Nitrogen and Phosphorus Availability and the Role of Fire in Heathlands at Wilsons Promontory

1994 ◽  
Vol 42 (3) ◽  
pp. 269 ◽  
Author(s):  
MA Adams ◽  
J Iser ◽  
AD Keleher ◽  
DC Cheal
Keyword(s):  
Phosphatase Activity ◽  
C:N Ratio ◽  
Soil Nutrient ◽  
Fire Frequency ◽  
P Availability ◽  
Native Plant ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pools ◽  
Inorganic P ◽  
Eucalypt Forests

Analyses of carbon, nitrogen and phosphorus in heathland soils at Wilsons Promontory and on Snake Island show that the effects of fire, including repeated fires, are confined to the surface 2 cm. The uppermost soil in long-unburnt heathlands is rich in these elements and usually has a smaller C:N ratio compared with the soil below. Indices of N and P availability (C:N ratios, concentrations of potentially mineralisable N and extractable inorganic P, phosphatase activity) are similar to those in highly productive eucalypt forests-a finding in conflict with past assessments of nutrient availability in heathlands. Phosphatase activity and concentrations of carbon, nitrogen and potentially mineralisable N were less in soils from repeatedly burnt heathlands than in soils from long unburnt heathlands whereas there was a greater concentration of extractable inorganic P in soils from repeatedly burnt heathlands. The balance between nitrogen input and loss is dependent on fire frequency and present-day management of heathland (and other native plant communities with low nutrient capitals) should recognise that over- or under-use of fire will significantly alter soil nutrient pools and availability and that these changes may alter community species composition and productivity.

scholarly journals Phosphatase activity and organic phosphorus turnover on a high Arctic glacier

2009 ◽  
Vol 6 (1) ◽  
pp. 2697-2721 ◽  
Author(s):  
M. Stibal ◽  
A. M. Anesio ◽  
C. J. D. Blues ◽  
M. Tranter
Keyword(s):  
Phosphatase Activity ◽  
Organic Phosphorus ◽  
High Arctic ◽  
Organic P ◽  
Glacier Surface ◽  
Nutrient Pools ◽  
Inorganic P ◽  
Low Concentrations ◽  
Arctic Glacier

Abstract. Arctic glacier surfaces harbor abundant microbial communities consisting mainly of heterotrophic and photoautotrophic bacteria. The microbes must cope with very low concentrations of nutrients and with the fact that both the dissolved and debris-bound nutrient pools are dominated by organic phases. Here we provide evidence that phosphorus (P) is deficient and limiting in the supraglacial environment on a Svalbard glacier, we show how the microbial community responds to the P stress and we quantify the contribution of the microbes to the cycling of the dominant organic P in the supraglacial environment. Incubation of cryoconite debris revealed significant phosphatase activity in the samples (19–67 nmol MUP g−1 h−1), which was controlled by the concentration of inorganic P during incubations and had its optimum at around 30°C. The phosphatase activity rates measured at near-in situ temperature and substrate concentration imply that the available dissolved organic P can be turned over by microbes within ~3–11 h on the glacier surface. By contrast, the amount of potentially bioavailable debris-bound organic P is sufficient for a whole ablation season. However, it is apparent that some of this potentially bioavailable debris-bound P is not accessible to the microbes.

Development of a phosphatase activity assay using excised plant roots

Soil Research ◽  
2014 ◽  
Vol 52 (2) ◽  
pp. 193 ◽  
Author(s):  
Jaya Das ◽  
Nicholas Comerford ◽  
David Wright ◽  
Jim Marois ◽  
Cheryl Mackowiak
Keyword(s):  
Phosphatase Activity ◽  
Plant Species ◽  
Organic Phosphorus ◽  
Plant Stress ◽  
Develop Model ◽  
P Availability ◽  
Organic P ◽  
Inorganic P ◽  
Abiotic Degradation ◽  
Microbial Systems

Root phosphatase mediated mineralisation of organic phosphorus (P) can affect P availability in agricultural and forest landscapes. Phosphatases hydrolyse organic P into inorganic P that can be taken up by plants. We developed a method to determine mineralisable organic P by phosphatases exuded by excised live roots/microbial systems. We used excised greenhouse- and field-grown roots with para-nitrophenylphosphate, glucose-1-phosphate and phytic acid as sources of organic P. Experimental variables were analysed including linearity of the reaction, presence of inorganic P, organic P exuded from roots, possible abiotic degradation of organic P, and background inorganic/organic P. Organic P mineralisation by root–phosphatase complexes was found to be linear through 6 h. Phosphorus contaminants into the system were found to be within 10% of mineralised organic P. We used this technique to answer questions about organic P bioavailability, including effect of organic P sources, plant species, plant variety, plant stress and root conditions. Overall, this method was sensitive to organic P source and plant stress of greenhouse and field-grown roots, plant species and root physiological conditions. Unlike other methods used to determine phosphatase activity, this method is not limited by lengthy preparation to develop model plants, nor is there any restriction on the choice of organic P or plant species. Our results suggest that this is an attractive method for determining organic P mineralisation specificity among and within plant species, and it can be easily integrated into routine laboratory analyses.

scholarly journals Phosphatase activity and organic phosphorus turnover on a high Arctic glacier

2009 ◽  
Vol 6 (5) ◽  
pp. 913-922 ◽  
Author(s):  
M. Stibal ◽  
A. M. Anesio ◽  
C. J. D. Blues ◽  
M. Tranter
Keyword(s):  
Phosphatase Activity ◽  
Organic Phosphorus ◽  
High Arctic ◽  
Organic P ◽  
Glacier Surface ◽  
Nutrient Pools ◽  
Inorganic P ◽  
Low Concentrations ◽  
Arctic Glacier

Abstract. Arctic glacier surfaces harbour abundant microbial communities consisting mainly of heterotrophic and photoautotrophic bacteria. The microbes must cope with low concentrations of nutrients and with the fact that both the dissolved and debris-bound nutrient pools are dominated by organic phases. Here we provide evidence that phosphorus (P) is deficient in the supraglacial environment on a Svalbard glacier, we quantify the enzymatic activity of phosphatases in the system and we estimate the contribution of the microbes to the cycling of the dominant organic P in the supraglacial environment. Incubation of cryoconite debris revealed significant phosphatase activity in the samples (19–67 nmol MUP g−1 h−1). It was inhibited by inorganic P during incubations and had its optimum at around 30°C. The phosphatase activity measured at near-in situ temperature and substrate concentration suggests that the available dissolved organic P can be turned over by microbes within ~3–11 h on the glacier surface. By contrast, the amount of potentially bioavailable debris-bound organic P is sufficient for a whole ablation season. However, it is apparent that some of this potentially bioavailable debris-bound P is not accessible to the microbes.

FERTILIZATION SYSTEM AS A WAY OF SOIL FERTILITY AND STABILIZATION OF FIELD CROP ROTATION PRODUCTIVENESS

1970 ◽  
pp. 38-41
Author(s):  
V. T. Sinegovskaya ◽  
E. T. Naumchenko
Keyword(s):  
Soil Fertility ◽  
Crop Rotation ◽  
C:N Ratio ◽  
Mineral Fertilizer ◽  
Organic Fertilizers ◽  
Nitrogen And Phosphorus ◽  
Rotation System ◽  
Mobile Phosphorus ◽  
Crop Rotation System ◽  
Fertilizer System

The article presents the results of comparative evaluation of the efficiency of the long-term application of mineral and organic fertilizers in the crop rotation system. It was found that the application of the mineral fertilizer system increased the value of hydrolytic acidity of the soil from 4,30 to 5,29 mg-eq per 100 g of soil, the indicator of metabolic acidity decreased from 5,2 to 4,9 pH units. By the end of the 11th rotation for both fertilizer systems, the content of mobile phosphorus increased by more than 4 times relative to the initial value, its mobility indicator – by 2,2-3,2 times compared with the control. The use of the organo-mineral system was accompanied by an increase in the content of humus by 0,35 % and a decrease in the C:N ratio from 11,2 to 8,9. The increased productivity of wheat was revealed when applying nitrogen and nitrogen-phosphorus fertilizers against the background of prolonged use of the mineral and organo-mineral fertilizer system. The change in wheat productivity by 56 % depended on the content of mineral nitrogen, mobile phosphorus, humus in the topsoil, and on the phosphate ion mobility. Soybean productivity depended on soil fertility indicators only by 24 %: the relationship between soybean productivity and the mineral forms of nitrogen and phosphorus is weak and direct, between productivity and P2O5 mobility - weak and inverse, with humus - moderate and direct.

Evidence of temperature control of production and nutrient cycling in two interior Alaska black spruce ecosystems

1981 ◽  
Vol 11 (2) ◽  
pp. 259-274 ◽  
Author(s):  
Keith Van Cleve ◽  
Richard Barney ◽  
Robert Schlentner
Keyword(s):  
Black Spruce ◽  
Mineral Soil ◽  
Soil Nutrient ◽  
North Slope ◽  
Nutrient Pools ◽  
Soil Biological Activity ◽  
Nutrient Mineralization ◽  
Interior Alaska ◽  
Soil Temperatures ◽  
And Function

Selected indices of structure and function were used to evaluate the effect of differing soil thermal regimes on soil-permafrost-dominated (muskeg) and permafrost-free (north-slope) black spruce ecosystems in interior Alaska. The poorly drained, permafrost site displayed cooler soil temperatures and higher soil moisture content than were encountered on the well-drained north slope. Mineral soil nutrient pools generally were largest on the permafrost site. However, low soil temperature acted as a negative feedback control, suppressing soil biological activity, nutrient mineralization, and tree primary production to lower levels on the soil-permafrost-dominated site as compared with the permafrost-free site. Forty percent larger accumulation of tree biomass and 80% greater annual tree productivity occurred on the warmer site.

The effect of riparian restoration on channel complexity and soil nutrients

2017 ◽  
Vol 68 (11) ◽  
pp. 2041 ◽  
Author(s):  
J. Patrick Laceby ◽  
Nina E. Saxton ◽  
Kate Smolders ◽  
Justine Kemp ◽  
Stephen J. Faggotter ◽  
...  
Keyword(s):  
Soil Nutrients ◽  
Riparian Vegetation ◽  
Soil Nutrient ◽  
Nutrient Retention ◽  
River Channel ◽  
Channel Width ◽  
Riparian Restoration ◽  
Nitrogen And Phosphorus ◽  
Elemental Geochemistry ◽  
Channel Complexity

Restoration of riparian vegetation may reduce nutrient and sediment contamination of waterways while potentially enhancing stream channel complexity. Accordingly, the present study used a paired-site approach to investigate the effects of mature regrowth riparian vegetation on river channel morphology and soil nutrients (i.e. nitrogen and phosphorus), comparing four sites of degraded (pasture) and reforested reaches. A revised rapid assessment of riparian condition (RARC) was used to validate the site pairings. Riparian soil nutrient and elemental geochemistry were compared between paired sites, along with two parameters of channel width complexity and two for channel slope complexity. The RARC analysis confirmed the validity of the paired site design. The elemental geochemistry results indicated that underlying geology may affect the paired site analyses. Reaches with mature regrowth vegetation had greater channel width complexity but no difference in their riverbed slope complexity. In addition, degraded reaches had higher soil nutrient (i.e. nitrogen and phosphorus) concentrations, potentially indicative of the greater nutrient retention of pasture grass sites compared with mature regrowth forested reaches with less ground cover. Overall, the present study indicates that restoring mature regrowth riparian vegetation may increase river channel width complexity, although it may require canopy management to optimise the nutrient retention potential necessary to maximise the effect of riparian restoration strategies on freshwater environments.

scholarly journals Seasonal variation in AMF colonisation, soil and plant nutrient content in gypsum specialist and generalist species growing in P-poor soils

2021 ◽  
Author(s):  
Andreu Cera ◽  
Estephania Duplat ◽  
Gabriel Montserrat-Martí ◽  
Antonio Gómez-Bolea ◽  
Susana Rodríguez-Echeverría ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Nutrient Availability ◽  
Soil Nutrient ◽  
Nutrient Status ◽  
Nutrient Content ◽  
P Availability ◽  
Plant Nutrient ◽  
Rhizospheric Soil ◽  
Soil Nutrient Availability ◽  
Generalist Species

Abstract Aims Gypsum soils are P-limited atypical soils that harbour a rich endemic flora. These singular soils are usually found in drylands, where plant activity and soil nutrient availability are seasonal. No previous studies have analysed the seasonality of P nutrition and its interaction with the arbuscular mycorrhiza fungi (AMF) colonisation in gypsum plants. Our aim was to evaluate the seasonal changes in plant nutrient status, AMF colonisation and rhizospheric soil nutrient availability in gypsum specialist and generalist species. Methods We evaluated seasonal variation in the proportion of root length colonised by AMF structures (hyphae, vesicules and arbuscules), plant nutrient status (leaf C, N and P and fine root C and N) and rhizospheric soil content (P, organic matter, nitrate and ammonium) of three gypsum specialists and two generalists throughout a year. Results All species showed arbuscules within roots, including species of Caryophyllaceae and Brassicaceae. Root colonisation by arbuscules (AC) was higher in spring than in other seasons, when plants showed high leaf P-requirements. Higher AC was decoupled from inorganic N and P availability in rhizospheric soil, and foliar nutrient content. Generalists showed higher AC than specialists, but only in spring. Conclusions Seasonality was found in AMF colonisation, rhizospheric soil content and plant nutrient status. The mutualism between plants and AMF was highest in spring, when P-requirements are higher for plants, especially in generalists. However, AMF decoupled from plant demands in autumn, when nutrient availability increases in rhizospheric soil.

scholarly journals GIS based Soil Nutrient Assessment of Available Macro and Micronutrients in Tommaladahalli Microwatershed of Chikkamagaluru District, Karnataka, India

2021 ◽  
Vol 10 (9) ◽  
pp. 510-517
Author(s):  
S. Anitha ◽  
K. T. Gurumurthy Ganapathi
Keyword(s):  
Interpolation Method ◽  
Soil Nutrient ◽  
Nutrient Status ◽  
Nitrogen And Phosphorus ◽  
Available Nitrogen ◽  
Entire Study ◽  
Available N ◽  
Standard Procedures ◽  
Entire Study Area ◽  
Available Nutrient Status

An investigation was undertaken in Tommaladahalli (566.13 ha) micro-watershed of Tarikere taluk, Chikkamagaluru district of Karnataka to assess available nutrient status in the surface soils. About 118 surface soil samples were collected grid wise by using cadastral map at 250 m grid interval and were analyzed for their fertility status using standard procedures. Soil fertility maps were prepared by means of interpolation method called Krigging. The results revealed that the pH, electrical conductivity, and organic carbon were ranged from 5.37 to 9.06, 0.065 to 0.466 dS m-1 and 0.33 to 1.62 per cent respectively. The available N, P2O5, K2O were ranged from 175.6 to 545.6 kg ha-1, 11.8 to 61.1 kg ha-1 and 122.7 to 491.4 kg ha-1, respectively. The available nitrogen and phosphorus were low to medium, where as potassium content was medium to high in the entire study area. Micronutrients viz. zinc, iron and boron were sufficient and were ranged from 0.34 to 1.17 mg kg-1, 2.03 to 21.86 mg kg-1 and 0.30 to 0.89 mg kg-1 respectively.

scholarly journals Element budgets in an Arctic mesocosm CO<sub>2</sub> perturbation study

2012 ◽  
Vol 9 (8) ◽  
pp. 11885-11924 ◽  
Author(s):  
J. Czerny ◽  
K. G. Schulz ◽  
T. Boxhammer ◽  
R. G. J. Bellerby ◽  
J. Büdenbender ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Ocean Acidification ◽  
Nutrient Dynamics ◽  
Temporal Dynamics ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pools ◽  
Dissolved Organics ◽  
Elemental Stoichiometry ◽  
Element Budgets ◽  
Wall Growth

Abstract. Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining the temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and fluxes, in particular due to uncertainties in constraining air/sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification using KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation) all relevant element pools and fluxes of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down some of the mentioned uncertainties. Water column concentrations of particulate and dissolved organic and inorganic constituents were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution, as well as estimates of wall growth were developed to close the gaps in element budgets. Future elevated pCO2 was found to enhance net autotrophic community carbon uptake in 2 of the 3 experimental phases but did not significantly affect particle elemental composition. Enhanced carbon consumption appears to result in accumulation of dissolved organic compounds under nutrient recycling summer conditions. This carbon over-consumption effect becomes evident from budget calculations, but was too small to be resolved by direct measurements of dissolved organics. The out-competing of large diatoms by comparatively small algae in nutrient uptake caused reduced production rates under future ocean CO2 conditions in the end of the experiment. This CO2 induced shift away from diatoms towards smaller phytoplankton and enhanced cycling of dissolved organics was pushing the system towards a retention type food chain with overall negative effects on export potential.

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