scholarly journals Bottom Sediment Characteristics of a Tropical Lake: Lake Tana, Ethiopia

Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Mebrahtom G. Kebedew ◽  
Seifu A. Tilahun ◽  
Fasikaw A. Zimale ◽  
Tammo S. Steenhuis
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Bottom Sediment ◽  
Total Nitrogen ◽  
Available Phosphorus ◽  
Northwestern Part ◽  
Sediment Characteristics ◽  
Lake Tana ◽  
Sediment Samples ◽  
Water Hyacinths

Sediment concentration of rivers in developing countries has been increasing greatly over the last 50 years due to the conversion of forest to continuously cultivated land with the increasing population. Few studies have addressed its effect on sedimentation and water quality of the lakes by analyzing bottom sediment characteristics. In this study, the objective was to investigate the spatial distribution (and their interrelationships) of the bottom sediment characteristics in the largest lake in Ethiopia, Lake Tana where water hyacinths have been spreading rapidly during the last decade. Sediment samples were collected from the lake bottom at 60 locations and analyzed for texture, organic matter, total nitrogen, and available phosphorus. Bottom sediment samples had a median of 75% clay, 13% silt, and 9% sand. Clay was greatest in the northwestern part and smallest in the areas near the major rivers entering or exiting the lake. Clay percentage and lake depth were strongly correlated. The mean organic matter content of bottom sediment was 16 g kg−1, total nitrogen 0.8 g kg−1, and Olsen available phosphorus 19 mg kg−1. Phosphorus concentrations peaked where water hyacinths were found in the northeastern part of the lake. This study will serve as a baseline for future water quality and sedimentation changes in Lake Tana. In particular, it might aid in explaining the spread of the water hyacinths.

scholarly journals The Relationship of Lake Morphometry and Phosphorus Dynamics of a Tropical Highland Lake: Lake Tana, Ethiopia

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2243 ◽  
Author(s):  
Mebrahtom G. Kebedew ◽  
Aron A. Kibret ◽  
Seifu A. Tilahun ◽  
Mulugeta A. Belete ◽  
Fasikaw A. Zimale ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Water Column ◽  
Available Phosphorus ◽  
Lake Morphometry ◽  
Lake Tana ◽  
Dissolved Phosphorus ◽  
Phosphorus Dynamics ◽  
Water Hyacinths ◽  
The Relationship

Lakes hold most of the world’s fresh surface water resources. Safeguarding these resources from water quality degradation requires knowledge of the relationship between lake morphometry and water quality. The 3046-km2 Lake Tana in Ethiopia is one of the water resources in which the water quality is decreasing and water hyacinths have invaded. The objective of this study is to understand the interaction between the lake morphometry and water quality and specifically the phosphorus dynamics and their effect on the water hyacinths. A bathymetric survey was conducted in late 2017. Various morphometric parameters were derived, and both these parameters and sediment available phosphorus were regressed with the dissolved phosphorus. The results show that, with a wave base depth that is nearly equal to a maximum depth of 14.8 m, the bottom sediments were continuously suspended in the water column. As a result of the resuspension mixing, we found that the dissolved phosphorus in the water column decreased with lake depth and increased with sediment available phosphorus (R2 = 0.84) in the northern half of the lake. This relationship is not as strong in the south due to a large flow of Gilgel Abay to the outlets. Water hyacinths were found where the lake was shallow and the available phosphorus was elevated. The large reservoir of sediment phosphorus will hamper any remedial efforts in removing the water hyacinths.

scholarly journals Recognition of Environmentally Vulnerable Depositional Facies in the Chacahua Lagoon, Oaxaca, Mexico

2005 ◽  
Vol 32 (2) ◽  
pp. 17 ◽  
Author(s):  
FELIPE RÍOS ◽  
GELIA SANDOVAL ◽  
ALFREDO FRÍAS
Keyword(s):  
Cluster Analysis ◽  
Grain Size ◽  
Organic Matter ◽  
Bottom Sediment ◽  
Environmental Conditions ◽  
Environmental Concern ◽  
Environmental Indicators ◽  
Depositional Facies ◽  
Sediment Samples ◽  
Insight Into

Over the years, human activity and environmental problems have impacted the Chacahua Lagoon in the State of Oaxaca, Mexico. In an attempt to gain more insight into the current environmental conditions of this lagoon, twenty-eight bottom sediment samples were collected in August 2003. Using depth, physical properties (grain-size and texture) and biological characteristics (organic matter and CaCO3 contents) of sediments as environmental indicators, three depositional facies were identified implementing cluster analysis, each facies seems to be under the influence of different processes. In terms of environmental concern, it was determined that the central part of the lagoon presents a high potential of pollutant sorption, thus this sector should be closely monitored.

scholarly journals Effect of Mid-Term Cropping System Adoption on Soil Chemical Properties at Changunarayan Municipality, Bhaktapur, Nepal

2021 ◽  
Vol 8 (2) ◽  
pp. 80-89
Author(s):  
Saroj Koirala ◽  
Santosh Shrestha ◽  
Prashanta Raut ◽  
Bikram Pandey ◽  
Arbindra Timilsina
Keyword(s):  
Organic Matter ◽  
Total Nitrogen ◽  
Soil Ph ◽  
Cropping Systems ◽  
C:N Ratio ◽  
Chemical Properties ◽  
Soil Chemical Properties ◽  
Future Research ◽  
Available Phosphorus ◽  
Wide Range

Soil chemical properties plays a crucial role in crop yield. In this study, we evaluated the chemical properties of soils under three different cropping systems practiced for more than five years in Changunarayan municipality of Bhaktapur district of Nepal. The cropping systems includes- (i) cultivation inside polyhouse (Treatment A: polyhouse), (ii) paddy-wheat rotation (Treatment B: P-W), and (iii) paddy-wheat-vegetable rotation (Treatment C: P-W-V). Thirty-nine composite samples (13 replicates from each site) were taken from the area based on variation in landforms. Soil pH, organic matter (%), total nitrogen (%), available phosphorus (mgkg-1), and available potassium (mgkg-1) were evaluated for each sample. The study revealed that the soil pH was acidic and ranges between 4.71 and 5.39, organic matter (1.6-2.39%), total nitrogen (0.091-0.13%), phosphorus (4.48-29.24mg kg-1) and potassium (88.04-109.52 mg kg-1). A significant lower mean pH (4.71), and higher mean organic matter (2.39%), total nitrogen (0.13%) and available phosphorus (29.24 mgkg-1) were observed in cultivation under polyhouse. Incorporation of vegetable in paddy-wheat system gave significant (p<0.05) higher accumulation of soil phosphorus and consistently raised other nutrient status. Moreover, cultivation under polyhouse raised C:N ratio (10.55) significantly than other system. This finding can be relevant to wide range of readers that focus on soil chemical properties and can be used in developing future research strategy and sustainable soil management system in the area.

Effects of shifting and continuous cultivation of cassava (Manihot esculenta) intercropped with maize (Zea mays) on a forest alfisol in south-western Nigeria

1992 ◽  
Vol 118 (2) ◽  
pp. 195-198 ◽  
Author(s):  
A. O. Aweto ◽  
O. Obe ◽  
O. O. Ayanniyi
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Total Nitrogen ◽  
Continuous Cultivation ◽  
Exchange Capacity ◽  
Sodium Cation ◽  
Organic Fertilizers ◽  
Available Phosphorus ◽  
Calcium Magnesium ◽  
Forest Soil Organic Matter

SUMMARYSoils in farmlands near Ibadan, Nigeria, where shifting or continuous cultivation of cassava intercropped with maize is practised, were sampled in February 1990 and their characteristics compared with those of similar, uncultivated, forest soil. Organic matter, total nitrogen, exchangeable calcium, magnesium, potassium and sodium, cation exchange capacity and pH were lower in the cultivated soils. Continuous cultivation exerted a greater effect on soil organic matter, total nitrogen and available phosphorus status then did shifting cultivation. It is suggested that inorganic and organic fertilizers and mulch should be applied to cultivated soil to conserve the soil nutrients. Fallows of 3–6 years following 1–3 years of cropping appeared incapable alone of adequately restoring soil fertility. They should, therefore, be supplemented with fertilizer applications.

scholarly journals Soil pH and Nutrient Characteristics of Newly-added Cultivated Land in Heyang, China

2020 ◽  
Vol 204 ◽  
pp. 01013
Author(s):  
Gang Li ◽  
Ruiqing Zhang ◽  
Ying Wang ◽  
Nan Lu ◽  
Yang Wei ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Total Nitrogen ◽  
Soil Ph ◽  
Ph Value ◽  
Organic Matter Content ◽  
Matter Content ◽  
Available Phosphorus ◽  
Cultivated Land ◽  
Soil Available Phosphorus

In order to understand the soil pH and main nutrient characteristics of newly added cultivated land in the eastern part of Guanzhong, and 160 soil samples were collected in 2016, the soil pH, organic matter, total nitrogen, available phosphorus and available potassium in Heyang County were studied The suitability distribution of the indicators, using stepwise regression and path analysis methods, analyzes the direct relationship between soil pH and soil nutrients, and provides a theoretical basis for improving the newly added cultivated land. The results showed that the soil pH in Heyang County varied from 8.42 to 9.67, the soil organic matter content varied from 3.46 to 17.93 g/kg, the soil total nitrogen content varied from 0.13 to 5.61 g/kg, and the soil available phosphorus changed The range is 1.73 ~ 63.06 mg/kg, and the soil available potassium range is 46.50 ~ 523.74. The newly added soil has a certain nutrient basis, but it should be further adjusted and improved during the cultivation process. The direct positive effect on soil pH value is mainly soil organic matter, and the direct negative effect is mainly soil available phosphorus. By adjusting the organic matter, total nitrogen, available phosphorus and available potassium in the soil, the pH value of the soil can be effectively improved, so that the newly cultivated soil is suitable for the growth of local crops.

scholarly journals Soil nutrient evolution under different vegetation types in semiarid loess area

2021 ◽  
pp. 969-976
Author(s):  
Lirong He ◽  
Yuhu Luo
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nutrients ◽  
Total Nitrogen ◽  
Organic Fertilizer ◽  
Nutrient Balance ◽  
Soil Nutrient ◽  
Available Phosphorus ◽  
Vegetation Types ◽  
Nitrogen And Phosphorus

The soil nutrient characteristics under three vegetation types of arbor ( I ), shrub ( II ) and herb ( III ) were studied by mathematical statistics method combined with field investigation and indoor detection analysis. The change characteristics of soil nutrients under different land use patterns were discussed. The results showed that the average contents of soil organic matter, total nitrogen, available phosphorus and available potassium were 21.30 and 0.65 g/kg, 3.67 and 67.61 mg/kg, respectively. Compared with grassland, woodland has better effect on fertilizer conservation in the Loess Plateau. In the process of soil nutrient improvement, the nutrient indexes such as organic matter, total nitrogen, available phosphorus and available potassium increased synchronously, and the soil alkaline environment that was not conducive to plant growth was also gradually improved. In the correlation between soil nutrients, available phosphorus and available potassium have good relative independence. In the future, organic fertilizer should be applied in this area, and nitrogen and phosphorus fertilizers should be supplemented to improve soil organic matter, nitrogen and phosphorus content, and to ensure soil nutrient balance by optimizing fertilization methods. In addition, in the case of uneven distribution of soil nutrients in the soil profile, it is recommended to take appropriate soil ploughing and reasonable human management measures to improve soil nutrient status, achieve high-quality sustainable development of soil, and promote the positive succession of vegetation communities. Bangladesh J. Bot. 50(3): 969-976, 2021 (September) Special

scholarly journals Status of Soil Fertility in a Community Forest of Nepal

2013 ◽  
Vol 1 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Anup KC ◽  
Govinda Bhandari ◽  
Subigya Prabhat Wagle ◽  
Yubraj Banjade
Keyword(s):  
Organic Matter ◽  
Forest Soil ◽  
Total Nitrogen ◽  
Complex Mixture ◽  
Soil Parameters ◽  
Available Phosphorus ◽  
Community Forest ◽  
The Status ◽  
Phosphorus And Potassium ◽  
Living Organisms

Soil is a complex mixture of mineral nutrients, organic matter, water, air and living organisms. The primary nutrients for plant growth are organic matter, nitrogen, phosphorus and potassium. In order to find the status of pH, organic matter (C), total nitrogen (N), available phosphorus (P) and available potassium (K) in forest soil, the study was conducted in Ghwangkhola Sapaude Babiyabhir Community Forest in Putali Bazaar Municipality-8, Syangja, Nepal. Soil parameters are analyzed through different standard methods followed worldwide by many soil scientists. Soil pH of sample in all three strata was slightly acidic and varies from 5.7 to 7.18. The carbon percentage was high and varies from 0.65% to 2.39%. The total nitrogen in soil was medium and varies from 0.09% to 0.12%. The concentration of available phosphorus in soil was high and varies from 73.71 kg/ha-93.23 kg/ha. The concentration of available potassium on soil was quiet low and varies from 2.54 kg/ha-4.23 kg/ha. Higher organic matter in the forest land indicate low activities of nitrogen losing process, which is due to the closed nutrient cycling and minimal disturbance in the natural forest system. So, addition of fertilizer rich in potassium and increasing pH is recommended to maintain potassium fertility and neutral pH in the forest soil. DOI: http://dx.doi.org/10.3126/ije.v1i1.8528 International Journal of Environment Vol.1(1) 2013: 56-67

scholarly journals Soil Fertility Mapping of Different VDCs of Sunsari District, Nepal Using GIS

2018 ◽  
Vol 6 (2) ◽  
pp. 142-151
Author(s):  
Nabin Rawal ◽  
Keshav Kumar Acharya ◽  
Chet Raj Bam ◽  
Kamal Acharya
Keyword(s):  
Organic Matter ◽  
Soil Fertility ◽  
Total Nitrogen ◽  
Hot Water ◽  
Available Phosphorus ◽  
Silty Clay ◽  
Clay Loam ◽  
Fertility Status ◽  
The Mean ◽  
Soil Fertility Status

Soil fertility degradation has become a major problem for agricultural management in Nepal. A detailed soil fertility status of different VDCs of Sunsari district was investigated during 2015 and soil related crop production constraints were identified for proper utilization of agricultural land. Total 131 numbers of geo-referenced (GPS based) composite surface soil samples (0-15 cm) were collected from eleven Village Development Committees of Sunsari District. The sample points were recorded with a differential global position system and mapped using Geographic Information System (GIS). Soils were analyzed for mechanical composition, pH, organic matter, total nitrogen, available phosphorus, potassium and micronutrients like Boron, Zinc, Copper and Iron. About 38.9% soils were found to be silty clay loam, 20.6% were silty clay, 19.1% were clay loam and 21.4% were of other textural classes. Most of the soils were acidic and only few were neutral and slightly alkaline in nature. Soil Organic matter varies from 3.57% to 0.28% with a mean value of 1.53 %. The mean total nitrogen, available phosphorus, potassium was found to be 0.08%, 44.37 kg/ha and 128.04 kg/ha respectively. The mean hot water extractable Boron, DTPA extractable Copper, Zinc and Iron was found to be 0.14, 0.06, 0.15 and 10.71 mg/kg respectively. Thematic maps were prepared for each soil parameters using ArcGis10.1 software and ordinary Kriging interpolation was used in order to predict values for not sampled locations. The fertility maps provide the readymade source of information about soil fertility status and serve as the decision making tool for successful raising and development of crops. It can be concluded from the above study that GPS and GIS based soil fertility maps helps farmers, scientists, planners and students in providing soil test based fertilizer recommendation for intensive and sustainable site specific crop production.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 142-151 

scholarly journals Recognition of Environmentally Vulnerable Depositional Facies in the Chacahua Lagoon, Oaxaca, Mexico

2004 ◽  
Vol 31 (2) ◽  
pp. 17
Author(s):  
Felipe RÍOS ◽  
Gelia SANDOVAL ◽  
Alfredo FRÍAS
Keyword(s):  
Cluster Analysis ◽  
Grain Size ◽  
Organic Matter ◽  
Bottom Sediment ◽  
Environmental Conditions ◽  
Environmental Concern ◽  
Environmental Indicators ◽  
Depositional Facies ◽  
Sediment Samples ◽  
Insight Into

Over the years, human activity and environmental problems have impacted the Chacahua Lagoon in the State of Oaxaca, Mexico. In an attempt to gain more insight into the current environmental conditions of this lagoon, twenty-eight bottom sediment samples were collected in August 2003. Using depth, physical properties (grain-size and texture) and biological characteristics (organic matter and CaCO3 contents) of sediments as environmental indicators, three depositional facies were identified implementing cluster analysis, each facies seems to be under the influence of different processes. In terms of environmental concern, it was determined that the central part of the lagoon presents a high potential of pollutant sorption, thus this sector should be closely monitored.

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