scholarly journals The effects of biocrusts on soil parameters in a semi-arid pediment at north-eastern Iran

2020 ◽  
Vol 22 (1) ◽  
pp. 5-19
Author(s):  
Adel Sepehr ◽  
Atoosa Gholamhosseinian ◽  
Iraj Emadodin
Keyword(s):  
Heterotrophic Bacteria ◽  
Mineral Soil ◽  
Soil Surface ◽  
Soil Parameters ◽  
Eastern Iran ◽  
North Eastern ◽  
Study Zone ◽  
Bare Soils ◽  
Sodium And Potassium ◽  
Semi Arid

The biocrusts are organized by soil-surface communities of biota that live within or on the very top of soil surface and play an important role in soil conservation. They include lichens, mosses, fungi, cyanobacteria, eukaryotic algae, and other heterotrophic bacteria. The interaction between biocrusts and soil is very important and good awareness from that help to better manage soil specially in arid and semi-arid areas. The linkage between cyanobacteria species and soil physicochemical parameters and mineralogy in two geomorphic zones in the northeastern Iran was studied. Samples were collected in summer along a linear transect by using 50 x 50 cm quadrates for each study zone. Individual mineral soil particles were analyzed by a scanning electron microscopy (SEM). The amounts of Na, K, Ca, and Mg contents as well as EC and SOC altered significantly between two study zones. Biocrusts increased levels of organic carbon, pH, calcium carbonate, exchangeable sodium and potassium percentages. The main soil properties of SOC, CaCO3 and amount of clay changed among biocrust sand bare soils.

Land use effects on soil quality indicators in north-eastern Iran

Soil Research ◽  
2008 ◽  
Vol 46 (1) ◽  
pp. 27 ◽  
Author(s):  
A. Golchin ◽  
H. Asgari
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Water Table ◽  
Land Use Changes ◽  
Clay Content ◽  
Soil Surface ◽  
Eastern Iran ◽  
North Eastern ◽  
Dispersible Clay ◽  
Cultivated Soils

Forest and grassland soils in north-eastern Iran are being degraded and destroyed by inappropriate agricultural activities. This study investigated effects of land-use changes on several indicators of soil quality (SQ) in this area. We found higher organic carbon (OC) and total nitrogen (N) contents in virgin soils (under forests and pastures) than in cultivated soils. Distribution of OC throughout the soil profile was influenced by the type and length of tillage operations performed at different sites. Cultivation reduced OC content of the subsoil (0.50–1.00 m) and contributed to a more uniform distribution of organic matter in the plough layer (0–0.50 m) by mixing upper and lower horizon soils and incorporating of organic inputs to a greater depth. In 4 of 5 sites, tilled soils had lower ECe and SAR values than the virgin soils, but when the water table was near the soil surface, the ECe and SAR values were higher in cultivated sites. This suggests that when the water table is deep, the quality of salt-affected virgin soils may be improved by cultivation and leaching of excess salts to deeper layers. In 4 of 5 sites, the virgin soils had slightly greater clay content than the tilled soils, but these soils also had 41–89% less dispersible clay than their cultivated counterparts. The virgin soils had 2–31-fold greater aggregate stability, 4–33% lower bulk density, 6–31% higher water-holding capacity (at 0.3 bar suction), higher cation exchange capacity (CEC), and higher respiration rate than the cultivated soils. The results of this study indicate that frequent tillage and use of summer fallow deteriorates SQ by decreasing SOC and enhancing soil erosion through decreased structural stability and increased mechanically dispersible clay. The results stress the need for farming practices that preserve OC in soils in order to reduce flooding and erosion risks.

scholarly journals The Least Square Adjustment for Estimating the Tropical Peat Depth Using LiDAR Data

2020 ◽  
Vol 12 (5) ◽  
pp. 875 ◽  
Author(s):  
Bambang Kun Cahyono ◽  
Trias Aditya ◽  
Istarno
Keyword(s):  
Prediction Models ◽  
Mineral Soil ◽  
Depth Map ◽  
Soil Surface ◽  
Absolute Error ◽  
Least Square ◽  
Soil Parameters ◽  
Lidar Data ◽  
Significant Difference ◽  
Drilling Data

High-accuracy peat maps are essential for peatland restoration management, but costly, labor-intensive, and require an extensive amount of peat drilling data. This study offers a new method to create an accurate peat depth map while reducing field drilling data up to 75%. Ordinary least square (OLS) adjustments were used to estimate the elevation of the mineral soil surface based on the surrounding soil parameters. Orthophoto and Digital Terrain Models (DTMs) from LiDAR data of Tebing Tinggi Island, Riau, were used to determine morphology, topography, and spatial position parameters to define the DTM and its coefficients. Peat depth prediction models involving 100%, 50%, and 25% of the field points were developed using the OLS computations, and compared against the field survey data. Raster operations in a GIS were used in processing the DTM, to produce peat depth estimations. The results show that the soil map produced from OLS provided peat depth estimations with no significant difference from the field depth data at a mean absolute error of ±1 meter. The use of LiDAR data and the OLS method provides a cost-effective methodology for estimating peat depth and mapping for the purpose of supporting peat restoration.

Nutrient cycling by mound building termites in low fertility soils of semi-arid tropical Australia

Soil Research ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. 375 ◽  
Author(s):  
RJ Coventry ◽  
JA Holt ◽  
DF Sinclair
Keyword(s):  
Soil Surface ◽  
Plant Nutrients ◽  
Low Fertility ◽  
Soil Horizon ◽  
Termite Mounds ◽  
North Eastern ◽  
Tropical Australia ◽  
Chemical Attributes ◽  
Turn Over ◽  
Semi Arid

The capacity of three species of mound-building termites, Amitermes vitiosus Hill, Drepanotermes perniger (Froggatt), and Tumulitermes pastinator (Froggatt), to turn over plant nutrients was quantified in a semi-arid tropical woodland near Charters Towers in north-eastern Queensland. Various chemical attributes of the red and yellow earth soils, of low inherent fertility and unmodified by recent termite activity, are compared with those of the mounds of the three termite species and with the underlying, termite-modified soils. The mounds contain 21 Mg ha-l of soil, representing only 1% of the total mass of soil in the Al soil horizon but 5-7% of the plant nutrients in this system. Nutrients in the termite mounds, temporarily withheld from plant growth, are eventually returned to the soil surface by erosion of abandoned mounds. We estimate that the termites can turnover annually 300-400 kg ha-1 of soil material with nutrient levels 2-7 times that of the Al soil horizon.

Estimation of sediment load and erosion of different geological units: A case study from a basin of north-eastern Iran

2021 ◽  
Vol 18 (6) ◽  
pp. 1591-1608
Author(s):  
Maryam Tajbakhshian ◽  
Abolfazl Mosaedi ◽  
Mohamad Hosein Mahmudy Gharaie ◽  
Sayyed Reza Moussavi Harami
Keyword(s):  
Sediment Load ◽  
Eastern Iran ◽  
North Eastern ◽  
Geological Units

scholarly journals Biochar Chemistry in a Weathered Tropical Soil: Kinetics of Phosphorus Sorption

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 295
Author(s):  
Marina Moura Morales ◽  
Nicholas Brian Comerford ◽  
Maurel Behling ◽  
Daniel Carneiro de Abreu ◽  
Iraê Amaral Guerrini
Keyword(s):  
Mineral Soil ◽  
Soil Surface ◽  
Kinetic Studies ◽  
Inorganic Phosphorus ◽  
Initial Reaction ◽  
Phosphorus Sorption ◽  
P Sorption ◽  
Published Research ◽  
Kinetics Of

The phosphorus (P) chemistry of biochar (BC)-amended soils is poorly understood. This statement is based on the lack of published research attempting a comprehensive characterization of biochar’s influence on P sorption. Therefore, this study addressed the kinetic limitations of these processes. This was accomplished using a fast pyrolysis biochar made from a mix of waste materials applied to a highly weathered Latossolo Vermelho distrofico (Oxisol) from São Paulo, Brazil. Standard method (batch method) was used. The sorption kinetic studies indicated that P sorption in both cases, soil (S) and soil-biochar (SBC), had a relatively fast initial reaction between 0 to 5 min. This may have happened because adding biochar to the soil decreased P sorption capacity compared to the mineral soil alone. Presumably, this is a result of: (i) Inorganic phosphorus desorbed from biochar was resorbed onto the mineral soil; (ii) charcoal particles physically covered P sorption locations on soil; or (iii) the pH increased when BC was added SBC and the soil surface became more negatively charged, thus increasing anion repulsion and decreasing P sorption.

Direct seeding of black spruce in northwestern Ontario: Seedbed relationships

1994 ◽  
Vol 70 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa
Keyword(s):  
Seedling Establishment ◽  
Black Spruce ◽  
Mineral Soil ◽  
Soil Surface ◽  
Direct Seeding ◽  
First Year ◽  
Strongly Correlated ◽  
Seedling Mortality ◽  
Northwestern Ontario ◽  
Seedbed Preparation

A series of spot seeding experiments was set out on coarse-textured upland sites in northwestern Ontario to investigate how black spruce (Picea mariana [Mill.] B.S.P.) seedling establishment and growth could be improved by site selection and seedbed preparation. Virtually all germination occurred within the first growing season. Annual seedling mortality rates were greatest during the first year, then declined steadily and stabilized at low levels (<10%) after the third year. The highest fifth-year establishment ratios (seedlings/viable seed sown) were found on seedbeds derived from materials near the mineral soil/humus interface. On wetter sites (i.e., higher Soil Moisture Regimes) the best seedbeds occurred closer to the soil surface. Mean fifth year establishment ratios for the best seedbeds were 0.032 on moderately fresh to fresh sites, 0.146 on very fresh to moderately moist sites, and 0.082 on moist to very moist sites. On adjacent lowland sites, slow-growing, compact Sphagnum mosses had a mean establishment ratio of 0.179. Mean fifth-year seedling heights on upland sites ranged from 12 to 14 cm, and were not strongly correlated with site or seedbed type. Key words: direct seeding, black spruce, seedbed, seedling establishment, site type and germination

scholarly journals An Improved Method to Estimate Soil Hydrodynamic and Hydraulic Roughness Parameters by Using Easily Measurable Data During Flood Irrigation Experiments and Inverse Modelling

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1581
Author(s):  
Mohamed Alkassem Alosman ◽  
Stéphane Ruy ◽  
Samuel Buis ◽  
Patrice Lecharpentier ◽  
Jean Bader ◽  
...  
Keyword(s):  
Soil Surface ◽  
Surface Flow ◽  
Performance Criteria ◽  
Soil Parameters ◽  
Well Performance ◽  
Estimation Errors ◽  
Hydraulic Roughness ◽  
Infiltration Model ◽  
Estimation Uncertainty ◽  
Using Data

Surface irrigation is known as a highly water-consuming system and needs to be optimized to save water. Models can be used for this purpose but require soil parameters at the field scale. This paper aims to estimate effective soil parameters by combining: (i) a surface flow-infiltration model, namely CALHY; (ii) an automatic fitting algorithm based on the SIMPLEX method; and (iii) easily accessible and measurable data, some of which had never been used in such a process, thus minimizing parameter estimation errors. The validation of the proposed approach was performed through three successive steps: (1) examine the physical meaning of the fitted parameters; (2) verify the accuracy of the proposed approach using data that had not been served in the fitting process; and (3) validate using data obtained from independent irrigation events. Three parameters were estimated with a low uncertainty: the saturated hydraulic conductivity Ks, the hydraulic roughness k, and the soil water depletion ∆θ. The estimation uncertainty of the soil surface depressional storage parameter H0 was of the same order of magnitude of its value. All experimental datasets were simulated very well. Performance criteria were similar during both the fitting and validation stages.

scholarly journals Effects of substrate availability and competing vegetation on natural regeneration of white spruce on logged boreal mixedwood sites

2018 ◽  
Vol 48 (4) ◽  
pp. 324-332 ◽  
Author(s):  
Nicola A. Kokkonen ◽  
S. Ellen Macdonald ◽  
Ian Curran ◽  
Simon M. Landhäusser ◽  
Victor J. Lieffers
Keyword(s):  
Picea Glauca ◽  
Natural Regeneration ◽  
Negative Impact ◽  
Mineral Soil ◽  
Soil Surface ◽  
White Spruce ◽  
Solid Wood ◽  
Seedling Mortality ◽  
Competing Vegetation ◽  
Survival And Growth

Given a seed source, the quality of available substrates is a key factor in determining the success of white spruce (Picea glauca (Moench) Voss) natural regeneration. We examined the influence of substrate and competing vegetation on survival and growth of natural regeneration of white spruce up to 4 years following harvesting in deciduous-dominated upland boreal mixedwood sites. Feather moss, thick soil surface organic layers, litter, and solid wood were poor substrates for establishment. Early successional mosses establishing on mineral soil, thin organics, and rotten wood were generally favourable microsites but were not highly available on postharvest sites. Mineral soil substrates were not as suitable as expected, likely because on a postlogged site, they are associated with unfavourable environmental characteristics (e.g., low nutrient availability, exposure). There was some evidence that survival and growth of seedlings were improved by surrounding vegetation in the first years, but heavy competing vegetation had a negative impact on older seedlings. Burial by aspen litter greatly increased seedling mortality, especially when combined with a brief period of submergence due to heavy spring snowmelt. The results provide insight into conditions under which natural regeneration could be an option for establishing white spruce following harvesting of deciduous-dominated boreal mixedwood forests.

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