Influence Of Soil Type Research Articles

Runoff from tropical alpine grasslands increases with areal extent of wetlands

Tropical alpine grasslands of the northern Andes, commonly known as the páramo, provide abundant high-quality water for downstream populations as well as a variety of other environmental services. Yet, very little is known about the role that landscape characteristics play in the hydrologic functioning of these ecosystems. To help fill this knowledge gap, we investigated the relationships between various landscape attributes and hydrology in a wet páramo ecosystem of southern Ecuador. Using linear regression analysis, we examined the influence of soil type, vegetation cover, catchment area, geology, and topography on runoff coefficient, streamflow rates, and evapotranspiration. Our study site is located at the Zhurucay River experimental catchment, which is composed of seven nested microcatchments ranging in size from 0.20 to 7.53km2 and in elevation from 3200 to 3900ma.s.l. We found that (1) water yield accounts for a high percentage of the water budget; (2) runoff coefficient and specific discharge are strongly correlated with the extent of Andean páramo wetlands (Histosol soils and cushion plants), and also increase with catchment size; (3) conversely, inferred evapotranspiration is the highest in catchments having the greatest percentages of upland terrain (Andosol soils and tussock grasses); and (4) low flows are highly positively correlated with steep slopes. These results suggest that in the high-elevation tropical grasslands of the Andes, runoff coefficient and specific discharge increase with catchment size because as catchment size increases, so does the relative area of permanently near-saturation zones (Andean páramo wetlands); likely because of reduced available storage capacity of the Andean páramo wetlands, and their hydrologic connectivity to the stream network.

Soil type-dependent effects of a potential biocontrol inoculant on indigenous bacterial communities in the rhizosphere of field-grown lettuce.

Bacterial biocontrol strains used as an alternative to chemical fungicides may influence bacterial communities in the rhizosphere and effects might differ depending on the soil type. Here we present baseline data on the effects of Pseudomonas jessenii RU47 on the bacterial community composition in the rhizosphere of lettuce grown in diluvial sand, alluvial loam and loess loam at the same field site. 16S rRNA gene fragments amplified from total community DNA were analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. DGGE fingerprints revealed that in three consecutive years (2010-2012) RU47 had a slight but statistically significant effect on the bacterial community composition in one (2010), two (2011) or all the three soils (2012). However, these effects were much less pronounced compared with the influence of soil types. Additional pyrosequence analysis of samples from 2011 showed that significant changes in bacterial community compositions in response to RU47 inoculation occurred only in alluvial loam. Different taxonomic groups responded to the RU47 application depending on the soil type. Most remarkable was the increased relative abundance of OTUs belonging to the genera Bacillus and Paenibacillus in alluvial loam. Pyrosequencing allowed side-effects of the application of bacterial inoculants into the rhizosphere to be identified.

Influence of soil type, cultivar and Verticillium dahliae on the structure of the root and rhizosphere soil fungal microbiome of strawberry.

Sustainable management of crop productivity and health necessitates improved understanding of the ways in which rhizosphere microbial populations interact with each other, with plant roots and their abiotic environment. In this study we examined the effects of different soils and cultivars, and the presence of a soil-borne fungal pathogen, Verticillium dahliae, on the fungal microbiome of the rhizosphere soil and roots of strawberry plants, using high-throughput pyrosequencing. Fungal communities of the roots of two cultivars, Honeoye and Florence, were statistically distinct from those in the rhizosphere soil of the same plants, with little overlap. Roots of plants growing in two contrasting field soils had high relative abundance of Leptodontidium sp. C2 BESC 319 g whereas rhizosphere soil was characterised by high relative abundance of Trichosporon dulcitum or Cryptococcus terreus, depending upon the soil type. Differences between different cultivars were not as clear. Inoculation with the pathogen V. dahliae had a significant influence on community structure, generally decreasing the number of rhizosphere soil- and root-inhabiting fungi. Leptodontidium sp. C2 BESC 319 g was the dominant fungus responding positively to inoculation with V. dahliae. The results suggest that 1) plant roots select microorganisms from the wider rhizosphere pool, 2) that both rhizosphere soil and root inhabiting fungal communities are influenced by V. dahliae and 3) that soil type has a stronger influence on both of these communities than cultivar.

Effect of low temperature and soil type on the decomposition rate of soil organic carbon and clover leaves, and related priming effect

The purpose of this study was to improve the temperature response function to be used in models of soil organic carbon (SOC) and litter mineralisation. A clay soil and a sandy soil with equivalent weather and cultivation history were incubated for 142 days at 0, 4, 8.5 or 15 °C, which is representative for the natural temperature range above 0 °C of these soils. The soils were incubated with or without 13C labelled clover leaves in gas tight chambers. In absence of added plant litter, the decomposition rate [mol CO2 (mol substrate-C)−1 day−1] of SOC followed a first order reaction and it was twice as fast in the sandy soil as in the clay soil. Contrary to our hypothesis, the relative response of SOC mineralisation rate to temperature was the same in both soils; it was well described by an Arrhenius function and it could also be approximated as a linear function of temperature. The mineralisation of clover leaves was affected by soil type, and was slower in the clay than in the sandy soil. Also the initial temperature sensitivity of the clover decomposition (to 18% decomposed) could be approximated by a linear function. SOC mineralisation was enhanced (priming effect) by the presence of clover; the relative increase was most conspicuous at 0 °C (150–250% over 142 days, depending on the soil) and decreased with temperature (+40% at 15 °C). At the start of the incubation and up to 52 days of incubation the priming effect was correlated with the amount of CO2 derived from mineralisation of clover leaves. We suggest that the effect of soil type on the diffusivity of enzymes could be an important mechanism affecting the decomposition rate and probably also the volume of soil exposed to priming around decomposing litter.In conclusion, the temperature sensitivity of the decomposition was in the order: priming < plant litter < sandy soil SOC = clay soil SOC. For the purpose of modelling, we present parameterised equations for mineralisation rates of SOC and clover leaves as function of soil temperature range 0–15 °C. Regarding modelling of priming, there is scope for relating it to litter decomposition and the influence of soil type on the diffusion of enzymes from microorganisms around the litter surface. The effect of soil type on plant litter decomposition and soil priming should be considered in models that predict nitrogen mineralisation based on the C/N stoichiometry of substrates and decomposition products.

A Coupled Mathematical Model to Predict the Influence of Nitrogen Fertilization on Crop, Soil and Groundwater Quality

Intensified use of nitrogen based fertilizers in agriculture has resulted in a significant increases in soils and groundwater nitrate concentrations all over the world. Here we propose a new coupled model which describes the physical transport and biogeochemical dynamics of the water and nitrogen compounds in a soil-water-plant-groundwater system. Our model takes into account water infiltration into an unsaturated porous medium, the complex biogeochemical cycle of nitrogen in soils, nitrate leaching from the agricultural system toward the aquifer’s water table, and the dispersion of nitrates in the groundwater. We calibrate our model and analyse the influence of soil type, precipitation or irrigation regime and fertilization schedules on leaching to groundwater as well as the temporal and spatial evolution of the nitrate pollutant plume in the aquifer. Simulations indicate that in order to achieve high crop yields while minimizing nitrogen loading to soils and groundwater we need to create an optimal balance between the amount of chemical fertilizers and water applied to crops on one hand, and the amount of nitrate and water used by plants on the other. We find that medium soils are more suitable for a sustainable corn production than coarse soils, ensuring both higher yield and less nitrate pollution of the aquifer. Regardless of soil type and irrigation schedule, a gradual fertilization throughout the plant life cycle reduces the potential for leaching and aquifer pollution. For medium soils, a more modest irrigation schedule results in more nitrate available for crops and less net leaching to the groundwater.

RESPONSE OF LATERALLY LOADED SINGLE PILE IN SANDY SOIL

Pile foundations are often required to resist lateral loading. Lateral loads come from a variety of sources including wind, earthquakes, waves, and ship impacts. The lateral capacity of a pile is usually much smaller than the axial capacity and as a result groups of piles are often installed to increase the lateral capacity of the entire foundation system. When vertical or plumb pile groups do not provide sufficient lateral resistance the piles can be battered in order to mobilize some of the higher axial capacity to resist the lateral load. Several methods are available for predicting the ultimate lateral resistance to piles in sandy soil. However, these methods often produce significantly different ultimate resistance values. This makes it difficult for practicing engineers to effectively select the appropriate method when designing laterally loaded piles in sandy soil. In this paper, lateral load behavior of single piles in sandy soil was studied, for different L/D ratio by changing the diameter and length of pile. The analysis was carried out considering long free-head pile. The influence of soil type, effect of pile length and pile diameter on the pile response was observed and the results obtained by IS2911Part1 (sec2) and Matlock & Reese were presented.

BEHAVIOR OF LATERALLY LOADED PILES IN COHESIVE SOILS

Pile foundations are often required to resist lateral loading. Lateral loads come from a variety of sources including wind, earthquakes, waves, and ship impacts. So, it is important to know the lateral load resistance capacity of pile foundation. This requires estimation of ultimate loads based on which safe working loads will be assessed and also estimation of pile deflections to ensure that serviceability aspects are accounted in the design Several methods are available for predicting the ultimate lateral resistance to piles in clay soil. However, these methods often produce significantly different ultimate resistance values. This makes it difficult for practicing engineers to effectively select the appropriate method when designing laterally loaded piles in clay soil. In this paper, lateral load behavior of single piles in clay soil was studied, for different L/D ratio by changing the diameter and length of pile. The analysis was carried out by considering free head pile. The influence of soil type, effect of pile length and pile diameter on the pile response was observed and the results obtained by IS2911Part1 (sec2) were compared with the Broms method. Also deflection and lateral load were calculated for a typical pile for various L/D ratio and their results were presented

Understanding cultivar-specificity and soil determinants of the cannabis microbiome.

Understanding microbial partnerships with the medicinally and economically important crop Cannabis has the potential to affect agricultural practice by improving plant fitness and production yield. Furthermore, Cannabis presents an interesting model to explore plant-microbiome interactions as it produces numerous secondary metabolic compounds. Here we present the first description of the endorhiza-, rhizosphere-, and bulk soil-associated microbiome of five distinct Cannabis cultivars. Bacterial communities of the endorhiza showed significant cultivar-specificity. When controlling cultivar and soil type the microbial community structure was significantly different between plant cultivars, soil types, and between the endorhiza, rhizosphere and soil. The influence of soil type, plant cultivar and sample type differentiation on the microbial community structure provides support for a previously published two-tier selection model, whereby community composition across sample types is determined mainly by soil type, while community structure within endorhiza samples is determined mainly by host cultivar.

Evaluation of compost influence on soil water retention

The experiment was focused on evaluation of influence of compost application on soil water retention. Soil retention is a major soil water property that governs soil functioning as a ecosystem. Soil moisture forms a major buffer against flooding, and water capacity in subsoil is a major factor for plant growth. The effects of changes in soil water retention depend on the proportions of the textural components and the amount of organic carbon present in the soil. During seasons of 2009 and 2010, experiments at two sites of different soil conditions prepared by addition of compost doses of 50 and 100 t.ha−1 were carried out. Changes of humidity were continuously monitored and recorded by soil moisture sensors. Results showed that application of compost of above mentioned doses positively affected water retention of the soil. Organic matter, applied at the above mentioned amount has a positive effect on soil moisture retention, regardless of possible influence of soil type, grassing and amount of rainfalls. Outcomes of experiment become bases for recommended compost doses as well as for technical proposal of compost application processes.

Assessment of terrestrial gamma radiation dose rate (TGRD) of Kelantan State, Malaysia: Relationship between the geological formation and soil type to radiation dose rate

Terrestrial gamma radiation dose rates (TGRD) of Kelantan State were measured in situ using a portable [NaI(TI)] micro roentgen (µR) survey meter. The TGRD rates ranged between 44 and 500 nGy h−1 with a mean value of 209 ± 8 nGy h−1. The distribution of these measurements in various districts of the state shows the statistically the influence of geology and soil types on the dose rate values. The data obtained could be used in formulating safety standard and radiological guidelines.

Soil type influence on yield quantity and quality at grape varieties for white wines obtained in the viticultural centre Blaj.

The study was conducted in 2011-2012 at Reasearch Station for Viticulture and Enology (SCDVV)Blaj and aimed the pretability of varieties for quality white wines (FeteascAƒ regalAƒ 21 Bl, Sauvignon 9 Bl,Traminer roz 60 Bl, Muscat Ottonel 12 Bl and Neuburger 10 Bl) in pedogenesis conditions of entiantrosoland eutricambosol soil from TA¢rnave vineyard. In terms of varieties were conducted observations andmeasurements on bud viability, fertility and productivity elements, production obtained per vine andcrop quality in terms of climatic conditions of the two years analyzed. Fertility and productivity arecorrelated with each other and directly affects the production of grapes. Thus, agro biological value wasdetermined in conditions of the varieties studied in Blaj wine center (2011 and 2012) on the two soiltypes. In terms of lithology, TA¢rnave vineyard is characterized by the predominance of clays, marls andPanonian and Sarmatian gravels (ridges and hillsides) and the loess (Pleistocene and Holocene terraces)of the sediments formed soil formation.We determined the main agrochemical soil fertility parameters(pH, total nitrogen, phosphorus and potassium). Blaj vineyard has a long tradition, especially in thedirection of the cultivation of grapes for the production of quality white wines, while those studied inthis paper, rich assortment of varieties for white wine vineyard TA¢rnave.

Modeling of ground motion rotational components for near-fault and far-fault earthquake according to soil type

The motion of a point is specified completely through six components, three translational and three rotational. Three rotational components of ground motion are classified to two rocking components and one torsional component. The transitional components of ground motion are easily measurable by standard techniques, whereas the rotational components are not directly accessible. In this study, the rotational component of production technique was described, and the influences of soil type and the distance from the fault on the rotational component were investigated. The results showed that the effect of the rotational components is more significant in low periods. Also, the value of the normalized response spectra for soft soil is more than stiff soil, but for far-fault earthquake, it is less than near-fault earthquake.

NifH pyrosequencing reveals the potential for location-specific soil chemistry to influence N2 -fixing community dynamics.

A dataset of 87 020 nifH reads and 16 782 unique nifH protein sequences obtained over 2 years from four locations across a gradient of agricultural soil types in Argentina were analysed to provide a detailed and comprehensive picture of the diversity, abundance and responses of the N2 -fixing community in relation to differences in soil chemistry and agricultural practices. Phylogenetic analysis revealed an expected high proportion of Alphaproteobacteria, Betaproteobacteria and Deltaproteobacteria, mainly relatives to Bradyrhizobium and Methylosinus/Methylocystis, but a surprising paucity of Gammaproteobacteria. Analysis of variance and stepwise regression modelling suggested location and treatment-specific influences of soil type on diazotrophic community composition and organic carbon concentrations on nifH diversity. nifH gene abundance, determined by quantitative real-time polymerase chain reaction, was higher in agricultural soils than in non-agricultural soils, and was influenced by soil chemistry under intensive crop rotation but not under monoculture. At some locations, sustainable increased crop yields might be possible through the management of soil chemistry to improve the abundance and diversity of N2 -fixing bacteria.

Effect of hillslope position and manure application rates on the persistence of fecal source tracking indicators in an agricultural soil.

The influence of liquid dairy manure (LDM) application rates (12.5 and 25 kL ha) and soil type on the decay rates of library-independent fecal source tracking markers (host-associated and mitochondrial DNA) and persistent (>58 d) population structure was examined in a field study. The soils compared were an Aquic Haplorthod and a Typic Haplorthod in Nova Scotia, Canada, that differed according to landscape position and soil moisture regime. Soil type and LDM application rate did not influence decay rates (0.045-0.057 d). population structure, in terms of the occurrence of abundance of strain types, varied according to soil type ( = 0.012) but did not vary by LDM application rate ( = 0.121). Decay of ruminant-specific (BacR), bovine-specific (CowM2), and mitochondrial DNA (AcytB) markers was analyzed for 13 d after LDM application. The decay rates of BacR were greater under high-LDM application rates (0.281-0.358 d) versus low-LDM application rates (0.212-0.236 d) but were unaffected by soil type. No decay rates could be calculated for the CowM2 marker because it was undetectable within 6 d after manure application. Decay rates for AcytB were lower for the Aquic Haplorthod (0.088-0.100 d), with higher moisture status compared with the Typic Haplorthod (0.135 d). Further investigation into the decay of fecal source tracking indicators in agricultural field soils is warranted to assess the influence of soil type and agronomic practice on the differential decay of relevant markers and the likelihood of transport in runoff.

Parametric analyses of evapotranspiration landfill covers in humid regions

Natural soils are more durable than almost all man-made materials. Evapotranspiration (ET) covers use vegetated soil layers to store water until it is either evaporated from the soil surface or transpired through vegetation. ET covers rely on the water storage capacity of soil layer, rather than low permeability materials, to minimize percolation. While the use of ET covers in landfills increased over the last decade, they were mainly used in arid or semi-arid regions. At present, the use of ET covers has not been thoroughly investigated in humid areas. The purpose of this paper is to investigate the use of ET covers in humid areas where there is an annual precipitation of more than 800 mm. Numerical analyses were carried out to investigate the influences of cover thickness, soil type, vegetation level and distribution of precipitation on performance of ET covers. Performance and applicability of capillary barriers and a new-type cover were analyzed. The results show that percolation decreases with an increasing cover thickness and an increasing vegetation level, but the increasing trend becomes unclear when certain thickness or LAI (leaf area index) is reached. Cover soil with a large capability of water storage is recommended to minimize percolation. ET covers are significantly influenced by distribution of precipitation and are more effective in areas where rainy season coincides with hot season. Capillary barriers are more efficient than monolithic covers. The new cover is better than the monolithic cover in performance and the final percolation is only 0.5% of the annual precipitation.

Carbon mineralization in two ultisols amended with different sources and particle sizes of pyrolyzed biochar

Biochar produced during pyrolysis has the potential to enhance soil fertility and reduce greenhouse gas emissions. The influence of biochar properties (e.g., particle size) on both short- and long-term carbon (C) mineralization of biochar remains unclear. There is minimal information on the potential effects of biochar particle sizes on their breakdowns by soil microorganism, so it is unknown if the particle size of biochar influences C mineralization rate and/or stability in soils. In order to evaluate the effect of different sources (BS) and particle sizes (BF) of biochar on C loss and/or stability in soils, an incubation study on C mineralization of different biochar sources and particle sizes was established using two soils (ST): Norfolk soil (fine loamy, kaolinitic, thermic, typic Kandiudults) and Coxville soil (fine loamy kaolinitic, thermic, Paleaquults). In separate incubation vessels, these soils were amended with one of two manure-based biochars (poultry litters, PL; swine solids, SS) or one of two lignocellulosic-based biochars (switchgrass, SG; pine chips, PC) which were processed into two particle sizes (dust, <0.42mm; pellet, >2mm). The amount of CO2 evolved varied significantly between soils (p⩽0.0001); particle sizes (p⩽0.0001) and the interactions of biochar source (p⩽0.001) and forms of biochars (p⩽0.0001) with soil types. Averaged across soils and sources of biochar, CO2-C evolved from dust-sized biochar (281mgkg−1) was significantly higher than pellet-sized biochar (226mgkg−1). Coxville soils with SS biochar produced the greatest average CO2-C of 428mgkg−1 and Norfolk soils with PC had the lowest CO2-C production (93mgkg−1). Measured rates of carbon mineralization also varied with soils and sources of biochar (Norfolk: PL>SS>SG⩾PC; Coxville: PC>SG>SS>PL). The average net CO2-C evolved from the Coxville soils (385mgkg−1) was about threefold more than the CO2-C evolved from the Norfolk soils (123mgkg−1). Our results suggest different particle sizes and sources of biochar as well as soil type influence biochar stability.

Siberian elm responses to different culture conditions under short rotation forestry in Mediterranean areas

This work explores the possibilities of biomass production, for energy purposes, of Siberian elm in Mediterranean areas, including marginal lands with poor soil and low water availability. To achieve this, the influence of soil type, planting density, and water availability on biomass production were analyzed after the first 3 years of the growing cycle in 2 different locations. Moreover, a method to estimate biomass production as a function of some morphological parameters of the trees, as well as the use of leaf water potential as a good indicator of trees' water status, are discussed. The analysis of parameters having an influence on elm growth showed that soil type is the most important factor to obtain a good yield. In soils with enough nutrients and higher water-holding capacity, biomass productions in the range 13-14 Mg DM ha^{-1} were achieved even under rainfed conditions. In irrigated plots, Siberian elm production was more than double the production of biomass under rainfed conditions; however, significant differences were not found between the 2 different irrigation doses under study. Biomass yield was greater for the highest planting density (6666 plants ha^{-1}). Leaf water potential has been shown to be a useful tool for finding out plant water status. Tree growth showed a direct relationship to midmorning leaf water potential, and it was equal to 0 for leaf water potentials lower than -1.83 MPa; this value indicates a great resistance to drought by the species.

EFFECT OF SOIL TYPE AND STORAGE CONDITION ON FRUIT QUALITY OF PUMPKIN

The results of pumpkin fruits storage in natural environment of storage facilities during six months are presented. The influence of soil type and pumpkin variety on the content of main chemicals and changes of fruit quality during storage has been found. After six month of storage as a result of fruit spoiling, the quality of pumpkin fruits was reduced up to 22,6$24,4% in cv. Krupnoplodnaya and up to 5.9$7.7 % in cv. Kroshka. The excess of nitrates and toxic elements above the maximum permissible values in the fruits of all varieties of pumpkin was not observed.

Application and Characterization of an Artificial Grime for Photovoltaic Soiling Studies

Effective evaluation and prediction of photovoltaic performance loss due to soiling require consistent test methods. Natural soil accumulation is time-consuming and location specific, and thus does not provide reproducible results across different geographic regions. Therefore, we have demonstrated a laboratory technique to artificially apply soil to a specimen and quantify the resulting effects of the film on the transmission of incident light. An artificial soil analogue was formulated with NIST-traceable components and applied to the specimen using an aerosol spray gun. This approach produced consistent soil coatings, which were directly correlated to electrical performance loss of multicrystalline Si cells in a laboratory setting. Two independent measurement techniques were used to quantify the influence of the layer of artificial soil on the spectral transmission of light. It was found that the performance loss due to deposited soil could be effectively predicted over a range of mass loadings. Furthermore, it was demonstrated that the composition of the blend, termed “standard grime,” had a significant and repeatable influence on performance loss. The methods presented here provide the basis for further study of the influence of specific soil types on the performance loss of PV systems. It is envisioned that these laboratory studies could be coupled with field studies to better understand these effects.

Climate and soil type together explain the distribution of microendemic species in a biodiversity hotspot.

The grasshopper genus Caledonula, endemic to New Caledonia, was studied to understand the evolution of species distributions in relation to climate and soil types. Based on a comprehensive sampling of 80 locations throughout the island, the genus was represented by five species, four of which are new to science, of which three are described here. All the species have limited distributions in New Caledonia. Bioclimatic niche modelling shows that all the species were found in association with a wet climate and reduced seasonality, explaining their restriction to the southern half of the island. The results suggest that the genus was ancestrally constrained by seasonality. A molecular phylogeny was reconstructed using two mitochondrial and two nuclear markers. The partially resolved tree showed monophyly of the species found on metalliferous soils, and molecular dating indicated a rather recent origin for the genus. Adaptation to metalliferous soils is suggested by both morphological changes and radiation on these soils. The genus Caledonula is therefore a good model to understand the origin of microendemism in the context of recent and mixed influences of climate and soil type.