scholarly journals Growth and phytoremediative capacity of Eleusine indica in a typical farmland soil under previous exposure to organochlorine pesticide

2021 ◽  
Vol 20 (1) ◽  
pp. 25-55
Author(s):  
Musa Saheed Ibrahim ◽  
Geoffrey Obinna Anoliefo ◽  
Ohanmu Edos. O
Keyword(s):  
Morphological Changes ◽  
Polluted Soil ◽  
Test Plant ◽  
Soil C ◽  
Eleusine Indica ◽  
Soil P ◽  
Ph Values ◽  
Farmland Soil ◽  
Remediation Efficiency ◽  
Soil Mix

This study investigated the growth and phytoremediative response of Eleusine indica in a typical farmland soil that had been exposed to organochlorine pesticides. Different soil treatments were obtained by mixing pesticide polluted soil (P) with control soil (C) in ratios, 1P:99C, 5P:95C, 50P:50C, 25P:75C, 75P:25C, 100P and 100C. Three-leaf tillers of the test plant were sown in all the treatments for 3 months. The results revealed that there were no significant differences in all plant morphological parameters measured between plants in P impacted soils and C-soil. All the pH values were acidic, although an increase in pH and decrease in conductivity was observed with the introduction of the test plant. There was reduction in total pesticide residual (TPR) contents in the soil as a result of the plant activities. Significant reduction in q – BHC, α – chlordane and ϒ – chlordane was observed in the P1:C99 soil mix; a 90% remediation efficiency (1.663 mg kg-1 ) was registered in the all treatments. This study thus presents E. indica as a potential concentration-dependent phytoremediator of pesticide, with no significant morphological changes.

Applying Model for Water Pollution commencing Non-Point Resource Based on Statistical Data in River

2020 ◽  
Vol 51 (1) ◽  
pp. 03-04
Author(s):  
Leon Kirk
Keyword(s):  
Statistical Data ◽  
Nonpoint Source ◽  
Direct Result ◽  
Soil Tests ◽  
Soil P ◽  
Water Condition ◽  
Farmland Soil ◽  
Source Contamination ◽  
Landscape Geography ◽  
Spatial Area

Eutrophication is an overall contamination issue, when the directresource contamination is proficiently unnatural; contamination load from non-point foundation has the expanding extent in the complete burden. The investigation on non-point foundation contamination is a significant perspective in the exploration on water condition contamination. The nonpoint source contamination, highlighted by broad inclusion, dynamic intricacy and troublesome evaluation of precise spatial area and release degree, is a solution and troublesome concern for the investigation of water condition contamination. In this magazine, an improved fare co-efficient strategy is projected to gauge non-point foundation contamination load in watersheds, same thinking about the impacts of precipitation and the decrease of toxin during the time spent vehicle. The measures of downpour and overflow are enormous in soaked years, so the non-point foundation contamination heaps created are huge too in different years, the non-point foundation contamination loads are fewer a direct result of less precipitation in typical water years. Non-point resource contamination factors are investigated, for example, precipitation, land use, landscape, geography and soil P speciation in farmland soil tests in forest soil tests, and in orchardland soil tests.

scholarly journals Biodegradation of natural bitumen by Providencia stuartii isolated from heavy oil contaminated soil

2017 ◽  
Vol 19 (2) ◽  
pp. 353-358
Keyword(s):  
Optical Density ◽  
Heavy Oil ◽  
Degradation Products ◽  
Polluted Soil ◽  
Gas Chromatography Mass Spectrometry ◽  
Natural Bitumen ◽  
Soil P ◽  
Independent Variables ◽  
Providencia Stuartii ◽  
New Compounds

Abundance and availability of unconventional petroleum has led to intensified exploitation and exploration of the bitumen reserves. This has however led to environmental pollution. This study investigated the ability of Providencia stuartii isolated from heavy oil polluted soil to degrade natural bitumen. Temperature, pH and incubation period were independent variables used for optimization of degradation while optical density was used as dependent variable. Optical density was measured using a UV-Vis spectrophotometer. Residual bitumen/degradation products were analyzed using gas chromatography- mass spectrometry (GC-MS). Optical densities obtained ranged from 0.002 to 0.408. Optimum optical density of 0.408 was obtained at 40 oC and pH 7 after 13 days of incubation. There were significant changes in the composition of bitumen after analysis with GC-MS with detection of new compounds due to degradation. The GC-MS results showed the presence of some degradation products such as benzene (1-butylhexyl), benzene (1-propylheptyl) and 23, 28-bisnor-17.β.(h)-hopane. This study revealed the excellent ability of P. stuartii in degrading bitumen contaminated environment.

Rate of recycling of sulfur from urine, feces and litter applied to the soil surface

Soil Research ◽  
1994 ◽  
Vol 32 (3) ◽  
pp. 543 ◽  
Author(s):  
GJ Blair ◽  
AR Till ◽  
C Boswell
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Surface ◽  
Plant Litter ◽  
Test Plant ◽  
Soil P ◽  
S Uptake ◽  
Organic Matter Pool ◽  
Preferential Uptake ◽  
Soil Organic Matter Pool

The recycling of S from plant litter, dung and urine is an important process for supplying S for pastures. A pot experiment was conducted where 35S-labelled litter (25% white clover/38% ryegrass/21% weed) and S-35-labelled urine and faeces collected from sheep fed the same herbage as was used as litter was surface applied to pots and the fate of the applied S was followed for 100 days with ryegrass as the test plant. In camp soil, 45% of the S applied in urine was taken up by ryegrass plants within 12 days of application. In non-camp soil, the uptake of urine-S was about 20% over the same period. Cumulative uptake of 35S from urine in camp soil was subsequently restricted, with a maximum of 60% eventually measured in plants after 100 days. Mean rates of release of S (0-37 days) from litter and faeces was respectively 16.2 and 4.5 mg g-1 day-1. The calculated half-times from S in the two materials were respectively 43 and 154 days under controlled environmental conditions with adequate moisture. Litter S followed organic matter (OM) decomposition, but faecal S release was initially more rapid than faecal OM decomposition. There was little S release from faeces after day 25. Rather, S was immobilized in faeces during the 25-100 day period. The decomposition of litter and faeces was divided into an initial rapid process during which soluble S and more labile S was released, followed by a slower process involving the release of S from tissues more resistant to mineralization. The uptake of 35S from labelled materials was initially more rapid than would be expected for total S released from the added litter and faeces and the 35Suptake effect was short-lived relative to the continued effect of added material on total S uptake. The preferential uptake of 35S from the surface-applied material appears to be due to limited root development at the early stages of the experiment. Movement of 35S into the soil organic matter pool was very rapid; 58.4% of urine S was in the soil organic matter fraction in the non-camp soil by day 6. The amount of applied S in the organic matter equilibrated at about day 75. The accumulation of applied S from the materials added was greater than that recorded in previously reported studies for inorganic sulfate (e.g. about 50%). Soil P and S status had little effect on rates of release of S. from the applied materials, however, the effect of the camp and non-camp soil on total S recycling was markedly different as a result of the different amounts of plant growth and thus S uptake in the two soils. The decomposition of litter indicated peak rates of S release at two specific times over the 100 days and indicated successional changes in micro-organism activity. With faeces, the experiment was not continued for sufficiently long to show micro-organism effects.

EFFECT OF EXCESS FEEDLOT MANURE ON CHEMICAL CONSTITUENTS OF SOIL UNDER NONIRRIGATED AND IRRIGATED MANAGEMENT

1986 ◽  
Vol 66 (2) ◽  
pp. 303-313 ◽  
Author(s):  
J. F. DORMAAR ◽  
T. G. SOMMERFELDT
Keyword(s):  
Organic Matter ◽  
Chemical Constituents ◽  
Soil C ◽  
Soil P ◽  
Total Soil ◽  
Labile Phosphorus ◽  
Moisture Regimes ◽  
Labile P ◽  
Recommended Level

A long-term field experiment was initiated in 1973 to determine the safe loading capacity of a Lethbridge loam (Dark Brown Chernozemic) with feedlot manure. The effect of 10 yr of feedlot manure loading was examined by analyzing a number of inorganic and organic matter constituents of the Ap horizon. Although soil C, P, and enzyme activities increased as feedlot manure additions to the soil increased, these increases diminished at triple the recommended loading regimes. Phosphatase activity was checked by increased labile phosphorus levels. Levels of adenosine 5′-triphosphate increased but fluctuated with time under various moisture regimes. The C:N ratios, percent monosaccharide C of total soil C, and the ratio of deoxyhexoses to pentoses remained constant while the percentage of manure C retained decreased as feedlot manure loading increased. The distribution between pentoses and hexoses was strongly affected by feedlot manure levels while the deoxyhexose percentage of the sum of the eight monosaccharides determined remained about the same. Feedlot manure additions, at triple the recommended level, increased the labile P as a percentage of total soil P to around 50%. Although mineralization did not keep pace with the quantities applied, the presence of undecomposed manure did not seem to have harmful agronomic effects. Key words: ATP, feedlot manure, labile phosphorus, monosaccharides, organic matter

scholarly journals Elevation Gradient Altered Soil C, N, and P Stoichiometry of Pinus taiwanensis Forest on Daiyun Mountain

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1089
Author(s):  
Lan Jiang ◽  
Zhongsheng He ◽  
Jinfu Liu ◽  
Cong Xing ◽  
Xinguang Gu ◽  
...  
Keyword(s):  
Elevation Gradient ◽  
C:N Ratio ◽  
Phosphate Fertilizer ◽  
High Elevation ◽  
Driving Factors ◽  
Slope Position ◽  
Elevation Gradients ◽  
Soil C ◽  
Soil P ◽  
C And N

Researches focused on soil carbon (C), nitrogen (N), and phosphorus (P) content and the stoichiometry characteristics along elevation gradients are important for effective management of forest ecosystems. Taking the soil of different elevations from 900 to 1700 m on Daiyun Mountain as the object, the elevation distribution of total C, N, and P in soil and their stoichiometry characteristics were studied. Also, the driving factors resulting in the spatial heterogeneity of soil stoichiometry are presented. The results show the following: (1) The average soil C and N content was 53.03 g·kg−1 and 3.82 g·kg−1, respectively. The content of C and N at high elevation was higher than that of at low elevation. Soil phosphorus fluctuated with elevation. (2) With increasing elevation, soil C:N ratio increased initially to 17.40 at elevation between 900–1000 m, and then decreased to 12.02 at elevation 1600 m. The changing trends of C:P and N:P were similar, and they all fluctuated with elevation. (3) Elevation, soil bulk density, and soil temperature were the main factors influencing the variation of soil C, N, and C:N. Soil pH and slope position were the driving factors for soil P, C:P, and N:P. The soil is rich in C and N, and has less total phosphorus on Daiyun Mountain. Raising the level of phosphate fertilizer appropriately can help to improve soil fertility and promote plant growth as well. In light of this information, in the near future, it will be necessary to conduct separation management of C, N, and P with regular monitoring systems to maintain favorable conditions for soil.

Organic phosphorus speciation in Australian Red Chromosols: stoichiometric control

Soil Research ◽  
2016 ◽  
Vol 54 (1) ◽  
pp. 11 ◽  
Author(s):  
Melinda R. S. Moata ◽  
Ashlea L. Doolette ◽  
Ronald J. Smernik ◽  
Ann M. McNeill ◽  
Lynne M. Macdonald
Keyword(s):  
Organic Matter ◽  
Soil Type ◽  
Organic Phosphorus ◽  
Organic Matter Content ◽  
Matter Content ◽  
31P Nmr Spectroscopy ◽  
Chemical Forms ◽  
Organic P ◽  
Soil C ◽  
Soil P

Organic phosphorus (P) plays an important role in the soil P cycle. It is present in various chemical forms, the relative amounts of which vary among soils, due to factors including climate, land use, and soil type. Few studies have investigated co-variation between P types or stoichiometric correlation with the key elemental components of organic matter– carbon (C) and nitrogen (N), both of which may influence P pool structure and dynamics in agricultural soils. In this study we determined the organic P speciation of twenty Australian Red Chromosols soils, a soil type widely used for cropping in Australia. Eight different chemical forms of P were quantified by 31P NMR spectroscopy, with a large majority (>90%) in all soils identified as orthophosphate and humic P. The strongest correlations (r2 = 0.77–0.85, P < 0.001) between P types were found among minor components: (i) between two inositol hexakisphosphate isomers (myo and scyllo) and (ii) between phospholipids and RNA (both detected as their alkaline hydrolysis products). Total soil C and N were correlated with phospholipid and RNA P, but not the most abundant P forms of orthophosphate and humic P. This suggests an influence of organic matter content on the organic P pool consisting of phospholipid and RNA, but not on inositol P or the largest organic P pool in these soils – humic P.

scholarly journals Poly(-caprolactone)/graphene oxide composite systems: A comparative study on hydrolytic degradation at extreme pH values

2020 ◽  
Vol 10 (6) ◽  
pp. 892-902
Author(s):  
Alberto J. Campillo-Fernández ◽  
Pablo González-Reed ◽  
Ana Vidaurre ◽  
Isabel Castilla-Cortázar
Keyword(s):  
Graphene Oxide ◽  
Degradation Kinetics ◽  
Morphological Changes ◽  
Hydrolytic Degradation ◽  
Degradation Behavior ◽  
Composite Systems ◽  
Ph Values ◽  
Speed Up ◽  
Poly Caprolactone ◽  
Degradation Time

Polycaprolactone/Graphene oxide (PCL/GO) composites are shown to be promising substrates for tissue engineering as their degradation behavior is a key aspect in this type of application. The present paper studies the effect of different GO contents (0.1, 0.2 and 0.5 wt%) of PCL/GO composites on accelerated hydrolytic degradation at extreme pH values. Degradation kinetics at pH 13 is strongly affected by GO content, and speed up at higher percentages. The composite with 0.5 wt% of GO was completely degraded in 72 hours, while degradation at pH 1 presents a different profile and seems to have an induction period that lasts more than 1500 hours. Morphological changes, molecular weight distribution, weight loss, degree of swelling and calorimetric properties were investigated as a function of degradation time. According to the results obtained, the addition of small percentages of GO significantly influences the degradation behavior of the composites acting as degradation modulators.

scholarly journals Effects of slope aspect on altitudinal pattern of soil C:N:P stoichiometry in alpine forest of Tibet

2021 ◽  
Vol 269 ◽  
pp. 01012
Author(s):  
Jiangrong Li ◽  
Qiqiang Guo ◽  
Heping Ma ◽  
Weilie Zheng
Keyword(s):  
Soil Temperature ◽  
Altitudinal Gradient ◽  
Sampling Site ◽  
Slope Aspect ◽  
C:N:P Stoichiometry ◽  
Soil C ◽  
Soil P ◽  
Soil Nutrition ◽  
Significant Difference ◽  
Stoichiometric Ratios

Knowledge of altitudinal patterns in soil C, N and P distribution is important for understanding biogeochemical processes in mountainous forests, yet the influence of slope aspects on soil stoichiometry has been largely neglected in previous studies. In this paper, a total number of 150 topsoil samples at four altitudes (3700, 3900, 4100, 4380 m a.s.l.) on sunny and shady slopes of Sygera mountains in the Southeastern Tibet were collected. Soil C, N and P contents, and pH, were measured. Soil temperature, moisture and richness of plant species were investigated at each sampling site. The results showed that: 1) in sunny slope, soil C, N and P concentrations increased with the increase in altitude, whereas soil C:N, C:P, and N:P decreased along the altitudinal gradient on s. Soil moisture was the main regulator of soil nutrition and stoichiometric ratios. 2) In shady slope, soil C and N contents had no significant difference along the altitudinal gradient except the higher values at low altitude, whereas soil P increased first and then decreased. Soil C:N increased with the increase in altitude, whereas C:P and N:P decreased first and then increased. Soil temperature and species richness were the main factors influencing soil nutrition and stoichiometric ratios. 3) Decoupling of soil C:N:P stoichiometry was observed in shady slope owing to changes in soil pH and temperature. 4) The rich contents of soil C and P were observed at two slopes along the altitudinal gradient, and high capacity of N supply existed at the topsoil in shady slope. These results suggested that slope aspect plays an important role in shaping the altitudinal pattern of soil C:N:P stoichiometry in mountainous forests.

Filament Formation in Listeria monocytogenes

1995 ◽  
Vol 58 (9) ◽  
pp. 1031-1033 ◽  
Author(s):  
LOWELL L. ISOM ◽  
ZUBIN S. KHAMBATTA ◽  
JON L. MOLUF ◽  
DANIEL F. AKERS ◽  
SCOTT E. MARTIN
Keyword(s):  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Morphological Changes ◽  
Filament Length ◽  
Filament Formation ◽  
Adaptation Mechanism ◽  
Growth Environment ◽  
Adverse Conditions ◽  
Ph Values ◽  
Nacl Concentration

Listeria monocytogenes strains SLCC 5764 cells were challenged with various NaCl concentrations and levels of pH. Cells were propagated in tryptic soy broth containing 250 to 1,500 mM NaCl or TSB at pH values ranging from 3.5 to 9.5.Microscopic analyses of the listerial cells following incubation revealed morphological changes under several adverse conditions. Filament formation occurred at NaCl concentrations above 1,000 mM with an increase in filament length as NaCl concentration increased. The same phenomenon was observed at pH values of 5.0 to 6.0 (adjusted with citric acid) and at pH &gt; 9.0 (NaOH). The length of the filaments increased as the growth environment became more challenging. Cellular elongation of L. monocytogenes cells grown under these conditions suggests that an adaptation mechanism for survival may be involved. Since long filament structures may form under certain stressful conditions, these observations may be useful in preventing misidentification of L. monocytogenes.

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