Assessing the microbiological,biochemical, soil-physical and hydrological effects of amelioration of degraded soils in semiarid Spain

The way of improving degraded soils fertility and particularly of improving its microbial activity is to add “young” exogenous organic matter that contribute to provide labile organic matter to stimulate the life of the microorganisms existing in the soil. This organic matter will also improve both the retention and hydraulic characteristics of the degraded soils, all this contributing to soil restoration. In this study, the microbiological, biochemical, soil-physical and hydrological effects of the addition of a municipal solid waste compost to a degraded soil in El Campello, SE Spain were evaluated in a field experiment. Soil samples from experimental plots were analyzed 6 and 18 months after soil amendment. In both sampling time treated plots showed significantly higher microbial biomass carbon and dehydrogenase activity values than control, indicating that soil microbial population’s development and activity were stimulated by compost addition, this effect being not ephemeral but lasting in the time. Soil urease activity was not affected by compost addition while protease hydrolysing N-α-benzoil-L-argininamide (BAA) activity was strongly stimulated by the incorporation of compost into the soils. Phosphatase and β-glucosidase activities were also stimulated by the organic amendment, this stimulation being particularly noticeable 18 months after the compost addition. Nevertheless, this increase in soil microbial populations and activity did not result in an increase in soil aggregation and hydrological parameters. This can be due to the high content of carbonates and Ca²⁺ ions in these calcareous soils, that lead to an initially high content of water-stable macroaggregates. Presented at the International Conference on Bioclimatology and Natural Hazards, Poľana nad Detvou, Slovakia, 17–20 September 2007.     

Effects of different organic waste amendments on soil microaggregates stability and molecular sizes of humic substances

Three soils which had been amended for several years with pig slurry, cattle slurry, and sewage sludge were dry-sieved to obtain microaggregates in the size range of 250–125, 125–50, and <50 μm. With amendments, aggregate size distribution of whole soils was shifted to larger sizes, especially for the most fragile soil, whereas percent content of microaggregates decreased except for the lower size aggregates of the fragile soil. Particle size distribution of microaggregates revealed an increase in percent sand and a reduction of percent silt and clay in the <50 μg size fraction for all soils. These results showed the aggregation effect induced by the organic waste additions. Aggregate stability of microaggregates revealed significant correlation with humic substances content (humic acids alone and humic plus fulvic acids) and non significant with total organic matter substantiating the belief that humic substances are the predominant binding agents in this aggregation range. Molecular weight distribution of humic acids extracted from microaggregates of unamended soils demonstrated that the lower the soil aggregate size distribution, the larger the contribution of the high molecular weight fraction. All microaggregates from amended soils showed a progressive increase of the high molecular weight humic acids with decreasing size, reaching a maximum in the <50 μm fraction. In this aggregate size a parallel enhancement of the aggregate stability was also evident. It is concluded that a close relationship exists between aggregate stability and high molecular weight humic substances. Additions to soils of organic material containing high molecular weight constituents would represent a useful management practice to improve aggregate stability.     

Olive orchard amended with two experimental olive mill wastes mixtures: effects on soil organic carbon, plant growth and yield

Amendments of olive orchard soil with two different preparations of olive mill solid waste (OMWMs) at the rate of 9tonha(-1) per year for five years in two different plots were compared with an industry standard soil amendment using urea. Both the OMWMs amendments showed significant increases in total organic carbon and humic substances in soil of approximately 40% and 58%, respectively, without negative effects on tree growth and yield. This work has shown that olive oil mill waste (OMW) can be recycled safely using the bioremediation system used in this study. We suggest that this system is particularly beneficial to organic farming and is an alternative solution to direct spreading of raw OMW on farm lands.     

Reclamation of a burned forest soil with municipal waste compost: macronutrient dynamic and improved vegetation cover recovery

The reclamation of burned soils in Mediterranean environments is of paramount importance in order to increase the levels of soil protection and minimise erosion and soil loss. The changes produced in the content of total organic carbon (TOC), N (Kjeldahl) and available P, K, Ca and Mg by the addition of different doses of a municipal solid waste compost to a burned soil were evaluated during one year. The effect of organic amendment on the improvement in the vegetation cover after one year was also evaluated. The organic amendment, particularly at a high dose, increased the TOC and N-Kjeldahl content of the soil in a closely related way. The levels of available K in soil were also enhanced by the organic amendment. Although the effects on all three parameters tended to decrease with time, their values in the amended soils were higher than in the control soil, which clearly indicates the improvement in the chemical quality of the soil brought about by the organic amendment. The available P content did not seem to be influenced by organic treatment, while available Mg levels were higher than in the control during the first 4 months following organic amendment. The application of compost to the burned soil improved its fertility and favoured rapid vegetal recovery, thus minimising the risk of soil erosion.     

Soil biochemical activity and growth response of rice Oryza sativa in flyash amended soil

Soil amended with different proportions of flyash, a solid waste generated from coal-fired thermal power plants, was evaluated as a soil conditioner and nutrient supplement during a field study on the growth of rice, Oryza sativa. Generally, pH and organic carbon (OC) content did not increase significantly (P > 0.05) in flyash amended soil, but significant increases (P < 0.05) in soil conductivity (32%), available phosphorus (48%) and organic matter (OM, 29%) were observed during harvest at the 20 t ha-1 flyash application rate. Amylase, invertase, dehydrogenase and protease activities, and CO2 evolution increased in flyash amended soil over the control. The pigment (chl-a, chl-b, and carotenoid) content in rice plants did not vary significantly (P > 0.05) between different flyash amendments. Total plants biomass and aboveground biomass increased (P < 0.05) significantly (17% and 25%, respectively) at the 20 t ha-1 flyash application. However, there was a retarded growth of underground biomass. Grain and straw yield increased by 21% and 18%, respectively, at 17.5 t ha-1 flyash amendment when compared to the control. Although, a significant increase (P < 0.05) in plant biomass and grain yield in flyash amended soil is encouraging from the point of waste disposal and management, elucidation of reasons for retarded growth in underground biomass will require additional research based on long-term studies.     

Efficacy of organic wastes amendment on the establishment and biomass yield of grass species on a degraded Alfisol

Abstract

Deficiencies of organic matter and essential nutrients are important features of derelict/degraded lands; these characteristics have profound effects on the establishment of functional soil-plant systems on such lands. This work reports on the impact of organic wastes amendments on the establishment, growth and biomass yield of grass mixtures grown on a degraded soil. The experimental site was a heavily compacted and eroded land due to excavation (scrapping) of topsoil layer for urban construction activities. Zero, 10 and 20cm layers each of substrates collected from an old (abandoned) municipal refuse and from site affected by long-term surface disposal of livestock litter and topsoil collected under fallow vegetation were applied on soil surface, before the establishment of a mixture of grass species. Substrates collected from old municipal refuse contained high amount of essential nutrients and metals and, on application, produced upward shift in soil pH and electrical conductivity. Nevertheless, these properties neither significantly retarded plant growth nor impaired biomass yield. Plant establishment and biomass yield were comparable under topsoil application and organic waste amended soil and produced significantly higher biomass yield when spread at 20cm layers were made of them. This experimental group also produced superior biomass yield over the unamended control. The agronomic benefits of organic waste incorporation stemmed from improved soil properties in surface horizon and contents of essential nutrients supportive of the establishment and development of plant cover. Nutrient supply is related to soil organic matter status, organic wastes are therefore important to the reconstruction of effective nutrient cycling and the eventual functional soil-plant system on this degraded ecosystem. The goal of these revegetation efforts is to improve soil and plant productivity, plant diversity, conservation of native grasslands and aesthetic.     

The Effects of Organic Amendments on the Restoration of a Disturbed Coastal Sage Scrub Habitat

The effectiveness of organic mulch as a simple means of enhancing the restoration of disturbed lands by providing a competitive edge to native perennials, such as Artemisia californica (California sagebrush), over exotic annuals, such as Avena fatua (wild oat), was studied by investigating the effect of organic amendments on microbial activity and nitrogen immobilization through both soil analysis and aboveground plant growth. The addition of organic amendment resulted in an increase in microbial activity, a parallel increase in nitrogen immobilization, and no significant differences in total soil nitrogen. It is likely that nitrogen was gradually being removed from its more available form of nitrate and being immobilized in the tissues of the increasing microbial biomass. The survival rate of planted native perennial seedlings of A. californica in organic amended plots was almost double that of control-plot seedlings, and plant volume was significantly higher. When the availability of nitrogen was reduced through increased immobilization, amended plots established an environment more conducive to native perennial shrubs, allowing them to outcompete exotic annuals for water and nutrients. This simple procedure could have major implications for enhancing the restoration of disturbed lands.     

Influence of one or two successive annual applications of organic fertilisers on the enzyme activity of a soil under barley cultivation

The effect of cow manure and two rates of addition of municipal solid waste (MSW) compost on the enzymatic activity of a soil supporting barley cultivation was studied and compared with mineral fertilisation (MF). The experiment was carried out in unirrigated land in field conditions for two years. One set of plots was fertilised only once, at the start of the experiment, while another set of plots was fertilised annually (before each sowing). In general, the organic amendments stimulated soil enzyme activity but mineral fertilisation did not. The annual addition of large quantities of MSW compost, in general, led to lower levels of enzyme activity than similar rates of amendment in the plots receiving a single addition, probably because of the toxic effect which the heavy metals incorporated with the MSW compost had on microbial development. In the second year, plot receiving a single application of organic amendment showed higher protease hydrolysing casein, beta-glucosidase and dehydrogenase activities than control or soil with mineral fertilisation. This implied that the addition of organic waste, and particularly MSW compost, had a catalysing effect in the soil which lasted for the following years. Barley yields obtained with organic amendments were, in general, similar to, or even higher, than those obtained with mineral fertilisation. The annual addition of high doses of compost had an inhibitory effect on enzyme activity and barley yield (compared with the results obtained with the low addition of compost) due to the negative effect of the heavy metals incorporated with the compost.     

Application of different organic amendments in a gasoline contaminated soil: effect on soil microbial properties

The effects of four organic wastes, including cotton gin crushed compost (CC), poultry manure (PM), sewage sludge (SS) and organic municipal solid waste (MSW) on some biological properties of a Xerollic Calciorthid soil polluted with gasoline at two loading rates (5% and 10%) were studied in an incubation experiment. Three hundred grams of sieved soil (<2mm) were polluted with gasoline and mixed with PM at a rate of 10%, CC at a rate of 17.2%, SS at a rate of 23.1%, or MSW at a rate of 13.1%, applying to the soil the same amount of organic matter with each organic amendment. An unamended soil, non polluted (C) and polluted with gasoline at 5% (G1) and 10% (G2) rate were used as reference. Soil samples were collected after 1, 30, 60, 90, 120, 180 and 270 d of incubation and analyzed for microbial biomass carbon, respiration and dehydrogenase, urease, beta-glucosidase, phosphatase and arylsulfatase activities. At the end of the incubation period, soil biological properties were higher in organic amended soils than in C, G1 and G2 treatments. In particular, soil microbial biomass carbon and dehydrogenase, urease, beta-glucosidase, phosphatase and arylsulfatase activities increased 87.1%, 92.9%, 88.7%, 93.2%, 78.2% and 85.3%, respectively for CC-amended soils respect to G2, 85.7%, 82.3%, 87.3%, 92.2%, 76.7% and 83.6%, respectively for PM-amended soils; 82%, 90%, 84.8%, 89.9%, 74.1% and 80%, respectively for SS-amended soils; and 71.3%, 78.3% 26.2%, 38.2%, 79.7% and 88.6%, respectively for MSW-amended soils. Since the adsorption capacity of gasoline was higher in CC than the PM, SS and MSW-amended soils, it can be concluded that the addition of organic wastes with higher humic acid concentration is more beneficial for remediation of soils polluted with gasoline.     

Municipal solid waste compost dose effects on soil microbial biomass determined by chloroform fumigation-extraction and DNA methods

We evaluated the relationship between microbial biomass C and N (B_C and B_N) as estimated by the chloroform fumigation-extraction (CFE) method and microbial biomass DNA concentration in a loam-clayey wheat cultivated soil. The soil received municipal solid waste compost at rates of 40 or 80 t ha^?1 and farmyard manure at 40 t ha^?1. Microbial biomasses C and N and DNA concentration centration showed the highest values for microorganisms counts with compost and farmyard manure at 40 t ha^?1. Compost applications at 40 t ha?1 improve the micro-organisms growth than that of 80 t ha^?1. Moreover a significant decrease of soil microbial biomass was noted after fertilisation for three years. The presence of humic acid and proteins impurities in DNA extracts; even in important level as in F-treated soil; did not affect the microbial biomass. The decrease of microbial biomass was due to heavy metals content elevation in compost at 80 t ha^?1 treated soil. Thus the highest rate of municipal solid waste compost induced the lowest ratio of biomass C to soil organic carbon and the lowest ratio of biomass N to soil organic nitrogen. There was a positive relationship between B_C, B_N and DNA concentration. DNA concentration was significantly and positively correlated with B_C and with B_N. However there was a negative correlation between either micro-organisms numbers and DNA concentration, or B_C and B_N. The comparison of the two used methods DNA extraction and CFE showed the lowest coefficient of variation (cv %) with DNA extraction method. This last method can be used as an alternative method to measure the microbial biomass in amended soils.     

New approaches to establish optimum moisture content for compostable materials

This paper reports on the persistence of total and immobilised enzyme activities (urease and phosphatase) in a soil amended with organic wastes containing high levels of total-urease and phosphatase activity. Fresh organic materials showed the highest values for both total-enzymatic activities. The addition of organic waste to soil increased both total-enzymatic activities in the soil, which, after 360 days, showed values above those of the control. Immobilised enzymes were also higher in the fresh wastes than in the soil with compost, while the specific enzymatic activity levels (enzymatic activity per unit of carbon) were similar. The immobilised urease activity was greater in the amended soil than in the control. At the beginning of the incubation period, the immobilised urease activity was significantly higher in the soil amended with fresh organic wastes than with compost. However, this activity decreased with incubation, whilst the compost-immobilised urease activity increased with time. The effect of organic amendment on immobilised phosphatase activity was similar to that shown by immobilised urease but less pronounced. The persistence of both enzymes was significantly higher in the soil amended with compost than in that amended with fresh materials.     

选择性抑菌剂对添加稻草红壤旱土团聚体磷素微生物转化的影响

为了进一步探明红壤旱土磷素微生物固持的机理,采用室内模拟培养试验研究了微生物类群对红壤旱土团聚体(0.2～2mm)磷素转化的作用.结果表明:在培养90d期间,添加稻草处理能显著提高红壤旱土团聚体的微生物生物量碳、生物量磷、提取磷(Olsen法)和有机磷的含量.在培养前期(5～30d),与添加稻草处理比较,稻草+真菌抑制剂(放线菌酮)、稻草+细菌抑制剂(四环素+链霉素硫酸盐)处理团聚体微生物生物量碳含量分别降低10.5%～31.8%和6.8%～11.6%,前者的降低幅度显著大于后者(P0.01),此后加入抑菌剂处理团聚体微生物生物量碳基本保持稳定.添加细菌抑制剂处理团聚体微生物生物量磷含量在培养5～20d期间比加真菌抑制剂处理高10.0%～28.8%,差异显著(P0.01).表明真菌和细菌均参与红壤旱土团聚体磷素的固持,但真菌的作用明显大于细菌.     

Determinants of Soil Microbial Communities: Effects of Agricultural Management, Season, and Soil Type on Phospholipid Fatty Acid Profiles

Abstract Phospholipid fatty acid (PLFA) profiles were measured in soils from organic, low-input, and conventional farming systems that are part of the long term Sustainable Agriculture Farming Systems (SAFS) Project. The farming systems differ in whether their source of fertilizer is mineral or organic, and in whether a winter cover crop is grown. Sustained increases in microbial biomass resulting from high organic matter inputs have been observed in the organic and low-input systems. PLFA profiles were compared to ascertain whether previously observed changes in biomass were accompanied by a change in the composition of the microbial community. In addition, the relative importance of environmental variables on PLFA profiles was determined. Redundancy analysis ordination showed that PLFA profiles from organic and conventional systems were significantly different from April to July. On ordination plots, PLFA profiles from the low-input system fell between organic and conventional systems on most sample dates. A group of fatty acids (i14:0, a15:0, 16:1ω7c, 16:1ω5c, 14:0, and 18:2ω6c) was enriched in the organic plots throughout the sampling period, and another group (10Me16:0, 2OH 16:1 and 10Me17:0) was consistently lower in relative abundance in the organic system. In addition, another group (15:0, a17:0, i16:0, 17:0, and 10Me18:0) was enriched over the short term in the organic plots after compost incorporation. The relative importance of various environmental variables in governing the composition of microbial communities could be ranked in the order: soil type > time > specific farming operation (e.g., cover crop incorporation or sidedressing with mineral fertilizer) > management system > spatial variation in the field. Measures of the microbial community and soil properties (including microbial biomass carbon and nitrogen, substrate induced respiration, basal respiration, potentially mineralizable nitrogen, soil nitrate and ammonium, and soil moisture) were seldom associated with the variation in the PLFA profiles. Received: 3 February 1997; Accepted: 7 August 1997     

Evaluation of pulverized trommel fines for use as a soil amendment

Pulverized trommel fines collected from the City of Chicago’s municipal solid waste were applied as a soil amendment over a 2-year period to evaluate: (1) their effects on soil quality by measuring soil elemental concentrations, pH, organic matter and cation exchange capacity; (2) their potential for pathogen transfer. A secondary objective was to examine crop growth, yield and productivity. Total and fecal coliform, Enterococci, Escherichia coli, Staphylococci and Salmonella were below minimum detection limits in trommel fines. Trommel fines contained 894.5 ± 171.4 mg/kg Pb, and when applied at a rate equivalent to 9.95 mt/ha dry wt, resulted in a soil Pb concentration increase of 18.80 mg/kg, thereby limiting lifetime trommel fine application to 15.9 years before reaching the 300 ppm IEPA (USEPA) regulatory limit. Trommel fines were subjected to a shake extraction procedure and resulting leachate Pb samples were 88.7% below the IEPA (USEPA) regulatory limit (5 mg/l). For the first year, corn yield was significantly higher on soil amended with trommel fines than soil amended with inorganic nitrogen fertilizer. During the second year, soybean yield was significantly lower on soil amended with trommel fines than on soil amended with inorganic fertilizer due to lower plant population. Results of this study suggest that trommel fines can be land applied as a soil amendment if best management practices are followed.     

Growth response of Pinus halepensis to inoculation with Pisolithus arhizus in a terraced rangeland amended with urban refuse

A field experiment was carried out to evaluate the growth response of Pinus halepensis seedlings inoculated with Pisolithus arhizus and planted in a terraced rangeland amended with urban solid refuse. The application of the organic amendment mediated a significant increase in soil fertility and soil water content. Twenty seven months after planting seedling survival rates did not differ significantly among treatments and were above 95% in all cases. Growth of P. halepensis was significantly (p<0.01) enhanced by the refuse application independently of their mycorrhizal status at the beginning of the experiment. A multiple regression analysis including available soil P concentration and sorptivity as independent variables explained up to 60% of the variance in pine growth observed across treatments. Inoculation with P. arhizus also significantly (p<0.01) enhanced pine growth with repect to the controls grown in both amended and nonamended plots. It was conduded that the combination of soil terracing, refuse amendment and P. arhizus inoculation significantly improved the performance of Pinus halepensis, and this methodology could be successfully applied in afforestation programmes in semiarid and degraded sites.     

Pyrolysis-field ionization mass spectrometry of agricultural soils and humic substances: Effect of cropping systems and influence of the mineral matrix

Whole soil samples, extracted humic substances, the corresponding fulvic (FA) and humic acids (HA) and the extraction residues (humins) from long-term, agricultural test plots were investigated by in-source pyrolysis-field ionization mass spectrometry (Py-FIMS). For the soils distinct differences in the chemical composition of the organic matter in differently managed fields were observed. The FI mass spectra of the extracted humic substances gave complementary chemical information, as they cover a larger mass range compared to the whole soil spectra. The chemical, structural information of the conventional alkaline extraction residues was demonstrated by Py-FIMS spectra to be similar to that of the related soil samples. Influences of mineral matrix to organic matter ratios were studied on mixtures of extracted humic substances with defined mineral components such as quartz, basalt, iron oxide (Fe₂O₃), Ca-montmorillonite, kaolinite and illite. It was shown that in these mixtures the number of mass signals detected and the covered mass range decreased, when organic carbon concentrations (C_org) in this synthetic mineral matrix dropped below 2% (w/w). Limitations in the direct application of Py-FIMS might arise in the case of natural soil samples with C_org concentrations below 0.5% (w/w), high contents of swelling clay minerals and iron oxides. ei]{gnR}{fnMerckx}     

Studies on the ecology of actinomycetes in an agricultural soil amended with organic residues: I. identification of the dominant groups of <Emphasis Type="Italic">Actinomycetales</Emphasis>

The main objective of this investigation was to study the Actinomycetales community in a Tunisian agricultural soil amended with different amounts of municipal solid waste compost (MSWC) or farmyard manure (FM). It was shown, by using the 16S rDNA polymerase chain reaction—restriction fragment length polymorphism and sequencing methods for Actinomycetales isolates, tow major clusters. The cluster SI is composed of tow related families: Streptomycetaceae, dominant family and Pseudonocardiaceae. However, SII is composed of Nocardioidaceae family. The application of FM or MSWC increases the Actinomycetales number and affects their diversity by inhibition, stimulation or contribution of some species in soil. It was also shown, by the application of molecular techniques to soil samples using selective primers, that these three groups of Actinomycetales remain dominant even after 5 years of organic amendment application in soil.     

Relationships between Soil Organic Status and Microbial Community Density and Genetic Structure in Two Agricultural Soils Submitted to Various Types of Organic Management

The effects of soil organic management on indigenous microorganisms were studied by comparing mulching straw (S), conifer compost (CC), and conifer bark (CB) as well as grass landing with grass (G), clover (Cl), and fescue (F) in a silty–clay soil (Macon), and by incorporating vine shoot (VS) and single and double doses of farmyard manure (FM) and mushroom manure (MM) in a calcareous sandy soil (Chinon). Soil physicochemical and microbial characteristics were assessed at each site at two depths by sampling at 0–5 and 5–20 cm for the Macon site and 0–10 and 10–20 cm for the Chinon site. Changes in the quantity of soil organic matter (SOM), through an increase in C_org and N_org contents, and in its quality, through modifications in the C/N and humic acid/fulvic acid ratios, were essentially recorded at the surface layer of treated plots with differential magnitudes according to the inputs and soil type. Quantitative modifications in microbial communities were assessed by means of C-biomass measurements and resulted in an increase in microbial densities fitted with the increase of C_org and N_org contents. However, the deduced C incorporation in microbial biomass was negatively correlated with the C/N ratio, demonstrating a strong influence of the type of organic management on the rate of microbial processes. Qualitative modifications in microbial communities were evaluated by the characterization of the genetic structure of bacterial and fungal communities from DNA directly extracted from the soil, using bacterial and fungal automated ribosomal intergenic spacer analysis. Organic amendments led to changes in the bacterial and fungal communities of both sites. However, the magnitude and the specificity of these changes were different between sites, organic amendments, and microorganisms targeted, revealing that the impact of organic management is dependent on the soil and organic input types as well as on the particular ecology of microorganisms. A co-inertia analysis was performed to specify the role of the quantity and quality of SOM on the modifications of the genetic structure. A significant costructure was only observed for Macon plots at 0–5 cm between the bacterial genetic structure and the SOM characteristics, demonstrating the influence of the relative amount of the different humic substances (humic and fulvic acids) on microbial composition.     

Effects of municipal waste compost and sewage sludge on proton binding behavior of humic acids from Portuguese sandy and clay loam soils

The effects of amendment with municipal solid waste compost (MSWC) and sewage sludge (SS) on acid-base properties of soil humic acids (HAs) were investigated. For this purpose, HAs were isolated from MSWC and SS and two different Portuguese soils, one sandy and the other clay loam, either unamended or amended with MSWC or SS at a rate of 60 t ha(-1), and analysed by potentiometric titrations at various ionic strengths (0.01, 0.05, 0.1 and 0.3M) over the pH range from 3.5 to 10.5. All titration data were fitted with the NICA-Donnan model and the variations of model parameters between the various HA samples were discussed. The HAs from MSWC and SS had lower acidic functional group contents and higher proton binding affinities than the control soil HAs. Amending soils with MSWC and SS determined a decrease of acidic functional group contents and an increase on proton binding affinities of soil HAs. These effects were more evident in SS-amended soil HAs than in MSWC-amended soil HAs, and in clay loam soil HA than in sandy soil HA.     

Effect of organic amendments on some physical, chemical and biological properties in a horticultural soil

The aim of the present work was to assess the response of selected soil physical, chemical and biological properties, after two applications of different organic amendments to a soil with an extended horticultural use. Vermicompost from household solid waste (HSW) and from horse and rabbit manure (HRM), and chicken manure (CM) were applied at rates of 10 and 20 Mg ha(-1). The proportion of water stable soil aggregates (Ws) was significantly higher (p < 0.05) in HSW, HRM and CM at 20 Mg ha(-1). The proportion of ethanol stable soil aggregates (Es) was significantly higher in HSW, HRM and CM at 20 Mg ha(-1), and CM at 10 Mg ha(-1). After the first amendment application, HSW and HRM at 20 Mg ha(-1) resulted in higher soil organic carbon (SOC), while all the treatments showed a significant increase after the second amendment application. Linear relationships were found between Ws and Es with SOC. An increment in microbial respiration in all the amended plots was observed with the exception of HRM at the rate of 10 Mg ha(-1).