Phosphorus status of soils from contrasting forested ecosystems in southwestern Siberia: effects of microbiological and physicochemical properties

Abstract. The Siberian forest is a tremendous repository of terrestrial organic carbon (C), which may increase owing to climate change, potential increases in ecosystem productivity and hence C sequestration. Phosphorus (P) availability could limit the C sequestration potential, but tree roots may mine the soil deep to increase access to mineral P. Improved understanding and quantification of the processes controlling P availability in surface and deep soil layers of Siberian forest ecosystems are thus required. The objectives of the present study were to (1) evaluate P status of surface and deep soil horizons from different forest plots in southwestern Siberia and (2) assess the effects of physicochemical soil properties, microbiological activity and decomposition processes on soil P fractions and availability. Results revealed high concentrations of total P (879–1042 mg kg−1 in the surface mineral soils) and plant-available phosphate ions. In addition, plant-available phosphate ions accumulated in the subsoil, suggesting that deeper root systems may mine sufficient available P for the trees and the potentially enhanced growth and C sequestration, may not be P-limited. Because the proportions of total organic P were large in the surface soil layers (47–56% of total P), we concluded that decomposition processes may play a significant role in P availability. However, microbiological activity and decomposition processes varied between the study plots and higher microbiological activity resulted in smaller organic P fractions and consequently larger available inorganic P fractions. In the studied Siberian soils, P availability was also controlled by the physicochemical soil properties, namely Al and Fe oxides and soil pH.

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Phosphorus status of soils from contrasting forested ecosystems in Southwestern Siberia: combined effects of plant species and climate

Biogeosciences Discussions ◽

10.5194/bgd-9-6365-2012 ◽

2012 ◽

Vol 9 (6) ◽

pp. 6365-6408 ◽

Cited By ~ 1

Author(s):

D. L. Achat ◽

M. R. Bakker ◽

L. Augusto ◽

D. Derrien ◽

N. Gallegos ◽

...

Keyword(s):

Climate Change ◽

C Sequestration ◽

P Availability ◽

Inorganic P ◽

Local Climate ◽

Phosphate Ions ◽

Decomposition Processes ◽

Diffusive Phosphate Ions ◽

Mineral Soils ◽

Surface Mineral

Abstract. The Russian boreal forest, which mainly consists of extensive forests in Siberia, is the largest continuous forest region on Earth and represents 70 % of the world's boreal forest. Siberian forest is a tremendous repository of terrestrial organic carbon (C), which may increase owing to climate change, potential increases in ecosystem productivity and hence C sequestration. Phosphorus (P) availability could limit the C sequestration potential, but tree roots may mine the soil deeper to increase access to mineral P. Improved understanding and quantification of the processes controlling P availability in surface and deep soil layers of forest ecosystems are thus required. Relative contributions of organic and inorganic P and, consequently, P availability in forest ecosystems depend on decomposition processes, which could be strongly affected by vegetation composition, temperature, precipitation, and their changes due to a warming climate. The objectives of the present study were to (1) evaluate P status of surface and deep forest soil horizons from two contrasted biomes in Southwestern Siberia (i.e. forest steppe in the West Siberian plain and blackish ("chernevaya" in Russian) taiga in the low Salair mountains) and (2) assess the effects of vegetation (siberian fir stand, common aspen stand and herbs in a forest gap) and local climate on soil P fractions. Results revealed high contents in total P (645–1042 mg kg−1 in the surface mineral soils) and available inorganic P (diffusive phosphate ions in one week = 83–126 mg kg−1). In addition, there was an accumulation of diffusive phosphate ions in the subsoils resulting from differences between soil horizons in total inorganic P and soil properties. Consequently, deeper root systems may mine substantial amounts of available P for the trees and the potential enhanced growth and C sequestration due to climate change should thus a~priori not be P-limited. High proportions of total organic P (47–56 % of total P in the surface mineral soils) show that decomposition processes potentially play a significant role in P availability. Results show that decomposition processes are affected by vegetation (deciduous broadleaved trees, evergreen coniferous, herbs) and local climate (precipitations; snow cover with its isolating effect on soil). Results on the effects of plant species and local climate improved our understanding of the potential effects of climate change on P availability through warming and vegetation redistribution.

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Improved Plant Diversity as a Strategy to Increase Available Soil Phosphorus

10.24047/bc103143 ◽

2019 ◽

Vol 103 (1) ◽

pp. 43-45 ◽

Cited By ~ 1

Author(s):

Carlos Crusciol ◽

João Rigon ◽

Juliano Calonego ◽

Rogério Soratto

Keyword(s):

Crop Yields ◽

Soil Phosphorus ◽

Cropping System ◽

P Availability ◽

P Fractions ◽

Crop Species ◽

Soil P ◽

Residue Decomposition ◽

Available Soil Phosphorus ◽

Crop Residue Decomposition

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.

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Seasonal Variations and Thinning Effects on Soil Phosphorus Fractions in Larix principis-rupprechtii Mayr. Plantations

Forests ◽

10.3390/f10020172 ◽

2019 ◽

Vol 10 (2) ◽

pp. 172 ◽

Cited By ~ 2

Author(s):

Huixia Tian ◽

Xiaoqin Cheng ◽

Hairong Han ◽

Hongyuan Jing ◽

Xujun Liu ◽

...

Keyword(s):

Seasonal Variations ◽

Management Practice ◽

Management Strategies ◽

Chemical Properties ◽

P Availability ◽

P Fractions ◽

Soil P ◽

Thinning Intensity ◽

Soil P Fractions ◽

P Bioavailability

Thinning is a common management practice in forest ecosystems. However, understanding whether thinning treatment will change the availability of phosphorus (P) in soils, and the effect of thinning on the seasonal dynamics of soil P fractions, are still limited. The objective of the present study was to assess seasonal variations in soil P fractions under different forest thinning management strategies in a Larch (Larix spp.) plantation in northern China. To accomplish this, we examined soil P fractions, soil physical–chemical properties, and litter biomass under control (CK), light (LT), moderate (MT) and high thinning (HT) treatments. Data were collected during the growing season of 2017. We found that most P fractions varied seasonally at different soil depths, with the highest values occurring in the summer and autumn. When compared to CK, MT enhanced the inorganic P (Pi) concentration extracted by resin strip (R-Pi). Labile organic P (Labile Po), moderately labile P and total P (TP) also increased in both MT and HT treatments irrespective of season. In contrast, less-labile Pi and Po fractions were lower in LT than in CK, especially when examining deeper soil layers. Our results suggest that LT leads to a strong ability to utilize Po and less-labile Pi. Moreover, the effect of thinning did not tend to increase with thinning intensity, P availability was maximized at the MT. Ultimately, we show that MT can improve soil P bioavailability and is recommended in Larix principis-rupprechtii Mayr. plantations of North China. Our results emphasize that the effect of thinning management on soil microenvironment is an important basis for evaluating soil nutrients such as soil P bioavailability.

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Mixed Cropping as Affected by Phosphorus and Water Supply

Agronomy ◽

10.3390/agronomy10101506 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1506

Author(s):

Bettina Eichler-Löbermann ◽

Stefanie Busch ◽

Nicolai David Jablonowski ◽

Mareike Kavka ◽

Christine Brandt

Keyword(s):

Water Supply ◽

Biomass Yield ◽

Sharp Decrease ◽

P Availability ◽

Mixed Cropping ◽

P Fractions ◽

Pot Trials ◽

Labile P ◽

Water Holding ◽

P Supply

In a future exposed to threats of climate change, sustainable biomass production will be crucial. Maize (Zea mays) and sorghum (Sorghum sp.) are important crops for human and animal nutrition, as well as for bioenergy. The aim of this study was to investigate maize and sorghum in mixed cropping with soybean (Glycine max) and faba bean (Vicia faba) regarding biomass yield, drought tolerance, phosphorus (P) availability, and enzyme activity in soil as affected by the single and combined effects of water and P supply in two outdoor pot trials with rainout shelters. Maize had the highest biomass under sufficient water supply (80% water holding capacity, WHC), but a sharp decrease of its biomass of about 60% was measured when water was limited (30% WHC). In the mixtures, drought induced reduction of biomass was less than 40%. For mixed cropping usually higher contents of labile P fractions in soil than for sole cropped monocots were found. This was especially true for the combined stress of water and P deficit and can be partly explained by a higher activity of the acid phosphatase in the soil of the mixtures. A higher yield stability of the crop mixtures makes them a suitable agronomic alternative to sole cropped maize or sorghum under suboptimal conditions of water and P shortage.

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Dynamics of phosphorus fractions in soils treated with dairy manure

Soil Research ◽

10.1071/sr18325 ◽

2020 ◽

Vol 58 (3) ◽

pp. 289

Author(s):

L. B. Braos ◽

A. C. T. Bettiol ◽

L. G. Di Santo ◽

M. E. Ferreira ◽

M. C. P. Cruz

Keyword(s):

P Uptake ◽

Dairy Manure ◽

P Availability ◽

Organic P ◽

Triple Superphosphate ◽

P Fractions ◽

Inorganic P ◽

Soil P ◽

Plant P Uptake ◽

Inorganic P Fractions

The evaluation of phosphorus (P) transformations in soil after application of manure or mineral P can improve soil management and optimise P use by plants. The objectives of the present study were to assess organic and inorganic P forms in two soils treated with dairy manure and triple superphosphate and to establish relationships between soil P fraction levels and P availability. Soil organic and inorganic P fractions were quantified using a pot experiment with two soils, a typical Hapludox and an arenic Hapludult, with three types of fertiliser treatments applied (no fertiliser application, application of dairy manure, and application of triple superphosphate, by adding 100 mg P dm–3 in the form of fertiliser in the two latter treatments) and four incubation times (15, 45, 90, and 180 days). Inorganic P was fractionated into aluminium-bound, iron-bound, occluded, and calcium-bound P. Organic P was extracted sequentially using sodium bicarbonate, hydrochloric acid, microbial biomass, sodium hydroxide, and residual organic P. After incubation, maize plants were cropped to quantify dry matter yield and absorbed P. Application of dairy manure resulted in a significant increase in most of the organic P fractions, and application of triple superphosphate led to a significant increase in inorganic P fractions. Both fertilisers raised labile organic P fractions in the two soils. The major sinks of P in Hapludox were occluded and fulvic acid-associated P. In contrast, the major sink of P in Hapludult was iron-bound P. The available P levels were stable after application of dairy manure, and decreased with time when fertilised with triple superphosphate. In the Hapludox, the organic P fractions had a significant positive correlation with P uptake by plants. The results suggest that organic P mineralisation plays a more significant role in plant P uptake in the Hapludox soil and inorganic P forms are the main contributors to plant P uptake in the Hapludult soil.

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Soil phosphorus fractionation after co-applying biochar and paper mill biosolids

Canadian Journal of Soil Science ◽

10.1139/cjss-2020-0098 ◽

2020 ◽

Author(s):

Noura Ziadi ◽

Xiangru Zhang ◽

Bernard Gagnon ◽

Eric Manirakiza

Keyword(s):

Sandy Loam ◽

Paper Mill ◽

Phosphorus Fractionation ◽

Stable Form ◽

P Availability ◽

P Fractions ◽

Soil P ◽

Soil P Fractions ◽

Soil P Availability ◽

Incubation Study

In recent decades, there has been a growing interest in the recycling of organic materials such as paper mill biosolids (PB) and biochar for use as soil amendments. However, the benefits of co-application of PB and biochar and its effects on soil P availability remain unknown. An incubation study was conducted on two acidic soils to assess the effect of two PB types (2.5% w/w) co-applied with three rates (0%, 2.5%, and 5% w/w) of pine (Pinus strobus L.) biochar on soil P fractions. An unfertilized control and a mineral NP fertilizer were used as a reference. Soil P fractions were determined by Hedley procedure after 2 and 16 weeks of incubation. Material fractionation indicated that the PB containing the highest total P and the lowest Al content had the highest proportion of labile P, whereas most P in the biochar was in a stable form. The incubation study revealed that the P-rich PB increased P availability in both soils to a level comparable to mineral fertilizer at the end of the incubation. The addition of biochar to PB, however, did not affect soil P availability, but the highest rate induced a conversion of P fixed to Al and Fe oxides towards recalcitrant forms, particularly in the sandy loam soil. We conclude that co-applying biochar and PB could be more beneficial than application biochar alone and soils amended with such a mixture would be expected to release part of their P slowly over a longer period of time.

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CoupModel (v6.0): an ecosystem model for coupled phosphorus, nitrogen and carbon dynamics – evaluated against empirical data from a climatic and fertility gradient in Sweden

10.5194/gmd-2020-65 ◽

2020 ◽

Author(s):

Hongxing He ◽

Per-Erik Jansson ◽

Annemieke Gärdenäs

Keyword(s):

Climate Change ◽

Terrestrial Ecosystems ◽

C Sequestration ◽

Forest Growth ◽

N Leaching ◽

P Availability ◽

Soil N ◽

Soil C ◽

Fertility Gradient ◽

P Cycle

Abstract. This study presents the integration of the phosphorus (P) cycle into CoupModel (Coup-CNP). The extended Coup-CNP enables simulations of coupled carbon (C), nitrogen (N) and P dynamics for terrestrial ecosystems which explicitly consider mycorrhizal interactions. The model was evaluated against observed forest growth and measured leaf C/P, C/N and N/P ratios in four managed forest regions in Sweden. The four regions form a climatic and fertility gradient from 64° N in the North to 56° N in South Sweden with the mean annual temperature varying between 0.7–7.1 °C and the soil C/N and C/P ratios between 19.8–31.5 and 425–633, respectively. The growth of the southern forests was found to be P-limited, with harvested biomass representing the largest P loss over the studied rotation period. The simulated P budgets revealed that southern forests are losing P while northern forests are close to a steady state in P availability. Mycorrhizal fungi account for half of the total plant P uptake across all four regions, which highlights the importance of fungal-tree interactions in Swedish forests. Sensitivity analysis results demonstrated that the highest forest growth occurs at a soil N/P ratio of 15 to 20. A soil N/P ratio above 15–20 resulted in decreased soil C sequestration and total P leaching, but significantly increased N leaching. The development and evaluation of the new Coup-CNP model demonstrate that P fluxes need to be further considered in studies of how climate change will influence C turnover and ecosystem responses. We conclude that the potential P-limitation of terrestrial ecosystems highlights the need of a proper consideration of the P cycle in biogeochemical models. The inclusion of the P cycle is necessary in order to make models reliable tools for assessing long-term impacts of climate change and N deposition on C sequestration and N leaching.

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Effect of Freeze–Thaw Cycles on Phosphorus Fractions and Their Availability in Biochar-Amended Mollisols of Northeast China (Laboratory Experiment)

Sustainability ◽

10.3390/su11041006 ◽

2019 ◽

Vol 11 (4) ◽

pp. 1006 ◽

Cited By ~ 1

Author(s):

Ying Han ◽

Xiangwei Chen ◽

Byoungkoo Choi

Keyword(s):

Moisture Content ◽

Path Coefficient ◽

P Availability ◽

P Fractions ◽

P Fractionation ◽

Soil P ◽

Freeze Thaw ◽

Soil P Fractions ◽

Labile P ◽

Biochar Amendment

Freeze–thaw cycles stimulate the release of available soil phosphorus (P) in winter, and biochar as a soil amendment could improve P availability. Nevertheless, it is unclear how freeze–thaw cycles and biochar amendment interact to affect the soil P fractions and their availability in winter, particularly under different soil water conditions. We simulateda freeze–thaw cycle experimentto assess the effects of three factors on soil P fractions: soil moisture content (22%, 31%, and 45%), frequencies of freeze–thaw cycles (0, 1, 3, 6, and 12 times) and biochar amendment (soil and biochar-amended soil). Modified Hedley sequential P fractionation was conducted to measure the soil P fractions. Increasing the number of freeze–thaw cycles increased soil labile P fractions in the soil with the lowest moisture content (22%). After biochar amendment, the content of labile P decreased as the number of freeze–thaw cycles increased. Biochar amendment enhanced P availability in Mollisols owing to the direct effect of NaOH-Po, which has a large direct path coefficient. Principal components analysis showed that moisture content was a major factor influencing the variation in the P fractions. The P fractions were separated by the interactive effects of biochar amendment and freeze–thaw cycles in soils with a higher moisture content (45%), indicating that the effects of freeze–thaw cycles on P availability appear to be more pronounced in biochar-amended Mollisols of higher water contents.

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