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Soil Amendment (soil + amendment)

Distribution by Scientific Domains

Life Sciences	38%
Earth and Environmental Science	33%
Chemistry	22%

Selected Abstracts

Restoration of a Mediterranean Postfire Shrubland: Plant Functional Responses to Organic Soil Amendment

RESTORATION ECOLOGY, Issue 5 2010
Marie Larchevêque
We investigated the potential of plant functional responses to speed up restoration in a postfire ecosystem. The patterns of change in plant nutrient uptake and water potential after compost amendment were monitored for 2 years in a 7-year-old postfire shrubland in southeastern France. We studied four different stress-tolerant species with contrasting life traits: three shrub species and a perennial herb. Three treatments were applied: control, 50 and 100 Mg/ha of fresh cocomposted sewage sludge and green waste. In both compost treatments, concentrations of all the macronutrients increased. The amendment improved N and cation nutrition, but the positive effect of compost on plant nutrient status was most apparent on leaf P concentrations, indicating that P was a limiting nutrient in this shrubland. Compost had no significant short-term effect on trace metal concentrations in plants. The plant nutrition response of different species to the compost varied; the nutritional status of Brachypodium retusum and Cistus albidus improved the most, whereas that of Quercus coccifera and Ulex parviflorus improved the least. Woody species exhibited no increase in N stocks. Phosphorus accumulation was also about three times higher in plots amended at 50 Mg/ha than in control plots for B. retusum and C. albidus. The severe summer drought of 2003 altered the compost effect. Contrary to our expectations, plants on amended plots did not exhibit a better water status in summer: the effect of the summer drought had a greater effect on water status than did the compost treatment. [source]

To what extent are soil amendments useful to control Verticillium wilt?

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2009
Nieves Goicoechea
Abstract The genus Verticillium includes several species that attack economically important crops throughout the world. The control of Verticillium spp. becomes especially difficult when they form microsclerotia that can survive in the field soil for several years. It has been common practice to fumigate soil with chemicals such as methyl bromide and/or chloropicrin to control soil-borne fungal pathogens. Other chemicals that are used against Verticillium spp. are the antifungal antibiotic aureofungin, the fungicides benomyl, captan, carbendazim, thiram, azoxystrobin and trifloxystrobin and the plant defence activator acibenzolar- S -methyl. However, the potential risks involved in applying phytochemicals to crop plants for both the environment and human health, together with their limited efficacy for controlling Verticillium -induced diseases, support the need to find alternatives to replace their use or improve their efficacy. Soil amendment with animal or plant organic debris is a cultural practice that has long been used to control Verticillium spp. However, today the organic farming industry is becoming a significant player in the global agricultural production scene. In this review, some of the main results concerning the efficacy of several soil amendments as plant protectors against Verticillium spp. are covered, and the limitations and future perspectives of such products are discussed in terms of the control of plant diseases. Copyright © 2009 Society of Chemical Industry [source]

Characterization of biochar from fast pyrolysis and gasification systems

ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2009
Catherine E. Brewer
Abstract Thermochemical processing of biomass produces a solid product containing char (mostly carbon) and ash. This char can be combusted for heat and power, gasified, activated for adsorption applications, or applied to soils as a soil amendment and carbon sequestration agent. The most advantageous use of a given char depends on its physical and chemical characteristics, although the relationship of char properties to these applications is not well understood. Chars from fast pyrolysis and gasification of switchgrass and corn stover were characterized by proximate analysis, CHNS elemental analysis, Brunauer-Emmet-Teller (BET) surface area, particle density, higher heating value (HHV), scanning electron microscopy, X-ray fluorescence ash content analysis, Fourier transform infrared spectroscopy using a photo-acoustic detector (FTIR-PAS), and quantitative 13C nuclear magnetic resonance spectroscopy (NMR) using direct polarization and magic angle spinning. Chars from the same feedstocks produced under slow pyrolysis conditions, and a commercial hardwood charcoal, were also characterized. Switchgrass and corn stover chars were found to have high ash content (32,55 wt %), much of which was silica. BET surface areas were low (7,50 m2/g) and HHVs ranged from 13 to 21 kJ/kg. The aromaticities from NMR, ranging between 81 and 94%, appeared to increase with reaction time. A pronounced decrease in aromatic CH functionality between slow pyrolysis and gasification chars was observed in NMR and FTIR-PAS spectra. NMR estimates of fused aromatic ring cluster size showed fast and slow pyrolysis chars to be similar (,7,8 rings per cluster), while higher-temperature gasification char was much more condensed (,17 rings per cluster). © 2009 American Institute of Chemical Engineers Environ Prog, 2009 [source]

Lime and cow slurry application temporarily increases organic phosphorus mobility in an acid soil

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2007
P. N. C. MurphyArticle first published online: 13 OCT 200
Summary Phosphorus loss from agricultural soils to water is recognized as a major contributor to eutrophication of surface water bodies. There is much evidence to suggest that liming, a common agricultural practice, may decrease the risk of P loss by decreasing P solubility. An unsaturated leaching column experiment, with treatments of control and two lime rates, was carried out to investigate the effects of liming on P mobility in a low-P acid Irish soil, which was sieved and then packed in columns. Phosphorus was applied at the soil surface in the form of KH2PO4 in solution or as cow slurry. Soil solution was sampled at time intervals over depth and analysed for P fractions. Organic P (OP) was the dominant form of P mobile in soil solution. Liming increased OP mobility, probably through increased dispersion of OP with increased pH. Slurry application also increased OP mobility. Results indicated the potential for OP loss following heavy (100 m,3 ha,1) cow slurry application, even from low-P soils, and suggested that liming may increase this risk. Reactive P (RP) was sorbed strongly and rapidly by the soil and did not move substantially below 5 cm depth. As a result, Olsen-P values in the top 2 cm were greatly increased, which indicates an increased risk of RP loss in overland flow. Lime showed little potential as a soil amendment to reduce the risk of P loss. [source]

Immobilization of the heavy metals Cd, Cu and Pb in an acid soil amended with gypsum- and lime-rich industrial by-products

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2004
V. Illera
Summary In situ stabilization of heavy metals in contaminated soils by the addition of various types of soil amendment is an attractive technique for remediation. We investigated the potential of three industrial by-products (phosphogypsum, red gypsum and dolomitic residue) for boosting the heavy metal sorption capacity of an acid soil (patents pending, Spanish applications no 200201704 and 200201375) by using sorption isotherm experiments. The three by-products were found substantially to increase the retention of lead, cadmium and copper on the solid components of the soil. The increase in lead retention of the soil horizons upon the addition of both phosphogypsum and red gypsum was dominated by the formation of anglesite minerals. The dolomitic residue increased the metal retention capacity of the soil horizons through the precipitation of laurionite-type minerals as well as cadmium and copper hydroxy-chlorides. In addition to the batch sorption study, we used scanning electron microscopy to investigate the metal sorption processes in the soil by the effect of the treatments. Lead was frequently found to be linked to the edge charges of kaolinite minerals. The three metals were found to be associated with organic matter in the Ap horizon treated with the three by-products. Finally, the three metals were found to be associated with undissolved dolomitic residue particles. [source]

Decomposition of Allelopathic Plants in Soil

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2005
T. D. Xuan
Abstract Higher plants with strong allelopathic properties are commonly incorporated into soil for weed-control purposes. To understand the phytotoxic variation in the soil, which can be utilized for weed control through the use of allelopathic plants, the decomposition of alfalfa (Medicago sativa L. cv. Rasen) and kava (Piper methysticum L.) after soil amendment were evaluated. Both alfalfa and kava strongly inhibited barnyardgrass and monochoria growth for up to 10 days (80,100 % weed control). After 20,25 days, the magnitude of inhibition was drastically reduced, but was still effective (50 % weed control). A number of phenolic acids were detected in the soil even 50 days after incorporation in low concentration, but their concentrations reached a maximum after 10,15 days and were efficacious until 20,25 days. Phenolic acids varied between alfalfa and kava. The variations in electrical conductivity (EC) and osmotic pressure (OP) were strongly related to chemicals and toxic compounds exuded into the soil during decomposition and were proportional to the magnitude of inhibition observed, whereas pH did not appear to be correlated with inhibition. The decomposition of several unknown inhibitors present in kava was also analysed and assessed. Our findings indicate that these growth inhibitors were almost disintegrated in soil after 10 days, but strong inhibition was detected until 25 days after amendment. Results from this study demonstrate that chemicals released from allelopathic plants incorporated into soil are toxic and cause inhibition of certain species and could be exploited as a biological tool for weed management. [source]

Survival of Sclerotium cepivorum Sclerotia and Fusarium oxysporum Chlamydospores in Soil Amended with Cruciferous Residues

JOURNAL OF PHYTOPATHOLOGY, Issue 6 2000
U. SmolinskaArticle first published online: 28 JUN 200
Abstract The use of cruciferous plant residues to reduce the amount of sclerotia of Sclerotium cepivorum and chlamydospores of Fusarium oxysporum f. sp. lycopersici in soil was investigated. Air-dried and crushed mustard (Brassica juncea) added to the soil effectively reduced the viability of fungal propagules. Consequently, the reduction of white rot of onion, caused by S. cepivorum and wild of tomato caused by F. oxysporum was observed. The addition of rapeseed (Brassica. napus cv. Bolko and B. napus cv. Gorczanski) residues to soil also resulted in a significant decrease of number of S. cepivorum sclerotia but the effect on F. oxysporum chlamydospores was variable. Introduction of the plant material increased the total number of bacteria, spore-forming bacteria, fluorescent pseudomonads, actinomycetes, and fungi in soil. One year after the soil amendment, the amount of sporeforming bacteria in treatments with cruciferous residues was higher as compared to the control soil without plant residues. The possible contribution of the decomposition of plant residues and soil micro-organisms to the reduction of the pathogens population is discussed. Zusammenfassung Untersucht wurde die Eignung von Kreuzblütler-Pflanzenresten zur Reduktion der Zahl der Sklerotien von Sclerotium cepivorum und der Chlamydosporen von Fusarium oxysporum f. sp. lycopersici im Boden. Wurden luftgetrocknete und zerkleinerte Senfpflanzen (Brassica juncea) als Bodenzusatz verwendet, so war die Lebensfähigkeit der pilzlichen Überdauerungsorgane deutlich verringert. Entsprechend wurde ein Rückgang der durch S. cepivorum hervorgerufenen Weißfäule der Zwiebel und der durch F. oxysporum hervorgerufenen Tomatenwelke beobachtet. Der Zusatz von Raps-Pflanzenresten (Brassica napus cv. Bolko und B. napus cv. Gorczanski) zum Boden führte ebenfalls zu einer signifikanten Abnahme der Zahl von S.-cepivorum -Sklerotien, doch die Wirkung auf die Chlamydosporen von F. oxysporum war unterschiedlich. Die Einbringung des Pflanzenmaterials erhöhte die Gesamtzahl an Bakterien, sporenbildenden Bakterien, fluoreszierenden Pseudomonaden, Actinomyceten und Pilzen im Boden. Ein Jahr nach der Bodenanreicherung war die Zahl sporenbildender Bakterien in den Varianten mit Kreuzblütler-Resten höher als in den Böden der Kontrollvariante ohne Pflanzenreste. Der mögliche Einfluß der Zersetzung der Pflanzenreste und der Bodenmikroorganismen auf die Reduktion der Pathogenpopulation wird diskutiert. [source]

Nutrient composition of tomato products prepared using tomato grown under sodic condition with gypsum and farmyard manure treatment

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2009
Varsha Rani
Abstract BACKGROUND: The use of sodic water for crop irrigation decreases the availability of nutrients such as nitrogen, calcium, magnesium and zinc to plants and harms crop yield and quality. Crops irrigated with sodic water have been utilised in various product formulations. Gypsum and farmyard manure (FYM) are known to provide good soil amendment under sodic water irrigation. This research was therefore conducted to study the variation in nutrient composition of tomato products prepared from tomatoes irrigated with canal water (control) and those irrigated with sodic water treated with gypsum and FYM at two levels, i.e. 50% neutralisation of sodicity (G1F2) and complete neutralisation of sodicity (G2F2). RESULTS: The contents of protein, fat, crude fibre, ash, carbohydrate and total soluble sugars in three types of tomato product were in the ranges 1.08,1.68, 0.20,0.31, 0.43,1.07, 0.83,1.06, 6.17,7.22 and 2.32,4.81 g kg,1 respectively. Tomato products prepared from tomatoes irrigated with G1F2 -treated water contained significantly (P < 0.05) less protein, fat, crude fibre, dietary fibre, calcium, magnesium, phosphorus, potassium, iron, zinc and sulfate but more ash, carbohydrate, total soluble sugars, oxalic acid, polyphenols, sodium, chloride and bicarbonate than those prepared from tomatoes irrigated with canal water and G2F2 -treated water. CONCLUSION: The results showed that tomato crops irrigated with sodic water treated with gypsum and FYM to varying extent were effective in maintaining and improving the nutrient composition of various tomato products. Copyright © 2009 Society of Chemical Industry [source]

The effect of incorporating straw or manure into the soil on the natural microflora of winter wheat

PLANT PATHOLOGY, Issue 5 2001
B. S. Rodgers-Gray
Over 3 years, five crops of winter wheat with different fertilization or pesticide treatments were grown in replicated plots in which straw, cattle manure or nothing was incorporated into the soil. It was previously shown that severities of several foliar diseases were reduced by the treatment with straw. Treatments with straw slightly increased leaf microbial numbers at growth stage (GS) 10, and significantly but slightly decreased numbers at GS 60 and 70, when averaged over all crops. There was no evidence of differences in potential for biological control between plots, because no differences were demonstrated between treatments in the proportion of phylloplane residents able to produce chitinase, siderophores or antibiotics. There was no link between soil and leaf nitrogen and microbial populations or soil amendment. The two youngest leaves of straw-treated plants remained green longer than leaves from untreated or manure-treated plants. Microbial numbers differed between crops, but within crops were more stable on leaves and ears than in soil. Soil populations were larger before the crops were sown. Bacteria predominated over fungi in all habitats throughout the growing season. The ratio of Gram-negative to Gram-positive bacteria recovered was similar on leaves and in soil, but not on ears. Soil and leaf microbes utilized similar carbon sources. More leaf epiphytes than soil microbes produced siderophores. The majority of identified organisms belonged to only a few species. Chromogenic organisms were more abundant on aerial surfaces. A fungicide, chlorothalonil, was applied in one crop; it reduced the microbial population but did not alter its composition (without affecting the reduction in disease due to straw). It is postulated that straw acts in the field by altering plant physiology and thus altering both microbial colonization and disease. [source]

Reducing salinity and organic contaminants in the Pearl Harbor dredged material using soil amendments and plants

REMEDIATION, Issue 4 2002
N. V. Hue
Phytoremediation is an emerging technique that can be used to economically remediate sites contaminated with trace elements and/or man-made organic contaminants. This technique was used on Pearl Harbor (Oahu, Hawaii) dredged material (PHDM) containing polycyclic aromatic hydrocarbons (PAHs) and some heavy metals. The dredged material was first amended with a high-calcium soil (Waialua Mollisol) and a biosolids-based compost at different proportions to yield varying salinity levels. A mixture that yielded an electrical conductivity (EC, a measure of salinity) of the saturated paste extract of 15 to 20 dS/m was identified and used to evaluate the salt tolerance of five plant species. Relative germination and one-month-old biomass indicated that common bermuda grass (Cynodon dactylon), seashore paspalum (Paspalum vaginatum), beach pea (Vigna marina), and cow pea (Vigna unguiculata) can produce at least 40 percent of biomass of the control at an EC of approximately 18 dS/m, suggesting the four plants are relatively salt tolerant. In contrast, Desmodium intortum either did not germinate or died within two weeks after germination at the same salinity level. A subsequent greenhouse experiment, using mixtures of the PHDM (0 or 25 percent dry weight), organic amendments (10 percent leucaena green manure or biosolids-based compost), and a Mollisol (65 or 90 percent dry weight) in 6-liter pots containing 4 kilograms of material yielded the following results: (1) A combination of transplanted seashore paspalum, seeded bermuda grass, and seeded beach pea was effective in taking up sodium (Na), thereby reducing salinity and making the medium more amenable to diversified microbes and plants, which may be effective PAH degraders; (2) total PAH concentration was reduced by about 30 percent after three months of active plant growth, but degradation of individual PAH members varied significantly, however; (3) leguminous green manure, as a soil amendment, was more effective than compost for use in bio- and/or phytoremediations; and (4) soil amendments, when applicable, could supplement living plants in reducing organic contaminants, such as PAHs. © 200 Wiley Periodicals, Inc. [source]

Road Slope Revegetation in Semiarid Mediterranean Environments.

RESTORATION ECOLOGY, Issue 1 2007
Part I: Seed Dispersal, Spontaneous Colonization
Abstract The importance of neighboring vegetation as a seed reservoir for spontaneous colonization of adjacent road slopes was analyzed in a semiarid region of east Spain. Two independent methodological approaches were used to examine the relative contribution of seed from neighboring vegetation and the efficiency of different seed dispersal strategies in plant colonization. We first used a randomization test to compare floristic similarity between road slopes, neighboring flora, and local flora (the regional species pool found in the same climate and soil conditions as the road slopes). Second, we compared seed dispersal mechanisms of road slope vegetation with those of the surrounding area using frequency analysis. Species composition of road slopes was more similar to that of the flora of adjacent surrounding areas than expected by chance. Anemochorous (wind-dispersed) plants were over-represented in road slopes 8 years after road slopes were built. We concluded that seed dispersal from neighboring vegetation is an important factor in the vegetative colonization of road slopes. However, this initial species pool was also strongly shaped by the harsh environmental conditions of roadcuts and southern aspect. These results have important implications in road slope restoration because they suggest that naturally vegetated areas should be maintained adjacent to road slopes to enhance seed immigration from species adapted to local site conditions, which will accelerate the successional process. The application of this single reclamation strategy and mixed strategies that combine the use of natural colonization and soil amendment for road slope restoration in Mediterranean environmental conditions is discussed. [source]

Co-existing grass species have distinctive arbuscular mycorrhizal communities

MOLECULAR ECOLOGY, Issue 11 2003
P. Vandenkoornhuyse
Abstract Arbuscular mycorrhizal (AM) fungi are biotrophic symbionts colonizing the majority of land plants, and are of major importance in plant nutrient supply. Their diversity is suggested to be an important determinant of plant community structure, but the influence of host-plant and environmental factors on AM fungal community in plant roots is poorly documented. Using the terminal restriction fragment length polymorphism (T-RFLP) strategy, the diversity of AM fungi was assessed in 89 roots of three grass species (Agrostis capillaris, Festuca rubra, Poa pratensis) that co-occurred in the same plots of a field experiment. The impact of different soil amendments (nitrogen, lime, nitrogen and lime) and insecticide application on AM fungal community was also studied. The level of diversity found in AM fungal communities using the T-RFLP strategy was consistent with previous studies based on clone libraries. Our results clearly confirm that an AM fungal host-plant preference exists, even between different grass species. AM communities colonizing A. capillaris were statistically different from the others (P < 0.05). Although grass species evenness changed in amended soils, AM fungal community composition in roots of a given grass species remained stable. Conversely, in plots where insecticide was applied, we found higher AM fungal diversity and, in F. rubra roots, a statistically different AM fungal community. [source]

To what extent are soil amendments useful to control Verticillium wilt?

Effect of temperature, organic amendment rate and moisture content on the degradation of 1,3-dichloropropene in soil,

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 12 2001
Robert S Dungan
Abstract 1,3-Dichloropropene (1,3-D), which consists of two isomers, (Z)- and (E)-1,3-D, is considered to be a viable alternative to methyl bromide, but atmospheric emission of 1,3-D is often associated with deterioration of air quality. To minimize environmental impacts of 1,3-D, emission control strategies are in need of investigation. One approach to reduce 1,3-D emissions is to accelerate its degradation by incorporating organic amendments into the soil surface. In this study, we investigated the ability of four organic amendments to enhance the rate of degradation of (Z)- and (E)-1,3-D in a sandy loam soil. Degradation of (Z)- and (E)-1,3-D was well described by first-order kinetics, and rates of degradation for the two isomers were similar. Composted steer manure (SM) was the most reactive of the organic amendments tested. The half-life of both the (Z)- and (E)-isomers in unamended soil at 20,°C was 6.3 days; those in 5% SM-amended soil were 1.8 and 1.9 days, respectively. At 40,°C, the half-life of both isomers in 5% SM-amended soil was 0.5 day. Activation energy values for amended soil at 2, 5 and 10% SM were 56.5, 53.4 and 64.5,kJ,mol,1, respectively. At 20,°C, the contribution of degradation from biological mechanisms was largest in soil amended with SM, but chemical mechanisms still accounted for more than 58% of the (Z)- and (E)-1,3-D degradation. The effect of temperature and amendment rate upon degradation should be considered when describing the fate and transport of 1,3-D isomers in soil. Use of organic soil amendments appears to be a promising method to enhance fumigant degradation and reduce volatile emissions. Published in 2001 for SCI by John Wiley & Sons, Ltd [source]

Control of black foot disease in grapevine nurseries

PLANT PATHOLOGY, Issue 4 2007
F. Halleen
Black foot disease of grapevines is a decline and dieback disease caused by a soilborne pathogen complex including Cylindrocarpon liriodendri, C. macrodidymum, Campylocarpon fasciculare and Campyl. pseudofasciculare. These pathogens cause primary infections of roots and basal ends of grafted cuttings in nursery soils. Thirteen fungicides were screened in vitro for mycelial inhibition of these pathogens. Prochloraz manganese chloride, benomyl, flusilazole and imazalil were the most effective fungicides tested, and were subsequently included in semi-commercial field trials. Basal ends of grafted cuttings were dipped in various chemical and biological treatments prior to planting in open-rooted nurseries. Black foot pathogens were not isolated from grafted cuttings prior to planting. Additional treatments involved soil amendments with Trichoderma formulations and hot water treatment of dormant nursery grapevines. Field trials were evaluated after eight months. Isolations from uprooted plants revealed low levels of black foot pathogens in the roots of untreated control plants, and significantly higher levels in basal ends of rootstocks. The incidence of black foot pathogens, as well as that of Petri disease pathogens, was not significantly and/or consistently reduced by the majority of chemical or biological treatments. However, these pathogens were not isolated from uprooted plants that were subjected to hot water treatment. It is therefore recommended that hot water treatment of dormant nursery plants be included in an integrated strategy for the proactive management of these diseases in grapevine nurseries. [source]

Reducing salinity and organic contaminants in the Pearl Harbor dredged material using soil amendments and plants

Seedling Establishment and Survival on Restored Campsites in Subalpine Forest

RESTORATION ECOLOGY, Issue 3 2007
David N. Cole
Abstract This study experimented with common restoration techniques (scarification, soil amendments, mulch, and seeding) on six closed wilderness campsites in subalpine forests in Oregon. Effectiveness in encouraging seedling establishment, growth, and survival was assessed every year for the first 7 years following treatment. Closure and restoration of the campsites increased the density of plants established from seed. Despite an original density of virtually zero, mean density of perennial plants was 55 plants/m2 7 years after closure. All the treatments, with the exception of the biodegradable mulch mat, increased plant density. Seven years after treatment, seeding had increased plant density 5-fold, whereas scarification and soil amendments (organic matter, compost, and soil inoculum) had each increased density 3-fold. The organic and compost amendments also had the positive benefit of increasing growth rates and shortening the time-to-reproductive maturity. Results suggest that restoration of the herbaceous cover on these campsites can occur rapidly using the techniques employed. All but one of the species we seeded established in substantial quantities and survived at densities exceeding their density in the naturally sparse herbaceous cover on these sites. Thirty-six perennial species volunteered on these sites. The remaining challenge is reestablishment of the shrub species that comprise much of the ground cover in these forests. These species seldom establish from seed. [source]