Mean Values Of Organic Carbon Research Articles

Effects of soil and water conservation practices and landscape position on soil physicochemical properties in Anuwa watershed, Southern Ethiopia

Ethiopia's main environmental problem has been soil erosion. To control and reverse the problem, soil and water conservation (SWC) techniques have been deployed over the past two to three decades. The purpose of this study is to evaluate the effect of implemented soil and water conservation measures on soil physicochemical properties in the Anuwa watershed, southern Ethiopia, under various conservation structures (Soil bund, Fanya Juu, Stone bund and Micro Basin) and topographic positions (upper, middle and lower) of conserved plots. The soil samples were collected from 45 locations to analyze topsoil texture, bulk density (ρd), pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), CEC, exchangeable Na+, K+, Ca2+, and Mg2+. All soil samples were analyzed using standard and recommended methods. Using the SPSS computer program 21, the effect of independent variables (SWC practices and landscape position) on the dependent variables (soil properties) was statistically tested. The significance test was performed using two-way ANOVA. The findings indicated that the SWC measure significantly decreases the percent values of sandy soil texture, while it increased the mean values of organic carbon, available phosphorus, exchangeable Na+, K+, Ca2+, Mg2+, and CEC (P < 0.05). The sand content, the bulk density, the SOC, and the total nitrogen showed statistically significant variations between the conserved and non-conserved upper topography (P < 0.05). The effects of conservation measures were significant in almost all soil physicochemical properties at P < 0.01 except for the silt content, bulk density, and Ca2+ in the lower topography. The study findings revealed that Fanya Juu SWC measures are by far the most efficient, and recommended method to minimizing soil erosion, and improving selected soil physical and chemical quality in the Anuwa watershed. Local governments and other stakeholders should work cooperatively to strengthen and sustain the implementation process.

Status and distribution of zinc in the soils of Thoubal District, Manipur India

Twenty surface soil samples were collected from different paddy fields of thoubal district, Manipur to determine status and different forms of zinc in the soils. All the soil samples were acidic in nature with mean value of pH 5.49. The mean value of electrical conductivity was 0.07 dSm-1. The mean value of organic carbon was 2.13%. The mean cation exchange capacity, available nitrogen, available phosphorus and available potassium were 17.37 [cmol(p+)kg-1], 315.16 kg ha-1, 26.39 kg ha-1 and 240.11 kg ha-1 respectively. The studied soils were fine-textured that is clay in the textural class. The mean value of available (DTPA extractable) zinc was 0.82 mg kg-1. The DTPA extractable zinc show positive and significant correlation with CEC. A negative and significant correlation was observed with pH. On the basis of average concentration, the distribution of zinc in the soil order was: WSEX-Zn (0.38 mg kg-1) < CRYOX-Zn (1.31 mg kg-1) < MnOX-Zn (1.95 mg kg-1) < AMOX-Zn (3.04 mg kg-1) < OCx-Zn (3.16 mg kg-1) < Res-Zn (82.79 mg kg-1). All the zinc fractions showed positive correlation with EC, OC, CEC, available nitrogen, available potassium, clay; and negative correlation with pH and available phosphorus. WSEX-Zn and Res-Zn showed the lowest and highest concentration among the all zinc fractions, respectively. Different zinc fractions were found to be correlated to eachother, suggesting the dynamic nature of the equilibrium existing between them. The highest correlation among zinc fractions was found between residual and total zinc indicating the dependence of these forms on each other.

An assessment of soil available nutrients status of Chunar area in Mirzapur District of eastern Uttar Pradesh

Present investigation was conducted to assess the physicochemical properties as well as available nutrients status of alluvial soils of Chunar area in Naryanpur block of Mirzapur district of eastern part of Uttar Pradesh. Naryanpur block has total net sown area of 17376 hectares. Altogether, ninety-eight surface soil samples were collected from the farmer's field of Chunar area covering eleven villages. The analysis of the soil samples revealed that majority of the soil samples fall under sandy clay loam to sandy loam. The soils were slightly acidic to moderately alkaline in reaction ranging from pH 6.3–8.9 with a mean pH value of 8.03. The electrical conductivity (EC) value ranged from 0.12 to 0.89 dS m−1 with a mean value of 0.30 dS m−1. Mean value of organic carbon (OC) was 4.6 g kg−1 and varied from 1.6–12.7 g kg−1, CaCO3 content varied from 0.08 to 3.4% with mean value of 1.05%. Mean values for nitrogen (N), phosphorus (P) and potassium (K) as obtained from the analysis were 229, 24.4, 232 kg ha−1, respectively. Overall, mean values for exchangeable Ca and Mg and available S were 14.5, 3.84 cmol(p+)kg−1 and 10.7 mg kg−1, respectively. The mean values for available Cu, Mn, Fe, Zn and B were 0.74, 4.99, 20.8, 0.85 and 0.43 mg kg−1, respectively. Available N, S and B were rated to be low in soils. Hence, there is need to supply these deficient nutrients through external organic and inorganic sources for sustaining crop productivity and soil health of Chunar area in Narayanpur block of Mirzapur district of eastern Uttar Pradesh.

Consequence of Groundwater Irrigation on Physico-chemical Properties of Soils of Kanholibara Village in Nagpur District, Maharashtra, India

A field experiment entitled “Effect of Groundwater irrigation on various soil properties of Kanholi-Bara in Nagpur District Was conducted during Kharif season of 2015-2016 at Kanholi-Bara of Hingana tahsil in Nagpur District Maharashtra, India. The soil samples were collected from that area comprises two source of irrigations viz well water and bore well water and soybean crop which were taken in these fields. The mean value of pH 7.79 was recorded with ground water irrigation and EC in groundwater irrigated soil 0.81 dS m-1.The organic carbon contains in ground water irrigated soil with high Sodium Absorption Ratio (SAR) and Residual Sodium Carbonate (RSC) was lower by 35.19 per cent less than mean value of organic carbon. The lowest available nitrogen, phosphorus and potassium status were 185.44, 15.65 and 178.80 kg ha-1 respectively were obtained with the application of ground water of high RSC and SAR. Whereas the highest accumulation of heavy metal in soil 1.16 mg kg-1 lead, 1.30 mg kg-1 Cobalt, 1.19 mg Kg-1Nikel and 0.037 mg kg-1 Cadmium were present in soil with the application of high SAR and RSC irrigation water. Due to continuous and injudicious irrigation with poor quality groundwater adversely affect the physical and chemical properties of soil.

Effects of Amendments with Different C/N/P Ratios on Plant and Soil Properties of a Pb-Zn Mine Tailings

A field trial was conducted with abandoned Pb-Zn mine tailings to evaluate the effectiveness of amendments with different C/N/P ratios on plant growth, soil nutrients and enzyme activities, and heavy metal concentrations in plant tissues and the mine tailings. The following results were noted. ①The application of amendments with different C/N/P ratios promoted plant growth and development. The vegetation cover and biomass increased from 2.0%-20.0% and 9.4-115 g·m-2 at 6 months to 62.5%-98.5% and 389-2358.3 g·m-2 at 30 months, respectively. ②When compared with the control tailings, the mean values of organic carbon, water organic carbon, nitrate nitrogen, and available phosphorus in the treatments with different C/N/P ratios increased 6.0%-93.3%, 1.3%-49.3%, 12.3%-214.7%, and 2.7%-81.3%, respectively. Similarly, the addition of amendments with different C/N/P ratios enhanced the soil enzyme activities of dehydrogenase, β-glucosidase, urease, and phosphatase 0.3-2.8, 0.1-1.4, 0.1-0.6, and 0.1-0.5 times those in the tailings. ③The addition of amendments with different C/N/P ratios decreased the concentrations of diethylenetriamine pentaacetate (DTPA)-extracted Cd, Cu, Pb, and Zn in the mine tailings and the accumulation of Cd, Cu, Pb, and Zn in plant tissues in different degrees. DTPA-Cd, DTPA-Cu, DTPA-Pb, and DTPA-Zn decreased 2.5%-40.2%, 1.4%-25.6%, 1.4%-15.2%, and 0.4%-24.9%, respectively, compared with the control tailings. ④Pearson's correlation coefficients showed that the vegetation cover and biomass were correlated positively with the soil nutrient elements and enzyme activities and negatively with DTPA-extractable metal concentrations. No correlations were observed between the plant metal concentrations and soil DTPA-extractable metal concentrations, nutrient elements, and enzyme activities. Generally, amendments with different C/N/P ratios aided phytostabilization of some types of mine tailings is the preferred option for full remediation of these mine wastelands.

An assessment of geo-morphology and hydro-biological factors of major wetlands of Bangladesh.

The present study investigates the geo-morphological features, hydro-biological profiles and resource characteristics of some selected wetlands in Brahmanbaria district, Bangladesh. Two categories of wetland have been classified on the basis of area such as the small category (40-100 ha), which belongs to 11 wetlands and the large category (100-200 ha) to nine wetlands. The mean depth of all the surveyed wetland does not exceed 3.29 ± 0.83 m. The mean value of organic matter was measured as 7.5 ± 6.34%. The maximum organic matter was recorded at Gagotia beel (24.60%) and the minimum organic matter was recorded at Kajolia beel (2.06%). The mean value of organic carbon was measured as 3.93 ± 3.33%. The highest amount of organic carbon was found at Gagotia beel (12.95%) while the lowest amount of organic carbon was observed at kajolia beel (1.08%). Soil texture indicates the percentage composition of sand, silt and clay in sediment. The average concentration of sand, silt and clay was recorded to be 53.31 ± 15.32, 17.61 ± 9.56 and 29.08 ± 12.87%, respectively. Among the 20 selected wetlands examined, 13 were found to be perennial wetlands where water is available throughout the year. There was significant difference among different wetlands in terms of organic carbon, organic matter, sand, silt and clay (P < 0.05) as analyzed by One Way Analysis of Variance (SPSS v.22). The sampling stations were presented as a map created by GIS (ArcMap v.10.1). This qualitative and quantitative assessment will not only provide new information about the geo-morphological and hydro-biological insights into the wetland but also will facilitate the development, management, and conservation of aquatic biodiversity in a significant and worthwhile manner.

Chemical characteristics and deposition fluxes of dust-carbon mixed coarse aerosols at three sites of Delhi, NCR

The present paper reports chemistry and fluxes of dust-carbon mixed coarse particles. For the purpose of this study, different carbonaceous fractions i.e. organic carbon ((OC), elemental carbon (EC) and carbonate carbon (CC) of atmospheric dust and their respective local soils were quantified at three sites of National Capital Region (NCR) of Delhi viz. Jawaharlal Nehru University campus (JNU), Connaught Place (CP) and Vishali area of Ghaziabad (GB). It has been observed that the OC and EC levels were approximately five to nine times higher in urban atmospheric dust than their corresponding soils, whereas CC levels were about three times higher than the corresponding soils. Average dustfall fluxes were significantly different at all the sites due to their different land-use patterns. At urban background site (JNU), the dust flux was lowest (172 mg/m2/day) followed by CP, a commercial site, (192 mg/m2/day) and GB, an industrial/residential area, (302 mg/m2/day). Similar to the dustfall pattern, the mean values of OC, EC and CC deposition fluxes were also observed to be lowest at JNU (9.2, 0.8 and 1.0 mg/m2/day, respectively) as compared to CP (12.2, 1.2 and 1.3 mg/m2/day, respectively) and GB sites (11.1, 1.1 and 1.4 mg/m2/day, respectively). Interestingly, unlike fine mode, different correlation pattern of OC and EC in coarse mode dust aerosols at three sites has suggested their independent deposition processes and source contribution. Fluxes of major water soluble inorganic ions (Na+, NH4+, K+, Ca2+, Mg2+, F−, Cl−, NO3− and SO42−) were also determined. Ca2+, Cl− and SO42− were found to be the major ionic species of water soluble fraction of the urban dust at all the sites. These interactions are corroborated by the morphology of the mixed aerosols. High levels of measured chemical species and their spatial distribution revealed close correspondence with the local emissions from transport, industries, biomass burning, road dust and construction activities etc.

Mapping of nutrients status by geographic information system (GIS) in Navagarh block under Janjgir district in Chhattisgarh

A study was conducted to assess available nutrient status of soils of Navagarh block in Chhattisgarh by GIS technique. Grid based surface (0-15 cm) drawn from the farmers' fields were analysed for their fertility status and mapped by geographic information system (GIS) technique from 125 villages of Navagarh block.The soil samples were analyzed for pH, EC, OC, N, P, K, Fe, Mn, Cu, Zn. The soil pH varied from 4.8 to 8.0 (mean 5.93) and indicated that soils were found to be moderately acidic to slightly alkaline in reaction. The electrical conductivity of soil water suspension ranged from 0.04 to 0.98 dS m -1 with a mean value of 0.20 dS m -1 and all soil samples under normal range (-1).The mean value of organic carbon was 0.55 per cent and about 90 per cent soils of this block comes under medium fertility group. The soils were low in available N content. It ranged from 87to 399 kg ha -1 with an average of 258 kg ha -1 . The status of available phosphorus varied from 1.52 to 29.33 kg ha -1 with a mean value of 12.88 kg ha -1 . The 96.82 per cent village soil samples from the study area can be classified as low fertility class. Nutrient index values were in low fertility class except 8 villages for N and 44 villages for P comes under medium nutrient index value. The available potassium varied from 88 to 503 kg ha -1 with a mean value of 279 kg ha -1 .The more than 90 per cent soil samples were classified as medium to high fertility class. The available iron, manganese, copper and zinc content ranged from 0.44 to 91.6 mg kg -1 (mean 25.47 mg kg -1 ), 0.32 to 84.4 mg kg -1 (mean 29.90 mg kg -1 ) and 0.16 to 28.1 mg kg -1 (mean 2.56 mg kg -1 ), 0.02 to 10.84 mg kg -1 (mean 1.61 mg kg -1 ), respectively in soil of Navagarh block. Most of soil samples were found in sufficient levels of Fe, Mn and Cu but 32.21per cent soil samples were deficient in Zn content. Soil nutrient index of overall soils group were found in low fertility class of nitrogen and phosphorus and high fertility class with respect to potassium. Most of the area of Navagarh block was covered by LLM, LLH and LMH categories.

Use of vermicompost to increase yield and better soil health

Maintenance or enhancement of soil quality is important for sustainable agricultural production. A field experiment was conducted in farmers fields of North Kamalnagar village of Teliamura sub-division of Khowai district. Surface soil samples were collected from the fields of farmers treated with vermicompost @ 2.5 tonnes per ha along with recommended dose of NPK taking cabbage as test crop. Comparison was made with control plot where no treatment was made. Mean values of organic carbon (OC) and available NPK were found higher in the treated fields which were low in control. In vermicompost treated soils the yield and weight per head of cabbage was found higher as compared to control plot.

Correlation studies on available sulphur and soil properties in soils of Dabhra block under Janjgir- Champa district in Chhattisgarh

The study was carried out for evaluation of soil fertility with respect to available sulphur status and its relationship with important physico-chemical characteristics in red and yellow soil of Dabhra block under Janjgir district of Chhattisgarh during 2013-14. Grid based surface (0-15 cm depth) soil samples were collected using global positioning system (GPS) from 126 villages from every 10 ha land area. The soil result revealed that pH varied from 4.1 – 8.4 (mean 5.7) and indicated that soils were found to be acidic to slightly alkaline in reaction. The electrical conductivity (EC) varied from 0.01 to 0.97dS m with a mean value of 0.16 dS mat 25C of the Dabhra block. The total salt content of these soils, expressed as EC, were categorized as 0.3 dSm. The soil ranged from 0.01-1.3 with a mean value of organic carbon 0.57 per cent, about 52.66 per cent soil of this block came under medium, 31.75 per cent sample under low and only 14.29 per cent sample had high range of fertility group. The soil was high in available S content. It ranged from 7.28 to 89.6 kg ha with an average of 35.02 kg ha. The available S in more than 44.37 per cent soil sample was classified as high, 21.89 per cent sample under medium and 33.72 per cent sample in low fertility class under fertility group. The correlation between available S and soil properties showed negative significant correlation with pH and positive significant correlation with OC.

준실시간 연속관측을 통한 제주 고산 PM2.5OC와 EC의 계절별 사례별 특성

At Gosan ABC superstation in Jeju Island, we measured organic carbon (OC) and elemental carbon (EC) in from October 2009 to June 2010 using a Sunset Laboratory Model-4 Semi-Continuous OC/EC Field Analyzer. It employs TOT (Thermal-Optical-Transmittance) method with NIOSH 5040 protocol and enables to continuously monitor OC and EC concentrations with 1-hour time resolution. The mean values of OC and EC for the entire period of measurements were and , respectively. The OC/EC ratio was 3 and EC accounted of total carbon (TC, TC

Selected Fertility Indices of Topsoil Impacted By Early Stage Erosion in Four Local Government Areas of Abia State Nigeria

The study evaluated the effect of rill erosion on soil fertility in Isuikwuato, Ohafia, Ukwa East and Ikwuano LGAs in Abia state, Nigeria. In each location, five composite topsoil samples of 0 – 20 cm depth were collected from sites which exhibited surface erosion and compared with non eroded soils of the same location. Soil fertility indices were significantly reduced in eroded soils, with mean values of organic carbon at 3.3% in non eroded areas, and only 1.9% in eroded soils. Nitrogen was also significantly lower in eroded soils (0.06% mean) than in non eroded soils (0.07%). Sodium Adsorption Ratio was significantly higher in eroded soils than non- eroded sites across all four locations (8.36 and 6.17 respectively), although salt concentrations were below salinity levels. There was no significant differences in pH, P, K, Ca, exchangeable acidity and effective cation exchange capacity (ECEC) due to rill erosion, even though the values were lower in eroded soils.

Soil Properties and Crop Yields along the Terraces and Toposequece of Anjeni Watershed, Central Highlands of Ethiopia

In the Highlands of Ethiopia, soil erosion is a pressing challenge causing deterioration of soil quality including soil fertility. To overcome this problem, the government has been taking various sustainable land management (SLM) measures. This study was conducted in 2011 to investigate the long-term impacts of soil conservation on soil qualities and crop performance at Anjeni watershed in the central highlands of Ethiopia. Soil and crop samples were collected from the lower (deposition), middle and upper (loss) zones of the terraces at a depth of 30cm.The test crops were maize (Zea mays) and bread wheat (Triticum aestivum). Soil samples were also taken at toe slope, foot slope, back slope, shoulder slope and crest positions of the watershed from 0-30 cm soil depth to evaluate the status of soil qualities along the catena. Results of the study showed that soil pH, exchangeable cations, available phosphorus, sum of exchangeable bases and percent base saturation showed non-significant difference between the loss zone and deposition zones, whereas higher mean value of organic carbon, and total nitrogen were obtained at the deposition zone than the loss zone. For both testing crops, higher mean yields were found at deposition zones followed by the middle zones while the lowest value was obtained from the loss zones. Soil pH, exchangeable cations, available phosphorus, sum of exchangeable bases, percent base saturation, organic carbon and total nitrogen showed significant variation due to slope position differences. Toe slope position followed by crest slope position showed higher mean value of the parameters. The shoulder slope position had the lowest mean value for all parameters. From the results of the study, it was possible to conclude that soil conservation measures implemented at Anjeni watershed reduced soils erosion, improved soil qualities and increased crop yield. It is, therefore, possible to recommend the need for scaling up of results obtained from learning watersheds on soil conservation activities to the highlands of Ethiopia to improve the soil quality and livelihoods’ of the society.

12,000-Year, preliminary results of the stable nitrogen and carbon isotope record from the Empakai Crater lake sediments, Northern Tanzania

The stable isotope compositions of organic carbon and nitrogen, the contents of organic carbon and nitrogen and C/N ratios for two cores recovered from the Empakai Crater at water depths of 11 and 20 m are used to document climatic changes in northern Tanzania. Eight 14C AMS dates determined on total organic matter (OM) indicate that the sedimentation rate in this lake is about 30 cm/ka for the late Pleistocene to early Holocene period. There are differences in the δ 13C values of organic carbon between the two cores, which may be a result of differences in location from the present shoreline and of different water depths. In the deeper-water core the δ 13C values show a general downcore decrease to the base of the core with a sharp change to lower values of about 4‰ at a depth of 100 cm (∼8.7 ka). The general trend of downcore decrease in 13C values can be attributed either to a systematic decrease in the relative proportion of C 4 type of OM, owing to an increase in precipitation and change in vegetation cover from grassland to forest, or to utilization of isotopically enriched carbon during photosynthesis. The δ 15N values show a general downcore increase with again a sharp change of about 5‰ to lower values at about 8.7 ka. A sharp change of about 5‰ and 4‰ to more depleted values at a depth of 100 cm of both 15N and 13C, respectively, suggests either hiatus or abrupt change in climatic condition from wetter conditions to drier conditions. There is enhanced preservation of OM in the lake as depicted by high mean values of organic carbon and nitrogen at both sites.

Spatial variability of organic carbon in a tussock grassland, Manorburn, Central Otago, New Zealand

The variability of topsoil organic carbon (OC) to a depth of 7.5 cm was measured in two adjacent tussock grassland plots to determine the effect of the proximity to tussock plants on OC levels and the effect of tussock abundance on OC variance and spatial variation. The plots were on Tawhiti soils near the Upper Manorburn Reservoir in Central Otago. A substantial cover of red tussock (Chionochloa rubra) was present on one plot but absent from the other. In both plots OC showed weak spatial dependency with nugget more than 50% of the sill. The range of spatial dependency of about 2 m was consistent with the natural spacing of tussock plants which was less than 1.5 m, with a mode of 0.5 m. However, no direct relationship was observed between OC levels of individual samples and tussock proximity. Weak spatial anisotropy in the variability was indicated with higher variance in the across‐slope direction than the down‐slope direction. Mean values of OC were significantly lower in the plot with low tussock cover than the plot with substantial cover of red tussock, but variance and spatial variability of carbon were not significantly influenced by the type of vegetative cover. Sampling strategies on similar soils should not have to take into account either species abundance or the proximity of samples to tussock plants. Sampling must be randomised to avoid a natural periodicity of about 2 m wavelength. At least 26 samples are required for an estimate of a mean with a 95% confidence interval of about ±0.25% OC concentration. OC values showed periodicity with wavelengths of about 2, 4, and 8 m when plotted along the sampled transects. This was confirmed by semivariograms. The maxima and minima were approximately circular in shape. The periodicity may be related to the clustering of tussock plants but there is no positive correlation between cluster density and OC.