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Effect of fine soil particles, tillage systems and polyacrylamide on wheat production and some soil chemical properties in arid regions

Effect of fine soil particles, tillage systems and polyacrylamide on wheat production and some soil chemical properties in arid regions

Promotion of all the growth and yield parameters of wheat except seed index has been observed at Location B (clay and silt = 38.5%) more than at location A (clay and silt = 25.2%). The improvement in growth and yield of wheat at location B could be attributed to soil texture. Higher percentage of fine particles (38.5 silt + clay) especially clay in location B than that of location A (25.2 silt + clay) considered the main reason for the improvement in growth and yield of wheat. presence of fine soil particles have been reported to improve water retention (Ismail, 2004), water holding capacity, (Reuter, 1994) and reduce plant nutrient losses, (Ismail and Ozawa, 2007) which ultimately enhance crop growth and yield (Obst, 1989; Carter et al., 1998). Besides this, fine soils also retain more organic matter, which play great role in improving crop growth and yield. The presence of significantly higher organic matter in location B than in location A can further strengthen this premise. Improvement in soil structure, aggregation, water holding capacity and nutrient availability were always accompanied with increasing the contents of soil organic matter, (Tanaka et al., 2005; Narayan and Lai, 2006, Ismail 2013).
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Effect of MSW Leachate on Soil Consistency under Influence of Electrochemical Forces Induced by Soil Particles

Effect of MSW Leachate on Soil Consistency under Influence of Electrochemical Forces Induced by Soil Particles

A significant increase in EC of the soil by the compost factory leachate was observed (Figure 3). This result can be explained as an increase in EC of pore fluid because of an increase in leachate constituent acting as charge carrier [9]. Electrical potentials of the soil may also give rise to movement of leachate and may cause change in the soil porosity [2].

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Comparison of potential and real erodibility of soil by wind

Comparison of potential and real erodibility of soil by wind

Areas the most susceptible to wind erosion were chosen for the comparison of potential and real ero- dibility of soil by wind. All the areas are located in the Southern Moravia, the south-east of the Czech Republic. Ambulatory measurements of parameters required for wind erodibility determination were done during 2006 in three districts that are heavily endangered by wind erosion (districts of Breclav, Znojmo and Uherske Hradiste). Potential and real erodibility by wind was determined from wind velo- city, soil humidity, content of clay and non-erodible soil particles. Potential soil loss does not go over the limit of the tolerable amount of soil loss 10 t.ha – 1 .year – 1 at any studied area, even though all the three
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Determination of wind erosion next to shelterbelts

Determination of wind erosion next to shelterbelts

Decrease in wind velocity on the leeward side infl u- ences the increase in humidity of the air and soil, which prevents soil from loss. Moist soil is heavier than dry one and resists easily to wind. Humidity infl uences the soil erodibility directly through the cohesive forces between soil particles and indirectly through the surface crust formation. Crusting is a dense layer at the soil sur- face that can reduce wind erosion dramatically on fi ne- textured soils (Skidmore, 1994).

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Evaluating Soil Carbon Pools and Losses in Long-term Organic and Conventional Farming Systems.

Evaluating Soil Carbon Pools and Losses in Long-term Organic and Conventional Farming Systems.

Corn cropping systems in the Southeast lose an estimated 1.4 tons of topsoil per acre per year, with a total of 4.2 million tons of topsoil lost annually (NRCS, 2006). Agricultural soil as sediment and nutrient runoff is the leading pollutant to our surveyed rivers and lakes (USEPA, 2010) with an estimated one third of the soil and associated nutrients carried by runoff and discharged into streams and water bodies. Topsoil losses have severe implications for farmers, as well as surrounding ecosystems and watersheds. Organic matter additions often lead to increased aggregation of soil particles, shown to increase infiltration and decrease water and nutrient runoff, as well as increase soil retention by stabilizing the soil surface from erosion. Management systems that incorporate organic additions as a primary nutrient source, such as those used in organic production, have been shown to increase SOC in agricultural soils. However, heavy reliance on tillage to control weeds in many organic systems may in parallel promote soil degradation and lead to increased runoff. Two indicators of microbial activity include soil microbial biomass and the quantity of labile fraction organic matter undergoing decomposition. Increases in microbial activity can lead to increased aggregation in agricultural soils due to the microbial production of extracellular polysaccharides, which in turn prevent sediment losses. In this project we seek to determine how long-term organic and conventional management systems under different tillage regimes impact soil biological properties and carbon losses. In particular our three objectives included to: 1) quantify labile fractions of organic matter based on different tillage and fertility
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Wien effect of Cd/Zn on soil clay fraction and their interaction

Wien effect of Cd/Zn on soil clay fraction and their interaction

This indicated that the ions adsorbed on the surfaces of yellow brown soil and boggy soil particles are easily dis- sociated in an applied electrical field, and paddy soil and yellow drab soil have stronger binding force for the two ion species. The mineralogy of soils were determined and shown in Table  2 in the manuscript. The dominant minerals of yellow brown soil and boggy soil were mainly montmorillonite–vermiculite group with have more charges and larger expansibility, while the main minerals of paddy soil and yellow drab soil were kaolinite group or hydromica group, with less charges or weaker expansibil- ity. As Fig. 1 shown, the boggy soil and yellow brown soil have more negative charges and cation exchange capac- ity. Consequently, yellow brown soil and boggy soil had strong binding capacity for Cd 2+ and Zn 2+ , while paddy
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A critical review on arbuscular mycorrhizal fungi and soil properties in natural systems

A critical review on arbuscular mycorrhizal fungi and soil properties in natural systems

(through the external hyphae), chemical (through enhanced nutrient uptake) and biological soil qualities increasing the soil stability (Figure 1).The mycorrhizal role in maintaining soil structure is important in all ecosystems (Ryan and Graham, 2002). Soil aggregation is one of the components of soil structure. Mycorrhizal fungi contribute to soil structure by growth of external hyphae into the soil to create a skeletal structure that holds soil particles together; creation by external hyphae of conditions that are conducive for the formation of microaggregates; enmeshment of micro aggregates by external hyphae and roots to form macroaggregates and directly tapping carbon resources of the plant to the soils (Miller and Jastrow, 2000). This direct access will influence the formation of soil aggregates, because soil carbon is crucial to form organic materials necessary to cement soil particles. Hyphae of AM fungi may be more important in this regard than hyphae of saprotrophic fungi due to their longer residence time in soil. Fungal hyphae are among the most important agents in soil aggregate stabilization among the soil biota, although effects of roots, soil bacteria and fauna are clearly significant as well (Degens, 1997). A new factor of presumably great importance in soil aggregation was discovered: glomalin (Wright and Upadhyaya, 1996). Glomalin produced by AMF and its concentration in aggregates (Wright and Upadhyaya, 1998) and soil (Rillig et al., 2001) correlate with the percentage of water-stable aggregates. The direct effect of glomalin was much stronger than the direct effect of AMF hyphae themselves, suggesting that this protein is involved in a very important hyphal mediated mechanism of soil aggregate stabilization, atleast for the 1–2 mm size class of aggregates (Rillig et al., 2001, 2002; Rillig, 2004). The extraradical hyphae also interact with components of the rhizosphere ISSN: 0975–833X
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Analysis of Factors Affecting Solidification Strength of Sludge in a Landfill Area of Shenzhen

Analysis of Factors Affecting Solidification Strength of Sludge in a Landfill Area of Shenzhen

DOI: 10.4236/wjet.2018.64052 795 World Journal of Engineering and Technology upper load as foundation. The solidification treatment of sludge by some on-site solidification methods can make it meet the requirements of foundation filling and has important significance for eco-city construction [1]. In-situ curing achieves the solidification effect of the sludge by adding a solidified material to the soft soil to cement the soil particles and dissipate the water. Domestic re- search on in-situ curing has focused on the choice and ratio of curing agents. Zhang Chunlei [2] solidified the dredged mud by adding a curing agent, which verified that the in-situ solidification method can improve the strength, defor- mation and permeability of the dredged mud. Lin Anzhen [3] studied the effect of in-situ solidification and found that the solidified dredged mud can be used as a filling material in practical engineering and its feasibility is analyzed. Foreign scholar Sezer [4] et al . used lime and fly ash as curing agents to obtain the varia- tion of sludge strength with the amount of curing agent through laboratory tests. Filz G M [5] et al . studied the strength of solidified sludge by incorporating dif- ferent amounts of curing agent to obtain the best ratio of cement and fly ash so- lidified sludge. Lin [6] and Ouhadi [7] used slaked lime and lime-fly ash as sludge solidifying agents respectively to determine the appropriate mix ratio and verify its feasibility. By studying the effect of organic matter on the in-situ solidi- fication method, Helene Tremblay [8] found that the strength of the solidified sludge decreased with the increase of the organic matter content in the curing agent. In the research of in-situ solidification method by domestic and foreign scholars, cement, fly ash, lime, slag and other solidified materials are often used as curing agents. In this paper, the dry soil rarely used in the study is used as in-situ solidified material, and combined with cement and gypsum; the effect of research on sludge strength is in a sludge landfill in Shenzhen.
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Prediction of molybdenum availability to plants in differentiated soil conditions

Prediction of molybdenum availability to plants in differentiated soil conditions

Soil samples were characterized for: pH – by the potentiometric method after extraction with 1 mol/L KCl (10 g of soil was suspended in 25 mL of KCl and equilibrated for 24 h) using a pH meter (apparatus: Schott, Mainz, Germany); available P – by the Egner-Riehm (DL) method (Egner and Riehm 1958); available Mo – after extraction in 1 mol/L HCl (10 g of soil was shaken with 100 mL HCl on a rotary shaker for 2 h at 120 rounds per min) by the inductively coupled plasma-atomic emission spectrometry (ICP-AES, IRYS Advantage ThermoElementar, Cambridge, UK); total Mo by the aqua regia digestion, determined by the ICP-AES; total organic carbon content – by dry combustion at high temperatures in a furnace with the collection and detection of evolved CO 2 (Tiessen and Moir 1993); content of soil parti- cles < 0.02 mm – by the laser diffraction method (Ryżak et al. 2007). In Poland, the content of soil particles < 0.02 mm determines the agricultural usefulness of soil. On this basis, four categories of soils are identified: very light (< 10% particles < 0.02 mm), light (10–20%), medium (20–35%) and heavy (> 35%).
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Experimental study on soil erosion under different soil composition using rainfall simulator

Experimental study on soil erosion under different soil composition using rainfall simulator

et al. (2013). They used the revised universal soil loss equation (RUSLE) to evaluate the impact of erosion on the local environment and discussed the effect of slope angle and length on erosion rate. Interesting approach to discuss the effect of soil chemical properties on soil erosion was done by Matsumoto et al. (2018). They found soil erosion rate was moderately increased under the acidic and alkaline conditions because the physical properties of soil were changed under different pH conditions: acidic conditions caused the aggregation of soil due to aluminum dissolution, whereas alkaline conditions weakened the connectivity between soil particles due to the repulsive force from the zeta potential. Additionally, many studies indicated the impor- tance of vegetation to reduce the soil loss and runoff (Valentin et al. 1999, Shi and Shao 2000, Nearing et al. 2005, Übelhör et al. 2014). Carrol and Tucker (2000) indicated the high risk of erosion on steeper gradients; however, the runoff and erosion can be reduced effectively due to the vegetation growth in the rehabilitation area of open-cut coal mine based on the field study. Davidová et al. (2015) showed
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Effect of Geogrid Aperture Size and Soil Particle Size on Geogrid-Soil Interaction under Pull-Out Loading

Effect of Geogrid Aperture Size and Soil Particle Size on Geogrid-Soil Interaction under Pull-Out Loading

Lopes and Lopes [8] studied pullout behavior of five different geosynthetics embedded in two different granular soils. They concluded that the influence of soil particle size on soil-geosynthetic interaction is important, but its significance depends on several factors. With drawn-film geogrids, the relative size of soil particles and geogrid apertures, and the thickness of the geogrid bearing members, determine the soil-geogrid interface shear resistance. A marked increase in soil-geogrid interface shear resistance was observed when the soil contained a significant percentage of particles with sizes slightly greater than the thickness of the geogrid bearing members, but smaller than the geogrid apertures.
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The distribution and diversity of actinomycetes in soil fractions

The distribution and diversity of actinomycetes in soil fractions

Sterile and nonsterile soil microcosms inoculated with Streptomyces coelicolor spores initially showed that the spores were not associated with the soil particles, however with incubatio[r]

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STUDY SOME PROPERTIES OF LOCAL AND STORM DUST PHENOMENA IN BAGHDAD CITY

STUDY SOME PROPERTIES OF LOCAL AND STORM DUST PHENOMENA IN BAGHDAD CITY

Particles become loosely held mainly due to drought, arid conditions, and various wind speeds. Dust includes soil particles, organic matter, and varieties of microbes because dust comes from soil and go through the atmosphere and rain water then to the land. This causes sanitary conditions particularly in cities. Therefore, this investigation was undertaken to study some properties of local and storm dust phenomena in Baghdad city in Iraq in June 2014 to January 2015.

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Application of Electrocoagulation and  Electrolysis on the Precipitation of Heavy Metals and Particulate Solids in Washwater from the Soil Washing

Application of Electrocoagulation and Electrolysis on the Precipitation of Heavy Metals and Particulate Solids in Washwater from the Soil Washing

The difficulties of physical separation in soil washing treatment are as follows: 1 the metal contaminants are strongly bound on soil particles; 2 the difference in density or surface pr[r]

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Soil Quality (PSU)

Soil Quality (PSU)

The number of water-stable aggregates in your soil shows its capacity to sustain its structure during the most extreme conditions (e.g., a heavy rainstorm after weather had dried the surface). Soils with low aggregate stability can constrict crops because they form surface crusts—which can reduce both water infiltration and air exchange, make the soil more difficult to manage, and reduce its ability to dry off quickly—and often have low biological activity. Aggregates are formed in part by exudates from bacteria, entanglement of soil particles in fungal hyphae, and digestion by earthworms. (See Illustration 6.) Low biological activity means reduced mineral cycling and competition with pest organisms. (Gugino 2007)
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Hygroscopic water is part of soil moisture that holds tightly to the surface of soil particles without evaporating at normal atmospheric temperatures, which is why it is considered unavailable to plants. The amount of hygroscopic water in soil depends on environmental conditions such as temperature, relative air humidity, pressure (22, 23), and on the specifi c surface area of a soil particle. Coarser particles like sand have small surface areas per gram (about 1 m 2 g -1 ),

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Assessment of potential risks associated with chemicals in wastewater used for irrigation in arid and semiarid Zones: A review

Assessment of potential risks associated with chemicals in wastewater used for irrigation in arid and semiarid Zones: A review

Ground water Could reach to ground water under highly permeable and shallow water table conditions or leach from poor organic matter soil, which lead to Groundwater contamination and they may contribute to adverse effect to human health if reach drinking water sources

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Wind erosion measurement on fallow lands of Yazd-Ardakan plain, Iran

Wind erosion measurement on fallow lands of Yazd-Ardakan plain, Iran

Wind erosion is a significant problem on 20 million ha of Iran, especially in central plains and coastal areas. Wind erosion samplers, meteorological equipments and measurement procedure have been developed over the last two centuries to measure the particles moving across the field in modes of creep, saltation and suspension. In recent research as the first technical measurement in Iran, wind erosion was measured with these advanced procedures. Field data was collected from a small (1.9 ha), square, fallow field with nonerodible boundaries. Wind erosion measurement equipment containing 14 clusters with samplers at 0.05, 0.10, 0.25, and 0.50 and 1.0m above the soil surface and a 4× surface creep sampler (0 to 0.02m height by 0.005m wide) was arranged in a circular pattern. The sampling cluster consisted of an array of five samplers each attached to a pivoting wind vane and each mounted at a different height on a central pole. This permitted field erosion data collection regardless of the wind direction and provided a range of field lengths with a minimum number of sampler locations. A combination equation of power and exponential functions expressed the variation of transition material to a height of 2m. An exponential model described the horizontal distribution of transported soil in the field. Twelve single events were recorded and analyzed between May 2006 and May 2007. Several inherent soil properties such as soil texture, organic matter and calcium carbonate content affect the erodibility of soil and change very slowly in research time. Other properties, such as surface roughness and aggregate crust strength are temporal and change rapidly in response to climatic conditions. Total soil mass transported across the fallow field was measured at 220.93 kg/m per year and soil loss at 1.356 kg/m 2
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Micromorphological characteristics of sandy forest soils recently impacted by wildfires in Russia

Micromorphological characteristics of sandy forest soils recently impacted by wildfires in Russia

of ash, charred material and erosion particles accumulating in fire-affected soils (Fig. 5). Non-decomposed organic tis- sue and residue infill the porous media in these soils. This is the result of an increment of raw forms of organic material in burnt soils. Organic matter under the effect of fire was poly- morphic (Fig. 5a, b; Stoops, 1986), while it is monomorphic in the soils of the control plot. The porous media infilling af- ter the fires was described previously by Nobles (2010); how- ever, in this case, it was an accumulation of Mn–Fe-enriched materials. Balfour and Woods (2007) observed similar re- sults in fire-affected soils. So, taking our data into account it is possible to conclude that the infilling of porous me- dia by material of a different composition is typical in burnt soils. Decreasing the porous media area was also described as being the result of an accumulation of ash (Balfour and Woods, 2007), and this explanation of porous media infill- ing is more appropriate to our case. The investigated soils are characterised by developed system of porous media; this is important regarding the heat penetration into soil and soil resistance to heating. The soils investigated are not as resis- tant to heating as clay texture ones, where the porous media are not as developed. Pores, cracks and other spaces make it possible for the combustion products to penetrate into the soil and affect the polycyclic aromatic hydrocarbons (PAHs) and other product accumulations.
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Pesticides and human health

Pesticides and human health

Pesticides are used to kill the pests and insects which attack on crops and harm them. Different kinds of pesticides have been used for crop protection for centuries. Pesticides benefit the crops; however, they also impose a serious negative impact on the soil. Excessive use of pesticides may lead to the destruction of biodiversity. Many birds, aquatic organisms and animals are under the threat of harmful pesticides for their survival. Pesticides are a concern for sustainability of environment and global st ability. Pollution as a result to overuse of pesticides and the long term impact of pesticides on the environment are also discussed in the paper.
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