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Advocacy of positive environmental assessment using soil microbial diversity and its vitality value

Advocacy of positive environmental assessment using soil microbial diversity and its vitality value

Advocacy of Positive Environmental Assessment using Soil Microbial Diversity and Its Vitality Value As an Index for Environmental Preservation Effects in Environmental Accounting N[r]

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Relationship between Peat Soil Characteristic and Its Nutrient Status as well as Soil Microbial and Macrofauna Diversities in Sago Palm Growing Area.

Relationship between Peat Soil Characteristic and Its Nutrient Status as well as Soil Microbial and Macrofauna Diversities in Sago Palm Growing Area.

The one of the natural resources are not optimally managed sago palm (Metroxylon spp). Sago as one of the plants native to Indonesia which is a commodity that has a very good development prospects for the future, in addition to the sago plant has the ability to grow in marginal lands. One of the inputs required by the land associated with land productivity on farm land is soil organic matter and nutrients are available in a number of balanced. Soil microorganisms and organism play an important role in accelerating the supply of nutrients and also as a source of soil organic matter. Among groups of soil microbes, bacteria and fungi are the most likely group to attention. The role of bacteria in the recycling of nutrients such as carbon, nitrogen and phosphorus are very important. The purpose of this study was to examine the relationship between peat soil characteristics associated with plant nutrients and microbial diversity and macrofauna in a sago plantation. The area is used as a plot observations is to consider the different types of land management, the land cover types in the area of community cultivation, sago plantations in the area PT.NSP and sago plantations in the area of PT. NSP on fire.
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Effect of solid waste compost on microbi

Effect of solid waste compost on microbi

to a burnt Calcic Rodoxeralf soil, and the changes in microbial populations, salt content, aggregate stability and bulk density were evaluated for 1 year. Initially, the addition of compost had a negative effect on soil microbial populations, but 3 months after compost ad- dition, the number of viable fungal propagules in- creased in all the amended soils. This positive effect lasted until the end of the experiment. From 30 days onwards, all the amended soils showed a greater total number of bacterial cell forming units than the una- mended burnt soil. Organic amendment increased the percentage of 2- to 4-mm aggregates, although the ef- fect on the stability of the 0.2- to 2-mm aggregates and on bulk density was less noticeable.
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Analysis of T RFLP data using analysis o 001

Analysis of T RFLP data using analysis o 001

The analysis of T-RFLP data has developed considerably over the last decade, but there remains a lack of consensus about which statistical analyses offer the best means for finding trends in these data. In this study, we empirically tested and theoretically compared ten diverse T-RFLP datasets derived from soil microbial communities using the more common ordination methods in the literature: principal component analysis (PCA), nonmetric multidimensional scaling (NMS) with Sørensen, Jaccard and Euclidean distance measures, correspondence analysis (CA), detrended correspondence analysis (DCA) and a technique new to T-RFLP data analysis, the Additive Main Effects and Multiplicative Interaction (AMMI) model. Our objectives were i) to determine the distribution of variation in T-RFLP datasets using analysis of variance (ANOVA), ii) to determine the more robust and informative multivariate ordination methods for analyzing T-RFLP data, and iii) to compare the methods based on theoretical considerations. For the 10 datasets examined in this study, ANOVA revealed that the variation from Environment main effects was always small, variation from T-RFs main effects was large, and variation from T-RF × Environment (T × E) interactions was intermediate. Larger variation due to T × E indicated larger differences in microbial communities between environments/ treatments and thus demonstrated the utility of ANOVA to provide an objective assessment of community dissimilarity. The comparison of statistical methods typically yielded similar empirical results. AMMI, T-RF- centered PCA, and DCA were the most robust methods in terms of producing ordinations that consistently reached a consensus with other methods. In datasets with high sample heterogeneity, NMS analyses with Sørensen and Jaccard distance were the most sensitive for recovery of complex gradients. The theoretical comparison showed that some methods hold distinct advantages for T-RFLP analysis, such as estimations of variation captured, realistic or minimal assumptions about the data, reduced weight placed on rare T-RFs, and uniqueness of solutions. Our results lead us to recommend that method selection be guided by T-RFLP dataset complexity and the outlined theoretical criteria. Finally, we recommend using binary or relativized peak height data with soil-based T-RFLP data for ordination-based exploratory microbial analyses.
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Analysis of T RFLP data using analysis o

Analysis of T RFLP data using analysis o

The analysis of T-RFLP data has developed considerably over the last decade, but there remains a lack of consensus about which statistical analyses offer the best means for finding trends in these data. In this study, we empirically tested and theoretically compared ten diverse T-RFLP datasets derived from soil microbial communities using the more common ordination methods in the literature: principal component analysis (PCA), nonmetric multidimensional scaling (NMS) with Sørensen, Jaccard and Euclidean distance measures, correspondence analysis (CA), detrended correspondence analysis (DCA) and a technique new to T-RFLP data analysis, the Additive Main Effects and Multiplicative Interaction (AMMI) model. Our objectives were i) to determine the distribution of variation in T-RFLP datasets using analysis of variance (ANOVA), ii) to determine the more robust and informative multivariate ordination methods for analyzing T-RFLP data, and iii) to compare the methods based on theoretical considerations. For the 10 datasets examined in this study, ANOVA revealed that the variation from Environment main effects was always small, variation from T-RFs main effects was large, and variation from T-RF × Environment (T × E) interactions was intermediate. Larger variation due to T × E indicated larger differences in microbial communities between environments/ treatments and thus demonstrated the utility of ANOVA to provide an objective assessment of community dissimilarity. The comparison of statistical methods typically yielded similar empirical results. AMMI, T-RF- centered PCA, and DCA were the most robust methods in terms of producing ordinations that consistently reached a consensus with other methods. In datasets with high sample heterogeneity, NMS analyses with Sørensen and Jaccard distance were the most sensitive for recovery of complex gradients. The theoretical comparison showed that some methods hold distinct advantages for T-RFLP analysis, such as estimations of variation captured, realistic or minimal assumptions about the data, reduced weight placed on rare T-RFs, and uniqueness of solutions. Our results lead us to recommend that method selection be guided by T-RFLP dataset complexity and the outlined theoretical criteria. Finally, we recommend using binary or relativized peak height data with soil-based T-RFLP data for ordination-based exploratory microbial analyses.
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Combined effects of clay immobilized Azo

Combined effects of clay immobilized Azo

In this assay, the effect of the microbial inoculant combined with or- ganic residue on soil properties might also be attributed to a greater promotion of biological activity in the rhizosphere soil of the C. albidus plants. In fact, microbial biomass C, glomalin, dehydrogenase, protease and urease activities were higher in the rhizosphere soil of MI + OR treatment in comparison to control plants and these parameters have frequently been used as indicators of soil microbial activity (Caravaca et al., 2002). Alguacil et al. (2003) also reported an increase in enzyme activities when measured in the rhizosphere soil of C. albidus after amendment with fermented sugar beet residue in a semiarid Mediterranean area. Enzyme activities are suf  ciently sensitive to indi- cate changes caused by microbial inoculation (Naseby and Lynch, 1997). Furthermore,A. brasilense and P. dispersa in combination with or- ganic amendment may release enzymes involved in the mineralization of organic matter. Thus, a positive correlation in MI + OR treatment has been reported between enzyme activity and microbial biomass C. How- ever, we observed a signi  cant decrease on microbial biomass C and soil respiration when the microbial inoculant treatment was applied inde- pendently, suggesting than the introduced microbiota presented a lower biological activity in comparison to the autochthonous soil micro- organisms. In general, the combined treatment was the most effective for increasing microbial activities in the soil of our experiment.
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Directory UMM :Data Elmu:jurnal:S:Soil Biology And Chemistry:Vol33.Issue1.Jan2001:

Directory UMM :Data Elmu:jurnal:S:Soil Biology And Chemistry:Vol33.Issue1.Jan2001:

Thus, the RQ value may vary depending on the composi- tion of available substrates, the current physiology of the soil microbial communities and microbial adjustment to the nutritional conditions although this is generally considered weak. Therefore, this ratio was determined in soils under various land use, in contrasting soil horizons of single systems and under different nutritional conditions. The RQ was compared for: (i) the basal metabolism, (ii) the ®rst 4 h after the addition of the readily available substrate which refers to the maximal initial respiratory response, MIRR, without signi®cant microbial growth, and (iii) the subsequent 20 h re¯ecting an initial period of microbial growth. This approach considers soils in northern Germany belonging to the interdisciplinary program `Ecosystem Research in the BornhoÈved Lake District' and long-term agricultural plots, with the main objective of studying the effects of sustainable land use, as well as soils from southern Germany with site-speci®c management practices of the research network `Agricultural Ecosystems, Munich'. Finally, one soil amended with straw and three types of fresh litter from typical ecosystems in northern Germany were analysed.
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Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol14.Issue2.Apr2000:

Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol14.Issue2.Apr2000:

One of the difficulties in attempting to understand relationships between plant and microbial community structure is that of description. It is relatively easy to qualify and quantify vegetation composition, whilst it is much more difficult to analyse the composition of soil microbial communities. Traditional culture-based measurements provide both a limited and selective representation of the total community as only 2–4% of bacteria may be readily isolated from soil (Olsen and Bakken, 1987). Phenotypic diversities of microbial populations in soils have been profiled by measur- ing potential function using BIOLOG (Garland and Mills, 1991), phospholipid fatty acid (PLFA) analysis (Frostegärd et al., 1996) and also fatty acid methyl ester (FAME) analysis (Cavigelli et al., 1995). Molec- ular techniques have also been applied to the study of microbial populations in environmental samples. These have tended towards the application of specific oligonucleotide probes directed at DNA (Guo et al., 1997), rRNA (e.g. Stahl et al., 1988; Kämpfer et al., 1996) or to rRNA sequence analysis of microbial com- munities (e.g. Giovannoni et al., 1990; Stackebrandt et al., 1993). In a more wide ranging approach, reassoci- ation kinetics of DNA extracted from soils have sug- gested that as many as 10,000 different bacterial types may be present in 100 g soil (Torsvik et al., 1996). Such a broad-scale approach based on the analysis of community DNA may offer a useful level of reso- lution for plant:microbe community analyses. Com- munity DNA can be analysed by techniques which provide different but complementary information about the overall genetic structure of the community. These include percent guanine + cytosine (%G + C) profiling (Holben and Harris, 1995; Griffiths et al., 1997; Clegg et al., 1998), community cross hybridis- ation (Lee and Fuhrman, 1990; Griffiths et al., 1996; Clegg et al., 1998) and reassociation kinetics (Torsvik et al., 1990; Ritz et al., 1997; Clegg et al., 1998), denaturing gradient gel electrophoresis (DGGE) (Muyzer et al., 1993) and terminal restriction length polymorphism (Liu et al., 1997).
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Directory UMM :Data Elmu:jurnal:S:Soil Biology And Chemistry:Vol32.Issue14.Dec2000:

Directory UMM :Data Elmu:jurnal:S:Soil Biology And Chemistry:Vol32.Issue14.Dec2000:

Earthworms are ubiquitous in soil and ingest large amounts of soil, organic matter and leaf litter. To assess changes in organic matter fractions after passage through the earthworm gut, we measured microbial biomass C, N and P and the fungal-to-bacterial ratios in worm- worked soil (WWS), obtained by incubating soil for 24 h with large numbers of the anecic earthworm Metaphire guillelmi (1:5 ratio of fresh weight worms: dry weight soil). Microbial biomass C, N and P were estimated by the fumigation±extraction methods, and fungal-to-bacterial ratios by selective inhibition using substrate induced respiration. Enzyme activities in the gut of M. guillelmi were also compared with an epigeic earthworm species Eisenia fetida. Activities of cellulase, protease, chitinase, acid and alkaline phosphatases, in gut, casts and uningested soil were measured.
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Directory UMM :Data Elmu:jurnal:S:Soil Biology And Chemistry:Vol33.Issue2.Jan2001:

Directory UMM :Data Elmu:jurnal:S:Soil Biology And Chemistry:Vol33.Issue2.Jan2001:

A limitation of the present model is that amino acids were treated homogeneously. Previous work showed that most amino acids support similar soil microbial populations, but that glycine (gly) is used by a smaller microbial popula- tion, and is degraded 61% as fast as glu (Lipson et al., 1999a). The current model would therefore overestimate the rate of gly uptake by microorganisms, although it should work well for most other amino acids. If gly represents a large portion of the free amino acid pool, then the measured R would be over-estimated, and the soil amino acid concen- tration would be under-estimated. The amino acid composi- tion of soil peptides is generally consistent across soil types (Schulten and Schnitzer 1998). In one study, glycine made up 8±9% of total amino acids in soil peptides (Senwo and Tabatabai, 1998). Using decay rate values for gly of 0.61 times that of glu, and assuming that liberation of gly from soil peptides is 0.08 times the total protease rate, the model produces only 5% higher total amino acid concentrations. However, the gly concentrations simulated using these inputs are 65% higher than those assuming the same R for gly. This could be signi®cant for plant uptake, as plants generally take up gly more rapidly than other amino acids (Kielland 1994; Schmidt and Stewart, 1997; Lipson et al., 1999a).
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Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol13.Issue3.Dec1999:

Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol13.Issue3.Dec1999:

The role of grass tussocks in supporting soil microbial biomass (SMB) in grazed ecosystems is not fully understood, nor is the spatial distribution of SMB in response to different grass species. We undertook a study in 1997 that examined ®ne-scale distributions of SMB in grazed experimental paddocks located in the eucalypt woodlands of northern Queensland, Australia. Levels of SMB were determined on soil samples collected at seven locations along 60 cm transects in the vicinity of three species of tussock grass (Bothriochloa ewartiana, Chrysopogon fallax, Heteropogon contortus) and bare spaces, in replicate paddocks under ®ve different grazing regimes. Data (n = 280) were analysed as a split±split plot in a randomised complete block. Slope position (block) and paddock management were the main plots, micro-patch type (tussocks and bare spaces) the split plot, and location around micro-patch the split±split plot. Paddock management, micro-patch, and location effects were signi®cantly (p < 0.05) different, as were management location and micro-patch location interactions. The highest SMB levels were recorded at tussock centres on ungrazed (control) and lightly grazed paddocks, with lower levels recorded on degrading (15±27% reduction), and degraded/ recovering (40±53% reduction) sites. Successively lower levels were noted from tussock centres outwards to the most distant locations (+30, ÿ 30 cm) with level of paddock degradation. High levels of SMB were noted around tussocks of B. ewartianaand C. fallax, while the lowest were recorded across bare patches (59% of levels for the above species). Heavy grazing reduced inputs of organic materials and carbon into the soil, thereby limiting resources available for microbial growth. Fine-scale monitoring of the plant±microbe±soil interface should be combined with large-scale measures of landscape response to properly describe degradation and recovery processes. # 1999 Elsevier Science B.V. All rights reserved.
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A New Method to Quantify the Impact of S

A New Method to Quantify the Impact of S

A new method to diagnose the environmental sustainability of specifi c orchard management practices was derived and tested. As a signifi cant factor for soil quality, the soil carbon (C) management in the topsoil of the tree-row of an integrated and organic apple orchard was selected and compared. Soil C management was defi ned as land management practices that maintain or increase soil C. We analyzed the impact of the soil C management on biological (microbial biomass C, basal respiration, dehydrogenase activity, respiratory quotient) and physical (aggregate stability, amount of plant-available water, conductive mean pore diameter near water saturation) soil properties. Soil in the alley acted as a reference for the managed soil in the tree row. h e total and hot-water–extractable C amounts served as a combined proxy for the soil C management. h e soil C management accounted for 0 to 81% of the degradation or enhancement of biophysical soil properties in the integrated and organic system. In the integrated system, soil C management led to a loss of C in the top 0.3 m of the tree row within 12 yr, causing a decrease in microbial activities. In the tree row of the organic orchard, C loss occurred in the top 0.1 m, and the decrease in microbial activities was small or not signifi cant. Regarding physical soil properties, the C loss in the integrated system led to a decrease of the aggregate stability, whereas it increased in the organic system. Generally, the impact of soil C management was better correlated with soil microbial than with the physical properties. With respect to environmental soil functions that are sensitive to the decrease in microbial activity or aggregate stability, soil C management was sustainable in the organic system but not in the integrated system.
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Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol15.Issue1.Agust2000:

Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol15.Issue1.Agust2000:

Despite the usefulness of these nucleic acid tech- niques for characterizing soil microbial communities, there are a number of limitations. As with most tech- niques that measure metabolic activity, storage of samples prior to processing can bias results. Shifts in active functional groups of prokaryotes have been observed when samples are stored aerobically or left at room temperature (reviewed in van Winzingerode et al., 1997). However, presumably this bias could be removed easily by immediate processing or freezing. Another limitation is that comparisons of activity among organisms or soil samples may be confounded by several factors. Extraction efficiency differs among soils and microorganisms, so that apparent differences in activity of particular organisms across soil samples can be an artifact of the extraction procedure (Moran et al., 1993). Some prokaryotic cells are more easily lysed than others, so that incomplete lysis of some species could result in underestimates of activity (van Winzingerode et al., 1997). Sequence amplification and detection are only as good as the probes used; or- ganisms with different affinities for the probes used will differ in their apparent activities (Zheng et al., 1996). Amplification bias has also been shown to oc- cur for templates that differ substantially in abundance, with preferential amplification of more abundant se- quences (Suzuki and Giovannoni, 1996). However,
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Directory UMM :Data Elmu:jurnal:S:Soil & Tillage Research:Vol53.Issue3-4.Feb2000:

Directory UMM :Data Elmu:jurnal:S:Soil & Tillage Research:Vol53.Issue3-4.Feb2000:

of tillage (e.g., Doran, 1980, 1987; Lynch and Panting, 1980; McGill et al., 1986; Granastein et al., 1987; Buchanan and King, 1992), regular cultivation is also well known to have a major effect upon the composi- tional structure of soil microbial communities and their attendant function in relation to nutrient cycling. The seminal work carried out at Horseshoe Bend in Geor- gia, USA, demonstrates this clearly (e.g., summarised in Coleman et al., 1994), where it was found that many of the effects of tillage related speci®cally to the composition of decomposer communities. Saprophy- tic fungi appeared to play a major role in regulating the decomposition of (predominantly surface-deposited) residues in no-till systems, whilst bacteria dominated in tilled soils (Hendrix et al., 1986; Holland and Coleman, 1987; Beare et al., 1992). Fungi also appear to contribute more to the formation and stabilisation of aggregates in no-till compared to tilled soils (Beare et al., 1992). It is possible that these effects are mediated by the repeated disruption of mycelia during tillage; indeed this effect may also partly account for the apparent reduction in soil-borne fungal diseases which can be induced through tillage. Earthworms have been consistently shown to be more abundant in no-till soils (e.g., Atlanvinyte, 1964; Parmelee et al., 1990; Francis and Knight, 1993; Fraser, 1994).
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The influence of land use change on the

The influence of land use change on the

this study was to determine the influence of land-use change on SOM distribution, and microbial biomass and respiration in an Andisol of the Chilean Patagonia. Treatments consisted of degraded natural prairie (DNP), thinned and pruned Pinus ponderosa plantations (PPP), and unmanaged second- growth Nothofagus pumilio forest (NPF). The soil was classified as medial, amorphic, mesic Typic Hapludands. Soil microbial respiration and microbial biomass were determined in the laboratory from soil samples taken at 0–5, 5–10, 10–20 and 20–40 cm depths obtained from three pits excavated in each treatment. Physical fractionation of SOM was performed in soil of the upper 40 cm of each treatment to obtain the three following aggregate-size classes: macroaggregates ( > 212 m m), mesoaggregates (212– 53 m m) and microaggregates ( < 53 m m). Plant C content was 68% higher in PPP than in DNP and 635% higher in NPF than in PPP. Total soil and vegetation C content in both DNP and PPP were less than half of that in NPF. Total SOC at 0–10 cm depth decreased in the order DNP (7.82%) > NPF (6.16%) > PPP (4.41%), showing that land-use practices affected significantly (P < 0.01) SOC stocks. In all treatments, microbial biomass C and respiration were significantly higher (P < 0.05) in the upper 5 cm. Soil microbial respiration was also correlated positively with microbial biomass C and SOC. The different land uses affect the formation of organic matter, SOC and microbial biomass C, which in turn will affect soil microbial respiration. Conversion of DNP to PPP resulted in a 44% decrease of SOC stocks in 0–10 cm mineral soil. The largest amount of SOC was stabilized within the mesoaggregate fraction of the less disturbed system, NPF, followed by PPP. In the long term, formation of stable mesoaggregates in soils protected from erosion can behave as C sinks.
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Soil biochemical indicators as a tool to (2)

Soil biochemical indicators as a tool to (2)

It has been shown that in the long-term organic manage- ment of agricultural soils positively influences soil properties (Schjonning et al., 2002; Tu et al., 2006a) since the addition of organic amendments can improve TOC accumulation in soil by increasing C pools with a slow turnover time (Lal and Kimble, 1997). Moreover, green manuring is considered a good agricultural practice because of its positive effect on soil fertility, quality and biodiversity (Stark et al., 2007). In the short-term, several studies supported the evidence of an increase of microbial biomass and activity under organic management, leading to high nutrients availability for plants (Zaman et al., 1999; Tu et al., 2003; Wang et al., 2004; Marinari et al., 2006). Tu et al. (2003) showed that enhanced soil microbial biomass and activity were associated with high net N mineralization rates, which resulted in larger N availability. In separate studies, Monokrousos et al. (2006) and Melero et al. (2006) found the activities of enzymes involved in the cycles of N and phosphorus (P) enhanced through the organic manage- ment, with beneficial effects for soil nutrients supply.
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Directory UMM :Data Elmu:jurnal:S:Soil & Tillage Research:Vol57.Issue1-2.Sept2000:

Directory UMM :Data Elmu:jurnal:S:Soil & Tillage Research:Vol57.Issue1-2.Sept2000:

The Dundee silt loam (®ne-silty, mixed thermic, Aeric Ochraqualf) soil used in this study was collected from a long-term tillage ®eld experiment near Stone- ville, Mississippi. The soil was collected at random from within ®ve replications of conventional tillage (CT) plots or long-term (11 years) NT plots. In the NT plots, no mechanical tillage practices were used on these plots since establishment of the research plots. The tillage practices used in the CT plots, would be considered reduced tillage for this geographical region, and consisted of cultivation with a disc harrow in the spring to a depth of 15±20 cm (4±6 weeks prior to planting). A ®eld cultivator was also used in CT plots before planting to smooth soil surface. Soil was collected at four depths: 0±2, 2±5, 5±10, and 10± 25 cm. The soils had no history of ¯uometuron appli- cation, and all plots received applications of glypho- sate [N-(phosphonomethyl)glycine] followed by paraquat (1,1 0 -dimethyl-4,4 0 -bipyridium ion) both 1.1 kg active ingrediant ha ÿ1 prior to soybean plant- ing to kill spring vegetation. The soil was sampled before planting in the spring 4 weeks after glyphosate application and 3 weeks after the CT soils were disked. Soils from each plot were passed through 2 mm sieve and soil moisture was determined. Organic carbon was determined by dichromate diges- tion (Nelson and Sommers, 1982). Fluorescein diace- tate hydrolysis was used as a general indicator of soil microbial activity (SchnuÈrer and Roswall, 1982). Soil microbial biomass was determined by chloroform fumigation and determination of ninhydrin reactive compounds (Jorgenson and Brooks, 1990) corrected for ninhydrin reactive components in non-fumigated soil. Soil for degradation and sorption studies was a composite prepared by mixing equal oven dry weight equivalents from all ®ve replicates collected from ®eld plots for each tillage and soil depth.
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Earthworm and Soil Carbon Sequestration after Twenty One Years of Continuous No-tillage Corn-Legume Rotation in Indonesia

Earthworm and Soil Carbon Sequestration after Twenty One Years of Continuous No-tillage Corn-Legume Rotation in Indonesia

Different from microbial biomass C, the only treat- ment that affected (p<0.05) soil organic C in rhizo- spher was tillage system. Minimum tillage had the highest soil organic C, but it was not different from NT (Table 3). It seems that soil microbial biomass C and organic C in rhizosphere are consistently higher than those in non rhizosphere. This is related to the higher root exudates as substrate for microorganism activity resulting in more microbial biomass (Wang, et al., 2001), and higher soil organic matter with respect to rhizosphere. In contrast, soil organic C in non-rhizosphere at depth of 0-20 cm was not signifi - cantly (p<0.05) affected by any treatment, even by tillage system. This was attributable to a dilution ef- fect of sampling depth on soil organic carbon. In fact, there is a mark stratification of soil organic matter with soil under long-term NT (Blevins et al., 1984; Unger, 1991). After 20 years of study in Texas it was showed that soil organic carbon storage under no- tillage for all cropping sequence at 0-5 cm depth was 64% greater than conventional tillage, but at 5-15 cm,
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Engineering of soil biological quality from nickel mining stockpile using two earth worm ecological groups

Engineering of soil biological quality from nickel mining stockpile using two earth worm ecological groups

Abstract: Earthworms have the ability in modifying soil biological quality for plant growth. Their ability is mostly depending on its ecological groups. The objectives of the research were to study the influence of two ecological groups of earthworms on soil microbial activity and soil micro-fauna abundance, and to know the potential of soil modified by earthworms as plant growth medium. Eight combination of individual earthworm from epigeic and endogeic groups was applied into pot that was filled by soil from two years of nickel stockpile and each treatment was repeated by five times. The experiment was following complete randomize design procedure. After sixteen days of research, the soil sample from each pot was analyzed for soil FDA activity, number of flagellate and nematodes. Furthermore, one kg of the soil from each pot was taken and every pot was grown by Paraserianthes falcataria seedling with the age of five days and continued its growth for two months. The results indicated that the soil FDA activity, number of flagellate and nematodes among treatments were significantly differences. In addition, it indicated the significant differences in dry weight of shoot, root, total plant, and root to shoot ratio of P. falcataria seedlings. It concluded that the combination of an individual number of epigeic and endogeic earthworms improved soil biological quality of stock pile, amd most suitable for seedlings growth in nickel mining area.
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