Cm In Depth Research Articles

Phytoremediation efficacy of native vegetation for nutrients and heavy metals on soils amended with poultry litter and fertilizer

Poultry litter on agricultural lands could introduce nitrogen (N), phosphorus (P), heavy metals in soil and ground water. Native vegetations were identified to assess efficacy for phytoremediation of nutrients and metals from soil and water. Objective was to measure capability of multi-year native species to remove metals, nutrients, and prevent Nitrate-N leaching below the rooting zone. Treatments were distributed in four replicates with/without fertilization. Suction lysimeters were installed at 30, 60, and 90-cm depths in 3 of 4 replicates. Species were identified, recorded, five specified cuttings sampled. Plant, soil, water samples were prepared and analyzed by spectroscopy. Nitrate-N extraction, nitrates in water samples were determined using flow injection analysis. Fertilized plots (NVM) had 39% more biomass yield than unfertilized plots (NVN). In plants, nutrient and metal concentrations varied significantly with 14% increase in Zn, 36% and 26% in K and Mg over NVN for first and second year. Uneven between NVM and NVN, topsoil had higher values for most nutrients and metals. Largest P and (NO3−)−N in plant and water were observed from NVM. Cultivation of native vegetation appears to be an effective approach for remediation of excess nitrates-N, P, heavy metals from surface and sub-surface zones of the soil.

Considering spatio-temporal dynamics of soil water with evapotranspiration partitioning helps to clarify water utilization characteristics of summer maize under deficit irrigation

Continuously increasing the utilization efficiency of agricultural water resources is vital to ensuring future water and food security. Deficit irrigation (DI) could provide a solution to optimize crop water productivity. Research on the spatio-temporal dynamics of soil water coupled with evapotranspiration partitioning is important for clarifying summer maize (Zea mays L.) water utilization characteristics and crop water productivity under different DI strategies, especially in semi-arid regions. Consequently, a three-year field experiment with full irrigation (CK) and eight DI treatments (T1–T8, comprised of combinations of 100 %, 80 %, and 60 % of crop evapotranspiration) was conducted. Data from large-scale weighing lysimeters, micro-lysimeters, and TDR sensors were combined to assess daily root water absorption at different soil depths, actual evapotranspiration (ETa) partitioning into plant transpiration (T) and soil water evaporation (E), and water use efficiency (WUE). Results showed that soil water consumption mainly occurred in the 0–40 cm, 0–60 cm, and 0–80 cm soil layers during the maize growth stages of planting–V6, V6–V12, and V12–R6, respectively. Water absorption above the 60-cm soil depth accounted for more than 92 % of the total water consumption. The appropriate irrigation wetting depth for summer maize could be controlled in the top 80-cm layer to avoid deep percolation. DI affected soil water distribution and availability, and thus decreased soil water consumption rate (WCR) and root water absorption amount. Under moderate water deficit conditions, WCR was rapidly restored to the non-water-stressed irrigation treatment level, and even exceeded that level in the deeper layers after a subsequent irrigation was applied, especially in the early maize growth stages. E/ETa was 31.0–32.5 % under full irrigation. DI decreased total soil water evaporation amount, but increased the E/ETa ratio. The threshold soil water value for defining when maize was subjected to water stress was 22.0 % (72 % of FC) during V3–V12, and 18.0 % (60 % of FC) during V12–R1. Our results suggest that less water was used in T1 (moderate DI) than with the full irrigation treatment. WUE increased by 5.5 %–7.5 % as irrigation amount decreased by 12.3–14.5 % and yield decreased by 3.3 %–8.0 %. These results improve our understanding of maize water consumption characteristics with regard to soil water absorption in different soil layers and evapotranspiration partitioning, and provide implications for efficient water management in arid areas of northwest China.

Evaluating soil moisture content under maize coverage using UAV multimodal data by machine learning algorithms

Timely and accurate estimation of soil moisture content (SMC) is essential for precise irrigation management at the farm scale. Unmanned aerial vehicle (UAV) remote sensing with a high spatiotemporal resolution has become a promising method for SMC monitoring. Many existing SMC models have only been tested at a specific crop growth stage using a single type of sensor, and the effects of growth stage and irrigation variation on SMC estimation accuracy remain unclear. To address these limitations, this study used UAV-based multimodal data to quantify SMC in a maize field under various levels of irrigation over two years using three machine learning algorithms (MLA): partial least squares regression (PLSR), K nearest neighbor (KNN), and random forest regression (RFR). The results demonstrated that multimodal data fusion improves the SMC estimation accuracy regardless of the MLA, especially the joint use of thermal and multispectral data. Among three SMC regression models, the RFR model produced the most accurate SMC estimation for the two growing seasons regardless of sensor combinations. The RFR model using all three types of data generated the most accurate and robust SMC estimation at the vegetative stage with R2 of 0.68 and 0.78, and rRMSE of 20.82% and 19.36% for 10- and 20-cm soil depths, respectively; it also produced the best SMC estimation accuracy under well-watered and mild to modest deficit irrigation treatments for both soil depths. The study shows that the high spatial–temporal maps of SMC using UAV-based multimodal data has promising potential for supporting decision-making in irrigation scheduling at the farmland scale.

REGRESSION MODEL OF TOPOGRAPHY WITH THE DISTRIBUTION OF SELECTED SOIL PROPERTIES IN NORTHEAST AKWA IBOM STATE, NIGERIA

Regression model of topography with the distribution of selected soil properties in Northeast Akwa Ibom State, Nigeria was carried out. The aim was to establish a regression model of topography with the distribution of selected soil properties in Northeast Akwa Ibom State for soil properties predictions and management. Topographic map (or elevation map) of the study area was generated from digital elevation model (DEM) at 30m resolution acquired from United State Geological Survey (USGS). It was classified into three elevation classes of lower elevation (0-50 masl), middle elevation (50-100 masl) and higher elevation (100-150 masl) to guide field sampling. With the aid of Global Positioning System (GPS), the classes obtained from topographic map were cross-checked (ground-truthing) in the field. Modified Conditioned Latin Hypercube Sampling Method was used in selecting observation points. Each observation point was purposively selected to fall within the classes of topographic map to give a good coverage of both feature space (classes of topographic map) and geographical space (study area). A total of 120 soil samples were collected at a depth of 0-30cm and 30-60 cm using soil auger. The samples were taken to the laboratory for analysis. The results revealed variation in soil properties among the three topographic classes under study. Sand fraction was significantly higher (p > 0.05) in lower elevation than other elevation classes while silt and clay fractions were significantly higher (p > 0.05) in the middle and higher elevations than lower elevation in the study area. Soil pH was significantly higher (p > 0.05) (slightly acid) in the lower elevation than middle and higher elevations (moderately acid). Electrical conductivity and base saturation were significantly higher (p > 0.05) in the lower elevation than middle and higher elevations. Organic carbon, total N, ECEC, exchangeable Mg and exchangeable K were significantly higher (p > 0.05) in the middle elevation than that of lower and higher elevations. Available P of higher elevation was significantly higher (p > 0.05) than that of lower and middle elevations. The study also showed that topography accounted for 3 % variation of sand and silt fractions; 5 % variation of clay fraction and 4 % variation of soil pH. Topography also explained 19 % variation of available P, 8.4 % variation of exchangeable K and 5.5 % variation of organic carbon and total N in the study area. The remaining fractions of variation may be attributed to other factors of soil formation such as parent material, climate, organism and time.

3-D Freehand Ultrasound Calibration Using a Tissue-Mimicking Phantom With Parallel Wires.

This article describes a method used to calibrate 3-D freehand ultrasound systems based on phantoms with parallel wires forming two perpendicular planes, such as the usual general-purpose commercial phantoms. In our algorithm, the phantom pose is co-optimized with the calibration to avoid the need to precisely track the phantom. We provide a geometrical analysis to explain the proposed acquisition protocol. Finally, we give an estimate of the system accuracy and precision based on measurements acquired on an independent test phantom. We obtained error norms of 1.6 mm up to 6 cm of depth and 3.5 mm between 6 and 14 cm of depth, in total average. In conclusion, it is possible to calibrate ultrasound tracked-probe systems with a reasonable accuracy based on a general-purpose phantom. Contrarily to most calibration methods that imply the construction of the phantom, the present algorithm is based on a standard phantom geometry that is commercially available.

Sobrevivência e distribuição do banco de sementes de arroz daninho após 22 anos de cultivo de arroz em diferentes sistemas

ABSTRACT: Weedy rice (Oryza sativa L.) is the most problematic weed in rice fields due to the few control management alternatives to control it, because of the genetic similarity with the crop. Different cropping systems (regarding soil preparation before sowing) have been used as options to control the persistence and emergence of the weed seedbank. Therefore, the objective of this study was to evaluate the longevity and vertical distribution of weedy rice seeds in the soil seedbank after 22 years of different rice cropping systems. Data was analyzed as a two-way factorial, with cropping systems carried out for 22 years [no-tillage (NT), conventional tillage (CT), wet direct-seeded (WDS)] as one factor and sampling depth (0-2, 2-5, 5-10 and 10-20 cm) as the other factor. The number of whole and deteriorated seeds per m-2 were assessed, as well as the viability (%). No effect between the systems were detected up to 5 cm, however at 5-10 cm CT and WDS showed higher amount of seeds, and WDS at 10-20 cm. As the sampling depth increased, NT showed fewer amount of seeds, while less reduction of the soil seedbank was observed in WDS. CT and WDS spread viable seeds in the soil profile from 0 to 20 cm depth. After 22 years there are viable weedy rice seeds up to 10 cm of depth in the three cropping systems and there is no difference among them up to 5 cm of depth, demonstrating the serious problem of the seedbank for this species.

Composição e estrutura da comunidade de diatomáceas bentônicas de marismas do sul do Brasil e sua relação com variáveis ambientais

Abstract: Aim This study focused on the spatiotemporal variation of the benthic diatom community structure in salt marshes from the Patos Lagoon estuary and their relationship with environmental variables. Methods Samplings were carried out in the winter of 2010 and summer of 2011 (during El Niño and La Niña) in sites with different sediment granulometry, salinity, and distances from the Atlantic Ocean. The surface sediment was collected using a core (10 cm in diameter and 2 cm in depth) and the benthic diatoms were removed following the Trapping method, allowing the observation of live diatoms. Results The richness values (18 and 48 taxa), evenness (0.41 and 0.68), and Shannon diversity indices (2.02 and 3.31 bits/ind.) variations were not significative between the sites and seasons, although temperature and salinity differed significatively between winter and summer. However, the diatom's composition and distribution were related to temperature, salinity, and sediment particle size. Mainly the species Hippodonta hungarica, Luticola simplex Navicula cf. cryptotenelloides, N. erifuga, N. jacobii, Nitzschia filiformis var. conferta, Planothidium frequentissimum and Tryblionella calida were associated with lower temperature and lower salinity in the winter. The species Navicula cf. cryptocephala, N. phylleptosomaformis, Nitzschia pusilla, N. frustulum, N. scalpelliformis and Pseudostaurosiropsis geocollegarum were associated with higher temperature and higher salinity in the summer. Birraphid diatom taxa, mainly species of the genus Navicula and Nitzschia, were frequent or abundant in sandy sediments, and monoraphids, such as Planothidium frequentissimum, were frequent in sites where silt and clay predominated. Conclusions The composition of the benthic diatoms revealed variation between the sites in the winter and summer seasons, during El Niño and La Niña episodes. In winter, high rainfall and freshwater runoff maintained oligohaline condition in the marshes, while in summer, flooding with meso-poly-euhaline waters changed the diatom composition. The granulometry was an important factor in explaining the distribution of the birraphid and monorhapid taxa.

Soil-vegetation relationship in savanic formations of the Jalapão, Brazil.

Understanding the influence of fine-scale abiotic filters on plant communities can provide important insights into floristic patterns of the Brazilian Cerrado. We aimed to evaluate the interactions of the soil and the plant community composition with their distribution in different sandy environments of Brazilian Cerrado, the Jalapão region. Eight environments were sampled, each with ten plots of 20 × 50 m. All woody individuals presenting circumference at soil height ≥ 10 cm were sampled. Subplots of 5 × 15 m were demarcated, where woody individuals with a circumference at soil height ≥ 5 and < 10 cm were sampled. Subplots of 2 × 2 m were also demarcated to sample herbaceous individuals. Soil samples varying from 0 to 20 cm of depth were collected for each plot (20 × 50 m). Overall, 20000 individuals that belong to 338 species and 76 families were sampled. The dominant family was Fabaceae. There were significant differences among the environments regarding species richness and soil. The analyzed soils are extremely poor and with a tendency to sandy texture, small chemical and/or physical variations imply differences in the distribution of vegetation. Our study revealed abiotic filters exerted crucial fine-scale effects on plant community in the Jalapão region.

Treatment of a Chronical Infected Wound in a Cat with Sterile Lucilia Sericata Larvae

The larvae of the green bottle fly Lucilia Sericata have been successfully used throughout history as a debridement method for chronic and infected wounds. In 1929, Alexander Fleming's discovery of penicillin dramatically reduced the use of surgical larvae, but soon after the emergence of antibiotic resistance, sterile larvae re-emerged as an alternative in treatment. For a long time, sterile larvae applications were neglected in veterinary medicine. However, recently, both in the world and in Turkey, MDT is seen as an effective treatment method for chronic wounds of animals. The case of this case report is a 1-yearold male stray cat brought to a private clinic by a benefactor with a chronic infectious wound of 2.5x 2.5 cm and 0.5 cm in depth extending from the distal right hind leg cruris to the region of the ossa tarsi bones. It was decided to apply MDT to the wound using sterile 2nd instar Lucilia Sericata larvae. Sterile 2nd instar larvae were placed in the wound area daily and after 24 hours the larvae were removed, the area was cleaned and then new larvae were placed. Larval treatment was applied 7 times and until the last larva application, the large and infected wound gradually shrank and 100% healing was achieved. In this study, it was reported that Lucilia Sericata larvae showed high recovery in the treatment of chronic wounds of animals and the importance of evaluating them among treatment alternatives was emphasized.

尖峰岭热带天然林不同土层细菌群落多样性和组成的海拔变异规律

PDF HTML阅读 XML下载 导出引用 引用提醒 尖峰岭热带天然林不同土层细菌群落多样性和组成的海拔变异规律 DOI: 10.5846/stxb202203090570 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（32171643，U1703332） The altitudinal patterns of bacterial community diversity and composition at different soil depths in Jianfengling mountain tropical forest Author: Affiliation: Fund Project: The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤微生物群落结构沿海拔梯度的变异是微生物生物地理学分异和群落空间分布的重要内容，然而，热带森林土壤微生物多样性及其群落特征的海拔模式尚不明确。研究海南省尖峰岭自然保护区0-20cm和20-40cm土壤细菌多样性和群落组成沿海拔梯度（400-1410m）的变化及其与环境因子的关系。结果表明：在0-20cm土壤微生物生物量碳、生物量氮和生物量磷随海拔升高（峰顶降低）而增加，20-40cm土壤微生物生物量碳、生物量氮和生物量磷随海拔升高呈先升高后降低趋势；整体上，变形菌门、放线菌门、酸杆菌门、拟杆菌门、厚壁菌门在0-20cm中占优势，丰度总和占该层细菌总量的88.17%；变形菌门、放线菌门、酸杆菌门、厚壁菌门、绿弯菌门在20-40cm中占优势，丰度总和占该层细菌总量的90.82%；随海拔增加，0-20cm细菌多样性线性减少，20-40cm细菌多样性变化不显著；沿海拔梯度，0-20cm细菌群落组成可分为低（409-1018m），中（1018-1357m）和高（1410m）三个海拔聚集群落，20-40cm细菌群落组成随海拔无显著性变化；两土层细菌多样性与土壤pH显著正相关，土壤细菌群落组成在0-20cm主要受年均温度和pH影响，20-40cm受年均温度和土壤有机碳影响；根据Bray-Curtis指数，0-20cm和20-40cm土壤细菌相似性随地理距离的增加逐渐降低，细菌群落相似性随环境距离的增大也逐渐降低。总之，尖峰岭土壤细菌多样性和群落组成的海拔格局受土壤深度影响，且驱动细菌群落组成变化的因素在土层间不同，暗示在未来气候变化背景下，热带森林0-20cm和20-40cm土壤微生物群落可能具有不同的响应机制。 Abstract:The variation of soil microbial community structure along the altitudinal gradient is an important content of microbial biogeographic differentiation and community spatial distribution. However, the altitudinal pattern of soil microbial diversity and its community characteristics in tropical forests is not clear. This paper studied the changes of bacterial diversity and community composition and their relationship with environmental factors in 0-20cm and 20-40cm soil depths along the altitudinal gradient (400-1410 m) in Jianfengling Nature Reserve, Hainan Province. The results showed that the soil microbial biomass carbon, biomass nitrogen and biomass phosphorus increased with the elevation of 0-20cm (the peak decreased), and the soil microbial biomass carbon, biomass nitrogen and biomass phosphorus increased first and then decreased with the elevation of 20-40cm. On the whole, Proteobacteria, Actinomycetes, Acidobacteria, Bacteroidetes and Firmicutes are dominant in 0-20cm, and the total abundance accounts for 88.17% of the total bacteria in this layer; Proteobacteria, Actinomycetes, Acidobacteria, Firmicutes and Chloroflexi are dominant in 20-40cm, and the total abundance accounts for 90.82% of the total bacteria in this layer. With the increase of altitude, the bacterial diversity decreased linearly in 0-20cm, and that of 20-40cm did not change significantly. The bacterial community composition of 0-20cm can be divided into three communities at low altitude (409-1018 m), medium altitude (1018-1357 m), and high altitude (1410 m) and the bacterial community composition of 20-40cm has no significant change with altitude. There was a significantly positive correlation between bacterial diversity and soil pH in the two soil depths. The composition of soil bacterial community was mainly affected by mean annual temperature and pH at 0-20cm, and by mean annual temperature and soil organic carbon at 20-40cm. According to the Bray Curtis index, the similarity of bacteria in 0-20cm and 20-40cm soil depths decreased with the increase of geographical distance, and the similarity of bacterial community also decreased with the increase of environmental distance. In a word, the altitudinal pattern of soil bacterial diversity and community composition in Jianfengling is affected by soil depth, and the factors driving the change of bacterial community composition are different among soil depths. It is suggested that the soil microbial communities in 0-20cm and 20-40cm of tropical forests may have different response mechanisms under the background of future climate change. 参考文献 相似文献 引证文献

Carbon storage of Mangrove Sediments in Kibani, Eastern Niger Delta, Nigeria: Implications on the Environment

The amount of carbon stored in the mangrove sediments in Kibani area of Eastern Niger Delta was quantified. The objectives were to determine the sediment bulk density (SBD) and organic carbon concentration (%C), and estimate the amount of organic carbon stock in the top 100-cm depth of mangrove sediments and its carbon dioxide equivalent (CO2 e). A total of 312 sediment samples were collected from 24 different sampling points at seven locations. An open-cylindrical gouge auger of 100-cm length and 5-cm diameter was designed and fabricated for the purpose of sediment sampling. Field measurement, laboratory analysis, data presentation and result presentation followed the Guidelines for Forest Carbon Measurement, Monitoring and Reporting. The sediment type has a major control on the distribution of organic carbon. The lithology is a typical of mangrove forest and included peat and clay with pockets of sands. Sediment bulk density (SBD) and %C ranged from 0.95 g/cm3 to 1.97 g/cm3 (mean = 1.30 g/cm3 ) and 0.9 % to 33.6 % (mean = 12.48 %) respectively. Carbon stocks ranged from 24.12 ± 15.18 Mg C ha-1 to 3245.76 ± 15.18 Mg C ha-1 (mean value = 39.80 Mg ha-1) while CO2 e ranged 88.52 ± 15.18 Mg CO2 ha-1 to 11,911.94 ± 15.18 Mg CO2 ha-1 (mean = 2,348.07 ± 15.18 Mg CO2 ha-1). The total carbon stock of the study area was estimated at 947.78 ± 55.64 Gg C, equivalent to 3,478.36 ± 55.64 Gg CO2 . The study revealed that 732,595.71 ± 55.64 Mg of carbon dioxide is stored in the sediments. This amount could either be removed or released to the atmosphere through forest management practices and/or degradation to exacerbate climate change and /or mitigate it. It is recommended that Niger Delta region of Nigeria should be protected against all anthropogenic-related degradation which influence the amount of carbon storage.

The short term effect of tillage on soil physicochemical properties in Bayelsa State, Nigeria

The objective of the research was to determine the effect of different tillage methods on some soil physicochemical properties in Niger Delta University Teaching and Research Farms. The land was divided into plots measuring 5 x 5 m with three replicates per treatment. Five tillage treatments considered were: No Till, hoeing, digging, hoeing + digging once, and hoeing + digging twice. Two samples were collected per plot at 0-15 cm and 15-30 cm depth. A total number of thirty (30) samples were collected from the field. The research was laid out using the Randomized Complete Block Design. Results showed that the tillage methods had no significant effect on the soil's chemical properties but influenced the physical. Mean pH across all plots ranged from 4.42–4.49 indicating strongly acidic state, electrical conductivity ranged 65.67-82 dS m-1 indicating no salinity stress, detrimental to crops; organic carbon and organic matter were moderate with a range of 18.52-21.55 g kg-1 and 37.03-43.10 g kg-1 respectively. Total nitrogen was at its moderate range of 7.88-12.17 g kg-1. Exchangeable acidity was low with a range of 1.52-1.71 cmol kg-1. The tillage methods influenced soil bulk density and porosity; the highest bulk density was recorded in the NT zone (1.18 g cm-3) which decreased steadily with an increase in tillage intensity. With the hoe+digging (twice) recording the lowest value of 0.94 g cm-3. Similarly, the highest porosity value was found in the tillage method with the lowest bulk density value (0.94 g cm-3: 64.7%), while the lowest was observed in the tillage method with the highest bulk density value (1.18 g cm-3: 55.7%). pH had positive correlation (P&amp;lt;0.05) with electrical conductivity (r=0.62), organic carbon (r=0.94), organic matter (r=0.90), and negative correlation with exchangeable acidity (r=-0.52). Organic carbon had strong positive correlation with organic matter (r=0.99), effective cation exchange capacity (r=0.69), clay (r=0.50), and total nitrogen (r=0.61). Silt (r=0.74) and clay (r=0.70) showed positive relationship with bulk density, while bulk density (r= -0.99) showed strong negative correlation with porosity. It is therefore recommended that crude tillage methods be used for sustainable and conservative agriculture.

Use of Surface Modified Calcium Oxide Nanoparticle in Immobilizing of Lead and Cadmium Contaminated Soil

Remediation is vital in advancing the agriculture yield and decreasing the hazard of food poisoning in contaminated soil. The aim of this study was to remediate lead and cadmium contaminated soil from Evbareke spare parts market using surface modified calcium oxide nanoparticle (SMCON). Soil samples were collected from Evbareke spare parts market, Benin City, Edo state Nigeria, using quadrant sampling method at the depth of 0-15cm using soil auger. The soil samples obtained were physicochemically and geochemically characterized. The SMCON was synthesized and characterized using Fourier Transform-Infra Red, Scanning electron spectroscopy and x-ray diffraction. A leaching experiment was carried out to authenticate the immobilization efficiency and capacity of SMCON on the lead and cadmium in the contaminated soil. The SMCON efficiency for lead and cadmium immobilization in the contaminated soil increased with increase in immobilizer up to the optimum 4% of SMCON in contaminated soil for lead and ≤1% of SMCON for cadmium. Likewise, the immobilization capacity of SMCON in the contaminated soil also revealed that more of lead and cadmium were immobilized as SMCON content in the contaminated soil mixture increased, thereby disallowing leaching of lead and cadmium from the contaminated soil. The SMCON effectively decreased the lead and cadmium in the soil by in situ adsorption, ion exchange and complexation mechanism thus reducing its accessibility for uptake by plants and its transmission to man and animals.

Regrowth of Lowland Ecotype Cyperus rotundus L. in Response to Soil Depth, Shoot Clipping and Flooding Depth Interventions

Lowland ecotype Cyperus rotundus L. (LE-CYPRO) has tubers that can grow and survive under flooded conditions. However, information on the responses of its tubers to the combination of soil depth or shoot clipping with flooding is unavailable. Two experiments were conducted to determine the germination and regrowth of LE-CYPRO tubers in response to soil depth, shoot clipping and flooding depth interventions. Experiment 1 involved pre-sprouted (PS) and non-sprouted (NS) tubers subjected to three soil depths (0, 5 and 10 cm) and three flooding depths (0, 3 and 5 cm); Experiment 2 used PS tubers subjected to shoot clipping at periods of 10, 20 and 30 days after planting (DAP) under three water conditions (saturated, early flooding and late flooding). Irrespective of soil depths, PS and NS tubers had 100% germination and regrowth without flooding (0-cm flooding depth). When planted at the soil surface (0-cm soil depth) and flooded by 3- to 5-cm, only 50 and 40% of PS while 20% of NS tubers germinated. No germination was seen on tubers buried under 5- to 10-cm soil depths and flooded by 3- to 5-cm depths. Revived PS tubers buried and flooded for 100 days at 0-, 5- and 10-cm depths had 20 to 60% germinations at 3-cm flooding depth and 20 to 70% at 5-cm flooding depth; NS tubers had 40 to 50% germinations at 3-cm flooding depth and 40% at 5-cm flooding depth. Growth variables of the weed at shoot clipping periods of 10, 20 and 30 DAP were comparable to the control under saturated conditions. Growth variables were reduced by 68 to 97.3% and 21.7 to 100% when aided by early and late flooding, respectively. This information could be used in the formulation of effective and comprehensive weed management for LE-CYPRO.

MICRONUTRIENTS (Zn, Cu, Fe, Mn, B) AVAILABILITY STATUS IN THE SOILS OF SARGODHA DISTRICT, PUNJAB, PAKISTAN

&#x0D; &#x0D; &#x0D; Soil micronutrient deficiency is a major factor in achieving the optimal yields of the crops. To find a possible solution for this deficiency is surveying the micronutrient status of soils at a specific site. Thus current research focused on variability of soil properties and indicated the spatial pattern of soil micronutrients in Sargodha district, Punjab, Pakistan. 40000 soil samples were collected through Random soil sampling to assess soil micronutrient status at a depth of 0-15cm. . Soil samples were analysed to measure the soil Zinc (Zn), Copper (Cu), Iron (Fe), Manganese (Mn) by DTPA extraction method and quantified by Flame Atomic Absorption Spectroscopy. Hot-water soluble (HWS) Boron (B) was determined by spectrophotometer. In this study, properties of soil were investigated with the help of statistical and interpolation methods (Kriging). The available Zn, Fe, Cu, Mn and B ranged from 0.1 to 5 mg/kg, 0.2 to 10 mg/kg, 0.1 to 5 mg/kg, 0.2 to 10 mg/kg and 0.1 to 4.74 mg/kg, respectively, with mean value of 0.82 mg/kg, 4.9 mg/kg, 0.87 mg/kg, 4.04 mg/kg and 0.5 mg/kg, respectively, with standard deviation 0.35, 1.9, 0.383, 1.8, and 0.14, respectively. Regarding “Poor” class out of 40,000 analysed samples, 13% samples were deficient in Zn, 0% in Cu, 43% in Fe, 2% in Mn, and 41% in B. Regarding “Marginal” category 63% samples were at marginal deficient/adequate in Zn, 14% in Cu, 0% in Fe, 87% in Mn, and 59% in B. Regarding “Adequate” category, 24% samples were at adequate level in Zn, 86% in Cu, 57% in Fe, 11% in Mn, and 0% in B. The alarming situation was appeared for B which demands immediate mitigating steps to cover up the deficiency and should be incorporated essentially in fertilizer recommendation.&#x0D; &#x0D; &#x0D;

IMPACT OF MUNICIPAL SOLID WASTE DUMP SITES ON SOIL PROPERTIESIN AKURE METROPOLIS, ONDO STATE, NIGERIA

This study was designed to assess the impact of solid waste on soil quality in Akure. Four (4) dumpsites and a control site were selected for the study. Three (3) sample collection points were mapped out from the selected dumpsites; at the base of the dumpsite; 20m from the base (to determine the level of contamination within the dumpsite) and 50m away from the dumpsite (to determine the impact on soil away from the dumpsite). Using a soil auger soil samples were collected at depths of 0-15cm (top soil) and 15 30m (sub soil) from each sample collection point and the control site. A total of twenty six (26) soil samples were collected and analyzed in the laboratory. Thirty (30) soil quality parameters which include pH, EC, Fe3+, K+, Zn2+, NO3--, PO43--, Mn2+, Ni2+, Cd2+, Organic Carbon,. were determined in the samples.Mean concentration of the physico chemical parameters shows no variation between the various dumpsites and the control site for both the top and sub soil with the exception of Fe3+. Fe3+ content was higher at Igbatoro dumpsite with a mean of 161.91mg/kg as against 36.36, 33.19, 6.34 and 4.96mg/kg for Edema, Orire, Ado dumpsite and control site respectively for the top soil and 105.73mg/kg as against 27.74, 69.28, 36.63 and 4.63mg/kg for Edema, Orire, Ado dumpsite and control site respectively for sub soil.The concentration of Cd2+was highest in Igbatoro dumpsite than the other studied dumpsites and the control for both top soil and sub soil. The ANOVA result revealed that there was no significant variation in soil quality among the dumpsites. The paired wise t test at 95% confidence level) showed no significant difference in the quality of soil between the two depths (0 15cm and 15 30cm) at the selected dumpsites. There is need for the siting of a standard waste management facility and better waste disposal measures taking into consideration the status of Akure as a state capital and a city.

Spatiotemporal variation characteristics of hourly soil temperature in different layers in the low-latitude plateau of China

Soil temperature change has considerable impact on land surface energy and water balances, and hence on changes in weather/climate, surface/subsurface hydrology, and ecosystems. However, little is known regarding the spatiotemporal variations and influencing factors of changes in hourly soil temperature (depth: 5–320 cm) in low-latitude highland areas. This study analyzed the hourly soil temperature at each hour during 2004–2020 and at 08:00, 14:00, and 20:00 (Beijing Time) during 1961–2020. The results revealed the following. 1) As soil depth increased, average soil temperature increased in autumn and winter, and decreased annually and in spring and summer. It exhibited significant increase during 00:00–23:00 annually, seasonally, and monthly, especially at depths of 40–320 cm during 2004–2020. Average soil temperature increased at 08:00 and decreased at 14:00 and 20:00 with increasing soil depth, but the opposite trend was found annually, seasonally, and monthly at 08:00, 14:00, and 20:00 during 1961–2020. 2) With increasing elevation, average soil temperature decreased at 08:00, 14:00, and 20:00 at depths of 5–20 cm, and showed significant increase trend at 08:00 and 14:00 at depths of 10–20 cm (except at 14:00 at 10-cm depth). 3) At 5-cm depth, the critical accumulated soil temperature of ≥12°C and 14°C extended the potential growing season during 1961–2020. 5) Significant uptrend of hourly soil temperature annually, seasonally, and monthly potentially leads to additional release of carbon to the atmosphere and increased soil respiration, reinforcing climate warming. These findings contribute to better understanding of the variation of shallow soil temperatures and land–atmosphere interactions in low-latitude highland areas.

Effect of aspect ratio of a corrugated cavity filled with porous media on the coefficient of heat transfer.

Solar power, thermal storage facilities, reactor cooling and microelectronic devices are all examples of renewable energy use natural convection heat transfer from a heated supplier to a chilly environment or enclosure. The purpose of this research is to investigate the influence of porous media on the convective heat transfer coefficient and the modified Rayleigh number as a function of the cavity's aspect ratio. This study investigated the free convective 3D flow then heat transmission in a cavity that has a width of 20 cm in width, a depth of 2.7 cm in depth, and varying heights of 20, 25 and 30 cm. The cavity has an anisotropic fluid-filled porous wavy enclosure with steady-state incompressible flow. The bottom surface radiates heat with a steady heat flux. (300, 500, 700, 900, 1100 W/m²), while the top is exposed to the environment at 25 C˚ (h=25 W/m²) and other walls are adiabatic. Rayleigh’s number range (3.13* to 2.61* ) (1.9* ), aspect ratio (As=1,1.25,1.5), porosity (ɛ=0.36), permeability (k=7.593* m²), amplitude (a=1.5 cm). The findings indicate that increasing the heat flow alters the temperature profile. progressively increases the pressure and velocity. The highest value for the heat transfer coefficient and modified Rayleigh No. was obtained when the aspect ratio was 1.

Comparative assessment of carbon sequestration potential of different types of wetlands in lower Gangetic basin of West Bengal, India.

Wetlands provide a great ecological service by accumulating and sequestering carbon in their soils and thus help in mitigating climate change caused due to global warming. However, the capacity and efficiency of different types of wetlands vary considerably depending upon the nature of the wetland, hydrology, biogeochemistry, climatic condition, and many other factors. In the present paper, we have studied the carbon accumulation and sequestration in three different wetlands, one sewage fed, and two floodplain oxbow lakes in the West Bengal state of India. The selected wetlands vary in terms of ecological regimes such as water volume, depth, link channel, agricultural runoffs, primary productivity, macrophyte coverage, and fishery. The carbon accumulation in the wetlands, which varied from 48.53 to 143.17Mg/ha up to 30-cm depth of soil, was much higher than that in the corresponding upland sites. The difference was much higher in the floodplain wetlands. So the study revealed that wetlands are better carbon sinks than the corresponding reference sites and the carbon sequestration potential varies according to the type of wetlands. A positive correlation was also observed between macrophyte coverage and the amount of C stored in the wetlands.

Prolonged Effect of Forest Soil Compaction on Methanogen and Methanotroph Seasonal Dynamics.

Methane (CH4) oxidation by methanotrophic bacteria in forest soils is the largest biological sink for this greenhouse gas on earth. However, the compaction of forest soils by logging traffic has previously been shown to reduce the potential rate of CH4 uptake. This change could be due to not only a decrease of methanotrophs but also an increase in methanogen activity. In this study, we investigated whether the decrease in CH4 uptake by forest soils, subjected to compaction by heavy machinery 7years earlier, can be explained by quantitative and qualitative changes in methanogenic and methanotrophic communities. We measured the functional gene abundance and polymorphism of CH4 microbial oxidizers (pmoA) and producers (mcrA) at different depths and during different seasons. Our results revealed that the soil compaction effect on the abundance of both genes depended on season and soil depth, contrary to the effect on gene polymorphism. Bacterial pmoA abundance was significantly lower in the compacted soil than in the controls across all seasons, except in winter in the 0-10cm depth interval and in summer in the 10-20cm depth interval. In contrast, archaeal mcrA abundance was higher in compacted than control soil in winter and autumn in the two soil depths investigated. This study shows the usefulness of using pmoA and mcrA genes simultaneously in order to better understand the spatial and temporal variations of soil CH4 fluxes and the potential effect of physical disturbances.