanoparticles, CS and CB prepared by pyrolysis at 300 °C (with a weight ratio of 2% and 5%) were added to two types of soil contaminated with copper oxide nanoparticles (CuO NPs) to study the effects of CS and CB application on soil properties, wheat seedling growth, and metal transport. Our results showed that both 2% and 5% additions of CS and CB enhanced the nitrogen, phosphorus, and potassium fertility of both soils. In red earth (acidic), the addition of 2% and 5% of CB significantly increased soil pH (9.24% ~ 18.4%), wheat growth (12.2% ~ 14.9%), chlorophyll content (significantly increased by 32.3% for 2% CB treatment), and decreased antioxidant enzyme activity and membrane lipid peroxidation. In fluvo-aquic soil (alkaline), CS and CB did not increase soil pH, only 5% of CB significantly promoted wheat growth (by 11.0%), and decreased antioxidant enzyme activity, whereas 2% of CB reduced chlorophyll content (by 22.2%). Furthermore, 2% and 5% of CS and CB affected the transport of Cu in wheat, decreasing the translocation factor in red earth but increasing it in fluvo-aquic soil. Principal component analysis showed that 5% of CB had the best alleviating effect on CuO NPs toxicity in red earth, compared to CS. Taken together, CB obtained by pyrolysis at 300 °C appears to be an effective soil amendment specifically for red earth.Highlights• Corn straw (CS) and straw-derived biochar (CB) were used to mitigate CuO NP toxicity• 5% of CB showed the best mitigation effect on CuO NP toxicity in red earth• CS and CB had no significant mitigation on CuO NP toxicity in fluvo-aquic soilGraphical

Reversible Multimode Luminescence Modulations in Photochromic-Translucent Yb3+/Eu3+ Codoped K0.5Na0.5NbO3 Ceramics.

Luminescent tunable materials have promising application potential in optical switches, optical information storage, and so on. Although europium (Eu) is a good downconversion red luminescent rare earth element, there are few studies on the upconversion luminescence and photochromism of Eu-doped potassium sodium niobate (KNN) ferroelectrics. In this paper, Eu3+ and Yb3+ codoped KNN translucent ferroelectric ceramics were synthesized and the effect of Yb3+ content on the luminescence and photochromism is studied. Both the up- and downconversion luminescence intensity and decay rate before and after photochromism can be well controlled by Yb3+ content. That is, an upconversion luminescent translucent ceramic that can be completely discolored by 405 nm light illumination for 10 s was obtained. The luminescence modulations are closely related to the evolution of oxygen vacancy and crystal field around the luminescence center, which can be verified by the illumination-induced electron paramagnetic resonance (EPR) signal and local piezoresponse switching behavior variation as well as the discovery of energy level splitting and spectral line shift. We believe that this work shows a paradigm for designing high-performance reversible multimode luminescence modulation ferroelectric ceramics.

Mitigation Measures of Swelling Characteristics in Alkali-Contaminated Red Earth using Fly Ash and GGBS Blends

Alkali contamination induces swelling in the inherently non-swelling soils, resulting in heave severely damaging the sub and superstructures. Stabilization measures must be taken in vulnerable areas to prevent such colossal losses. Considerable research has been conducted regarding the swelling behavior of soils contaminated with alkalis and the impact of subsequent stabilization techniques utilizing different industrial byproducts and pozzolanic materials. However, there is a paucity of such studies on the Red Earth (RE) of the Visakhapatnam region. Furthermore, limited attention was given to the effects of extremely low concentrations of alkalis on the swelling behavior of soils. RE in the study area of the Visakhapatnam region predominantly consists of quartz, kaolinite, and hematite. In phase 1 of the experimental analysis, RE was contaminated with a highly dilute NaOH solution (0.05 N), and the resulting swell characteristics were investigated. A free swell of 10% was observed. One-dimensional standard oedometer tests revealed an equilibrium swelling of 5.6%, indicating significant potential for substantial heave and subsequent damage. X-ray diffraction (XRD) analysis revealed the formation of natrolite and analcime zeolites with a hollow structure, which caused the swell. Peaks of silicate minerals like paragonite and ussingite were also observed, indicating the dissolution of authigenic minerals and new precipitations even at lower concentrations of NaOH. In phase 2, swell tests were conducted on a mixture of contaminated red earth (50% w/w), fly ash (25% w/w), and ground granulated blast furnace slag (GGBS, 25% w/w), and it was observed that the swelling was completely arrested. XRD analysis unveiled that even though siliceous zeolites were formed, the development of chrysotile, attapulgite, tobermorite, and dicalcium silicate effectively inhibited the swelling with their pozzolanic behavior.

Influence of Copper Chelation by EDTA on Growth, Survival and Development of Plumed Cockscomb (Celosia argentea) Cultivar (TVL 8) in Clay, Loamy, Sandy Garden Top and Red Earth Soils

Influence of Copper Chelation by EDTA on Growth, Survival and Development of Plumed Cockscomb (Celosia argentea) Cultivar (TVL 8) in Clay, Loamy, Sandy Garden Top and Red Earth Soils

In silico and in vitro Assessment of Indigenous Organic Practices on Germination and Seedling Metrics of Compact Cotton using GerminaR R Software Package

Background: Cotton crop is sensitive in its young stages i.e. stand establishment. Cotton seeds are fuzzy and messy in handling and field sowing. Delinting is a necessary process done commonly using acids and are comprehensively not protective. Optimal plant population, growth and persistence are strongly influenced by germination and establishment. In line with this, it is necessary and needful of an hour to find an alternative, eco-friendly, ecologically safe and low cost seed treatment method. Methods: The experiment was conducted in two methods viz., a petridish method and roll-towel method with seed treatment methods viz., cowdung and red earth mix treated with and without biofertilizer and compared with acid-delinted and fuzzy seeds. The germino-metrics were determined using GerminaR package, an interactive web application and statistical analysis was performed using R software package v. 4.2.1. Result: The summative effect of seed treatment with fresh cow dung, red earth and biofertilizer (Azospirillum and Phosphobacteria) per kg of seeds at respective quantities (0.5:0.25:0.12) recorded significantly maximal germination indices and seedling growth determinants. This present study would be a complementary to comprehensively promote the use of indigenously available natural materials as an alternative to acids in cotton seed delinting.

The Colourant Mapping Project: approaching the evidence of colourant production in the Aegean during the Hellenistic and Roman Period through Kea, Kos and Rhodes

Over the last decades, polychromy research has provided insight into the rich variety of materials that composed the ancient Mediterranean palette, including minerals, rocks, earths, metal oxides, lakes and pyrotechnological products. Even though polychromy is considered an important aspect of ancient Greek and Roman art, the organisation of colourant production and trade remains rather underexplored. This is possibly due to the inherent complexity of pigments and dyes as archaeological materials and the variability of possible sources. Recent methodological advances have demonstrated the potential to trace the provenance of raw materials and to identify colourant production loci. This paper introduces the Colourant Mapping Project (CMP), which we are currently developing as a novel bibliographic and dissemination tool for researching colourant production and trade. The Aegean islands of Kea, Kos and Rhodes are three case studies included in the CMP that provide varied evidence of colourant production through a combined methodology using literary sources, archaeological and geological information for evaluating potential colourant production sites. Kea is mentioned in ancient texts as an excellent source of red earth, controlled by Athenian exportation legislation. The geology of Kea supports this; however, no earth pigment production sites are currently known and archaeometric evidence connecting to local raw materials is lacking. Kos, on the other hand, lacks historical evidence for local colourant production while a recently well-described multicrafting workshop and abundant archaeological finds substantiate colourant production on this island. The geological evidence also supports a local provenance for some of the materials processed on Kos (earth pigments), yet raw materials such as copper (for Egyptian blue) still required importation from elsewhere. Lastly, Rhodes was praised for its lead white and murex purple production by ancient writers and archaeological evidence might verify both, although not as clearly as is the case of Koan colourant production. The geological information for Rhodes also hints at raw material importation as no local lead ore deposits are known. The aim of the CMP is therefore twofold: on the one hand to evaluate the contribution of varied pieces of evidence to colourant provenancing and production, and on the other to situate the evidence of local colourant production within the context of Mediterranean networks of economic and cultural exchange. An ever-increasing and openly accessible bibliographic reference tool such as the CMP enables the investigation of the provenance of raw materials and colourants and can contribute to the reconstruction of ancient exchange networks.

FATIGUE CHARACTERISATION OF MARTIAN CONCRETE: A REVIEW

Spacecraft have been dispatched to Mars as part of human missions aimed at exploring new frontiers, driven by the observed similarities between the red planet and Earth. This endeavour has facilitated the development of construction materials suitable for human settlements on Mars. To determine the optimal properties for constructing habitable infrastructure for humans on Mars, research efforts have led to the discovery of Martian concrete, composed of sulphur and Martian simulants that had been produced without water, which is in scarce supply on Mars. By utilising egolith available near the construction site, structures can be built efficiently and rapidly, supporting the establishment of sustainable human habitats on Mars. Several studies have been conducted to address the challenges associated with identifying the ideal proportions of Martian concrete. Given the extreme and harsh conditions on Mars, there is a growing interest in understanding how the properties of Martian concrete can mitigate and alleviate fatigue resulting from the planet’s daily conditions, such as temperature variations and dusty storms, which impose cyclic loading on structures. Therefore, it is crucial to investigate the fatigue characteristics of Martian concrete. By evaluating the fatigue properties of Martian concrete, considering the selected appropriate mix design ratios, this study aims to contribute to understanding the impact of Martian conditions on construction practices. Ultimately, the findings of this study can assist future researchers in comprehending the effects of the Martian environment on the planet’s construction process.

Coupling effects of soil and vegetation from an ecosystem service perspective

Soil provides diverse ecosystem services (ESs) to people, yet anthropogenic activities result in the degradation and loss of soil ESs. Therefore, there is an urgent need to take effective measures to protect and manage soils for sustainable development. However, the differences in ESs across soil types are not well understood, and the coupling effects of soil and vegetation on ESs at different altitudes remain unclear. In this study, the composition of soil and vegetation types under different altitude gradients were analyzed and the differences/similarities of ESs (in terms of water yield, carbon storage, and soil conservation) among different soil types were identified. Following this, the optimal soil and vegetation combinations under different altitude gradients were determined from an ES perspective. The results revealed that soil types and ESs differed markedly at each altitude gradient. ESs in the high-altitude zone were significantly higher than those in the low-altitude zone (p < 0.01). There was an obvious difference in the ES supply capacity of soil types, with brown earths and dark felty soils exhibiting higher ESs compared to purplish soils, paddy soils, red earths, and yellow earths. The felty soils and alpine steppe combination, brown coniferous forest soils and evergreen needleleaf forest combination, and brown earths and evergreen broadleaf forest combination provided the highest water yield, carbon storage, and soil conservation, respectively. Vegetation can promote or inhibitat soil ESs, depending on the vegetation and soil types. Based on the results, detailed soil and vegetation management measures were proposed for different altitudes. Dark-brown earths and dark felty soils were identified as priority soil types for protection. This study provides an important reference for soil management and landscape restoration.

Vapor-phase biodegradation and natural attenuation of petroleum VOCs in the unsaturated zone: A microcosm study

Traditional natural attenuation studies focus on aqueous process in the saturated zone while vapor-phase biodegradation and natural attenuation in the unsaturated zone received much less attention. This study used microcosm experiments to explore the vapor-phase biodegradation and natural attenuation of 23 petroleum VOCs in the unsaturated zone including 7 monoaromatic hydrocarbons, 6 n-alkanes, 4 cycloalkanes, 3 alkylcycloalkanes and 3 fuel ethers. We found that monoaromatic hydrocarbon vapors were easily attenuated with significantly high first-order attenuation rates (9.48 d−1-43.20 d−1) in live yellow earth, of which toluene and benzene had the highest rates (43.20 d−1 and 28.32 d−1, respectively). The 13 aliphatic hydrocarbons and 3 fuel ethers all have relatively low attenuation rates (<0.54 d−1) in live soil and negligible biodegradation contribution. We explored the effects of soil types (black soil, yellow earth, lateritic red earth and quartz sand), soil moisture (2, 5, 10, and 17 wt%) contents and temperatures (4, 15, 25, 35 and 45 °C) on the vapor attenuation. Results showed that increasing soil organic matter (SOM) content, silt content, porosity and soil microorganism numbers enhanced contaminant attenuation and remediation efficiency. Increasing moisture content reduced the apparent first-order biodegradation rates of monoaromatic hydrocarbon vapors. The vapor-phase biodegradation had optimal temperature (∼25 °C in yellow earth) and increasing or decreasing temperature slowed down biodegradation rate. Overall, this study enhanced our understanding of vapor-phase biodegradation and natural attenuation of petroleum VOCs in the unsaturated zone, which is critical for the long-term management and remediation of petroleum contaminated site.

Acidification characteristics and its influencing factors of red paddy soil derived from four parent materials in Southeast of China

There are many types of parent materials of red paddy soil, however the acidification characteristics of paddy soil derived from different parent materials remain unclear in the past 40 years at Jiangxi Province, and the degree of soil properties on acidification is also still unknown. Therefore, four red paddy soil derived from Quaternary red earth (Qre), plate shale (P), red sand stone (Rs), granite (G) in Jiangxi Province was selected. We investigated the acidification characteristics and quantified the effect of soil factors on the acidification of red paddy soils derived from different parent materials. Results showed that related to the second soil survey (1980s), the pH of red paddy soil derived from four parent materials decreased by an average 0.47 unit, base saturation (BS%) decreased 13.93%, exchangeable acid (EA) and exchangeable aluminum (EAl) increased by 0.43 and 0.20 cmol·kg−1, respectively. The ∆pH of red paddy soil derived from Rs (0.56) and G (0.54) were higher than that of Qre (0.34) and P (0.32). The ∆BS% of of red paddy soil derived from G (22.53%) > Rs (17.61%) > Qre (8.27%) > P (2.66%). The ∆EA (0.76) and ∆EAl (0.62) of Rs is highest. The results of redundancy analysis (RDA) shown that soil properties of red paddy soil derived from four parent material could explain 43.1% variation of soil acidification. CEC7, silt, sand, and SOM could explain 36.3%, 4.6%, 1.4% and 1.2% variation of acidification, respectively. The difference of soil mineralogy including oxide and clay minerals is also the reason for the different acidizing characteristics of paddy soil derived from four parent material. Therefore, compared with the 1980s, there is significant acidification of red paddy soil in 2018 in Jiangxi Province. The acidification of red paddy soil derived from red sand stone and granite is higher than that of plate shale and Quaternary red earth. And, parent material affect acidification by soil physicochemical and mineralogical properties.

A STUDY ON HOW NUTRIENTS AND SHADE AFFECT THE GROWTH OF ANTHURIUM CUT FLOWERS

The effect of shade, growth medium, and their interaction on anthurium cut flower output was investigated using a Factorial totally randomised block design with 3 replications. Three levels of shade (85%, 75%, and 65%) and four combinations of growing media (coco peat + coconut husk, coco peat + brick pieces, coconut husk + brick pieces, red earth + sand (control), and red earth + sand at a ratio of 1:1) were used as main factors in this experiment, with a total of twelve interaction treatments. The per se and interaction impacts of shade and growing medium on the development, physiology, flowering, yield, quality characteristics, and nutrient content of anthurium plants were substantially impacted by the treatments