Nutrient Uptake: The Arbuscular Mycorrhiza Fungal Symbiosis as a Plant Nutrient Acquisition Strategy

2010 ◽  
pp. 137-167 ◽  
Author(s):  
Elke Neumann ◽  
Eckhard George
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Nutrient Uptake ◽  
Nutrient Acquisition ◽  
Plant Nutrient ◽  
Fungal Symbiosis ◽  
Acquisition Strategy

scholarly journals Possible source of ancient carbon in phytolith concentrates from harvested grasses

2012 ◽  
Vol 9 (5) ◽  
pp. 1873-1884 ◽  
Author(s):  
G. M. Santos ◽  
A. Alexandre ◽  
J. R. Southon ◽  
K. K. Treseder ◽  
R. Corbineau ◽  
...  
Keyword(s):  
Plant Tissue ◽  
Atmospheric Carbon Dioxide ◽  
Energy Dispersive Spectrometer ◽  
Nutrient Acquisition ◽  
Published Data ◽  
Plant Nutrient ◽  
Before Present ◽  
Sem Images ◽  
Carbon Dioxide Co2 ◽  
Scanning Electron

Abstract. Plants absorb and transport silicon (Si) from soil, and precipitation of Si within the living plants results in micrometric amorphous biosilica particles known as phytoliths. During phytolith formation, a small amount of carbon (<2%) can become occluded in the silica structure (phytC) and therefore protected from degradation by the environment after plant tissue decomposition. Since the major C source within plants is from atmospheric carbon dioxide (CO2) via photosynthesis, the current understanding is that the radiocarbon (14C) content of phytC should reflect the 14C content of atmospheric CO2 at the time the plant is growing. This assumption was recently challenged by 14C data from phytoliths extracted from living grasses that yielded ages of several thousand years (2–8 kyr BP; in radiocarbon years "Before Present" (BP), "Present" being defined as 1950). Because plants can take up small amounts of C of varying ages from soils (e.g., during nutrient acquisition), we hypothesized that this transported C within the plant tissue could be attached to or even embedded in phytoliths. In this work, we explore this hypothesis by reviewing previously published data on biosilica mineralization and plant nutrient acquisition as well as by evaluating the efficiency of phytolith extraction protocols from scanning electron microscope (SEM) images and energy dispersive spectrometer (EDS) analyses from harvested grasses phytolith concentrates. We show that current extraction protocols are inefficient since they do not entirely remove recalcitrant forms of C from plant tissue. Consequently, material previously measured as "phytC" may contain at least some fraction of soil-derived C (likely radiocarbon-old) taken up by roots. We also suggest a novel interpretation for at least some of the phytC – which enters via the root pathway during nutrient acquisition – that may help to explain the old ages previously obtained from phytolith concentrates.

scholarly journals Modelling effects of seasonal variation in water table depth on net ecosystem CO<sub>2</sub> exchange of a tropical peatland

2014 ◽  
Vol 11 (3) ◽  
pp. 577-599 ◽  
Author(s):  
M. Mezbahuddin ◽  
R. F. Grant ◽  
T. Hirano
Keyword(s):  
Seasonal Variation ◽  
Nutrient Uptake ◽  
Water Table ◽  
Water Table Depth ◽  
Hydrological Processes ◽  
Plant Nutrient ◽  
Predictive Capacity ◽  
Tropical Peatland ◽  
Tropical Peat ◽  
Dry Seasons

Abstract. Seasonal variation in water table depth (WTD) determines the balance between aggradation and degradation of tropical peatlands. Longer dry seasons together with human interventions (e.g. drainage) can cause WTD drawdowns making tropical peatland C storage highly vulnerable. Better predictive capacity for effects of WTD on net CO2 exchange is thus essential to guide conservation of tropical peat deposits. Mathematical modelling of basic eco-hydrological processes under site-specific conditions can provide such predictive capacity. We hereby deploy a process-based mathematical model ecosys to study effects of seasonal variation in WTD on net ecosystem productivity (NEP) of a drainage affected tropical peat swamp forest at Palangkaraya, Indonesia. Simulated NEP suggested that the peatland was a C source (NEP ~ −2 g C m−2 d−1, where a negative sign represents a C source and a positive sign a C sink) during rainy seasons with shallow WTD, C neutral or a small sink (NEP ~ +1 g C m−2 d−1) during early dry seasons with intermediate WTD and a substantial C source (NEP ~ −4 g C m−2 d−1) during late dry seasons with deep WTD from 2002 to 2005. These values were corroborated by regressions (P < 0.0001) of hourly modelled vs. eddy covariance (EC) net ecosystem CO2 fluxes which yielded R2 > 0.8, intercepts approaching 0 and slopes approaching 1. We also simulated a gradual increase in annual NEP from 2002 (−609 g C m−2) to 2005 (−373 g C m−2) with decreasing WTD which was attributed to declines in duration and intensity of dry seasons following the El Niño event of 2002. This increase in modelled NEP was corroborated by EC-gap filled annual NEP estimates. Our modelling hypotheses suggested that (1) poor aeration in wet soils during shallow WTD caused slow nutrient (predominantly phosphorus) mineralization and consequent slow plant nutrient uptake that suppressed gross primary productivity (GPP) and hence NEP (2) better soil aeration during intermediate WTD enhanced nutrient mineralization and hence plant nutrient uptake, GPP and NEP and (3) deep WTD suppressed NEP through a combination of reduced GPP due to plant water stress and increased ecosystem respiration (Re) from enhanced deeper peat aeration. These WTD effects on NEP were modelled from basic eco-hydrological processes including microbial and root oxidation-reduction reactions driven by soil and root O2 transport and uptake which in turn drove soil and plant carbon, nitrogen and phosphorus transformations within a soil-plant-atmosphere water transfer scheme driven by water potential gradients. Including these processes in ecosystem models should therefore provide an improved predictive capacity for WTD management programs intended to reduce tropical peat degradation.

Plant nutrient-acquisition strategies change with soil age

2008 ◽  
Vol 23 (2) ◽  
pp. 95-103 ◽  
Author(s):  
H LAMBERS ◽  
J RAVEN ◽  
G SHAVER ◽  
S SMITH
Keyword(s):  
Nutrient Acquisition ◽  
Plant Nutrient ◽  
Acquisition Strategies ◽  
Soil Age

Topsoil replacement depth and organic amendment effects on plant nutrient uptake from reclaimed natural gas wellsites

2006 ◽  
Vol 86 (5) ◽  
pp. 859-869 ◽  
Author(s):  
Francis Zvomuya ◽  
Francis J Larney ◽  
Olalekan O Akinremi ◽  
Reynald L Lemke ◽  
Vasile E Klaassen
Keyword(s):  
Nutrient Uptake ◽  
Organic Amendment ◽  
N Uptake ◽  
C:N Ratio ◽  
Wheat Crop ◽  
Plant Nutrient ◽  
Low Carbon ◽  
South Central ◽  
N Concentration ◽  
Cattle Feedlot

Sustained plant nutrient a vailability on reclaimed wellsites is critical to the successful restoration of crop productivity. This study evaluated topsoil replacement depth (TRD) (0, 50, 100, and 150% of mandatory TRD) and organic amendment [beef cattle feedlot manure, compost derived from straw-bedded cattle feedlot manure, wheat (Triticum aestivumL.) straw, alfalfa (Medicago sativaL.) hay, and unamended control] effects on nutrient uptake by a wheat crop at three abandoned gas wellsites in south-central Alberta. Grain N uptake increased by 0.055 kg ha-1 for each percent increase in TRD, reflecting the corresponding linear increase in grain N concentration. Low carbon to nitrogen (C:N) ratio amendments, particularly compost and alfalfa, were the most effective for improving grain N concentration and uptake. Conversely, N concentration and uptake were lowest for the high C:N (53:1) wheat straw amendment. Reclamation programs should, therefore, consider incorporation of the low C:N alfalfa or compost in order to safeguard against N deficiency in the first 1–2 yr following reclamation. Our results also show that high P amendments, such as manure and compost, are better choices for improving P uptake by spring wheat. These results emphasize the importance of topsoil replacement and amendment quality (C:N ratio and P concentration) in ensuring adequate N and P supply in the 1–2 yr following reclamation. Based on this, compost appears to be the best single amendment for ensuring enhanced uptake of both N and P on reclaimed wellsites in the short term. Key words: Topsoil replacement; organic amendments; reclamation; nitrogen; phosphorus

Cover crop species affect mycorrhizae-mediated nutrient uptake and pest resistance in maize

2019 ◽  
Vol 35 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Ebony G. Murrell ◽  
Swayamjit Ray ◽  
Mary E. Lemmon ◽  
Dawn S. Luthe ◽  
Jason P. Kaye
Keyword(s):  
Nutrient Uptake ◽  
Cover Crops ◽  
Cover Crop ◽  
European Corn Borer ◽  
Pest Resistance ◽  
Plant Nutrient ◽  
Crop Species ◽  
Maize Crop ◽  
Corn Borer ◽  
Maize Growth

AbstractArbuscular mycorrhizal fungi (AMF) can increase plant nutrient uptake and chemical defense production, both of which can improve plants’ ability to resist insect herbivory. Cover crops—non-commercial species planted in between cash crops in a crop rotation—can naturally alter both soil nutrients and AMF. We tested whether different cover crop species alter AMF colonization, plant nutrient status and plant–insect interactions in a subsequent maize crop. Cover crop species were either non-mycorrhizal, non-leguminous (canola, forage radish), mycorrhizal non-leguminous (cereal rye, oats), mycorrhizal leguminous (clover, pea) or absent (fallow). We measured the cascading consequences of cover crop treatment on maize root AMF colonization, maize growth and performance of an herbivorous insect (European corn borer) feeding on the maize. Maize AMF colonization was greater in plots previously planted with mycorrhizal (rye, oats) than non-mycorrhizal (canola, radish) cover crops or no cover crop (fallow). AMF colonization was linked to increased plant phosphorous and nitrogen, and maize growth increased with low plant N:P. Induced jasmonic acid pathway plant defenses increased with increasing maize growth and AMF colonization. European corn borer survivorship decreased with lower plant N:P, and insect development rate decreased with increased induced plant defenses. Our data describe a cascade in which cover crop species selection can increase or decrease mycorrhizal colonization of subsequent maize crop roots, which in turn impacts phosphorus uptake and may affect herbivory resistance in the maize. These results suggest that farmers could select cover crop species to manage nutrient uptake and pest resistance, in order to amend or limit fertilizer and pesticide use.

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