Soil phosphorus concentrations to minimise potential P loss to surface waters in Southland

Abstract. Excessive delivery of phosphorus (P) from agricultural landscapes to surface waters results in water quality impairment. The method of application of broiler litter to agricultural fields significantly affects P loss to surface waters via surface and subsurface flow pathways from agricultural landscapes. Subsurface-band application of broiler litter can help reduce P loss in surface and subsurface flows. Typically, leachate samples are collected using lysimeters or subsurface flows are sampled to assess the effectiveness of subsurface-band application of broiler litter in limiting P mobility. In this study, we tested a simple and inexpensive method of assessing effectiveness of subsurface-band application of broiler litter using ortho-P (PO4-P) measurements in soils. This method of measuring PO4-P concentration in soils showed that subsurface-band application of broiler litter helps to reduce P leaching, whereas surface application of broiler litter was not effective in reducing P leaching. The results of this study show that soil PO4-P measurements can be successfully used to assess the effectiveness of subsurface-band application of broiler litter in reducing P leaching. Keywords: Leachate, Manure, Nutrient management, Phosphorus, Surface runoff, Water quality.

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Soil controls of phosphorus in runoff: Management barriers and opportunities

Canadian Journal of Soil Science ◽

10.4141/cjss09106 ◽

2011 ◽

Vol 91 (3) ◽

pp. 329-338 ◽

Cited By ~ 97

Author(s):

Peter Kleinman ◽

Andrew Sharpley ◽

Anthony Buda ◽

Richard McDowell ◽

Arthur Allen

Keyword(s):

Water Quality ◽

Surface Waters ◽

Agricultural Soils ◽

Soil Phosphorus ◽

Short Term ◽

Runoff Water ◽

Sediment Delivery ◽

Persistent Problem ◽

Soil P ◽

Barriers And Opportunities

Kleinman, P. J. A., Sharpley, A. N., Budda, A. R., McDowell, R. W. and Allen, A. L. 2011. Soil controls of phosphorus in runoff: Management barriers and opportunities. Can. J. Soil Sci. 91: 329–338. The persistent problem of eutrophication, the biological enrichment of surface waters, has produced a vast literature on soil phosphorus (P) effects on runoff water quality. This paper considers the mechanisms controlling soil P transfers from agricultural soils to runoff waters, and the management of these transfers. Historical emphases on soil conservation and control of sediment delivery to surface waters have demonstrated that comprehensive strategies to mitigate sediment-bound P transfer can produce long-term water quality improvements at a watershed scale. Less responsive are dissolved P releases from soils that have historically received P applications in excess of crop requirements. While halting further P applications to such soils may prevent dissolved P losses from growing, the desorption of P from soils that is derived from historical inputs, termed here as “legacy P”, can persist for long periods of time. Articulating the role of legacy P in delaying the response of watersheds to remedial programs requires more work, delivering the difficult message that yesterday's sinks of P may be today's sources. Even legacy sources of P that occur in low concentration relative to agronomic requirement can support significant loads of P in runoff under the right hydrologic conditions. Strategies that take advantage of the capacity of soils to buffer dissolved P losses, such as periodic tillage to diminish severe vertical stratification of P in no-till soils, offer short-term solutions to mitigating P losses. In some cases, more aggressive strategies are required to mitigate both short-term and legacy P losses.

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Global phosphorus shortage will be aggravated by soil erosion

Nature Communications ◽

10.1038/s41467-020-18326-7 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 4

Author(s):

Christine Alewell ◽

Bruno Ringeval ◽

Cristiano Ballabio ◽

David A. Robinson ◽

Panos Panagos ◽

...

Keyword(s):

Soil Erosion ◽

Agricultural Soils ◽

Soil Phosphorus ◽

Chemical Fertilizer ◽

Rill Erosion ◽

Soil P ◽

P Loss ◽

Global Soil ◽

Spatially Distributed ◽

Food And Feed

Abstract Soil phosphorus (P) loss from agricultural systems will limit food and feed production in the future. Here, we combine spatially distributed global soil erosion estimates (only considering sheet and rill erosion by water) with spatially distributed global P content for cropland soils to assess global soil P loss. The world’s soils are currently being depleted in P in spite of high chemical fertilizer input. Africa (not being able to afford the high costs of chemical fertilizer) as well as South America (due to non-efficient organic P management) and Eastern Europe (for a combination of the two previous reasons) have the highest P depletion rates. In a future world, with an assumed absolute shortage of mineral P fertilizer, agricultural soils worldwide will be depleted by between 4–19 kg ha−1 yr−1, with average losses of P due to erosion by water contributing over 50% of total P losses.

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Changes in soil phosphorus availability and potential phosphorus loss following cessation of phosphorus fertiliser inputs

Soil Research ◽

10.1071/sr13168 ◽

2013 ◽

Vol 51 (5) ◽

pp. 427 ◽

Cited By ~ 12

Author(s):

R. J. Dodd ◽

R. W. McDowell ◽

L. M. Condron

Keyword(s):

Agricultural Soils ◽

Soil Phosphorus ◽

Pasture Production ◽

Soil P ◽

Olsen P ◽

P Loss ◽

P Concentration ◽

Rate Of Decline ◽

P Retention

Long-term application of phosphorus (P) fertilisers to agricultural soils can lead to in the accumulation of P in soil. Determining the rate of decline in soil P following the cessation of P fertiliser inputs is critical to evaluating the potential for reducing P loss to surface waters. The aim of this study was to use isotope exchange kinetics to investigate the rate of decline in soil P pools and the distribution of P within these pools in grazed grassland soils following a halt to P fertiliser application. Soils were sourced from three long-term grassland trials in New Zealand, two of which were managed as sheep-grazed pasture and one where the grass was regularly cut and removed. There was no significant change in total soil P over the duration of each trial between any of the treatments, although there was a significant decrease in total inorganic P on two of the sites accompanied by an increase in the organic P pool, suggesting that over time P was becoming occluded within organic matter, reducing the plant availability. An equation was generated using the soil-P concentration exchangeable within 1 min (E1 min) and P retention of the soil to predict the time it would take for the water-extractable P (WEP) concentration to decline to a target value protective of water quality. This was compared with a similar equation generated in the previous study, which used the initial Olsen-P concentration and P retention as a predictor. The use of E1 min in place of Olsen-P did not greatly improve the fit of the model, and we suggest that the use of Olsen-P is sufficient to predict the rate of decline in WEP. Conversely, pasture production data, available for one of the trial sites, suggest that E1 min may be a better predictor of dry matter yield than Olsen-P.

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Phosphorus loss assessment tools: a review of underlying concepts and applicability in cold climates

Environmental Science and Pollution Research ◽

10.1007/s11356-019-06800-9 ◽

2019 ◽

Vol 27 (4) ◽

pp. 3794-3802

Author(s):

Reza Habibiandehkordi ◽

D. Keith Reid ◽

Pradeep K. Goel ◽

Asim Biswas

Keyword(s):

Surface Waters ◽

Agricultural Land ◽

Assessment Tools ◽

Optimal Placement ◽

Quality Data ◽

Cold Climates ◽

Loss Assessment ◽

Water Quality Data ◽

Phosphorus Loss ◽

P Loss

AbstractIdentifying critical source areas (CSAs) of a watershed by phosphorus (P) loss assessment tools is essential for optimal placement of beneficial management practices (BMPs) to address diffuse P pollution. However, lack of significant progress in tackling diffuse P pollution could be, in part, associated with inefficacy of P loss assessment tools for accurately identifying CSAs. Phosphorus loss assessment tools have been developed to simulate P loss from the landscape where runoff is mainly driven by rainfall events. Therefore, they may underperform in cold climates where the land is often frozen during winter and runoff is dominated by snowmelt. This paper (i) reviews the strengths and weaknesses of current P loss assessment tools and their underlying assumptions in simulating soil P dynamics and P transfer to runoff, and (ii) highlights a number of challenges associated with modeling P transfer from agricultural land to surface waters in cold climates. Current P loss assessment tools do not appear to fully represent hydrological and biogeochemical processes responsible for P loss from CSAs, particularly in cold climates. Effort should be made to develop P loss assessment tools that are capable of considering P dynamics through the landscape as a result of abiotic perturbations that are common in cold climates, predicting runoff and P movement over frozen/partially frozen soils, and considering material-P connectivity between landscape and surface waters. Evaluating P loss assessment tools with water quality data is necessary to ensure such modifications result in improved identification of CSAs.

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Using nitrogen fertiliser to decrease phosphorus loss from high phosphorus soils

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2012.74.2894 ◽

2012 ◽

pp. 121-125 ◽

Cited By ~ 3

Author(s):

R.J. Dodd ◽

R.W. Mcdowell ◽

L.M. Condron

Keyword(s):

Soil Phosphorus ◽

Potential Method ◽

Mitigation Strategy ◽

N Leaching ◽

Soil P ◽

P Loss ◽

Fertiliser Application ◽

One Year ◽

N Rates ◽

Pasture Yield

Decline in soil phosphorus (P) concentrations is slow, and environmentally significant concentrations of P can be lost to water long after fertiliser application is decreased. One potential method to accelerate the decline in soil P concentrations is to increase plant uptake by applying nitrogen (N). A one-year lysimeter trial investigated P losses to leachate on three soil types receiving three rates of N fertiliser (0, 150 and 300 kg N/ha/yr) and zero or half maintenance P fertiliser, with regular cutting and removal of pasture. Increasing N input increased annual pasture yield and decreased DRP loss in leachate compared to the zero N treatment, without increasing nitrate or ammonium loss. Furthermore, treatments receiving half maintenance P at all N rates had lower P losses than the zero N and zero P treatment. Based on a cut and carry system, increasing N fertiliser in conjunction with decreasing P fertiliser has potential as a mitigation strategy to decrease P loss without compromising yields or increasing N leaching.

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Modelling Dissolved Phosphorus Losses from Accumulated Soil Phosphorus and Applied Fertilizer and Manure for a National Risk Indicator

Canadian Journal of Soil Science ◽

10.1139/cjss-2021-0049 ◽

2021 ◽

Author(s):

Keith Reid ◽

Kimberley D. Schneider

Keyword(s):

Soil Phosphorus ◽

Field Measurements ◽

The United States ◽

Accurate Estimation ◽

Risk Indicator ◽

Runoff Water ◽

Dissolved Phosphorus ◽

P Loss ◽

P Accumulation ◽

Phosphorus Losses

Balancing the weighting of various components of phosphorus loss in models is a critical but often overlooked step in accurate estimation of risk of P loss under field conditions. This study compared the P loss coefficients used to predict dissolved P losses from desorption from accumulated P in the soil, and those incidental to applications of P as fertilizer or manure, with extraction coefficients determined from actual P losses reported in literature for sites in Canada, with the addition of some sites with similar soils and climate from the northern tier of the United States. The extraction coefficients for dissolved P measured in runoff water was greater by a factor of 6.5X in year-round edge-of-field measurements than in runoff boxes, indicating that models using P extraction coefficients derived from runoff box experiments will be underestimating the magnitude of losses from P accumulation in soil. Differences among the measurement methods (runoff box, rainfall simulator or edge-of-field) were not evident for incidental losses from applied P, but current models appear to over-predict the losses of applied P. Good fit between measured and modelled DP concentrations were achieved by applying coefficients of 0.275 to the fertilizer equations, and 0.219 to the manure equations, implying that 72.5% of fertilizer P and 78% of manure P are not available for runoff. This study underlines the importance of considering the relative weights of the various components of P loss as new models are developed and validated.

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Phased addition of organic and phenolic acids with phosphate fertiliser increases P availability in an acid soil

Soil Research ◽

10.1071/sr13126 ◽

2013 ◽

Vol 51 (5) ◽

pp. 437 ◽

Cited By ~ 4

Author(s):

C. R. Schefe ◽

K. Tymms

Keyword(s):

Carboxylic Acids ◽

Phenolic Acids ◽

Soil Phosphorus ◽

Acid Soil ◽

Potassium Dihydrogen Phosphate ◽

Farming Systems ◽

Research Area ◽

Dihydrogen Phosphate ◽

P Availability ◽

P Loss

The role of carboxylic acids in increasing soil phosphorus (P) availability has been well established, using both organic and phenolic acids. However, the practical application of this knowledge in farming systems is still a developing research area. This study determined the amount of carboxylic acid required per unit P fertiliser for increased solution P concentrations and the optimum order of application, with carboxylic acids applied before (phased addition), or in conjunction with (co-addition), the P fertiliser. Two inorganic P fertilisers (potassium dihydrogen phosphate, KH2PO4; diammonium phosphate, DAP) were applied to an acid soil in conjunction with seven carboxylic acids (oxalic, malic, citric, 4-hydroxybenzoic, protocatechuic, 4-hydroxycinnamic, and caffeic acids) in a series of short-term adsorption and desorption experiments. When the carboxylic acids were applied to soil without P, they all increased solution P concentrations. When applied with P fertiliser, the highest solution P concentrations were measured when solutions of oxalic, citric, or protocatechuic acids were equilibrated with soil before the addition of DAP fertiliser (phased addition). In comparison, phased addition of KH2PO4 fertiliser with malic or citric acids resulted in the greatest potential for subsequent desorption of P from the soil. It is proposed that coating of DAP fertiliser granules with an organic/phenolic acid blend may enhance P fertiliser efficiency in acidic cropping soil through reduced P loss via adsorption onto soil surfaces.

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Effect of Leaching on Loss of Soil Phosphorus in Different Types of Sand Dune in Horqin Sandy Land, China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.3818 ◽

2013 ◽

Vol 726-731 ◽

pp. 3818-3827 ◽

Cited By ~ 1

Author(s):

Quan Lai Zhou ◽

De Ming Jiang ◽

Zhi Min Liu ◽

Alamusa ◽

Xue Hua Li

Keyword(s):

Soil Phosphorus ◽

Available Phosphorus ◽

Horqin Sandy Land ◽

Sandy Land ◽

Soil P ◽

P Loss ◽

Different Types ◽

The Difference ◽

P Leaching ◽

Total P

We simulated P leaching on active dune (AD), semi-stabilized dune (SSD) and stabilized dune (SD) under 140, 700 and 1400 mm of rainfall in Horqin Sandy Land Inner Mongolia, China. The results showed that the available phosphorus (AP) pool decreased by 5–50% in topsoil (0–10 cm), and increased by -5–220% in subsoil (10–20 cm) in AD, SSD, and SD soil. The total P (TP) pool in topsoil (0–10 cm) decreased by 1.8–5.0%, and increased by -5–4.6% in subsoil (10–20 cm) in AD, SSD, and SD soil. The P loss in the soils (0-20 cm) was 0.5–4.5% in AD, SSD, and SD soil. These data indicated that significant downward movement of P occurred during soil leaching. And, the movement of soil P by leaching can cause P loss and changes in vertical distribution of P. Moreover, the difference in P concentration, drawn up by plant roots, between topsoil and subsoil can buffer the P loss at the start of leaching. Therefore, vegetation restoration is essential to reduce P loss in sandy lands.

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Effect of variable soil phosphorus on phosphorus concentrations in simulated surface runoff under intensive dairy pastures

Soil Research ◽

10.1071/sr09025 ◽

2010 ◽

Vol 48 (3) ◽

pp. 231 ◽

Cited By ~ 13

Author(s):

L. L. Burkitt ◽

W. J. Dougherty ◽

S. M. Carlson ◽

D. J. Donaghy

Keyword(s):

Surface Runoff ◽

Soil Phosphorus ◽

Pasture Production ◽

Olsen P ◽

P Loss ◽

Linear Relationships ◽

Eastern Australia ◽

Wide Range ◽

Silty Loam ◽

Curvilinear Relationships

Intensive dairy operations in Australia regularly apply P fertiliser to maintain productive pasture species. However, extractable soil test P (STP) concentrations in this industry commonly exceed those required to maximise pasture production, a situation which can increase the risk of P loss to surrounding waterways. The current study examined relationships between STP (Olsen P and CaCl2 P) and surface runoff P concentrations from a red silty loam (Ferrosol), commonly used for pasture production in south-eastern Australia. Soil was mixed and re-packed into soil trays and a rainfall simulator was used to generate surface runoff. A wide range of soil Olsen P concentrations (0–20 mm, 15–724 mg/kg; 0–100 mm, 9–166 mg/kg) was created by surface-applying a range of P fertiliser rates 8 months before the rainfall simulations. A comparison of the 2 STP methods suggests that Australian soils have higher labile P concentrations for given Olsen P concentrations compared with those measured internationally, suggesting a greater likelihood of P loss in runoff. Furthermore, significant curvilinear relationships between STP and dissolved reactive P (DRP <0.45 µm) in surface runoff for both Olsen P depths (0–20 mm, r2 = 0.94; 0–100 mm, r2 = 0.91; P < 0.01) were determined, as well as significant linear relationships between DRP and both CaCl2 depths (0–20 mm, r2 = 0.83; 0–100 mm, r2 = 0.92; P < 0.01). This confirmed that the concentrations of P in surface runoff increased with increasing STP, providing further evidence of an urgent need to reduce excessive STP concentrations, to reduce the risk of P loss to the environment.

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