The Influence of Cascade Reservoir Construction on Labile Phosphorus in the Sediment of Lancang River

Abstract The influence of cascade reservoirs construction on labile phosphorus (P) is an important scientific problem in the Lancang River. The concentration of labile P in cascade deep-water reservoirs were determined, and the influence of cascade reservoirs construction on the DGT-labile P was analyzed. The construction of cascade reservoirs led to significant differences in concentrations of DGT-labile P, which in the upstream of Xiaowan (XW) Reservoir were differences from that in the downstream Nuozhadu (NZD) Reservoir. The P diffusion fluxes in XW Reservoir were − 8.59–250.50 ng·cm− 2·d− 1, and that in NZD Reservoir were 3.82–24.80 ng·cm− 2·d− 1. The P pollution of XW Reservoir was higher, highlighting the importance of controlling P pollution of XW Reservoir. The construction of cascade reservoirs had made the release of DGT-labile P more dependent on the reductive dissolution of Mn oxides. The early diagenesis transformed bio-availability P (BAP) remobilization into DGT-labile P that made the increase of DGT-labile P/BAP with depth. However, the DGT-labile P/BAP of upstream XW Reservoir was 7.8 times larger than that of downstream NZD Reservoir, which indicated that the construction of cascade reservoirs weakened the remobilization of P in sediment.

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Geochemical Fractions and Release Characteristics of Nitrogen in Sediments Along Deep-Water Cascade Reservoirs of the Lancang River

Environmental Engineering Science ◽

10.1089/ees.2021.0072 ◽

2021 ◽

Author(s):

Bo Yuan ◽

Mengjing Guo ◽

Wei Wu ◽

Xiaode Zhou ◽

Shuguang Xie

Keyword(s):

Deep Water ◽

Cascade Reservoirs ◽

Lancang River ◽

Geochemical Fractions

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The dynamics of acid-soluble phosphorus compounds in the course of winter and spring wheat germination under various thermic conditions. Part II. Labile phosphorus after hydrolysis of the acid-soluble fraction

Acta Agrobotanica ◽

10.5586/aa.1971.018 ◽

2015 ◽

Vol 24 (2) ◽

pp. 297-308

Author(s):

A. Barbaro

Keyword(s):

Low Temperature ◽

Phosphorus Content ◽

Soluble Fraction ◽

Phosphorus Compounds ◽

Labile Phosphorus ◽

Soluble Phosphorus ◽

Germination Temperature ◽

Wheat Germination ◽

Labile P ◽

Hydrolysis Of

The changes in labile phosphorus compounds content during germination of wheat were investigated. These compounds were determined in acid-soluble germ extracts separated into fractions according to the solubility of their barium salts. Low germination temperature was found to raise the labile phosphorus content in the fraction of insoluble barium salts. If we assume that labile P of this fraction consisted mainly of adenosinedi- and triphosphates, it would seem that the rise, in the ATP and ADP level under the influence of low temperature may be essential for initiating flowering in winter varieties.

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Inorganic Phosphorous, Lime and Vermicompost Induced Changes on Phosphorus Fractions and Other Properties of Acidic Soil of Cheha District, Ethiopia

10.21203/rs.3.rs-250222/v1 ◽

2021 ◽

Author(s):

Bereket Ayenew Alemu ◽

Asmare Melese

Keyword(s):

Acid Soils ◽

Inorganic Phosphorus ◽

Phosphorus Fractions ◽

Exchangeable Acidity ◽

Combined Application ◽

Randomized Design ◽

Labile Phosphorus ◽

P Fertilizer ◽

Labile P ◽

Inorganic Phosphorous

Abstract Background: In acid soils, soluble inorganic phosphorus is fixed by aluminum and iron, so that phosphorous availability to plant would be inhibited. Thus, an incubation study was conducted to evaluate the effects of lime, vermicompost, and mineral P fertilizer on the distribution of P fractions and oxalate and dithionite extractable aluminum and iron. The treatments consisted of three rates of phosphorous (0, 74.51 and 149.01 kg P ha-1), three rates of vermicompost (0, 5 and 10 ton VC ha-1) and four rates of lime (0, 5.70, 9.20, and 11.50 ton CaCO3 ha-1). The experiment was laid out as a complete randomized design in a factorial arrangement. Results: Combined application of lime, vermicompost and mineral P significantly increased (p<0.05) labile phosphorus fractions and decreased potential sorption capacities of the soil. As the increased soil pH, reduced exchangeable acidity and oxalate extractable Fe and Al the integrated applications of these amendments fixed aluminum and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool compared to sole application of the amendments. Conclusions: Combined applications of lime, vermicompost and inorganic P to acidic soils of Goha-1 in Cheha district could convey enhanced amount of available P and ensures the maintenance of higher levels of labile P. It might also contribute towards meeting crop P requirements.

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EFFECT OF EXCESS FEEDLOT MANURE ON CHEMICAL CONSTITUENTS OF SOIL UNDER NONIRRIGATED AND IRRIGATED MANAGEMENT

Canadian Journal of Soil Science ◽

10.4141/cjss86-031 ◽

1986 ◽

Vol 66 (2) ◽

pp. 303-313 ◽

Cited By ~ 6

Author(s):

J. F. DORMAAR ◽

T. G. SOMMERFELDT

Keyword(s):

Organic Matter ◽

Chemical Constituents ◽

Soil C ◽

Soil P ◽

Total Soil ◽

Labile Phosphorus ◽

Moisture Regimes ◽

Labile P ◽

Recommended Level

A long-term field experiment was initiated in 1973 to determine the safe loading capacity of a Lethbridge loam (Dark Brown Chernozemic) with feedlot manure. The effect of 10 yr of feedlot manure loading was examined by analyzing a number of inorganic and organic matter constituents of the Ap horizon. Although soil C, P, and enzyme activities increased as feedlot manure additions to the soil increased, these increases diminished at triple the recommended loading regimes. Phosphatase activity was checked by increased labile phosphorus levels. Levels of adenosine 5′-triphosphate increased but fluctuated with time under various moisture regimes. The C:N ratios, percent monosaccharide C of total soil C, and the ratio of deoxyhexoses to pentoses remained constant while the percentage of manure C retained decreased as feedlot manure loading increased. The distribution between pentoses and hexoses was strongly affected by feedlot manure levels while the deoxyhexose percentage of the sum of the eight monosaccharides determined remained about the same. Feedlot manure additions, at triple the recommended level, increased the labile P as a percentage of total soil P to around 50%. Although mineralization did not keep pace with the quantities applied, the presence of undecomposed manure did not seem to have harmful agronomic effects. Key words: ATP, feedlot manure, labile phosphorus, monosaccharides, organic matter

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Mobility of Iron-Cyanide Complexes in a Humic Topsoil under Varying Redox Conditions

Applied and Environmental Soil Science ◽

10.1155/2009/857640 ◽

2009 ◽

Vol 2009 ◽

pp. 1-6

Author(s):

Thilo Rennert ◽

Tim Mansfeldt

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Redox Potential ◽

Opposite Direction ◽

Redox Conditions ◽

Reductive Dissolution ◽

Redox Processes ◽

Iron Cyanide ◽

Cyanide Complexes ◽

Mn Oxides

The potentially toxic Fe-CN complexes ferricyanide,[FeIII(CN)6]3−, and ferrocyanide,[FeII(CN)6]4−, undergo a variety of redox processes in soil, which affect their mobility. We carried out microcosm experiments with suspensions of a humic topsoil (pH 5.3;Corg107 gkg-1) to which we added ferricyanide (20 mgl-1). We varied the redox potential (EH) from −280 to 580 mV by usingO2,N2and glucose. The decrease ofEHled to decreasing concentrations of Fe-CN complexes and partial reductive dissolution of (hydrous) Fe and Mn oxides. The dynamics of aqueous Fe-CN concentrations was characterized by decreasing concentrations when the pH rose and theEHdropped. We attribute these dependencies to adsorption on organic surfaces, for which such a pH/EHbehavior has been shown previously. Adsorption was reversible, because when the pH andEHchanged into the opposite direction, desorption occurred. This study demonstrates the possible impact of soil organic matter on the fate of Fe-CN complexes in soil.

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Effects of Canopy and Micro-irrigation under the Trees on Spatial Variations of Soil Labile Phosphorus and Metals in a Citrus Grove

HortScience ◽

10.21273/hortsci.39.3.606 ◽

2004 ◽

Vol 39 (3) ◽

pp. 606-610

Author(s):

Zhenli He ◽

David. V. Calvert ◽

Peter. J. Stoffella ◽

Mingkui Zhang

Keyword(s):

Water Soluble ◽

Citrus Paradisi ◽

Citrus Grove ◽

Soil P ◽

Horizontal Variation ◽

Labile Phosphorus ◽

Vertical Variations ◽

Northern Side ◽

Labile P ◽

Micro Irrigation

To evaluate effects of canopy and micro-irrigation under trees on accumulation and leaching of phosphorus (P) and heavy metals in agricultural sand soils, the horizontal and vertical variations of soil P and metals in a 408-m2 plot within a grove under grapefruit (Citrus paradisi Macf.) production near Fort Pierce, Fla., was examined. A high horizontal variation of labile soil P and metal concentrations was observed. Across the row, the highest values of pH, EC, water-soluble P, and all metals occurred in the soils under the canopies, and the lowest values occurred in the soils near the water furrow or the midway of the inter-row. Along the grapefruit row, the highest values of many measured variables occurred along the northern side of the citrus tree and close to the emitter. The downward movement of P, Cu, and Zn in the soils was more significant in the soils in open areas (near the water furrow and midway of inter-neighboring trees) than those under the canopies. The differences in labile P and metal spatial distributions in the soils were related to the location of emitter fertigation and differences in rainfall-induced leaching in the field. The results suggest that applying fertilizers to sites under the canopy rather than the spaces between the trees can minimize leaching losses of nutrients.

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Synchronous Cycle of Available Phosphorus, Iron, and Sulfur in the Sediment of Lancang River Reservoirs

Water ◽

10.3390/w13192691 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2691

Author(s):

Zheng Mu ◽

Yao Cheng ◽

Qiang Huang ◽

Mingming Hu ◽

Wei Dong ◽

...

Keyword(s):

Large Scale ◽

Solid Phase ◽

Available P ◽

Release Mechanism ◽

Available Phosphorus ◽

Lancang River ◽

Significant Difference ◽

Phosphorus Iron ◽

Deep Reservoir ◽

Labile P

Large-scale deep reservoirs associated with hydropower cascade development are known to influence the cycle of phosphorus (P). However, there is scarce information on the fractions and availability of P in sediments of large-scale deep reservoirs constructed due to hydropower cascade development. In this study, we researched the fractions and release mechanism of P in the sediments of large-scale deep reservoirs by analyzing the fractions and availability of P in the sediments of the Xiaowan (XW) and Nuozhadu (NZD) reservoirs in the middle and lower reaches of the Lancang River (China). According to the results, there is a significant difference in the P fractions in the sediments of the XW and NZD reservoirs, but not for the available P in the sediments. Compared to the NZD reservoir, there was less solid bioavailable phosphorus (BAP) in the sediments of the XW reservoir, but the replenishment degree of active solid phase P into pore water was higher in the XW. There was a significant positive correlation between the available P and the BAP; the Fe/P ratio measured by the diffusive gradients in thin films reflects the control of active iron (oxyhydr) oxides over labile P in the sediments. In addition to the reductive dissolution of iron-bound P, the release of P into the large deep reservoirs may be related to factors such as the sulfate reduction and the degradation of organic materials. The P cycling in deep reservoir sediments is mainly controlled by the Fe, and there is a clear spatial distribution of this mechanism in deep reservoirs.

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