Sorption and Environmental Risks of Phosphorus in Subtropical Forest Soils

Phosphorus (P) is one of the key limiting factors for the growth of forests and their net primary productivity in subtropical forest ecosystems. Phosphorus leaching of the forest soil to the catchment and groundwater in karst region is the main source of water eutrophication. Strong P sorption capacity of minerals is generally assumed to be a key driver of P leaching in subtropical ecosystems which varies among different soil types. Here, we estimated P adsorption capacity of the O/A and AB horizon in both limestone soil and red soil of subtropical forests by fitting the Langmuir and Freundlich isotherm to investigate the potential environmental risks of P. The maximum P sorption capacity ( Q m ), P sorption constant ( K L ), P sorption index (PSI), degree of P saturation (DPS), and maximum buffer capacity (MBC) were calculated. The results indicate that Q m of the O/A horizon in both soils were similar. Comparing these two soils, the red soil had a higher K L and MBC in the AB horizon; Q m of limestone soil was larger but K L was lower, indicating that the adsorption capacity of limestone soil was weaker and MBC was lower. There was no significant difference in PSI between the two soils. The DPS values of both soils were below 1.1%, indicating that P saturation is low in both subtropical forest soils due to the lack of marked anthropogenic disturbance. In the O/A horizon, P saturation associated with available P (DPSM3 and DPSOlsen) and that associated with P in the Fe-Al bound state (DPScitrate) were higher in the red soil than in the limestone soil. DPS did not differ significantly in the AB horizon, except for higher DPSM3 and DPScitrate in the red soil. The findings highlight the influence of the soil types on P adsorption. The P adsorption and buffering of red soils were higher than those of limestone soils, indicating a lower risk of P leaching in red subtropical forest soils.

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Mobility of inorganic and organic phosphorus forms under different levels of phosphate and poultry litter fertilization in soils

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832010000400019 ◽

2010 ◽

Vol 34 (4) ◽

pp. 1195-1205 ◽

Cited By ~ 5

Author(s):

Fabrício de Oliveira Gebrim ◽

Roberto Ferreira Novais ◽

Ivo Ribeiro da Silva ◽

Fernanda Schulthais ◽

Leonardus Vergütz ◽

...

Keyword(s):

Adsorption Capacity ◽

Sandy Loam ◽

Organic Phosphorus ◽

Block Design ◽

Poultry Litter ◽

Dry Weight ◽

Vertical Movement ◽

Soil Columns ◽

P Adsorption ◽

P Leaching

The eutrophication of aquifers is strongly linked to the mobility of P in soils. Although P mobility was considered irrelevant in a more distant past, more recent studies have shown that P, both in organic (Po) and inorganic forms (Pi), can be lost by leaching and eluviation through the soil profile, particularly in less weathered and/or sandier soils with low P adsorption capacity. The purpose of this study was to determine losses of P forms by leaching and eluviation from soil columns. Each column consisted of five PVC rings (diameter 5 cm, height 10 cm), filled with two soil types: a clayey Red-Yellow Latosol and a sandy loam Red-Yellow Latosol, which were exposed to water percolation. The soils were previously treated with four P rates (as KH2PO4 ) to reach 0, 12.5, 25.0 and 50 % of the maximum P adsorption capacity (MPAC). The P source was homogenized with the whole soil volume and incubated for 60 days. After this period the soils were placed in the columns; the soil of the top ring was mixed with five poultry litter rates of 0, 20, 40, 80, and 160 t ha-1 (dry weight basis). Treatments consisted of a 4 x 5 x 2 factorial scheme corresponding to four MPAC levels, five poultry litter rates, two soils, with three replications, arranged in a completely randomized block design. Deionized water was percolated through the columns 10 times in 35 days to simulate about 1,200 mm rainfall. In the leachate of each column the inorganic P (reactive P, Pi) and organic P forms (unreactive P, Po) were determined. At the end of the experiment, the columns were disassembled and P was extracted with the extractants Mehlich-1 (HCl 0.05 mol L-1 and H2SO4 0.0125 mol L-1) and Olsen (NaHCO3 0.5 mol L-1; pH 8.5) from the soil of each ring. The Pi and Po fractions were measured by the Olsen extractant. It was found that under higher poultry litter rates the losses of unreactive P (Po) were 6.4 times higher than of reactive P (Pi). Both the previous P fertilization and increasing poultry litter rates caused a vertical movement of P down the soil columns, as verified by P concentrations extracted by Mehlich-1 and NaHCO3 (Olsen). The environmental critical level (ECL), i.e., the P soil concentration above which P leaching increases exponentially, was 100 and 150 mg dm-3 by Mehlich-1 and 40 and 60 mg dm-3 by Olsen, for the sandy loam and clay soils, respectively. In highly weathered soils, where residual P is accumulated by successive crops, P leaching through the profile can be significant, particularly when poultry litter is applied as fertilizer.

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Sulfate retention and cation leaching of forest soils in response to acid additions

Canadian Journal of Forest Research ◽

10.1139/x91-005 ◽

1991 ◽

Vol 21 (1) ◽

pp. 32-41 ◽

Cited By ~ 2

Author(s):

William J. Fasth ◽

Mark B. David ◽

George F. Vance

Keyword(s):

Adsorption Capacity ◽

Forest Soils ◽

Soil Type ◽

Base Cations ◽

Soil Types ◽

Leaching Losses ◽

Organic S ◽

Cation Leaching ◽

Vacuum Extractor ◽

S Mineralization

A vacuum extractor was used to examine the effects of increased SO42− deposition on net S retention and cation leaching in three Maine Spodosols (Berkshire, Dixfield, and Rawsonville series) and an Illinois Alfisol. Columns (leached daily for 30 days with either a simulated throughfall solution containing 80 μequiv. SO42−•L−1 (pH = 4.77) or a simulated throughfall solution plus 200 μequiv. H2SO4•L−1 (pH = 3.66)) were constructed using O horizons over upper B (Bh or Bhs) and lower B (Bhs or BC) horizons for the Spodosols and two depth increments of bulked soil (0–12 and 12–25 cm) for the Alfisol. Leachate concentrations of base cations were dominated by Ca2+ and were generally greater in the Alfisol than in the Spodosol leachates. Declining concentrations of base cations and NH4+ with time led to an increase in Al3+ concentrations and a decrease in pH for some of the Spodosol leachates (e.g., leachate Al3+ increased from 19 μequiv. Al3+ •L−1 (day 2) to 194 μtequiv. Al3+ •L−1 (day 30), and pH decreased from 5.53 to 4.41, respectively, for the Dixfield high-S treatment). Columns that received the high-S treatment retained a greater percentage of the added S than those that received the low-S treatment because of increased SO42− adsorption in the former. High rates of net organic S mineralization were found for all soil types (e.g., 169 μg organic S•g−1 over 30 days for the Rawsonville Bhl horizon, 15% of the total S); no treatment effects were found for the amount of S mineralized. Trends in net S retention across soil type (within the same treatment) reflected increases in soil SO42− from adsorption, as well as decreases in organic S from mineralization. When net S mineralization was removed from leaching losses of S, trends in net S retention closely reflected SO42− adsorption differences (50, 23, 8, and 1% of the added S retained by the Rawsonville, Dixfield, and Berkshire series, and the Alfisol, respectively, for the high-S treatment). Because of the low SO42− adsorption capacity of the Alfisol relative to the Spodosols, organic processes were more important in affecting net S retention for the Alfisol. Inorganic processes of S retention were more important for the three Spodosols studied.

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Effect of Flooding Time on Phosphate Adsorption Desorption Characteristics of Two Acid Soils

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.195-196.1288 ◽

2012 ◽

Vol 195-196 ◽

pp. 1288-1293

Author(s):

Xing Hua Shao ◽

Jiang Zhong Zhang

Keyword(s):

Sorption Capacity ◽

Paddy Soil ◽

Acid Soils ◽

Red Soil ◽

Phosphate Adsorption ◽

P Adsorption ◽

Soil P ◽

P Sorption ◽

P Sorption Capacity ◽

Adsorption Desorption

In a laboratory incubation study, two soils were treated with distilled water, and flooded for a period of 0 (contr-ol), 1, 2, 3, 4, 8 weeks. P adsorption desorption characteristics of two soils were measured at the end of the incubation period. P a-dsorption increased with increasing levels of added P in two soi-ls. P adsorption of Paddy soil was comparatively lower than that of upland red soil. P adsorption data was found to fit Langmuir isotherms for two soils. Soil P adsorption maxima obtained from Langmuir isotherm varied from 1190 to 672 mg/kg for upland r-ed soil, and varied from 708 to 530 mg/kg for paddy soil. Floodi-ng decreased P adsorption capacity of upland red soil,increased soluble P (in 0.01M CaCl2) and equilibrium P concentration. For paddy soil, there was a large increase in the P sorption capacity after one week flooding, and then P sorption capacity decreased. The more adsorption maxima is, and the more desorption maxi-ma (Dm) is. Desorption rate constant (Kd) and bonding energy (b) varied inconsistently in two soils.

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Spatial variability of the molecular composition of humic acids from subtropical forest soils

Journal of Soils and Sediments ◽

10.1007/s11368-020-02862-2 ◽

2021 ◽

Author(s):

Li Jiang ◽

Jun Zhu ◽

Hui Wang ◽

Qingling Fu ◽

Hongqing Hu ◽

...

Keyword(s):

Spatial Variability ◽

Humic Acids ◽

Forest Soils ◽

Subtropical Forest ◽

Molecular Composition

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The effects of red soil in removing phosphorus from water column and reducing phosphorus release from sediment in Lake Taihu

Water Science & Technology ◽

10.2166/wst.2014.022 ◽

2014 ◽

Vol 69 (5) ◽

pp. 1052-1058 ◽

Cited By ~ 11

Author(s):

Lichun Dai ◽

Gang Pan

Keyword(s):

Water Column ◽

Lake Taihu ◽

Cost Effective ◽

Phosphorus Release ◽

Red Soil ◽

Natural Soil ◽

P Adsorption ◽

P Release ◽

The Cost ◽

Short Time

A natural red soil and a lanthanum-modified soil (LMS) were tested to compare their phosphorus (P) adsorption capacities and their effectiveness in removing P from the water column and reducing P release from sediment. The equilibrium of P adsorption demonstrated that the maximum P adsorption for the soil was 1.29 and 2.22 mg g−1 at pH 8.5 and 5.5, respectively, and for the LMS these were increased by 45.6 and 77.6% at pH 8.5 and 5.5, respectively, indicating that the soil was effective in P adsorption and the doping of lanthanum could substantially increase P adsorption. The sediment–water column incubation showed that, due to the P adsorption of the soil and LMS, the total P in the water column decreased by 58.5, 60.6, 68.2 and 77.2% for 180 g m−2 soil, 900 g m−2 soil, 180 g m−2 LMS and 900 g m−2 LMS treated systems, respectively, in a short time (6 h), and the capping layer substantially reduced the P release from sediment during column incubation, indicating that the soils were effective in reducing internal P load. However, considering the cost of LMS, the natural soil was suggested to be a cost-effective material to control internal P load.

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Microbial biomass in subtropical forest soils: effect of conversion of natural secondary broad-leaved forest to Cunninghamia lanceolata plantation

Journal of Forestry Research ◽

10.1007/s11676-006-0046-9 ◽

2006 ◽

Vol 17 (3) ◽

pp. 197-200 ◽

Cited By ~ 5

Author(s):

Qing-kui Wang ◽

Si-long Wang

Keyword(s):

Microbial Biomass ◽

Forest Soils ◽

Subtropical Forest ◽

Cunninghamia Lanceolata ◽

Broad Leaved Forest ◽

Leaved Forest

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Net and gross N transformation rates in subtropical forest soils under aerobic and anaerobic conditions

Journal of Soils and Sediments ◽

10.1007/s11368-014-1012-3 ◽

2014 ◽

Vol 15 (1) ◽

pp. 96-105 ◽

Cited By ~ 3

Author(s):

Wei Zhao ◽

Zucong Cai ◽

Zhihong Xu

Keyword(s):

Forest Soils ◽

Subtropical Forest ◽

Anaerobic Conditions ◽

N Transformation ◽

Transformation Rates ◽

Gross N Transformation ◽

Aerobic And Anaerobic ◽

Aerobic And Anaerobic Conditions

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Phosphorus requirements of some selected soil types in the Fiji sugarcane belt

The South Pacific Journal of Natural and Applied Sciences ◽

10.1071/sp14001 ◽

2014 ◽

Vol 32 (1) ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

M.S. Goundar ◽

R.J. Morrison ◽

C. Togamana

Keyword(s):

Soil Phosphorus ◽

Strong Association ◽

Clay Content ◽

Limiting Factors ◽

Soil Types ◽

Strong Positive Correlation ◽

P Leaching ◽

Phosphorus Requirements ◽

Physical And Chemical

The availability of phosphorus (P) in soil is perceived to be one of the limiting factors to sustainable sugarcane production in Fiji. The main objective of this research was to ascertain the amount of bioavailable phosphorus in some Fiji sugarcane growing area soils; this will be valuable in improving the determination of the required amount of inorganic fertilizer to be applied to the soil. In this study, twelve different soils were selected from the sugarcane belt of Fiji and phosphorus buffer index (PBI) and phosphorus isotherm experiments were performed. Soil physical and chemical parameters were also measured and Pearson’s correlation tests used to identify patterns. It was found that Oxisols had the highest PBI values ranging from 134 to 170 while Inceptisols had the lowest ranging from 33 to 54. The PBI data followed a similar pattern to the generated isotherm curves of the different soil types. Most interest was in identifying soils with low PBIs as they have greater potential for P leaching through runoff into waterways. Clay content showed a strong positive correlation with PBI (R = 0.76, p ≤ 0.005). There is strong association with phosphorus fixation in soil with increasing levels of Al and Fe in the soil. Phosphorus availability and P fixation varied with soil types.

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