Agriculture - Soil Management

Title

Resistance and resilience of the soil microbial biomass to severe drought in semiarid soils: The importance of organic amendments

Reference

Applied Soil Ecology
Volume 50, October 2011, Pages 27-36

Author(s)

S. Hueso,  T. Hernández, C. García

Study type

Peer Review Journal

Abstract

Changes in mean global air temperature and precipitation patterns, leading to longer drought periods and more extremely dry years, are predicted. The objective of this work was to assess whether a long period of severe drought can affect the growth and activity of the microbiota of a semiarid soil, as well as the effect of organic amendments on soil resistance and resilience to this severe drought. A soil incubation experiment was carried out over 60 days, under controlled conditions (25 °C and 60/80% day/night relative humidity), with two treatments: unamended (US) and amended (AS) with manure compost (100 t ha−1). Two levels of irrigation were imposed: (1) well-watered (MUS and MAS), the soil being maintained at 60% of its water-holding capacity (WHC), and (2) dry, without irrigation (DUS and DAS). Then, a single level of irrigation was established for 37 days, dry soils being irrigated under the same conditions than well-watered soils, to assess soil resilience to this period of drought. Under well-watered conditions, the soil water-soluble nitrogen contents were 73 and 88% higher, the microbial biomass carbon 63 and 48% higher, alkaline phosphomonoesterase activity 46 and 32% higher, β-glucosidase activity 16 and 25% higher and urease activity 30 and 19% higher for the US and AS treatments, respectively, compared with the dry conditions at the end of the experimental period. Furthermore, the organic amendment helped the soil to retain moisture and encouraged the growth and activity of soil microbial populations. However, a 2-month drought seems insufficient to destroy the native microbial biomass in the arid soil used in this study, indicating that it is well adapted to adverse climate conditions. Thus, microbiological and biochemical parameters experienced a rapid recovery after soil rewetting, DUS and DAS showing values similar to MUS and MAS, after rewetting, highlighting the resilience of this type of soil against drought stress.

Policy theme(s)

Agriculture >> Agricultural management >> Soil management
Climate change and energy >> Climate change adaptation >> Agricultural adaptation         
Soil >> Soil biodiversity

Keywords

Drought; Rewetting; Semiarid soils; Organic amendments; Microbiological properties; Soil enzymes

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Shortlisted for Science for Environment Policy News Alert

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http://www.sciencedirect.com/science/article/pii/S0929139311001582

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shuesomartos@yahoo.es

Title

Agricultural success from Africa: the case of fertilizer tree systems in southern Africa (Malawi, Tanzania, Mozambique, Zambia and Zimbabwe)

Reference

Source: International Journal of Agricultural Sustainability, Sustainable intensification: increasing productivity in African food and agricultural systems , pp. 129-136(8)

Author(s)

Authors: Ajayi, Oluyede Clifford; Place, Frank; Akinnifesi, Festus Kehinde; Sileshi, Gudeta Weldsesemayat

Study type

Peer Review Journal

Abstract

In response to the declining soil fertility in southern Africa and the negative effects that this leads to, such as food insecurity besides other developmental challenges, fertilizer tree systems (FTS) were developed as technological innovation to help smallholder farmers to build soil organic matter and fertility in a sustainable manner. In this paper, we trace the historical background and highlight the developmental phases and outcomes of the technology. The synthesis shows that FTS are inexpensive technologies that significantly raise crop yields, reduce food insecurity and enhance environmental services and resilience of agro-ecologies. Many of the achievements recorded with FTS can be traced to some key factors: the availability of a suite of technological options that are appropriate in a range of different household and ecological circumstances, partnership between multiple institutions and disciplines in the development of the technology, active encouragement of farmer innovations in the adaptation process and proactive engagement of several consortia of partner institutions to scale up the technology in farming communities. It is recommended that smallholder farmers would benefit if rural development planners emphasize the merits of different fertility replenishment approaches and taking advantage of the synergy between FTS and mineral fertilizers rather than focusing on `organic vs. inorganic' debates.

Policy theme(s)

Agriculture >> Agricultural management >> Food security
Agriculture >> Agricultural management >> Soil management
Sustainable development and policy assessment >> Sustainable economic development >> Sustainable development in developing countries

Keywords

agricultural innovation; agroforestry; development partnership; research for development; soil fertility; southern Africa

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Shortlisted for Science for Environment Policy News Alert

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N/A

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http://earthscan.publisher.ingentaconnect.com/content/earthscan/ijas/2011
/00000009/00000001/art00015
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o.c.ajayi@cgiar.org

Title

Biochar Incorporation into Pasture Soil Suppresses in situ Nitrous Oxide Emissions from Ruminant Urine Patches

Reference

Journal of Environment Quality, 2011; 40 (2): 468 DOI: 10.2134/jeq2010.0419

Author(s)

Arezoo Taghizadeh-Toosi, Tim J. Clough, Leo M. Condron, Robert R. Sherlock, Craig R. Anderson, Robin A. Craigie.

Study type

Peer Review Journal

Abstract

Nitrous oxide (N₂O) emissions from grazing animal excreta are estimated to be responsible for 1.5 Tg of the total 6.7 Tg of anthropogenic N₂O emissions. This study was conducted to determine the in situ effect of incorporating biochar, into soil, on N₂O emissions from bovine urine patches and associated pasture uptake of N. The effects of biochar rate (0–30 t ha–1), following soil incorporation, were investigated on ruminant urine–derived N₂O fluxes, N uptake by pasture, and pasture yield. During an 86–d spring-summer period, where irrigation rainfall occurred, the N₂O fluxes from 15N labeled ruminant urine patches were reduced by 50%, after incorporating 30 tha–1 of biochar. Taking into account the N₂O emissions from the control plots, 30 t ha–1 of biochar reduced the N₂O emission factor from urine by 70%. The atom% 15N enrichment of the N₂O emitted was lower in the 30 t ha–1 biochar treatment, indicating less urine–N contributed to the N₂O fl ux. Soil NO3-N concentrations were lower with increasing biochar rate during the first 30 d following urine deposition. No differences occurred, due to biochar addition, with respect to dry matter yields, herbage N content, or recovery of 15N applied in herbage. Incorporating biochar into the soil can significantly diminish ruminant urine-derived N₂O emissions. Further work is required to determine the persistence of the observed effect and to fully understand the mechanism(s) of the observed reduction in N₂O fluxes.

Policy theme(s)

Agriculture >>Agricultural management >> Soil management
Agriculture >> Agricultural pollution >> Agricultural emissions

Keywords

N/A

Entry Source:

N/A

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Shortlisted for Science for Environment Policy News Alert

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https://www.agronomy.org/publications/jeq/view/40-2/q10-0419.pdf
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arezoo.taghizadehtoosi@lincolnuni.ac.nz

Title

Reference

J. Environ. Monit., 2011, 13, 822-828
DOI: 10.1039/C0EM00611D

Author(s)

Wenchao Du, Yuanyuan Sun, Rong Ji, Jianguo Zhu, Jichun Wu and Hongyan Guo

Study type

Peer Review Journal

Abstract

The properties of nanoparticles and their increased use have raised concerns about their possible harmful effects within the environment. Most studies on their effects have been in aqueous systems. Here we investigated the effect of TiO2 and ZnO nanoparticles on wheat growth and soil enzyme activities under field conditions. Both of the nanoparticles reduced the biomass of wheat. The TiO2 nanoparticles were retained in the soil for long periods and primarily adhered to cell walls of wheat. The ZnO nanoparticles dissolved in the soil, thereby enhancing the uptake of toxic Zn by wheat. The nanoparticles also induced significant changes in soil enzyme activities, which are bioindicators of soil quality and health. Soil protease, catalase, and peroxidase activities were inhibited in the presence of the nanoparticles; urease activity was unaffected. The nanoparticles themselves or their dissolved ions were clearly toxic for the soil ecosystem.

Policy theme(s)

Chemicals >> Pollutants/hazardous substances >> Nanomaterials
Agriculture >> Agricultural management >> Soil management
Soil >> Threats to soil >> Soil contamination

Keywords

N/A

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Shortlisted for Science for Environment Policy News Alert

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N/A

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http://pubs.rsc.org/en/Content/ArticleLanding/2011/EM/c0em00611d
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hyguo@nju.edu.cn

Title

Diversity and Activity of Free-Living Nitrogen-Fixing Bacteria

Reference

Applied and Environmental Microbiology, 2010; 77 (3): 911
DOI: 10.1128/AEM.01250-10

Author(s)

C. H. Orr, A. James, C. Leifert, J. M. Cooper, S. P. Cummings.

Study type

Peer Review Journal

Abstract

Agricultural soils are heterogeneous environments in which conditions affecting microbial growth and diversity fluctuate widely in space and time. In this study, the molecular ecology of the total bacterial and free-living nitrogen-fixing communities in soils from the Nafferton Factorial Systems Comparison (NFSC) study in northeast England were examined. The field experiment was factorial in design, with organic versus conventional crop rotation, crop protection, and fertility management factors. Soils were sampled on three dates (March, June, and September) in 2007. Total RNA was extracted from all soil samples and reverse transcribed. Denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR) were used to analyze nifH and 16S rRNA genes in order to study free-living diazotrophs and the total bacterial community, respectively. Crop rotation was shown to have a significant effect on total bacterial diversity (and that of free-living N fixers) (P 0.001). On all three dates, nifH activity was higher in the conventional crop rotation. In contrast, qPCR analysis of free-living N fixers indicated significantly higher levels of activity in conventionally fertilized plots in June (P = 0.0324) and in plots with organic crop protection in September (P = 0.0143). To our knowledge, the effects of organic and conventional farming systems on free-living diazotrophs have never been studied. An increased understanding of the impacts of management practices on free-living N fixers could allow modifications in soil management practices to optimize the activity of these organisms.

Policy theme(s)

Agriculture>> Agricultural management>>Soil management
Agriculture>>Agricultural management>>Organic farming
Soil>>Soil biodiversity

Keywords

N/A

Entry Source:

N/A

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http://aem.asm.org/cgi/content/abstract/77/3/911 
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stephen.cummings@unn.ac.uk

Title

Biochar mediated alterations in herbicide breakdown and leaching in soil

Reference

Author(s)

D.L. Jones, G. Edwards-Jones and D.V. Murphy

Study type

Peer Review Journal

Abstract

Biochar application to soil has been proposed as a mechanism for improving soil quality and the long term sequestration of carbon. The implications of biochar on pesticide behavior, particularly in the longer term, however, remains poorly understood. Here we evaluated the influence of biochar type, time after incorporation into soil, dose rate and particle size on the sorption, biodegradation and leaching of the herbicide simazine. We show that typical agronomic application rates of biochar (10-100 t ha-1) led to alterations in soil water herbicide concentrations, availability, transport and spatial heterogeneity. Overall, biochar suppressed simazine biodegradation and reduced simazine leaching. These responses were induced by a rapid and strong sorption of simazine to the biochar which limits its availability to microbial communities. Spatial imaging of 14C-labeled simazine revealed concentrated hotpsots of herbicide co-localized with biochar in the soil profile. The rate of simazine mineralization, amount of sorption and leaching was inversely correlated with biochar particle size. Biochar aged in the field for 2 years had the same effect as fresh biochar on the sorption and mineralization of simazine, suggesting that the effects of biochar on herbicide behavior may be long lasting. We conclude that biochar application to soil will reduce the dissipation of foliar applied pesticides decreasing the risk of environmental contamination and human exposure via transfer in the food chain, but may affect the efficacy of soil-applied herbicides.

Policy theme(s)

Agriculture >> Agricultural management >> Soil management
Agriculture>>Agricultural pollution>>Pesticide pollution
Soil>>Threats to soil>>Soil contamination

Keywords

Black carbon, Charcoal, Pollutant flow, Triazine, Xenobiotic

Entry Source:

N/A

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Selected for Science for Environment Policy News Alert

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http://www.sciencedirect.com/science/article/pii/S0038071710004840
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d.jones@bangor.ac.uk

Title

Land application of organic waste - Effects on the soil ecosystem

Reference

Applied Energy
Volume 88, Issue 6, June 2011, Pages 2210-2218

Author(s)

M. Odlare, V. Arthurso, M. Pell, K. Svensson, E. Nehrenheim and J. Abubaker

Study type

Peer Review Journal

Abstract

Growing populations and the increasing use of existing resources has led to growth in organic waste emissions. Therefore, a sustainable approach to managing this waste has become a major concern in densely populated areas. Biological treatment is an efficient method for reducing the amount of organic waste, and for producing energy. A large number of biogas plants and compost facilities that use organic waste as a substrate for electricity and fuel production are being built around the world. The biological treatment process in these plants produces large amounts of organic waste, and there is therefore a growing need to find a sustainable use for this material. Organic waste, such as biogas residues and compost can be a valuable fertilizer for agricultural soils. They can serve as a source of plant nutrients and can also improve soil structure and water holding capacity. However, as organic residues are known to contain both heavy metals and organic contaminants there is a need for long term field experiments to ensure that soil and plant quality is maintained. In order to investigate the potential risks and benefits of using organic waste in agriculture, an 8 year field experiment was established in central Sweden. Under realistic conditions, compost and biogas residues from source-separated household waste were compared with traditional mineral fertilizer. We examined crop yield and soil chemical and microbiological properties. The main conclusion from the field experiment was that biogas residues resulted in crop yields almost as high as the mineral fertilizer NPS. In addition, several important soil microbiological properties, such as substrate induced respiration, potential ammonium oxidation and nitrogen mineralization were improved after application of both biogas residues and compost. Moreover, no negative effects could be detected from using either of the organic wastes. In particular the genetic structure of the soil bacterial community appeared to resist changes caused by addition of organic waste.

Policy theme(s)

Agriculture >> Agricultural management >> Soil management
Soil >> Soil biodiversity
Soil >> Threats to soil >> Soil contamination

Keywords

Microbial soil properties, Organic waste, Soil fertility, Soil properties

Entry Source:

Shortlisted for Science for Environment Policy News Alert

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N/A

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http://www.sciencedirect.com/science/article/pii/S0306261910005635
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monica.odlare@mdh.se

Title

Assessing soil quality under intensive cultivation and tree orchards in Southern Italy

Reference

Applied Soil Ecology
Volume 47, Issue 3, March 2011, Pages 184-194

Author(s)

Giuliano Bonanomi, Rosaria D'Ascoli, Vincenzo Antignani, Manuela Capodilupo, Lucia Cozzolino, Rossana Marzaioli, Gerardo Puopolo, Flora A. Rutigliano, Rosalia Scelza, Riccardo Scotti, Maria A. Rao and Astolfo Zoina

Study type

Peer Review Journal

Abstract

Concerns about groundwater contamination as well as pesticide residues in food and soil have fuelled vigorous debates about the sustainability of chemical-intensive agriculture. Search has been prompted for agronomic strategies with lower environmental hazards. In this multidisciplinary study we compared the characteristics of soils from 20 agricultural farms selected in five geographical areas of Southern Italy with different soil types. In each farm, fields with management regime classified as high-input (HIMR, intensive cultivation under plastic tunnels) or low-input (LIMR, tree orchards) were selected. Soil samples were analyzed for 31 parameters including physical and chemical properties (bulk density, water holding capacity, texture, pH, limestone, electrical conductivity, organic C to a depth of 0-20 and 20-40 cm, total N, P2O5, Ca2+, Mg2+, K+, Na+, cation exchange capacity), enzymatic activities (dehydrogenase, arylsulphatase, β-glucosidase, phosphatase and urease) and microbiological features (potential respiration, functional diversity of microbial populations by BIOLOG EcoPlates™, microbial biomass, fungal mycelium, culturable actinomycetes, bacteria and fungi, pseudomonads and bacterial species richness by 16S rDNA-DGGE). Finally, a soil bioassay was performed in order to evaluate the plant growth of a biotest plant (Lactuca sativa) and soil suppressiveness of the Rhizoctonia solani-L. sativa pathosystem.
Results showed that many soil properties were influenced by management regime more than by the sampling area. Compared to LIMR, HIMR soils consistently had reduced soil organic C (-24%), enzymatic activities, microbial biomass and fungal mycelium (-40% and -18%, respectively), functional diversity (-18%) and bacterial species richness (-14%). On the contrary, the same soils showed a remarkable increase in the values of the parameters related to the mineral soil fraction (electrical conductivity +370%; P2O5 +72%; Na+ +86%). Management regime did not affect cation exchange capacity, pH, limestone and soil texture. The lettuce bioassay showed a higher plant growth (+17%) in the LIMR compared to HIMR soils, despite the lower content of mineral nutrients. Suppression of R. solani was not influenced by management regime, but significant differences were recorded among farms. Differences among the assessed soil parameters indicate a trend of soil quality deterioration under the high-input management regime.

Policy theme(s)

Agriculture >> Agricultural management >> Soil management
Soil >> Soil biodiversity

Keywords

Agricultural management, Soil chemical and biological properties, Enzymatic activities, Microbial diversity, Rhizoctonia solani

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Selected for Science for Environment Policy News Alert

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N/A

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http://www.sciencedirect.com/science/article/pii/S0929139310002647
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giuliano.bonanomi@unina.it

Title

Assessing the fate of antibiotic contaminants in metal contaminated soils four years after cessation of long-term waste water irrigation

Reference

Science of The Total Environment
Volume 409, Issue 3, 1 January 2011, Pages 540-547

Author(s)

Fatima Tamtam, Folkert van Oort, Barbara Le Bot, Tuc Dinh, Sophie Mompelat, Marc Chevreuil, Isabelle Lamy and Médard Thiry

Study type

Peer Review Journal

Abstract

Spreading of urban wastewater on agricultural land may lead to concomitant input of organic and inorganic pollutants. Such multiple pollution sites offer unique opportunities to study the fate of both heavy metals and pharmaceuticals. We examined the occurrence and fate of selected antibiotics in sandy-textured soils, sampled four years after cessation of 100 years irrigation with urban wastewater from the Paris agglomeration. Previous studies on heavy metal contamination of these soils guided our sampling strategy. Six antibiotics were studied, including quinolones, with a strong affinity for organic and mineral soil components, and sulfonamides, a group of more mobile molecules. Bulk samples were collected from surface horizons in different irrigation fields, but also in subsurface horizons in two selected profiles. In surface horizons, three quinolones (oxolinic acid, nalidixic acid, and flumequine) were present in eight samples out of nine. Their contents varied spatially, but were well-correlated one to another. Their distributions showed great similarities regarding spatial distribution of total organic carbon and heavy metal contents, consistent with a common origin by wastewater irrigation. Highest concentrations were observed for sampling sites close to irrigation water outlets, reaching 22 µg kg-1 for nalidixic acid. Within soil profiles, the two antibiotic groups demonstrated an opposite behavior: quinolones, found only in surface horizons; sulfamethoxazole, detected in clay-rich subsurface horizons, concomitant with Zn accumulation. Such distribution patterns are consistent with chemical adsorption properties of the two antibiotic groups: immobilization of quinolones in the surface horizons ascribed to strong affinity for organic matter (OM), migration of sulfamethoxazole due to a lower affinity for OM and its interception and retention in electronegative charged clay-rich horizons. Our work suggests that antibiotics may represent a durable contamination of soils, and risks for groundwater contamination, depending on the physicochemical characteristics both of the organic molecules and of soil constituents.

Policy theme(s)

Agriculture >> Agricultural management >> Soil management
Soil >> Threats to soil >> Soil contamination

Keywords

Wastewater, Quinolones, Sulfonamides, Sandy soils, Distribution, Accumulation, Migration

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Shortlisted for Science for Environment Policy News Alert

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N/A

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http://www.sciencedirect.com/science/article/pii/S0048969710011186
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fatima.tamtam@upmc.fr

Title

Selection of phosphorus solubilizing bacteria with biocontrol potential for growth in phosphorus rich animal bone charcoal

Reference

Applied Soil Ecology
Volume 46, Issue 3, November 2010, Pages 464-469

Author(s)

J. Postma, E.H. Nijhuis and E. Someus

Study type

Peer Review Journal

Abstract

Bacteria with the ability to solubilize phosphorus (P) and to improve plant health were selected and tested for growth and survival in P-rich animal bone charcoal (ABC). ABC is suggested to be suitable as a carrier for biocontrol agents, offering them a protected niche as well as delivering phosphate to plants, meanwhile re-using P from waste of the food chain. Ninety-seven bacterial isolates from different soils were tested for their potential to dissolve P from ABC. Of these isolates, 60% showed positive scores; they belonged to the genera Arthrobacter, Bacillus, Burkholderia, Collimonas, Paenibacillus, Pseudomonas, Serratia, and Streptomyces. Twelve isolates from different taxonomic groups were selected for further research on growth ability and survival in ABC, and on their potential to control plant pathogens. The highest concentrations of P were dissolved by Pseudomonas chlororaphis and Bacillus pumilus, followed by Paenibacillus polymyxa, Burkholderia pyrrocinia and three Streptomyces isolates. P. chlororaphis and P. polymyxa showed strongest growth inhibition of plant pathogenic Pythium and Fusarium sp., followed by the Streptomyces spp. isolates.

Policy theme(s)

Agriculture >> Agricultural management >> Crop protection
Agriculture >> Agricultural management >> Soil management

Keywords

Biological control, Phosphorus mobilization, Antagonistic bacteria, Animal bone charcoal, Pythium aphanidermatum, Fusarium oxysporum f.sp. radicis lycopersici

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Shortlisted for Science for Environment Policy News Alert

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N/A

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http://www.sciencedirect.com/science/article/pii/S0929139310001630
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joeke.postma@wur.nl  

Title

Influences of non-herbaceous biochar on arbuscular mycorrhizal fungal abundances in roots and soils: Results from growth-chamber and field experiments

Reference

Applied Soil Ecology
Volume 46, Issue 3, November 2010, Pages 450-456

Author(s)

Daniel D. Warnock, Daniel L. Mummey, Brooke McBride, Julie Major, Johannes Lehmann and Matthias C. Rillig,

Study type

Peer Review Journal

Abstract

Biochar holds promise as an amendment for soil quality improvement and sequestration of atmospheric carbon dioxide. However, knowledge of how biochar influences soil properties, especially soil microorganisms, is limited. Three separate studies were conducted, with two studies using Plantago lanceolata as the AMF hosting plant, and a third being conducted in the field. Each of the three studies employed a different soil type. Furthermore, a total of five different biochars, and ten different biochar application rates, were used across the three experiments. All experiments had the goal to examine biochar influences on arbuscular mycorrhizal fungal (AMF) abundance in roots and AMF abundance (hyphal lengths) in soils. AMF abundance was either decreased or remained unchanged across all biochar treatments. When AMF abundances decreased, significant changes in soil properties, primarily in soil P availability, were observed. Application of large quantities (2.0% and 4.0%, w/w) of a lodgepole pine biochar, led to significant declines in AMF abundance in roots of 58% and 73% respectively, but not in soils. These declines in AMF abundance were accompanied by significant declines (28% and 34%) in soil P availability. After addition of a peanut shell biochar produced at 360 °C, P increased by 101% while AMF root colonization and extraradical hyphal lengths deceased by 74% and 95% respectively. Field application of mango wood biochar at rates of 23.2 and 116.1 t C ha−1 increased P availabilities by 163% and 208% respectively and decreased AMF abundances in soils by 43% and 77%. These findings may have implications for soil management where the goal is to increase the services provided by AMF.

Policy theme(s)

Agriculture >> Agricultural management >> Soil management
Soil >> Soil biodiversity

Keywords

Arbuscular mycorrhizal fungi, Root colonization, Extraradical hyphae, Biochar, Black carbon

Entry Source:

Shortlisted for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

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http://www.sciencedirect.com/science/article/pii/S0929139310001654
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matthias.rillig@fu-berlin.de