Tropical forests are vital global reservoirs of biodiversity and carbon (C). Deforestation and degradation of these ecosystems greatly threatens their capacity to provide crucial ecosystem functions and services, by altering complex plant-soil interactions and biogeochemical cycles underpinned by soil microbes. Forest disturbance is accelerating in Southeast Asia, through widespread selective logging (SL) and forest conversion to oil palm plantation (OP). This has major implications for soil microbial communities and functions, although effects of tropical forest disturbance on belowground biodiversity and the resistance and resilience of soil microbial nutrient and C-cycling are unresolved. The potential to restore soil microbial communities and essential functions is also largely unknown. The aim of this thesis was to evaluate impacts of tropical forest modification (degradation, conversion and restoration) on soil microbial community attributes, and implications for ecosystem biogeochemical ...
This project aims to map African soil microbiome and develop predictive toolkits based on soil microbiota and physico-chemical characteristics of soil to assess soil fertility and health. It will determine factors that influence microbial diversity and community structure in continentwide scale. This project will generate important knowledge on African soil microbiome and it will bridge current farming practices with the biotechnology industry, government agencies, and academia, and will fill the gaps between basic research and large-scale agricultural applications. At the same time, it will provide evidence of the economic and environmental benefits of improving predictive tools for assessing soil fertility and develop an index of soil microbiota richness that will improve fertilization recommendation in agroecosystems.. We are seeking highly motivated candidates with metagenomics, bioinformatics and biostatistics background or related fields. As the solution for such complex problem will ...
Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane), next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA) and denitrifying (nirK) genes), greenhouse gas flow and several soil physicochemical properties were evaluated. Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and
Previously... Re: [SANET-MG] Beneficial Soil Microbia] The question is how to get information on IM or IMOs, Indigenous Microorganisms. Well, there is a seminar on Indigenous Microorganisms at the Ecological Farming Conference in California, Jan. 22-25. Gil Carandang, a farmer from the Phillipines, will demonstrate some of the special cultures. http://www.eco-farm.org/efc/efc_main.html Concepts and practices on Indigenous Microorganisms, IM or IMO, originate with Han Kyu Cho and the Korean Natural Farming Association, or KNFA, going back 35 to 40 years. Yet, this knowledge has only come into English language in the last few years. There is one book in English, yet it is not available for-sale from any distributor that I can determine. Korean Natural Farming: Indigenous Microorganisms and Vital Power of Crop/Livestock Han Kyu Cho and Atsushi Koyama Korean Natural Farming Association, 1997. 172 p. Here is an address for KNFA: Korean Natural Farming Association (KNFA) 209-2 Woongok-ri, ...
div, The Gemmatimonadetes are a family of bacteria, given their own phylum (Gemmatimonadetes). This bacterium makes up about 2% of soil bacterial communities and has been identified as one of the top nine phyla found in soils; yet, there are currently only six cultured isolates.[1] Gemmatimonadetes have been found in a variety of arid soils, such as grassland, prairie, and pasture soil, as well as eutrophic lake sediments and alpine soils. This wide range of environments where Gemmatimonadetes have been found suggests an adaptation to low soil moisture.[2] A study conducted showed that the distribution of the Gemmatimonadetes in soil tends to be more dependent on the moisture availability than aggregation, reinforcing the belief that the members of this phylum prefer dryer soils.[3] The phylum Gemmatimonadetes is distinct from the phylum Cyanobacteria and may have diverged in early microbial evolution at least 3 billion years ago.[4] The first member of this phylum was discovered in 2003 in ...
The effects of monoterpenes on the degradation of 14C-2,4-dichlorophenol (DCP) were investigated in soils collected from areas surrounding monoterpene and non-monoterpene emitting vegetation. Indigenous microorganisms degraded 14C-2,4-DCP to 14CO2, after 1 d contact time. Degradation was enhanced by prior exposure of the soils to 2,4-DCP for 32 d, increasing mineralization extents up to 60%. Monoterpene amendments further enhanced 2,4-DCP degradation, but only following pre-exposure to both 2,4-DCP and monoterpene, with total 2,4-DCP mineralisation extents of up to 71%. Degradation was greatest at the higher monoterpene concentrations (≥ 1 μg kg-1). Total mineralisation extents were similar between concentrations, but higher than the control and the 0.1 μg kg-1 amendment, indicating that increases in monoterpene concentration has a diminishing enhancing effect. We suggest that monoterpenes can stimulate the biodegradation of 2,4-DCP by indigenous soil microorganisms and that monoterpene ...
Background: Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The Biomes of Australian Soil Environments (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at continental scale. As the characterisation of microbes rapidly expands, the BASE database provides an evolving platform for interrogating and integrating microbial diversity and function.. Findings: BASE currently provides amplicon sequences and associated contextual data for over 900 sites encompassing all Australian states and territories, a wide variety of bioregions, vegetation and land-use types. Amplicons target bacteria, archaea and general and fungal-specific eukaryotes. The growing database will soon include metagenomics data. Data are provided in both raw sequence (FASTQ) and analysed OTU table formats and are accessed via the projects data ...
Novel technologies continue to expand our understanding of microbial diversity and community structure. Metagenomic analysis [10, 45] has previously identified unexpectedly high bacterial phylogenetic and functional diversity. The long-term sustainability of soil contamination requires detailed knowledge of its biodiversity coupled to profound understanding for its functioning. Previous studies with 16S rRNA-based analyses using clone libraries [46-48], microarrays (for example, PhyloChip and GeoChip) [49-52], pyrosequencing [7, 53] and other approaches [54] showed that soil microbial communities are highly diverse and complex.. Here, we took opportunity to explore microbial diversity and its functioning in edible oil contaminated soil using 16S rRNA shotgun sequencing approach. This study provides a comprehensive survey of the microbial richness and composition of long-term oil contaminated soil microbial communities. Upon taxonomic analysis using different approaches (RDP classifier and LCA ...
Soil microbial process tests evaluate the native soil microbial communities exposed to the substance. From the database of cobalt toxicity to micro-organisms, there are 28 individual high quality NOEC/EC10 values evaluating 3 functional parameters (potential nitrification rate, glucose induced respiration and maize residue mineralization) from 10 natural soils collected from sites in Europe and North America. When expressed as added soil Co, these endpoints range from 5.5 mg Co/kg dw for Glucose induced respiration (Salpeteur et al, University of Leuven, 2007) to 4695 mg Co/kg dw for Maize residue respiration (Salpeteur et al, University of Leuven, 2007). Below are the accepted high quality studies for soil microorganisms used for derivation of the HC5 and terrestrial PNEC. Table X. High quality studies for soil microorganisms used for derivation of the HC5 and soil microorganism PNEC ...
This will be 2nd outdoor grow. I was wondering if I could reuse the same soil mix I used last year thats sitting in my grow bags (100 gal) or do I...
Soil microorganisms and their interactions The soil is considered as the land surface of the earth which provides the substratum for plant and animal life. The soil represents a favourable...
Compartmentalization of PDGF on extracellular binding sites dependent on exon-6-encoded sequences. Inclusion of methionine-S35 into liver slices of rats with alloxan diabetes in a medium containing glucose generic cialis or fructose Hence, fluopyram has a harmful effect on overall soil microbial activity, and tadalafil 20 mg rezeptfrei bestellen changed soil microbial community structure and function. Six males with type 2 diabetes mellitus and eight healthy controls were included.. Long sleep duration: a nonconventional indicator of arterial stiffness in Japanese at high risk of cardiovascular disease: side effects of cialis the J-HOP study. How does the number of susceptible cells influence the growth potential of the virus?. The presence of an osseous spur on the dorsoproximal aspect of MtIII in the absence of other radiological abnormalities may be an incidental finding. AfsR recruits tadalafil 5mg RNA polymerase to the afsS promoter: a model for transcriptional activation by SARPs. The ...
SUMMARY: The lipids of soil micro-organisms harvested from simple and complex media varied from 2 to 20% in bacteria, 10 to 20% in fungi, 2·5 to 15% (w/w) in algae. The bulk of the lipid usually consisted of polar compounds; paraffinic hydrocarbons comprised 0·008 to 2·7% in bacteria, 0·04 to 0·7% in fungi, 0·08 to 2·9% (w/w) in algae. Lipid contents of algae were more affected by growth medium composition than were those of the bacteria and fungi. Gas-liquid chromatography showed that the hydrocarbons were paraffins in the range C16-36. The hydrocarbon patterns varied with species and growth medium. A peak in the range C27-31 was usual in bacteria with sometimes a minor peak in the range C18-22. The fungi exhibited slightly more stable hydrocarbon patterns (except Trichoderma viride) than bacteria and most showed major and minor paraffin peaks in similar regions. The algae showed a peak at C17 regardless of the growth medium but Tetraspora gelatinosa showed an increase in C25 and C27 paraffin
Photosynthesis and decomposition are two fundamental and interconnected components of terrestrial biogeochemical cycles, and large variations in Carbon model projections are due to uncertainties surrounding these parameters. Although foliar Nitrogen and soil microbial activities exert key constraints on plant productivity and decomposition, these variables are seldom included in modeling endeavors because we lack robust methodologies to estimate these parameters across ecosystems. This research demonstrates how advances in remote sensing technologies and machine learning analytical approaches can overcome this limitation and help us understand the distribution and controls of foliar Nitrogen and microbial community biomass and exoenzyme activities across large spatial areas. I used airborne imaging spectroscopy data, provided by The National Ecological Observatory Network (NEON), combined with 475 samples collected across the U.S. to develop generalizable models for the prediction of foliar ...
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Fingerprint Dive into the research topics of Measuring respiration profiles of soil microbial communities across Europe using MicroResp™ method. Together they form a unique fingerprint. ...
Methods: The researchers examined 18 different antibiotics ranging from natural, semi-synthetic to synthetic which could target a wide range of bacterial families and included ciprofloxacin, penicillin and kanamycin which are some of the more commonly prescribed antibiotics in medicine. Seventy-five bacterial samples were isolated from 11 diverse soil samples ranging from farm soil (cornfields fertilised with manure from cows fed with antibiotics), urban soil and pristine soil (untouched forest areas). This method ensured that the bacteria were isolated from areas with varying degrees of exposure to human-made antibiotics. More than half of the samples included bacteria from the phylogenetic order of Burkholderiales and Pseudomonadales, both capable of inflicting disease in humans. Two antibiotic concentrations (20 mg/L and 1 g/L) were tested with one concentration (1 g/L) being 50 times greater than standard antibiotic resistance concentrations ...
Getting ready to plant your vegetable garden? Youll want to test your vegetable garden soil for nutrients, soil pH levels and the presence of toxins.
A nitrogen transformation test according to test guideline OECD 216 has been performed to examined soil microorganisms. Test substance concentrations up to 1000 mg/kg sdw has been incorporated into natural soil and the soil microorganisms were exposed for 28 days. After 28 days of exposure, a significant inhibition of the microbial nitrate transformation was observed for the test item concentrations 250, 500 and 1000 mg/kg soil dry weight. The no effect level (NOEC) has been determined to be 125 mg/kg sdw after 28 days exposure. The EC10 value for inhibition of the nitrate-N formation rate in soil has been calculated to 237 mg/kg sdw , the EC25 value has been 361 mg/kg sdw and the EC50 value has been determined to be 528 mg/kg sdw after 28 days. ...
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Paul, E. A. 2015. Soil microbiology, ecology, and biochemistry: An exciting present and great future built on basic knowledge and unifying concepts. Pages 1-14 in E. A. Paul, ed. Soil microbiology, ecology, and biochemistry. Academic Press, San Diego, CA ...
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Title: Uncultured soil bacterium clone SoilA-18 16S ribosomal RNA gene, partial sequence. Accession Number: DQ906983. Link to Dataset: https://www.ncbi.nlm.nih.gov/nucleotide/DQ906983. Repository: GenBank. Data Type(s): Nucleotide Sequence. Experiment Type(s): Genomic DNA. Organism(s): Bacteria. Summary: Uncultured soil bacterium clone SoilA-18 16S ribosomal RNA gene, partial sequence. Publication(s) associated with this dataset: h4.sbrppubs { padding: 0 5px 2px 5px; border-bottom: 1px solid #bfbeb5; margin: 1px 0 10px 0; text-align: left; } .pubs li { padding-bottom: 14px; } .pubs li img { border: 0px; } ...
The quality of your garden soil will contribute 50% to the success of your gardening business. Dont overlook its importance. Find out all you need to know
The taxonomic position of a soil isolate, strain E626, was evaluated using the polyphasic approach. The organism was found to have chemical and morphological features consistent with its assignment to
Addition of plant residue into soils improves soil physiochemical properties and its fertility. Rapeseed residue is an emerging N source to paddy soils via rice-rape double-cropping practice. The objective of this study was to evaluate the effects of rapeseed residue and eggshell waste on chemical changes and enzyme activity in the rice paddy soil. The powdered eggshells at 0, 1, 3, and 5% were ap ...
Can anybody suggest good website for soil microbiology or any experts around??? As I am specializing in biofertilizers I would like to have some information regd the same thanx bye ...
Dirt microorganisms play key tasks in ecosystem functioning and are known to be influenced by biotic and abiotic factors, such as flower cover or edaphic guidelines. large proportion of Ascomycota phylum (fungi), mostly in non-rainforest formations, and Planctomycetes phylum (bacteria) in all formations were observed. Interestingly, such patterns could be indicators of past disturbances that occurred on different time scales. Furthermore, the bacteria and fungi were affected by varied edaphic parameters as well as from the interplay between these two soil areas. Another striking getting was the living of a site effect. Variations in microbial areas between geographical locations may be explained by dispersal limitation in the context of the biogeographical island theory. In conclusion, each plant formation at each site possesses is certainly very own microbial community caused by multiple connections between abiotic and biotic elements. Introduction Garden soil microorganisms play essential jobs ...
Dirt microorganisms play key tasks in ecosystem functioning and are known to be influenced by biotic and abiotic factors, such as flower cover or edaphic guidelines. large proportion of Ascomycota phylum (fungi), mostly in non-rainforest formations, and Planctomycetes phylum (bacteria) in all formations were observed. Interestingly, such patterns could be indicators of past disturbances that occurred on different time scales. Furthermore, the bacteria and fungi were affected by varied edaphic parameters as well as from the interplay between these two soil areas. Another striking getting was the living of a site effect. Variations in microbial areas between geographical locations may be explained by dispersal limitation in the context of the biogeographical island theory. In conclusion, each plant formation at each site possesses is certainly very own microbial community caused by multiple connections between abiotic and biotic elements. Introduction Garden soil microorganisms play essential jobs ...
Iqbal and Ashraf. 2017. Rhizobacteria play an important role in plant defense and could be promising sources of biocontrol agents. Antagonism between soil microorganisms is a common phenomenon.
Understand how subsurface drainage affects crops and your farms soil system. Covers soil water, water balance and other key concepts.
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Flavonoid compounds produced by the roots of some sorghum plants positively affect soil microorganisms, which may help the crop to be more hardy, according to researchers who suggest the discovery is an early step in developing a frost-resistant line of the valuable crop for North American farmers.
also a known degrader of PAHs, however, was lower. Weighted and unweighted PCoA with UniFrac indicated that phylotypes were similar in the different treatments at day 0, but changed at day 1. After 14 days, phylotypes in the unamended and acetone-amended soil were similar, but different from those in the anthracene-spiked soil ...
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You are a graduate student working on a followship for a biotech companny .You are part of a group that will perform some scientiific research. You recieve various soil samples shipped to you from.
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You and your children will learn the basic principles of composting, build a compost container, and maintain the compost pile for a home-grown supply of free, organic compost to enrich your garden soil.
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Agricultural systems rely on healthy soils and their sustainability requires understanding the long-term impacts of agricultural practices on soils, including microbial communities. We examined the impact of 17 years of land management on soil bacterial communities in a New Zealand randomized-block pasture trial. Significant variation in bacterial community structure related to mowing and plant biomass removal, while nitrogen fertilizer had no effect. Changes in soil chemistry and legume abundance described 52% of the observed variation in the bacterial community structure. Legumes (Trifolium species) were absent in unmanaged plots but increased in abundance with management intensity; 11% of the variation in soil bacterial community structure was attributed to this shift in the plant community. Olsen P explained 10% of the observed heterogeneity, which is likely due to persistent biomass removal resulting in P limitation; Olsen P was significantly lower in plots with biomass removed (14 mg ...
The increasing temperature in Arctic tundra deepens the active layer, which is the upper layer of permafrost soil that experiences repeated thawing and freezing. The increasing of soil temperature and the deepening of active layer seem to affect soil microbial communities. Therefore, information on soil microbial communities at various soil depths is essential to understand their potential responses to climate change in the active layer soil. We investigated the community structure of soil bacteria in the active layer from moist acidic tundra in Council, Alaska. We also interpreted their relationship with some relevant soil physicochemical characteristics along soil depth with a fine scale (5 cm depth interval). The bacterial community structure was found to change along soil depth. The relative abundances of Acidobacteria, Gammaproteobacteria, Planctomycetes, and candidate phylum WPS-2 rapidly decreased with soil depth, while those of Bacteroidetes, Chloroflexi, Gemmatimonadetes, and candidate ...
The aim of this study was to evaluate a measuring technique for determining soil CO2 efflux from large soil samples having undisturbed structure under controlled laboratory conditions. Further objectives were to use the developed measuring method for comparing soil CO2 efflux from samples, collected in three different soil management systems at various soil water content values. The experimental technique was tested and optimised for timing of sampling by taking air samples after 1, 3 and 6 hours of incubation. Based on the results, the incubation time was set to three hours. The CO2 efflux measured for different soil management systems was the highest in the no-till and the lowest in the ploughing treatment, which was in accordance with measurements on accessible organic carbon for microbes. An increase in CO2 efflux with increasing soil water content was found in the studied soil water content range. Our results indicate that soil respiration rates, measured directly after tillage operations, ...
tags) Want more? 14 from Soil Microbiology and Biochemistry Slide Set. Horizon A), the microbial population is very high which decreases with depth of soil Soil microorganisms played a very important role in improving the soil fertility and productivity. Janice E. Thies, in Soil Microbiology, Ecology and Biochemistry (Fourth Edition), 2015. They are responsible for the characteristically earthy smell of freshly turned, healthy soil. In soil microbiology it was realised that simply extracting soils and counting microorganisms is not enough to characterise the soil microbiota and its significance for the functioning of soils e.g., Macura, 1974 . 14 from Soil Microbiology and Biochemistry Slide Set. Get powerful tools for managing your contents. • Dead forms of organic material - mostly dead plant parts (85%) • Living parts of plants - mostly roots (10%) • Living microbes and soil animals • Partly decayed organic matter is called humus Components of Soil Organic Matter. Unformatted text ...
Crop production requires adequate soil nitrogen; therefore a false conclusion may be made from only measuring carbon dioxide as a soil health indicator. In this study, one might conclude that sod was the most productive soil according to the field respiration test. However, soil nitrogen levels were the lowest in the sod treatment. This would result in poor crop performance. Soil health reports are needed that include nutrient levels, especially soil nitrogen. Soil conservation practices such as reduced tillage and cover crops have the ability to improve soil productivity. If farmers can measure these soil health improvements and the measurements correlate to crop production increases, then soil conservation will be practiced. The effect of soil moisture and temperature on soil nitrate, ammonium, and carbon dioxide can determine the accuracy of prediction for nitrogen availability (Clark, 2007). A soil health test conducted by V6 growth stage would be useful in corn production to allow farmers ...
Relationship of microbial activity and abundance to soil properties in Yucatan SDTF.Due to the lower water supply, SDTFs usually have a lower decomposition rate (25), higher soil C and N concentrations (33), and a more open N cycle (characterized by high N inputs and losses) than their wet counterparts (34). These properties can explain why the organic C contents found in these soils are larger than values reported for any other tropical soil (35). These soils also contain variable amounts of organic matter, which are in the same range as those reported for other Yucatan forest soils (27, 31). Furthermore, the experimental plots are found in nutrient-poor areas because of the regions recent geological origin, where karstic substrate dominates the landscape (30). In particular, recent studies have documented that karst soils contain abundant organic matter, which is mainly stored in the soil surface (36, 37). In addition, the karstic soils of the Yucatan have high potential to form aggregates ...
How soil microbes assimilate carbon-C, nitrogen-N, phosphorus-P, and sulfur-S is fundamental for understanding nutrient cycling in terrestrial ecosystems. We compiled a global database of C, N, P, and S concentrations in soils and microbes and developed relationships between them by using a power function model. The C:N:P:S was estimated to be 287:17:1:0.8 for soils, and 42:6:1:0.4 for microbes. We found a convergence of the relationships between elements in soils and in soil microbial biomass across C, N, P, and S. The element concentrations in soil microbial biomass follow a homeostatic regulation curve with soil element concentrations across C, N, P and S, implying a unifying mechanism of microbial assimilating soil elements. This correlation explains the well-constrained C:N:P:S stoichiometry with a slightly larger variation in soils than in microbial biomass. Meanwhile, it is estimated that the minimum requirements of soil elements for soil microbes are 0.8 mmol C Kg -1 dry soil, 0.1 mmol N ...
1. Bissett, Andrew, Alan E. Richardson, Geoff Baker, and Peter H. Thrall. Long-ter Land Use Effects on Soil Microbial Community Structure and Function. Applied Sol Ecology 51 (2011): 66-78. Print. 2. Bonkowski, Michael. Protozoa and Plant Growth: The Microbial Loop in Soil Revisited. New Phytologist 162.3 (2004): 617-31. Print. 3. Coleman, D. C. The Microbial Loop Concept as Used in Terrestrial Soil Ecology Studies. Microbial Ecology 28.2 (1994): 245-50. Print. 4. Ingham, Elaine R. Soil Biology. NRCS - Soil Quality / Soil Health. USDA, n.d. Web. 07 Apr. 2013. 5. Krumins, Jennifer A., Dick Van Oevelen, and Martinjn T. Bezemer. Soil and Freshwater and Marine Sediment Food Webs: Their Structure and Function. BioScience 63.1 (2013): 35-42. Print. 6. Powell, Jeff R. Linking Soil Organisms within Food Webs to Ecosystem Functioning and Environmental Change. Advances in Agronomy 96 (2007): 307-50. AGRICOLA. Web. 01 Apr. 2013. ...
1. Bissett, Andrew, Alan E. Richardson, Geoff Baker, and Peter H. Thrall. Long-ter Land Use Effects on Soil Microbial Community Structure and Function. Applied Sol Ecology 51 (2011): 66-78. Print. 2. Bonkowski, Michael. Protozoa and Plant Growth: The Microbial Loop in Soil Revisited. New Phytologist 162.3 (2004): 617-31. Print. 3. Coleman, D. C. The Microbial Loop Concept as Used in Terrestrial Soil Ecology Studies. Microbial Ecology 28.2 (1994): 245-50. Print. 4. Ingham, Elaine R. Soil Biology. NRCS - Soil Quality / Soil Health. USDA, n.d. Web. 07 Apr. 2013. 5. Krumins, Jennifer A., Dick Van Oevelen, and Martinjn T. Bezemer. Soil and Freshwater and Marine Sediment Food Webs: Their Structure and Function. BioScience 63.1 (2013): 35-42. Print. 6. Powell, Jeff R. Linking Soil Organisms within Food Webs to Ecosystem Functioning and Environmental Change. Advances in Agronomy 96 (2007): 307-50. AGRICOLA. Web. 01 Apr. 2013. ...
The plan released today lays out a series of goals for its action teams (or committees) to tackle. Beth Mason, NACDs North Central Region representative and Soil Health Champions Network lead, serves as co-chair on the groups Communications and Education Action Team alongside Ron Nichols, soil health communications coordinator for NRCS.. Each of SHIs goals fall under a general category. For instance, under Research, SHI proposes to enhance agricultural productivity and resilience through improved soil health by optimizing soils water holding capacity, water infiltration, and plant nutrient availability, and suppressing soil-borne diseases through soil health management systems. Its second research goal aims to quantify the environmental and human health benefits that result from improved soil health.. The group has also set out to determine how best to design and conduct large-scale soil health assessments, such as a National Soil Health Assessment. Other goals included quantifying the ...
Introduction. The decline of soil organic matter as a result of agricultural land use was identified for review, with the ultimate aim of developing a soil protection strategy and policy for South Africa. Organic matter is of great importance in soil, because it impacts on the physical, chemical and biological properties of soils. Physically, it promotes aggregate stability and therefore water infiltration, percolation and retention. It impacts on soil chemistry by increasing cation exchange capacity, soil buffer capacity and nutrient supply. Biologically, it stimulates the activity and diversity of organisms in soil.1. The organic matter content of soils is determined mainly by climate (rainfall and temperature), vegetation cover and, to a lesser extent, by topography, parent material and time. Changes in land use, however, can significantly impact on the organic matter content of soils. This impact usually results in the reduction of the organic matter content in soils. The largest of these ...
Soil samples (0-60 cm) were collected from poplar based agro-forestry system varying in age from 2-20 years to study changes in total soil organic C (SOC), available phosphorus (P) and potassium (K). Soil plough layer (0-15 cm) had significantly higher SOC concentration by 34, 61 and 83%, compared with 15-30, 30-45 and 45-60 cm soil depths, respectively. Soil organic C decreased significantly with increasing soil depth, regardless of the age of poplar plantation period. The concentration of available-P and K was significantly higher in the surface soil, and decreased with increasing soil depth. Available-P increased significantly (p|0.05) by 16.3-17.7% and available-K by 36.5-52.4% in soil plough layer (0-15 cm) under agro-forestry for 20-yrs, compared with soils under agro-forestry for 2-yrs. Soils under 20-yrs old agro-forestry system had 39.8% and 50.6% higher SOC in 0-7.5 cm and 7.5-15 cm soil depth, compared with soils under 2-yrs old plantation. These results revealed C and nutrients (P and K)
For this lab sandy soil can be obtained at a nursery. This soil will be labeled potting soil for Succulents, which typically grow in sandier soils. Loamy soil can be substituted with regular potting soil. Clay soil will have to be dug from a local source. If the soil is not a red or orange color, it may still have a lot of clay in it. High clay content soil, when wet, can be squeezed and it will retain the shape without falling apart. It also has a slimy quality when wet. This is the element of soil that makes it really stick to your boots. If you live in an area where you have good soil, digging down below the top soil usually results in a larger clay content as the clay particles tend to move down through the soil over time and compact deeper in the earth (its like the crumbs at the bottom of a bag of potato chips ...
Soils can vary on the same property. An easy way to identify your soil type is to fill a small jar with soil from your yard, shake it, and let the soil settle overnight. The following day you should notice distinct soil layers. Sandy soil tends to settle at the bottom, clay at the top, and silt in the middle.. Why Does Soil Matter?. Soil performs five essential functions; using the wrong type of soil or unhealthy soil can impede tree health by constricting roots from accessing the water and nutrients necessary. Soil helps regulate water, supports biodiversity, filters pollutants, provides physical support, and cycles nutrients. You can understand why attempting to plant a tree that requires less soil saturation may not thrive if its planted in silt or clay soil. Trees show signs of stress, possible signs that the soil isnt healthy include leaf discoloration, brittle limbs, and even stunted tree growth.. Its also important to dig a hole deep enough for tree roots to grow. Planting in shallow ...
Years of measurements have produced a lot of information on soil respiration. We know more or less how the respiration rate is related to changing environmental conditions, as plant respiration and soil respiration follows temperature exponentially. Approximately, respiration rates doubles for every 10°C increase in temperature. Soil water availability (REW) further regulates the respiration.. REW stands for Relative Extractable Water, and it refers to the amount of water in the soil available to plants and soil microfauna. Soil microbes that decompose soil organic matter function in soil water. In drying soil, the microbes have more difficulty accessing soil organic matter and the decomposition process gets slower. Root respiration also declines in very dry soil.. The effects of soil temperature and moisture can be expressed as a simple mathematical equation:. R = Max { 0 , f(REW) * r0 * q10T/10 - cr }. R stands for respiration expressed as the resulting carbon, r0 =1.1 µmol m-2 s-1, ...
First and foremost, we need to disturb soil less. The advent of no-till and reduced tillage methods have allowed us to increase the carbon content of soils.. No-till and direct-seeding methods place the seed directly into the soil, minimizing the disturbance associated with seedbed preparation. The lack of disturbance allows the roots and crop residues from the previous crops to form soil organic matter. It reduces the degradation of the soil organic matter already present in the soil.. In Canada, we are already benefiting from reduced tillage. In the Prairies, no-tillage agriculture has increased from less than five per cent of the land area in the early 1990s to almost 50 per cent in 2006.. The situation is a bit more complex in Eastern Canada. The regions soil type and climate make it less easy to build soil organic matter. At Dalhousies Atlantic Soil Health Lab, we are exploring the potential of various cropping practices to increase soil organic matter content in the soils of Atlantic ...
Soil Analysis: An Interpretation Manual is a practical guide to soil tests. It considers what soil tests are, when they can be used reliably and consistently, and discusses what limits their application. It is the first nationally accepted publication that is appropriate for Australian soils and conditions. The first three chapters review the general principles and concepts of soil testing, factors affecting soil test interpretation and soil sampling and handling procedures. The next two chapters describe morphological indicators of soil and include colour plates of major Australian agricultural soils. These are followed by a series of chapters which present soil test calibration data for individual elements or a related group of tests such as the range of soil tests used to interpret soil acidity. Each of these chapters also summarises the reactions of the particular element or parameter in the soil and describes the tests commonly used in Australia. The final chapter presents a structured ...
As a PhD student in the Department of Plant Pathology, I recently attended the Tilth Conference in Wenatchee, which provided me the opportunity to hear great presentations and spark my thinking on the topic of microbiomes. I am currently working on Brassica seed meal amendments for suppressing apple replant disease under the supervision of Dr. Mark Mazzola. Several presentations, including one by Dr. Mazzola, were inspiring to me at the conference.. Soil is the living thin skin of our planet, said Dr. David Granatstein in his presentation. Farmers care a lot about their soils and they are eager to figure out what factors contribute to a healthy soil. It is not an easy question since there is not a single model that fits everything. Soil health can be related to several factors, such as disease suppression, plant access to the water and access to nutrients. Carbon and organic matter are also important elements in the soil system that contribute to the support of a microbiome that is relatively ...
This study investigated the microbial degradation of C-14-labelled hexadecane, octacosane, phenanthrene and pyrene and considered how degradation might be optimised in three genuinely hydrocarbon-contaminated soils from former petroleum refinery sites. Hydrocarbon mineralisation by the indigenous microbial community was monitored over 23 d. Hydrocarbon mineralisation enhancement by nutrient amendment (biostimulation), hydrocarbon degrader addition (bioaugmentation) and combined nutrient and degrader amendment, was also explored. The ability of indigenous soil microflora to mineralise C-14-target hydrocarbons was appreciable; ,= 16% mineralised in all soils. Generally, addition of nutrients or degraders increased the rates and extents of mineralisation of C-14-hydrocarbons. However, the addition of nutrients and degraders in combination had a negative effect upon C-14-octacosane mineralisation and resulted in lower extents of mineralisation in the three soils. In general, the rates and extents of ...
The population of filamentous acetate-utilizing methanogens in paddy field soils was 2.0×10,SUP,4,/SUP, MPN/g dry soil in the submerged condition. They were able to form colonies in a deep agar medium, but not in a roll tube. Filamentous acetate-utilizing methanogens isolated from Kanagi, Japan (strain K-5) and Tsukuba, Japan (strain T-3) were divided into two types based on length of filaments. One type, strain K-5, formed a short chain which was dispersed easily by weak shaking. The other type, strain T-3, formed a long chain, which formed cotton-like flocs and was not dispersed by weak shaking. They had sheaths composed of a pair of adjacent membranes on the outside of the cell membranes. The 16S rRNA gene similarities of strain T-3 and K-5 to ,I,Methanosaeta concilii,/I, strain Opfikon were 100% and 99.5% respectively. Filamentous acetate-utilizing methanogens were also isolated from paddy field soils in various other regions of Japan. Our results suggest that ,I,Methanosaeta,/I, is ...
The uppermost layer of the earths crust is known as soil. It is a mixture of rock fragments and organic matter which has decomposed into constituent nutrients.Soil formation is influenced by the weathering and erosion processes that are defined by a regions climate. Apart from this, the nature of the parent rock, topography, vegetation cover etc., also determine the type of soil that is formed.Pedogenesis is the process of soil formation under the action of various forces of nature such as wind, flowing water etc.Soil can be classified into three types based on the texture of grains found in it.Sandy soils - if the size of soil grain is in the range of 2 to 0.05 mm.Silt - if the size of soil grain is in the range of 0.05 to 0.002 mm. It is usually found on the river bedsClayey soils - if the size of soil grain is less than 0.002 mmSandy soils have enough gaps between their grains to drain water quickly. Hence, these soils tend to be dry, light in weight, and well aerated.Clayey soils are more ...
Rhizosphere microorganisms play an important role in soil carbon flow, through turnover of root exudates, but there is little information on which organisms are actively involved or on the influence of environmental conditions on active communities. In this study, a 13CO2 pulse labelling field experiment was performed in an upland grassland soil, followed by RNA-stable isotope probing (SIP) analysis, to determine the effect of liming on the structure of the rhizosphere microbial community metabolizing root exudates. The lower limit of detection for SIP was determined in soil samples inoculated with a range of concentrations of 13C-labelled Pseudomonas fluorescens and was found to lie between 105 and 106 cells per gram of soil. The technique was capable of detecting microbial communities actively assimilating root exudates derived from recent photo-assimilate in the field. Denaturing gradient gel electrophoresis (DGGE) profiles of bacteria, archaea and fungi derived from fractions obtained from ...
Inoculation of soil with bacteria (a Gram-negative rod [PD2] and a 4- membered consortium [DC1]) accelerated mineralization of phenanthrene and pyrene (but not naphthalene) added individually to a pristine sand and a pristine organic soil. The half-life of naphthalene was 3.5 days in both soils whether inoculated or non-inoculated. However, the half-life of phenanthrene decreased from 86 days in non-inoculated sand soil and 80 days in the non-inoculated organic soil to 3.6 days in the sand and 3.1 days in organic soil when inoculated with PD2, and to 6.6 days in the sand and 8.7 days in the organic soil when inoculated with DC1. Phenanthrene mineralization ceased after 23 days in DC1-inoculated soil and was 71.3 ± 3.6% (sand) and 63.3 ± 2.8% (organic). This compared with 96.8 ± 3.8% (sand) and 102.8 ± 2.5% (organic) after 8 days in PD2-inoculated soil. Inoculation with DC1 (but not PD2) also accelerated mineralization of pyrene, where the half-life decreased from 155 days to 18 days in the sand soil
This two day Biologically-Based Soil Management Workshop is a cost effective option designed for businesses, schools and other organizations who would like to train groups of 10 people or more. An Earthfort instructor will come to your location and provide an in-depth overview of soil biology, testing, and remediation. Your team will learn about the interrelationships between soil biology and soil nutrient chemistry, so you can better manage the soil system, improving your crops and soil remediation practices.. In this workshop, you will explore the physical, chemical, and biological processes of the soil. Your own soils history, chemistry and biological makeup has unique management implications. Well give you the tools that work with your system rather than against it, saving you time and money. You are encouraged to send in a soil sample to our laboratory to have the soil biology and chemistry tested prior to the workshop so we can take a more in-depth look at a soil biology report. This ...
The research results in recent years have shown an essential microbiological degradation of soils exposed to convenctional agricultural technologies. It was shown that the pedo-microbiological degradation of arable soils is much more advanced compared with humus degradation; the pedo-microbiological parameters were found to be more sensitive (comparing to the soil organic matter content) and, consequently, could be used for tracing and assessing the ecological changes in soil on relatively early stage. Quality and quantity pedo-microbiological criteria were suggested for estimation, monitoring and prediction of arable soil quality.. ...
Carbon sequestration is a process where carbon from the atmosphere is stored in the soil, which helps lessen global warming. Plants, ocean, and the soil all capture and store carbon.. The soil of the Everglades, called peat, is largely made up of waterlogged, decomposing plant and animal materials. The peat soil stores a large amount of carbon compared to other soils across the globe.. When the Everglades Agricultural Area was drained, the soil was exposed to higher levels of oxygen. Decomposition of the plant and animal materials happens much faster with more oxygen. When the carbon in the soil decomposes, it becomes carbon dioxide gas. The mass of the soil decreases, and gas goes into the atmosphere. Its a big chemistry equation.. Its not easy to picture a soil that disappears, says Rodriguez. The most challenging process I have to explain - and the most striking - is how carbon in the soil goes from the soil to the atmosphere.. The process of soil subsidence can release significant ...
In soils and sediments, microbial reduction of iron (hydr)oxides and consequent formation of secondary iron minerals are important factors influencing many biogeochemical cycles and processes that include microbial methanogenesis. Here, we investigated methanogenic activity and microbial community of a paddy soil enrichment in response to different biomineralization pathways of ferrihydrite, which was reduced and transformed to magnetite and vivianite in the absence and presence of phosphate, respectively. For methanogenic degradation of both acetate and propionate, CH4 production rates in the magnetite cultures were significantly enhanced compared with the vivianite cultures. Characterization of 16S rRNA genes from methanogenic soil microbial community indicated that, (i) biomineralization of ferrihydrite was an important factor affecting soil microbial community structure; (ii) Geobacteraceae was only enriched in the vivianite cultures for both acetate- and propionate-fed incubations; and (iii) the
Canadas Boreal forest covers 35% of the landmass, much of which is managed by the natural resources industry. As the largest exporter of wood products globally, the Canadian forestry industry relies on sustainable productivity of the soil. Microbial communities and bioavailability of nutrients are critical components of the sustainability of continuously harvested lands, thus assessing their response to harvesting was the overarching objective of this study. Microbial community biomass and composition was assessed using phospholipid fatty acid (PLFA) analysis and DNA fingerprinting of the bacterial community and ammonia oxidizing bacteria (AOB). In situ nutrient availability and chemical soil parameters were also measured here. Six cutblocks similar to each other except for their age since harvesting were sampled in the summer of 2009 and 2010 in both the forest floor and mineral Ae horizons of Orthic Gray Luvisols of central Alberta in the Boreal Plain ecozone. Microbial communities of these ...
Soil Collection. A total of 98 soil samples that were distinct with respect to soil and site characteristics were collected from a wide array of ecosystem types in North and South America (see Table 3). Only soils unsaturated for the majority of the year were examined. Soils were collected near the height of the plant growing season at each location. To examine whether seasonal variation was important, an additional set of soil samples was collected 6 months after the initial collection at a subset of sites. At each site, the upper 5 cm of mineral soil was collected from 5-10 locations within a given plot of ≈100 m2 and composited into a single bulk sample. All soil samples were shipped to the University of California, Santa Barbara, within a few days of collection, where they were sieved to 4 mm, homogenized, and archived at -80°C.. Site and Soil Description. For sites in the U.S., climate information for each site was estimated from historical average data (1971-2000) provided by the ...
Now that weve established the composition and components of soil, and described a brief history of soil in Virginia, we can expand on what properties in soil promote growth. We can do this while examining different soils from around central grounds. Three areas we will highlight are Observatory Hill Field (Figure 2), Fayerweather Hall (Figure 3), and the Lawn (Figure 4).. Organic matter. Organic matter broadly alludes to the assortment of dead plant and animal material in the soil. This includes everything from ground-up leaves to compost. Organic matter is essential to soil for its wide range of benefits that it provides. These benefits include being able to supply nutrients for plants by providing surfaces where nutrients can be held in reserve in the soil, facilitate better drainage by loosening soil structure, store water in soil, help increase air drainage, and increase the activity and numbers of soil microorganisms (organic matter). The optimal level for organic matter in soil is about ...
Surfactants with solvent and wetting abilities are used in the formulation of herbicides to enhance spraying capabilities. These chemicals eventually enter into the soil and may disrupt different chemical, physical and biological processes. The aim of this study was to examine the effects on nutrient uptake in corn and soil microbial community due to application of surfactants at different rates, herbicides, and surfactant-herbicide combinations in silt loam and silty clay loam soils. Surfactants used were Activator 90, Agri-Dex and Thrust. Herbicides used were glyphosate, atrazine, and bentazon. Corn was planted in fertilized soils and moisture levels maintained. After seven weeks, plant foliage were ground and stored for elemental analyses with Inductively Coupled Plasma Emission Spectrophotometer (ICP). Soil samples were analyzed with Polymerase Chain Reaction (PCR-DGGE) and Phospholipid Fatty Acids analyses (PLFA) to assess microbial diversity. The treatments did not greatly affect nutrient ...
The concentration of CO2 in the Earths atmosphere has increased over the last century. Although this increase is unlikely to have direct effects on soil microbial communities, increased atmospheric CO2 may impact soil ecosystems indirectly through plant responses. This study tested the hypothesis that exposure of plants to elevated CO2 would impact soil microorganisms responsible for key nitrogen cycling processes, specifically denitrification and nitrification. We grew trembling aspen (Populus tremuloides) trees in outdoor chambers under ambient (360 ppm) or elevated (720 ppm) levels of CO2 for 5 years and analyzed the microbial communities in the soils below the trees using quantitative polymerase chain reaction and clone library sequencing targeting the nitrite reductase (nirK) and ammonia monooxygenase (amoA) genes. We observed a more than twofold increase in copy numbers of nirK and a decrease in nirK diversity with CO2 enrichment, with an increased predominance of Bradyrhizobia-like nirK ...
Stock farming plays an important role in the agriculture of alpine regions although deleterious effects on the soils are most pronounced here. We investigated the effects of cattle trampling on soil physical, chemical and microbial properties in a Swiss sub-alpine pasture. About 10% of the study site was bare of vegetation as a result of repeated cattle trampling and the bulk density of these bare steps was 20% higher than of the soils unaffected by trampling. In the upper 25 cm, soil organic carbon (SOC) concentrations and total SOC stocks were 35% and 20% respectively lower than on the vegetated slope. As compared with the vegetated slope, topsoils of the bare steps featured narrower C:N-ratios and were more enriched in the 15N isotope, with typical values of deeper soil layers. This indicates that bare soils primarily evolved by erosion and not by a compaction, which might, together with the reduced litter input, explain the lower SOC contents. The abundances of soil microbes, estimated by ...
Second, recognize that when we say healthy soils we are referring not only to oxygenated, aerobic soil structure but also to the abundance of beneficial microorganisms (microbes) that should exist in all productive soils. The famous adage Feed the Soil, Feed the Plant means that whatever we apply to the soil should feed the soil microbes and the plants too. We want our soils to be teaming with beneficial bacteria, fungi, nematodes, protozoans and micro-arthropods. Through the amazing work of Dr. Elaine Ingham, The Soil Foodweb, started in the mid 1990s, we now know of the incredible work that the invisible to the naked eye microbes do to grow and protect plants.. And we now know that plants give up to 80% of their manufactured photosynthesized food through the root system to directly attract and feed the microbes. The plant feeds the soil microbes and the soil microbes help the plants grow and protect them from diseases, pest insects and weeds. So to the soil do no harm. This is easily ...
Designed to provide students with fundamental knowledge of soil and soil composition. Includes study of soil types, formation factors, physical properties, biological properties, and basic soil chemistry. Units covering tillage, conservation, pH, soil management, plant nutrients, and fertilizer sources are also included. Students gain the skills required to interpret soil test reports and soil survey maps and recognize qualities of various soil types. Students perform soil sampling, residue measurements, compaction assessments, and soil loss determinations per crop rotation guidelines.. ...
Soil moisture is of primary importance for predicting the evolution of soil carbon stocks and fluxes, both because it strongly controls organic matter decomposition and because it is predicted to change at global scales in the following decades. However, the soil functions used to model the heterotrophic respiration response to moisture have limited empirical support and introduce an uncertainty of at least 4% in global soil carbon stock predictions by 2100. The necessity of improving the representation of this relationship in models has been highlighted in recent studies. Here we present a data-driven analysis of soil moisture-respiration relations based on 90 soils. With the use of linear models we show how the relationship between soil heterotrophic respiration and different measures of soil moisture is consistently affected by soil properties. The empirical models derived include main effects and moisture interaction effects of soil texture, organic carbon content and bulk density. When compared to
0 ^aThe soil system, by A. Burges.--Bacteria in soil, by F. E. Clark--Fungi in soil, by J. H. Warcup.--The actinomycetes, by E. Küster.--Soil algae, by J. W. G. Lund.--Protozoa, by J. D. Stout and O. W. Heal.--Nematoda, by C. O. Nielsen.--The enchytraeidae, by F. B. OConnor.--Lumbricidae, by J. E. Satchell.--Arthropoda (except acari and collembola) by F. Raw.--Acari, by J. A. Wallwork.--Collembola, by W. G. Hale.--Mollusca, by P. F. Newell.--The importance of antibiotics and inhibiting substances, by D. Park.--Soil micro-organisms and plant roots, by D. Parkinson.--The decomposition of organic matter in the soil, by A. Burges.--Soil micro-organisms and plant protection chemicals, by N. Walker ...
To explore how actively growing bacterial communities responded to the greenhouse treatment across soil depth and time of sampling, we incubated 5 g field moist soil subsamples in 100 ml falcon tubes with bromodeoxyuridine (BrdU). BrdU is a thymidine analog that can be used to analyze the proliferation of cells due to its incorporation into newly synthesized DNA (Borneman, 1999; Goldfarb et al., 2011; McMahon et al., 2011; Evans et al., 2014). Soil manipulations were completed in a 4 °C walk-in to help maintain soil temperatures during processing, and assays were initiated within 48 h of arrival in the lab (within a week of soil collection given transit time from Alaska). Soils were hand homogenized by horizon at the block level, and live coarse roots and rocks were removed. BrdU was added dropwise to soil samples as 1 ml of a 1.7 mM BrdU solution (made in sterile, Mili-Q H2O); the no BrdU control had 1 ml water added instead. Immediately following the BrdU or water-control addition, soils were ...
Abstract: Soil total nitrogen is an important indicator of soil fertility. In order to achieve a general applicability of the soil total nitrogen content detector developed based on the principle of spectroscopy, this paper selects the universal nitrogen-sensitive wavelength of soil suitable for different types of soil and models optimization. Firstly, the spectral characteristic curves of black soil, cinnamon soil and tidal soil were measured, the analysis found that under the same soil total nitrogen content, the absorbance curves of different types of soils are quite different. Then, the Monte Carlo non-information variable elimination (MC-UVE) algorithm was used to screen the soil total nitrogen sensitive wavelengths of the three soil types, the common sensitive spectral regions of different soil types were screened, and the spectral wavelength ranges were 895-911 nm, 1047-1065 nm, 1211-1232 nm, 1468-1482 nm, 1691-1699 nm and 2095-2109 nm. On the basis of the selected spectrum, the ...
TY - JOUR. T1 - Decomposition of soil organic matter as affected by clay types, pedogenic oxides and plant residue addition rates. AU - Singh, Mandeep. AU - Sarkar, Binoy. AU - Bolan, Nanthi S.. AU - Ok, Yong Sik. AU - Churchman, Gordon Jock. PY - 2019/7/15. Y1 - 2019/7/15. N2 - The interactive effects of the types and contents of soil clay fractions (SCFs) and plant-residue addition rates on soil organic carbon (SOC) stabilisation are largely unknown. We conducted incubation experiments by amending a sandy soil sample with kaolinitic-illitic, smectitic and allophanic SCFs and adding wheat residues to the mineral mixtures to compare their C stabilisation capacity. The rate of carbon (C) decomposition was higher in the kaolinitic-illitic SCF followed by smectitic and allophanic clay minerals. The supply of easily degradable C substrate from decomposing residues markedly influenced the SCFs abilities to stabilise SOC. The removal of sesquioxides from the SCFs significantly decreased their C ...
Phosphorus (P) is one of the leading causes of surface water quality decline in the United States, leading to algal blooms and hypoxia in lakes and streams. Decreasing conservation funds dictate that agencies such as the Natural Resources Conservation Service, maximizes its effectiveness and efficiency in implementing practices to address P management and runoff on agricultural lands. Additional information on P behavior in soil is needed to improve P management plans to reduce pollution risk at the watershed, farm, and field scales. This research focuses on the development of total soil P release models, to be included into assessment and management tools to better identify agricultural soils that pose the greatest threat to surface water if eroded, and to improve existing nutrient loss models. Soil P sorption behaviors and relationships with other soil properties were investigated on 313 agricultural surface soils from across the U.S. Different soil grouping schemes were investigated when analyzing
The Century model has successfully simulated soil organic matter dynamics in many agroecosystems. However, initial applications in southern Brazil produced mixed results. The objective of this study was to calibrate and validate Century 4.5 to simulate soil carbon (C) and nitrogen (N) dynamics under diverse soil management practices in subtropical Brazil. Soil C and N data from two long-term experiments established on a degraded Acrisol in the early 1980s were used. Treatments were conventional or no-tillage; grass or grass/legume cropping systems; and corn with or without mineral N fertilizer. The calibration process iteratively modified model parameters to match simulated values of C additions and Soil Organic Carbon (SOC) and Soil Organic Nitrogen (SON) stocks to field data measured throughout the 25 years of the experiments. Improved fit between measured and observed data was obtained after key parameter changes. Soil C and N stocks were simulated accurately after these modifications were ...
Many studies of the microbial ecology of agricultural ecosystems focus on surface soils, whereas the impacts of management practice and season on soil microbial community composition and function below the plough zone are largely neglected. Deep soils have a high potential to store carbon; therefore any management driven stimulation or repression of microorganisms in subsoil could impact biogeochemical cycling in agricultural sites. The aim of this study was to understand whether soil management affects microbial communities in the topsoil (0-10 cm), rooted zone beneath the plough layer (40-50 cm), and the unrooted zone (60-70 cm). In a field experiment with different crops [wheat (Triticum aestivum L.) and maize (Zea mays L.)] and agricultural management strategies (litter amendment) we analysed microbial biomass as phospholipid fatty acids (PLFAs) and enzyme activities involved in the C-cycle (β-glucosidase, N-acetyl-β-d-glucosaminidase, β-xylosidase, phenol- and peroxidase) across a depth ...