Alluvial Soils Research Articles

Integrating Remote Sensing and GIS-Based Map Analysis in Determining Spread of Built-Ups and Land-Use Dynamics of Terrain of Onitsha Metropolis, Anambra State, Nigeria

Land scarcity in most cases hampers development and encourages the misuse of land. The suitability of land must be considered before appropriating or allocating land for any use. Land supports the livelihood of every being on the Earth and therefore determines survival, success, and sustainability (sustainable living). This study aimed at integrating remote sensing and GIS-based analysis to determine the rate at which built-up areas have spread across the terrain of Onitsha Metropolis, Anambra State, Nigeria, and the dynamics of other land uses. This research involved both primary and secondary data. The primary data included measurements, direct field observations, and key informant interviews to understand people’s perceptions of the land use in the area. The secondary data included satellite images of the area obtained from USGS and analyzed using ArcGIS 10.2 for variations in the terrain of the Onitsha Metropolis; to determine the land use and land cover change (LULCC) of the Onitsha Metropolis over 40 years, published and unpublished articles and books were also consulted. The geological analysis of the study showed that the area of the Ogwashi/Asaba formation is 318.57 km2; the areas of the Nanka sands and Bende-Ameke are 423.07 km2 and 259.42 km2, respectively. The Nanka sands and Bende-Ameke formations are best suited for engineering construction purposes, while the Ogwashi/Asaba formation is suitable for agriculture and should be designated as a buffer zone or park. However, due to the unavailability of land as a result of the growing population and the proximity of the area to the city center, the area is being encroached upon, and a large area (about 30.40%) has been converted to built-up areas as of 2022. Forecast analysis showed that if the trend continues, 158.28 km2 (49.68%) of the alluvium soils of the Ogwashi/Asaba formation will be covered with buildings by 2072. The geology and the terrain of the Onitsha Metropolis determine the soil characteristics and the land use suitability; mapping the geological formations and overlaying these with the land use and land cover change of the area revealed the extent of the encroachment on the Ogwashi/Asaba formation, which must be discouraged.

Characterization of Novel Species of Potassium-Dissolving Purple Nonsulfur Bacteria Isolated from In-Dyked Alluvial Upland Soil for Maize Cultivation

Potassium (K) is immobilized within the clay minerals, making it unavailable for plant use. Therefore, the current study aimed to (i) select isolates of purple nonsulfur bacteria that can dissolve K (K-PNSB) and (ii) evaluate the production of plant-growth-promoting substances by the K-PNSB isolates. The results revealed that from in-dyked alluvial soils in hybrid maize fields, 61 K-PNSB isolates were obtained under the pH 5.50 conditions. The total dissolved K content (Kdis) by the 61 K-PNSB isolates fluctuated from 56.2 to 98.6 mg L−1. Therein, three isolates, including M-Sl-09, M-So-11, and M-So-14 had Kdis of 48.1–48.8 mg L−1 under aerobic dark condition (ADC) and 47.6–49.7 mg L−1 under microaerobic light condition (MLC). Moreover, these three isolates can also fix nitrogen (19.1–21.5 mg L−1 and 2.64–7.24 mg L−1), solubilize Ca-P (44.3–46.8 mg L−1 and 0.737–6.965 mg L−1), produce indole-3-acetic acid (5.34–7.13 and 2.40–3.23 mg L−1), 5-aminolevulinic acid (1.85–2.39 and 1.53–2.47 mg L−1), siderophores (1.06–1.52 and 0.92–1.26 mg L−1), and exopolymeric substances (18.1–18.8 and 52.0–56.0%), respectively, under ADC and MLC. The bacteria were identified according to their 16S rDNA as Cereibacter sphaeroides M-Sl-09, Rhodopseudomonas thermotolerans M-So-11, and Rhodospeudomonas palustris M-So-14. These potential bacteria should be further investigated as a plant-growth-promoting biofertilizer.

Phosphorus Availability from Rock Phosphates and Adsorption-Desorption Phenomenon in Red and Alluvial Soil as Affected by Phosphorus Solubilizing Bacteria (PSB), FYM and Vermicompost Application

ABSTRACT Phosphorus (P) is typically fixed in red soils (as Fe-P and Al-P). P release from different sources i.e. Rock-phosphate (RP), Farm Yard Manure (FYM), and Vermicompost (VC) is mainly governed either by adsorption, desorption, fixation, or ligand exchange. The present study was undertaken using phosphorus solubilizers Burkholdaria cariabensis (PSB1) and B. cepacia (PSB2), inorganic sources Udaipur Rock-phosphate (RP1) and Purulia Rock-phosphate (PR2) and organic sources (FYM and VC) applied in red and alluvial soils. Results showed that pH statistically on par and available P content were significantly varied in both soil type under laboratory incubation experiment at 15, 30, 45, and 60 days intervals. P adsorption and desorption experiments were also carried out taking heavy suspension of two P-solubilizers. Results showed that higher soluble P was recorded in FYM amended soils (T8, T9, T10 and T11) over the VC treated soils (T12, T13, T14 and T15) in both soils. Data showed that the RP1 have higher (34.00%) total P concentration as compared to RP2 (10.87%). Meanwhile, it was observed that higher P adsorption observed in red soils as compared to alluvial soils and vice-versa in case of desorption maxima, similarly higher P adsorption in PSB1 as compared to PSB2. A quantitative and qualitative study on organic acid secretions by Burkholdaria cariabensis and Burkholdaria cepacia needs to be carried out in the future.

The Multifaceted Soils of Himachal Pradesh, India: Types and Characteristics

The soils of Himachal Pradesh face a multitude of pressing issues that threaten their health and agricultural productivity. The diverse geographical features, temperature regimes and biological zones of Himachal Pradesh have resulted into a vast range of soil types in the state. Alpine, forest, alluvial and sub-mountain soils are the four major soil categories into which the state's soils can be generally divided. Only a particular species and adapted plants can thrive in the extreme weather circumstances of alpine soils, which are located at higher elevations and possess soils having thin, stony and acidic in reaction. The mid-hill areas are dominated by forest soils which are distinguished by their high levels of organic matter and nutrients. These soils support luxuriant vegetation and make effective agricultural methods possible. Alluvial soils, which are mostly found in river valleys and are deposited by ravine systems are extremely rich and perfect in fertility and suitable for growing a range of crops including vegetables, rice and maize. Located in the foothills, sub-mountain soil exhibits a blend of traits from alluvial and forest soils, thus providing a range of uses for horticulture and agriculture. In addition to supporting a diverse array of plant and animal life, Himachal Pradesh's varied soil types are vital to the region's agricultural economy. One of the biggest problems is soil erosion, which is made worse by the steep terrain and abundant rainfall in the area. This results in the loss of topsoil and decreased fertility. Deforestation, overgrazing, and unsustainable farming methods all contribute to land degradation, which further reduces biodiversity and soil quality. Furthermore, crop development is impacted by soil acidity in high-altitude regions, which restricts nutrient availability. However, these issues need efficient conservation measures and soil management techniques. In order to maintain Himachal Pradesh's rich biodiversity and agricultural potential for future generations, sustainable agricultural development and environmental protection in this ecologically sensitive area depend on an understanding of the complex soil dynamics. Addressing these interconnected issues requires a comprehensive approach, emphasizing sustainable land management practices, community engagement, and restoration efforts to preserve the vital soil resources of this ecologically sensitive region.

Exploring Indonesian coastal communities’ responses to the 2019 Ambon earthquake and their preparedness for future disasters

Since the seventeenth century, megathrust earthquakes and tsunamis have occurred and have been recorded in Maluku Province, Indonesia. The Maluku community lives on land of most alluvial soil, areas where tsunamis have occurred, besides the active path of seismic and volcanoes, which has negatively impacted humans during disasters. Therefore, learning from past communities’ responses and experiences is vital to decrease the risk associated with potential future disasters. However, studies about the Indonesian coastal communities’ seismic responses and preparedness at the grassroots level, particularly in Maluku Province, have yet to be done. Thirty survivors of the Mw 6.5 Ambon earthquake in 2019 with over a thousand aftershocks, living in the three coastal villages on Ambon Island, were selected as respondents in the semi-structured interviews. The research results showed that the survivors had various responses to the earthquake and its aftershocks. Religious belief was a critical factor for their capability to encounter calamities, besides social support that has helped them survive. The 2019 earthquake has also enhanced their creativity, engagement, and participation. Some disaster preparedness gaps still exist, although their experiences have taught them to be more aware and prepared for future disasters. The gaps are the early warning system availability, public education and information, risk transfer capability, protection development, humanitarian aid protocols and procedures, and health recovery. With its crucial recommendations, this study strengthens disaster governance in archipelagic countries like Indonesia and adds to the literature on how coastal communities handle multiple seismic disasters.

Evaluation of nitrogen use efficiency and N-supplying capacity on pomelo (Citrus grandis L. Osbeck) grown on alluvial soil in the Cuu Long Delta

The study was conducted to determine the nitrogen use efficiency (NUE) and the ability to provide nitrogen from alluvial soil for growing pomelo (Citrus grandis L. Osbeck) in the Mekong Delta. The experiment was arranged in a randomized complete block design including two treatments (NPK treatment: 673 N - 385 P2O5 -192 K2O g/plant and PK treatment: 0 N - 385 P2O5 - 192 K2O g/plant) and three replicates (3 plants for each replicate). The results showed that fruit yield was highest (39.1 kg/plant, N recovery efficiency of 53.8%) in the full NPK fertilization treatment and lowest in the PK fertilization treatment (18.5 kg/plant). Calculation results of the ability to supply nitrogen to pomelo trees in Chau Thanh, Hau Giang showed that alluvial soil had the ability to provide 49.6% of N and the remaining 50.4% from additional fertilizer sources for maximizing fruit yield.

Estimation of the Hydraulic Parameters of a Stratified Alluvial Soil in the Region of El Haouareb—Central Tunisia. Experiments, Empirical, Analytical and Inverse Models

Modeling water flow and contaminant transport in the unsaturated zone is a difficult task that relies heavily on good hydrodynamic soil characterization. This article presents a complementarity between experimentation, direct modeling and inverse modeling in order to provide a better estimate of the hydrodynamic parameters of stratified alluvial soil in the El Haouareb region of the Kairouane plain in Tunisia. A field sampling campaign was carried out. The samples collected underwent particle size analysis, bulk density measurements and infiltration tests using a mini-Muntz. In parallel, simple evaporation tests were applied to separate strata. In addition, a 2 m soil column was reconstituted and fitted with sensors to monitor water content, tension, temperature and electrical conductivity. An internal drainage test was performed on this monolith. Three methods were applied using experimental data to estimate soil hydrodynamic parameters. In the first method, pedotransfer functions were used (Rosetta platform) based on granulometric results and bulk density. In the second, water tension and water content monitored during the simple evaporation test were used to plot the soil–water retention curve (SWRC) using SWRC-Fit. In the third method, inverse modeling was applied to the internal drainage test. A comparison of the results showed that the inverse method had the lowest RMSE. Uncertainty analysis has been implemented for both the experimental and numerical set up.

Comparison of Nitrous Oxide Consumption of Paddy Soils Developed from Three Parent Materials in Subtropical China

Paddy soils developed from various parent materials are widely distributed in the subtropical region in China and have a non-negligible but unclear potential to consume nitrous oxide (N2O) due to long-term flooding. This study selected three of the most common paddy soils in subtropical China, developing from quaternary red soil (R), lake sediment sand (S), and alluvial soil (C), to study their total N2O consumption and total nitrogen (N2) production using N2-free microcosm experiments. These paddy soils were treated with N2O addition (N2O treatment) or helium (He) addition (CK treatment) and incubated under flooding and anoxic conditions. The results showed that three alluvial soils (C1, C2, and C3) consumed over 99.93% of the N2O accumulated in the soil profile, significantly higher than R and S soils (p < 0.05). And the N2 production in three C soils was also significantly higher than other soils, accounting for 81.61% of the total N2O consumption. The main soil factors affecting N2O consumption in C, S, and R soils were soil clay content (p < 0.05), soil sand content (R2 = 0.95, p < 0.001), and soil available potassium (AK) (p < 0.01), respectively. These results indicate flooding paddy soils, no matter the parent materials developed, could consume extremely large amount of N2O produced in soil profiles.

Estimating Total Rice Biomass and Crop Yield at Field Scale Using PlanetScope Imagery Through Hybrid Machine Learning Models

AbstractNear real-time crop monitoring has been a challenging due to the lack of high-resolution remote sensing images suitable for agricultural applications. The PlanetScope constellation, comprising approximately 130 Dove satellites, collects images of the entire Earth daily, with a resolution of 3.7 m. The high-resolution images from the PlanetScope satellite, along with vegetation indices, geo-environmental data, and soil and crop parameters, were utilized and analysed using machine learning models to enhance the accuracy of predicting total biomass and rice crop yield at the field scale. The study area, covering nearly 214 sample rice plots, was located in the Tarekswar block of Hooghly, West Bengal, India. Alongside ten vegetation indices and three Principal Component Analysis (PCA) soil nutrient levels, approximately thirty-six factors were analyzed to predict rice total biomass and crop yield using ten machine learning (ML) models, namely Random forest (RF), Extreme Gradient Boosting (XGB), Support Vector Machine (SVM), Bagging Tree (Treebag), Generalized Additive Models (gamSpline), Elastic Net (enet), Ordinary regression with LASSO penalty (rqlasso), Tree Models from Genetic Algorithm (evtree), Bayesian Regularized Neutral Networks (brnn), cubist models, and there hybrid of ensembles. Boruta and multi-collinearity analysis were also conducted for the selected factors to explore their influence levels. The study area exhibited robust rice yields ranging from 5 to 10 t/ha, accompanied by healthy biomass growth. Four ML models ─cubist, random forest, enet, and the hybrid model—showed promising predictions with R2 > 0.88. Most models classified less than 20 ha of the study area as falling into the “very-low suitable class”, showing the region’s suitability for rice cultivation due to its highly fertile alluvial soil. Boruta sensitive analysis revealed that nearly 24 individual factors significantly influenced the final crop yield including, organic carbon (OC), phosphorus (P), electrical conductivity (EC), mechanization level, and the majority of the vegetation indices. A critical analysis carried out through the Map query tool showed that five vegetation indices estimated via PlanetScope displayed strong correlations (exceeding 89%) in identifying areas with high to very high rice yields. The study can serve as a guideline for near-real-time crop monitoring in the near future, using high-resolution PlanetScope images.

Physico-chemical characteristics and quality assessment of soil in parts of the Banganga Basin in northeastern Rajasthan, NW India.

Soil is a vital natural resource that has a bearing on any developmental activity. A database comprising primary physicochemical characteristics and soil suitability would assist the planners in devising an appropriate land use policy and any intervention strategy for soil quality improvement. The physicochemical characteristics of soils in parts of the Banganga Basin, located in the semi-arid terrain of NW India were evaluated mainly through surface samples and sub-surface ones wherever sections were exposed in stream banks. The soil in the studied terrain is a Quaternary age, pale brown to dark brown and occasionally red, alluvial soil. Sandy loam is the dominant soil type, while sandy soil and loamy sand types also occur. The soil maintains a depth-wise consistency in physicochemical characteristics. The average soil pH value is 8.55, indicating a slightly alkaline and healthy soil. The soil has a high available nitrogen content (0.53 to 2.24%), adequate available phosphorus (23.58 and 62.18mg/kg), and low potassium (22.5 and 200mg/kg) contents. The organic carbon, Mg, and Ca levels are generally on the lower side. A consistency in overall soil characteristics is evident in the narrow range of the Soil Quality Index, varying between 10 and 14, and soil can be categorized into three categories with overlapping soil qualities.

Potential of novel Rhizobium strains as biofertilizer for improved groundnut (Arachis hypogaea L.) cultivation in Eastern India

ABSTRACT Comprehensive assessments were conducted on eight fast growing, novel Rhizobium isolates, short listed from a preliminary selection of 68 isolates obtained from root nodules of groundnut plants grown in diverse agro-climatic regions of eastern India. Additionally, two conventional rhizobia strains, viz. IGR6 and GN2, (collected from the Nodule Research Center, BCKV), were utilized for comparative analysis. Cluster analysis, based on carbon utilization and biochemical parameters, grouped all the test isolates with an average similarity level of 73%. The ability of the isolates to utilize a wide range of carbon sources, including hexoses, pentoses, and disaccharides, confirms their fast-growing nature. Further analysis through 16S rDNA extraction and nucleotide sequencing revealed that the promising fresh isolates exhibited 95–99% similarity to known Rhizobium species in public databases. When evaluated in pot culture experiments using new alluvial soil from the Gangetic Plains in eastern India, the native fresh isolate NRA1(PP355674) outperformed other isolates and conventional strains in terms of nodulation efficiency, plant dry matter production, and plant nitrogen uptake. This study highlights the significant potential of native Rhizobium isolates to surpass conventionally used strains in biological nitrogen fixation, supporting the development of sustainable, environmentally-friendly, and cost-effective agricultural practices.

Temporal and Spatial Variations of Soil Organic Carbon and the Influencing Factors in Shaanxi Province in Recent 30 Years

Soil organic carbon （SOC） variation is a significant indicator for the soil quality dynamic and global carbon cycle. Therefore, it is necessary to study the regional temporal and spatial distribution of SOC pool and the influencing factors. In this study, a total of 540 soil data and environmental variables were collected from Shaanxi Province during a 30-year period from 1985 to 2015, and univariate analysis of variance and path analysis were used to explore the temporal and spatial distribution characteristics of SOC content and the influencing factors of SOC change. The results showed that the SOC contents of Shaanxi Province in both 1985 and 2015 were the highest in central Shaanxi, followed by those in southern Shaanxi, and they were significantly higher than those in northern Shaanxi. From 1985 to 2015, the increase in SOC in southern Shaanxi was the highest （21.28%）, and that in central Shaanxi was 15.33%. The content of SOC in northern Shaanxi was decreased by 10.23%, caused by significant decrements in the bottom horizons of 60-80 cm and 80-100 cm. Compared with that in 1985, the increases in SOC content in the 0-100 cm soil profile （with every 20 cm as a horizon） ranged from 3.21% to 29.39% in 2015. The increase in SOC content of skeletal soils was largest, followed by that of alluvial soils. Correlation analysis and path analysis showed that SOC content was positively correlated with altitude, average annual precipitation, normalized vegetation index, and total nitrogen content and was in significant negative correlation with curvature, bulk density, and pH. Total nitrogen content was the main controlling factor affecting SOC content. The results of the study can provide reference for future carbon management measures in the region.

Studies on Effect of Genotypes and Planting Time on Growth and Corm Characters of Gladiolus

Gladiolus is an important cut flower crop, grown commercially in many parts of the globe. This flower has gained popularity owing to its incomparable beauty, attractive colours, various sizes and shapes of florets, variable spike length and long vase life. Gladiolus produces beautiful spikes from December to March in the plains and from June to September in the hills of India.Gladiolus is very rich in its varietal wealth therefore, varietal evaluation in a particular growing condition becomes necessity of time to find out suitable variety for a particular region. Improvement of any crop is a continuous process and long process as well and, in this crop, tremendous scope is available to improve the existing cultivars, besides, other economical plants, the growth and development of gladiolus is governed by its genetic makeup and environmental factors of the growing region and various management practices. Among the various agro-techniques, the optimum planting time is of outmost importance. The Present investigation efforts aim to standard time of planting and suitability of varieties for local climate and edaphic conditions of the Nalanda (Bihar). A field investigation was conducted during winter season of 2018-19 at Research Farm of Nalanda College of Horticulture, Noorsarai, Nalanda, Bihar. Corms of gladiolus cultivars viz., Red Beauty, Candyman, White Prosperity and Intrepid were planted at different planting dates. The soils of experimental site are newly formed alluvial soils with pH 7.40. The experiment consisted of 16 treatment combinations with four (04) varieties and four planting dates (D1- 25th Sept., D2- 10th October and D3- 25th Oct. and D4-10th Nov.) were laid out in split-plot-design with three replications. Minimum days to sprouting of corm (16.33 days), number of leaves per plant (11.27), length of leaves (86.87cm.) were with D2V2. However, maximum plant height (146.07 cm.) was in D2V1. Minimum days to initiation of spike (80.47 days), days taken to open first floret (95.07 days) and maximum length of spike (126.07cm.) were observed in D2V1. On the other hand, maximum numbers of florets per spike (21.20), fresh weight of flower spike (170.25 gm.), floret diameter (11.17cm.) and vase life (14.80 days) were in D2V3. Highest values for no. of corms per plant (1.40) and no. of cormels per plant (111.53) were noticed in D2V3. Besides, corm diameter (7.53 cm) and average weight of corm per plant (123.08 gm.) were found maximum in D2V1.

Pokrywa glebowa miasta Lublina (wschodnia Polska)

Lublin is a voivodeship city located in the Lublin Upland (Eastern Poland). The study aimed to present the spatial differentiation of soils of the city of Lublin and some of their properties. The knowledge of soil cover is very important for spatial planning and for protection and proper use of soil resources of each city. The environmental-genetic map of Lublin’s soils included in this work was made on the basis of soil-agricultural map in the scale 1:25 000 of Lublin and the soil-habitat map of the Świdnik Forest District. The soil units distinguished on the map were classified according to the Systematics of Soils of Poland (2019) and the international soil classification (World Reference Base for Soil Resources, WRB). The spatial variability of Lublin’s soils is determined by the occurrence of different parent rocks, relief, water relations, vegetation cover and human activities. The main soil units occurring within the city of Lublin include: brown soils (WRB: Eutric/Dystric Cambisols), rusty soils (Brunic Arenosols), podzolic soils (Albic Podzols), clay-illuvial soils/lessive soils (WRB: Albic/Haplic Luvisols), black earths (WRB: Gleyic Phaeozems), chernozemic rendzinas (WRB: Rendzic Phaeozems) and brown rendzinas (WRB: Calcaric Cambisols), chernozemic/black alluvial soils (WRB: Fluvic Phaeozems) and ordinary alluvial soils (WRB: Dystric/Eutric Fluvisols), peat soils (WRB: Hemic/Sapric Histosols) and murshic soils (WRB: Murshic Histosols), and technogenic soils (WRB: Urbic/Spolic/Ekranic Technosols). The grain size composition of Lublin’s soils is quite diverse, with the most common being silts, loams and sands with varying proportions of skeletal parts. The reaction of the Lublin soils studied also varies. Very acidic and acidic reaction is present mainly in podzolic and rusty soils and typical acid brown soils. In contrast, proper brown soils are slightly acidic to neutral in the upper genetic horizons. Lessive soils also have an acid reaction in the upper genetic horizons. Fluvisols have a slightly acidic to alkaline reaction, and black earths have a neutral to alkaline reaction. The alkaline reaction is found in rendzinas and technogenic soils, in which significant amounts of calcium carbonate are present. Soil organic matter is mainly accumulated in organic soils (peat and muck soils), as well as in the surface organic horizons (O) of forest soils. In the mineral soils of Lublin, the highest content of organic carbon (C-org) was found in such soils as black earths, chernozemic rendzinas, chernozemic alluvial soils and in some technogenic soils. The usable quality of Lublin’s soils is high. There is a phenomenon of management of land with high bonitation classes for non-agricultural purposes, despite the high fees for excluding such land from agricultural production.

Indica rice “Takanari” exhibited superiority to Japanese rice “Koshihikari” on N-uptake and biomass production under no-weeding practice

ABSTRACT Rice yield and whole biomass production are strongly related to the rice cultivar’s nitrogen (N) uptake ability and various meteorological conditions and management practices. Under different conditions, such as elevated CO2 with limited N-supply, the Indica cultivar” Takanari (Tak)” showed a higher N-uptake ability than the Japonica cultivar ‘Koshihikari (Kos).’ However, it is still unclear how Tak and Kos respond to N-uptake and biomass production under limited N conditions with or without weeding. For this reason, we conducted a pot experiment at Tsuruoka, Yamagata, Japan, in the 2022 rice growing season. Tak and Kos were transplanted individually and interplanted (Tak+Kos) in pots filled with 8.0 kg of air-dried alluvial soil from an organic rice farm with the main treatments of weeding and no weeding. Rice growth parameters (shoot height, tiller numbers, and leaf color) were investigated weekly, while rice biomass and N-uptake were measured after harvest. As a result, plant biomass and N-uptake were significantly different among all treatments. The rice biomass and N-uptake in weeding were significantly higher than those in no-weeding for both cultivars. Compared with Kos, Tak had significantly higher rice biomass and N-uptake for root, ear, and whole rice plants in all treatments, weeding practices, and planting modes. The ratios of aboveground biomass and N-uptake between Tak and Kos in interplanting were higher than their respective ratios in individual planting. Interplanting increased the aboveground biomass ratios between Tak and Kos by 16.24% and 27.43% in weeding and no-weeding conditions, respectively. The ratios of N-uptake in interplanting were higher than individual planting at 21.74% and 34.09% in weeding and no-weeding, respectively. Tak’s ability to compete with Kos on N-uptake and biomass production was increased when two rice cultivars were transplanted in the same pot under interplanting cultivation and no-weeding conditions.

Phosphorus distributions in alluvial soils of the Lower Mississippi River Basin: A case of dual legacies.

Legacies can become intertwined, none more so than the body of work of Dr. Andrew Sharpley examining agricultural nutrient delivery to waterbodies and the phosphorus (P) accumulation in agricultural soils, or "legacy P." Although Sharpley's work focused on the anthropogenic influence on soil P, our study suggests soils of the Lower Mississippi Alluvial Plain (MAP) represent a natural legacy with moderate levels of available P resulting from minimal anthropogenic input. In 2019, we collected surface (0-5cm) soil samples from four regionally dominant soil series in either cropland or forested land uses, spanning 76 locations within the MAP. Soil chemical and physical properties were measured utilizing a suite of extractions and texture analysis to correlate properties with soil P values. Total soil P did not vary between land uses. Mehlich-3 extractable P was slightly higher in cropland soils due to higher concentrations in Forestdale and Sharkey soils. Dundee, Forestdale, and Sharkey cropland soils showed significant associations between Mehlich-3-extractable iron (Fe) and P. Ratios of total carbon (TC) to total nitrogen (C:N) and TC to P (C:P) were consistent across all sampled soil series but differed between forest and cropland soils. These ratios are critical for establishing baseline soil nutrient values in simulation models and can be used to improve water quality model simulations that help guide P management in the MAP. As Sharpley routinely demonstrated, understanding sources of P is critical for developing an appropriate management strategy. This study provides critical knowledge on soil P dynamics in the MAP region.

Enhanced retention of hydrophobic pesticides in subsurface soils using organic amendments

The rapid global population growth since the early 2000s has significantly increased the demand for agricultural products, leading to widespread pesticide use, particularly organophosphorus pesticides (OPPs). This extensive application poses severe environmental risks by contaminating air, soil, and water resources. To protect groundwater quality, it is crucial to understand the transport and fate of these pesticides in soil and sediment. This study investigates the effects of hydrochars and biochars derived from sugar beet shreds (SBS) and Miscanthus×giganteus (MIS) on the retardation and biodegradation of OPPs in alluvial Danube sandy soil. The research is novel in its approach, isolating native OPP-degrading bacteria from natural alluvial sandy soil, inoculating them onto chars, and reapplying these bioaugmented chars to the same soil to enhance biodegradation and reduce pesticide leaching. The amendment of chars with immobilized Bacillus megaterium BD5 significantly increased bacterial abundance and activity. Metabarcoding of the 16S rRNA gene revealed a dominance of Proteobacteria (48.0–84.8 %) and Firmicutes (8.3–35.6 %). Transport modeling showed retardation coefficients (Rd) for OPPs ranging from 10 to 350, with biodegradation rates varying between 0.05 % and 75 %, indicating a positive correlation between retardation and biodegradation. The detection of biodegradation byproducts, including derivatives of phosphin, pyridine, and pyrazole, in the column leachate confirmed that biodegradation had occurred. Additionally, principal component analysis (PCA) revealed positive correlations among retardation, biodegradation, specific surface area (SSA), aldehyde/ketone groups, and bacterial count. These findings demonstrate the potential of biochar and hydrochar amendments to enhance OPP immobilization in contaminated soils, thereby reducing their leaching into groundwater. This study offers a comprehensive approach to the remediation of pesticide-contaminated soils, advancing both our fundamental understanding and the practical applications of environmental remediation techniques.

Soil Fertility Status of Paddy (Oryza Sativa L.) Growing Soils of Different Agro-climatic Zones, Telangana, India

The main occupation of Telangana State, India, is agriculture. Achieving food security requires intelligent management to increase land use productivity and production per unit area because of the expanding population and decreasing amount of agricultural land per capita. In this sense, assessing the productivity and fertility of the soil is a necessary step toward sustainable agricultural development. In the current study, paddy grown different soils in the districts of Telangana State were assessed for soil fertility using random sampling approach. This study was conducted to analyze the fertility characteristics of paddy cultivated soils in different districts of Telangana State. Collected 275 soil samples at 0-15cm depth under paddy crop grown during 2018-19 and 2019-20. The samples were found to be slightly acidic to alkaline in nature and low amount of soil organic matter. Soil nutrients such as available nitrogen (N), phosphorous (P) and potassium (K) ranged from 50-401 kg ha-1, 17-147 kg ha-1 and 60-842 kg ha-1 in red soil, 63-314 kg ha-1, 33-126 kg ha-1 and 95-460 kg ha-1 in black soil and 73-312 kg ha-1, 25-158 kg ha-1 and 153-458 kg ha-1 in alluvial soil, respectively. The paddy cultivated soil survey results conclusively indicate that the soil samples reveals normal soil reaction, electrical conductivity and low organic carbon (0.48% average) and widespread low nitrogen levels (91% of samples). Conversely, phosphorus availability is high (82% of samples) with an average content of 82 kg P2O5 ha-1, and potassium levels are notably elevated (57%).

Soil Genesis of Alluvial Parent Material in the Qinghai Lake Basin (NE Qinghai–Tibet Plateau) Revealed Using Optically Stimulated Luminescence Dating

Alluvial parent material soil is an important soil type found on the Qinghai–Tibet Plateau (QTP) in China. However, due to the limited age data for alluvial soils, the relationship between alluvial geomorphological processes and soil pedogenic processes remains unclear. In this study, three representative alluvial parent material profiles on the Buha River alluvial plain in the Qinghai Lake Basin, northeast QTP, were analyzed using the optical luminescence (OSL) dating method. Combined with physical and chemical analyses of the soil, we further analyzed the pedogenic process of alluvial soil. The alluvial parent material of the Buha alluvial plain predominately yielded ages between 11.9 and 9.1 ka, indicating that the alluvial soil began to form during the early Holocene. The development of the alluvial soil on the first-order terrace presents characteristics of entisol with multiple burial episodes, mainly between 8.5 and 4.0 ka, responding to the warm and humid middle Holocene and high lake levels.

Exploring of Bacterial Pigments from Thamirabarani River Alluvial Soil: Harnessing their Versatility in Dye and Paint Manufacturing

Color is a fundamental aspect of human life, playing a vital role in culture and industry. The paints and coatings industry, a significant sector within global manufacturing, has seen increased scrutiny due to its environmental and health impacts. Conventional paints contain harmful chemicals like volatile organic compounds (VOCs) and solvents, which pose risks to both workers and the environment. Recent shifts towards natural and bio-based pigments, particularly those derived from microorganisms, offer a promising alternative. Microbial pigments, such as those produced by chromogenic bacteria, provide eco-friendly, non-toxic colorants with additional benefits like antioxidant and antimicrobial properties. This review highlights the potential of bacterial pigments in various applications, particularly in the textile industry as natural dyes, and discusses their role in reducing the environmental footprint of synthetic pigments. The study also emphasizes the importance of further research into improving the production and stability of these bio- pigments for broader commercial use in industries such as food, cosmetics, and pharmaceuticals.