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. 2025 Feb 6;54(2):382–396. doi: 10.1002/jeq2.20677

Phosphorus and cover crop management practices affect phosphorus speciation in soils and eroded sediments

Kasuni H H Gamage 1, Ganga M Hettiarachchi 1,✉, Nathan O Nelson 1, Kraig L Roozeboom 1, Gerard J Kluitenberg 1, Peter J Tomlinson 1, DeAnn R Presley 1
PMCID: PMC11893283  PMID: 39915275

Abstract

Agricultural runoff often contains P in dissolved and sediment‐bound forms, decreasing surface water quality. No‐till and cover cropping conservation practices have been recommended for reducing erosion and nutrient loss from cropping systems. The overall aims of this study were to characterize and evaluate the effects of fertilizer (placement and source) and cover crop management on P speciation in surface runoff sediments and source soil. In 2014, a field‐scale experiment was established in a no‐till, corn (Zea mays L.)–soybean (Glycine max L.) cropping system with two cover crop treatments (with and without a winter crop; winter wheat [Triticum aestivum L.], rapeseed [Brassica napus L.], hairy vetch [Vicia villosa Roth], winter triticale [×Triticosecale Wittm.], and cereal rye [Secale cereale L.]) and three P fertilizer management treatments (no P, fall broadcast diammonium phosphate, and spring subsurface injected ammonium polyphosphate). Phosphorus fractionation in the source soil collected in the fall of 2019 and sediment samples collected throughout 2020 were analyzed using a modified sequential P extraction method to evaluate the cumulative effects of imposing the treatment factors over 5 years. The direct P speciation was done using X‐ray absorption near edge structure spectroscopy. The indirect P speciation (fractionation) results showed that the management practices affected the exchangeable, organic matter‐associated, and Fe‐bound P fractions in sediments and the exchangeable and residual fractions in source soil. Direct P speciation results showed a depletion of Fe‐associated P in soil and sediment from cover crop treatment, suggesting that Fe‐associated P species were affected by cover crops. Changes in soil and runoff sediment P speciation would change the proportions and forms of soluble and particulate P in runoff sediments and may influence P bioavailability in aquatic ecosystems. Developing P fertilizer and cropping system management options with an understanding of soil P transformations helps maintain environmental sustainability.

Core Ideas

  • Phosphorus and cover crop management differentially affected P pools in soil and sediments.

  • Cover crop treatment decreased Fe‐associated P in soil and sediments.

  • Cover crop root exudates might have impacted soil P sorption via enhanced dissolution or competitive sorption.

  • Cover crops resulted in more labile P in soil and sediments, potentially impacting surface water quality.

Abbreviations

BMP

best management practices

PEx

exchangeable phosphorus fraction

PFe

iron‐bound phosphorus fraction

PHum

organic matter associated P

PRes

residual phosphorus fraction

SEDEX

sedimentary extraction

XANES

X‐ray absorption near edge structure spectroscopy

1. INTRODUCTION

Phosphorus (P) is a vital crop nutrient, and crop producers worldwide apply P‐based fertilizers to achieve optimum yields. However, agricultural production has been identified as a significant source of sediment, nitrogen, and P pollution, leading to surface water quality issues (Sharpley & Tunney, 2000). The increase in P pollution in surface water is especially detrimental, although not exclusive, to freshwater bodies (Moody, 2011). Eutrophication and associated harmful algal blooms are conservatively estimated to cost the United States economy 2.4–4.6 billion dollars a year (Dodds et al., 2009). In addition to the severe economic impact, harmful algal blooms increase the risk of adverse health impacts on humans and animals (Hudnell, 2010). The linkage between non‐point agricultural P pollution and the degradation of surface water quality has led to the creation of agricultural best management practices (BMP) that reduce P loss. Therefore, to address environmental concerns such as erosion, nutrient loss, and water pollution, the United States Department of Agriculture Natural Resources Conservation Service (USDA‐NRCS) promotes conservation practices designed to reduce erosion and pollution while improving soil health, which includes changes in tillage practices and planting cover crops (NRCS, 2015).

In multiple ecoregions around the globe, no‐till has been shown to reduce sediment in the runoff by up to 80% (Smith et al., 2015; TerAvest et al., 2015). Cover crops have been shown to further reduce erosion by increasing surface plant biomass, improving aggregate stability by increasing soil organic matter, and increasing macropores from their root growth (Blanco‐Canqui et al., 2011; Eichler‐Löbermann et al., 2008). Cover crops can successfully disrupt P transportation routes, reduce erosion losses, and enhance water infiltration (Blanco‐Canqui & Ruis, 2020; Blanco‐Canqui et al., 2011; Loss et al., 2015; Ruffatti et al., 2019). However, the efficacy of cover crops for mitigating total and dissolved P losses has differed across various studies (Adler et al., 2020; Carver et al., 2022; Christianson et al., 2017; Liu et al., 2019; Macrae et al., 2021; Trentman et al., 2020). Therefore, in‐depth information about the interactions between cover crops and P fertilizer management and their effects on soil P chemistry is crucial for understanding cover crop impacts on P loss and developing new agricultural BMPs that account for all potential P losses.

Phosphorus can be found in dissolved or sediment‐bound forms in agricultural runoff. The dissolved P is mainly in the orthophosphate form, the main bioavailable form of P (Machesky et al., 2010). Sediment P is sorbed into clays, calcium carbonate, crystalline and amorphous hydrous iron, aluminum oxides, and organic material in surface runoff (Machesky et al., 2010). Although not readily available, sediment P helps to maintain and control dissolved P. Therefore, it may contribute to continued eutrophication. The P concentration in surface flow is often related to fertilization rates, P cycling in the plant‐soil system, and the amount of labile P in soils. Many studies have been done on sedimentary P speciation to understand P cycling and assess the bioavailability of P in estuarine and coastal environments (Coelho et al., 2004; W. Li et al., 2015; Ruttenberg, 1992; Spears et al., 2006). Zhang et al. (2020) investigated molecular P speciation associated with fluvial suspended sediments from two geologically contrasting agricultural catchments in Ireland to understand in‐stream particulate phosphorus cycling processes, which helps to design appropriate catchment management strategies to protect surface water quality and mitigate eutrophication. Similarly, understanding P speciation and P cycling under different agricultural and nutrient management practices will provide opportunities to design appropriate management practices to mitigate P losses from agricultural runoff. Although it is not an objective of this study, sediment P speciation will affect the eutrophication potential of agricultural runoff.

One commonly adopted method of identifying P species in sediment is the fractionation approach. The sedimentary extraction (SEDEX) procedure of Ruttenberg (1992) is one of the more thoroughly developed and tested chemical extraction schemes for sedimentary analysis. This method separates sediment P into five operationally defined pools. However, it suffers from intrinsic limitations such as artifacts associated with reagent selectivity and the inability to differentiate specific solid‐state P forms (e.g., amorphous vs. crystalline mineral P phases) (W. Li et al., 2015). In recent years, advanced spectroscopic techniques such as X‐ray absorption near edge structure spectroscopy (XANES) have been increasingly applied to complement the SEDEX and other extraction methods (Kizewski et al., 2011; W. Li et al., 2015; Liu et al., 2013). The P K‐edge XANES are nondestructive, element‐specific techniques that can probe the local molecular bonding environment around P atoms and thereby can be used to determine P species (Kar et al., 2011; Peak et al., 2002). In summary, individual techniques have certain limitations, but a combination of complementary techniques enhances species identification with greater certainty (Hettiarachchi et al., 2010; Lombi et al., 2011; Milani et al., 2015) and has been used successfully in different environments (W. Li et al., 2015).

Nelson et al. (2023) reported the agronomic and economic implications of the same study field and showed that the most profitable treatment was fall broadcast P fertilizer with no cover crop. Bourns et al. (2024) assessed the agronomic P use efficiency, and environmental P use efficiency, measured as the percent of P lost in runoff water in the same study field. The results showed that the P fertilizer and cover crop treatments did not influence phosphorus use efficiency, but both fall broadcast and spring injected management reduced environmental phosphorus use efficiency, with spring injected appearing to reduce it slightly less than fall broadcast.

This study was designed to understand how P speciation in eroded sediments and source soil is affected by P management practices and cover crops. We hypothesize that the speciation and solubility of P in sediment and source soil vary with P fertilizer source, application method or time of application, and presence or absence of a cover crop. We anticipate more total P in surface soil by fall broadcast diammonium phosphate than the subsurface applied ammonium polyphosphate. Further cover crops will result in higher bioavailable P in sediments due to less or weak sorption of P in soils rich with organic acid exudates. The objectives of this study were to characterize and evaluate the effects of 5 years of fertilizer (placement and source) and cover crop management on P speciation in surface runoff sediments from natural precipitation events and source soil (0–2.5 cm) collected from a no‐till corn (Zea mays L.)–soybean (Glycine max L.) rotation.

Core Ideas

  • Phosphorus and cover crop management differentially affected P pools in soil and sediments.

  • Cover crop treatment decreased Fe‐associated P in soil and sediments.

  • Cover crop root exudates might have impacted soil P sorption via enhanced dissolution or competitive sorption.

  • Cover crops resulted in more labile P in soil and sediments, potentially impacting surface water quality.

2. MATERIALS AND METHODS

2.1. Field site

This study was conducted at the Kansas Agricultural Watershed field laboratory near Manhattan, Kansas. The field laboratory had 18 small‐scale watersheds (i.e., plots), about 0.5 ha in size (Figure 1), each equipped with a 0.46‐m H‐flume and automated water sampler (ISCO Teledyne 6700 or 6712 series with a 730‐bubbler unit). Plots were separated from each other with berms and terraces to control runoff. The soil type was Smolan (fine, smectitic, and mesic Pachic Argiustolls) with silt loam to silty clay loam surface texture and a 3%–7% slope. Prior to study initiation, the soil pH measured in 1:1 soil:water (Watson & Brown, 1998) ranged from 6.4 to 7.5, the total P measured by salicylic sulfuric digestion (Bremner & Mulvaney, 1982) ranged from 316 to 446 mg kg−1, and the Mehlich‐3 extractable P (Frank et al., 1998) ranged from 10 to 44 mg kg−1 for the 0‐ to 5‐cm depth. The site has been in a continuous no‐till, corn‐soybean rotation since its establishment in 2014. Before that, this field site was under conventional tillage management in a winter wheat (Triticum aestivum L.)–soybean rotation. The location has a hot, humid, continental climate with mean annual temperature of 12.9°C and mean annual precipitation of 889 mm, with 95% of precipitation occurring when the mean daily temperature is above freezing (Figure S1). Therefore, runoff in the region occurs in response to liquid precipitation in excess of infiltration and percolation, with the vast majority of runoff events occurring during the frost‐free period from April 15 to October 15.

FIGURE 1.

FIGURE 1

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Plot map with treatments and watershed outlets for the Kansas Agricultural Watershed (KAW) field laboratory.

2.2. Experimental design

Treatments were organized in a 2 × 3 complete factorial of cover crop and P management factors in a randomized complete block design (blocked by landscape position). Selected fertilizer sources and application methods reflected the common practices among farmers in the region. There were two levels of cover crop management: no cover and with cover crop. There were also three levels of P management: no P fertilizer control, fall surface broadcast as diammonium phosphate (61 kg P2O5 ha−1 year−1), and spring subsurface injected at 4–5 cm below and 5 cm to the side of the seed at planting as ammonium polyphosphate (61 kg P2O5 ha−1 year−1). Phosphorus application rates are based on build‐and‐maintain P fertilizer recommendations for the region given the initial Mehlich‐3 extractable P of 17 mg kg−1 for the 0‐ to 15‐cm soil depth (Leikam et al., 2003). Cover crops have been planted annually since 2014, including winter wheat, rapeseed (Brassica napus L.), and hairy vetch (Vicia villosa Roth) (2014); winter wheat (2015); winter triticale (×Triticosecale Wittm.) and rapeseed (2016 and 2017); and winter wheat and rapeseed (2018). Cereal rye (Secale cereale L.) was planted on September 27, 2019, and terminated with herbicide on May 18, 2020, immediately following soybean planting. Soybean was harvested on October 07, 2020. Further agricultural management details can be found in Carver et al. (2022) and Nelson et al. (2023).

2.3. Sediment sample collection and processing

Flow‐weighted composite surface runoff samples were collected from each plot from May 25, 2020, to November 25, 2020. A 200 mL sub‐sample of runoff was collected for every 1 mm of surface runoff and composited in a 10 L Nalgene carboy for each precipitation event that produced runoff. The runoff samples were removed from the field within 24 h after runoff had ceased and stored at 4°C until further processing. The runoff samples were then centrifuged for 20 min at 10,000 rpm (16,900 RCF), and the sediments were collected and freeze‐dried. Some runoff events yielded low quantities of sediments; therefore, sediment samples from multiple runoff events were combined into time intervals of varying duration: Time period 1 (May 25 to June 27: four events), 2 (July 9 to July 21: four events), and 3 (July 30 to November 25: three events). A detailed outline of the runoff events is given in Figure S2. For each time period, 18 sediment samples were used for the analysis.

2.4. Soil sample collection and processing

Soil sampling was conducted from September 26, 2019, to October 01, 2019, after treatment had been in place for 5 years. There were three composite soil samples collected from each plot, consisting of 21 individual soil cores within a 3 m radius of the three geo‐referenced subplot locations. Residue was cleared from the soil surface, and the soil cores were sectioned into 0‐ to 2.5‐, 2.5‐ to 5‐, and 5‐ to 15‐cm depths. The 0‐ to 2.5‐cm depth samples were used for this study. All soil samples were air‐dried and ground to pass through a 2‐mm sieve. The three subplot samples were analyzed separately.

2.5. Sequential extraction

Phosphorus fractionation in sediments for three time periods and source soil was evaluated using a modification (Baldwin, 1996) of the SEDEX extraction scheme (Ruttenberg, 1992). Briefly, 0.2 ± 0.005 g of sediment or soil was weighed into 50 mL centrifuge tubes, and the solid‐to‐solution ratio was maintained at 1:100. Then, the sediment or soil was sequentially exposed to a series of solutions intended to target specific P species (Table 1). The Baldwin (1996) modification incorporates an additional 16 h, 1 M NaHCO3 step (PHum) after the exchangeable phosphorus fraction (PEx) step to differentiate organic matter‐associated P, which may otherwise be co‐extracted during the iron‐bound phosphorus fraction (PFe) step. All samples were centrifuged after extraction at 2000 rpm (3380 RCF) for 10 min and filtered through Whatman No. 42 filter papers (GE Healthcare Bio‐Sciences). Samples were washed with 20 mL Milli‐Q water after the first extraction step and 20 mL 1 M MgCl2 between remaining extraction steps. Phosphorus in samples from the first two steps (PEx and PHum) was quantified colorimetrically using a Beckman‐Coulter DU‐800 spectrophotometer (Murphy & Riley, 1962), and samples from the remaining steps were analyzed using an inductively coupled plasma optical emission spectrometer (ICP‐OES, 720‐ES, Varian). The supernatants of steps one and two (PEx and PHum) were separately digested by combining 2.5 mL of solution with 500 µL sulfuric acid and heating to 100°C for 1 h, and digested samples were analyzed using the procedure of Murphy and Riley (1962). This was done to determine “Other P (non‐molybdate reactive P)” in each step by comparing pre‐ and post‐digestion. The other P results between replicates were highly variable, possibly due to polyphosphate hydrolysis post‐extraction, and were thus deemed unreliable to present.

TABLE 1.

Summary of the modified sequential sedimentary extraction (SEDEX) protocol used on sediment and source soil samples.

Extractant and condition Targeted P fraction
1 M MgCl2 pH 8 for 2 h at 25°C Exchangeable or loosely sorbed P (PEx)
1 M NaHCO3 pH 7.6 for 16 h at 25°C Organic matter associated P (PHum)
0.3 M Sodium citrate with 1 M NaHCO3 pH 7.6 for 8 h at 25°C with 1.125 g of Na dithionite (citrate bicarbonate dithionite ‐ CBD) Fe‐bound P (PFe)
1 M Na acetate with acetic acid pH 4 for 6 h at 25°C Authigenic carbonate fluorapatite plus biogenic apatite plus CaCO3‐bound P (PCa)
1 M HCl 16 h at 25°C Detrital apatite plus other inorganic P (PDe)
1 M HCl 16 h after ashing at 550°C at 25°C Residual phosphorus fraction a (PRes)
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a

Soil residual P was calculated by subtracting the summation of P in steps 1–5 from total P.

2.6. Synchrotron X‐ray analysis

The X‐ray absorption near‐edge structure spectroscopy analysis was performed for sediment samples from time period 1 and 3 and composite soil samples of the three‐point samples for each plot. The P K‐edge XANES data were collected at Sector 9‐BM‐B, Advanced Photon Source, Argonne National Laboratory, Argonne, IL. All spectra, including the P2O5 standard used for energy calibration, were collected with a solid‐state drift detector in fluorescence mode. A 7‐mm sediment/soil pellet was prepared with the KBr Quick Press Kit (International Crystal Laboratories), mounted on the sample holder with double‐sided carbon tape (SPI Supplies), and then placed into a helium‐filled chamber for analysis. Three and four scans were collected per source soil and sediment samples, respectively, at a range of 2.1 to 2.4 keV.

Background correction, normalization, and linear combination fitting of the experimental spectra were completed in Athena (v.0.9.25) (Ravel & Newville, 2005) according to the concepts set forth by Werner and Prietzel (2015). Previously collected P reference standards were also used, and the P2O5 standard spectra were collected during each run for spectral alignment (Khatiwada et al., 2012; Weeks & Hettiarachchi, 2020). Briefly, three or four scans were merged to reduce noise. Pre‐edge and normalization ranges were not fixed, allowing for each sample's maximized fit. All spectra were adjusted such that E0 of 2149 eV corresponded to one‐half the height of the white line peak. Reference spectra were eliminated if they comprised <5% of the calculated composition, and the fitting was repeated.

2.7. Statistical analysis

All sediment and soil data from sequential extraction were analyzed in SAS (SAS Institute, 2011) using the Proc MIXED procedure. The cover crop and P treatments and their interaction were considered fixed effects, and replication was considered a random effect. Soil data from the three subplots were averaged prior to ANOVA. Tukey's honestly significant difference test was used to compare all treatments at a p = 0.05 significance level.

3. RESULTS AND DISCUSSION

3.1. Sequential extraction of P pools—Soils and sediments

The sequential extraction results showed that P fertilizer and cover crop management affected the exchangeable P (PEx), organic matter associated P (PHum), and iron‐bound P (PFe) fractions in sediments and PEx and residual P (PRes) fractions in source soil (Tables S1 and S2). Previous work in the same study field by Carver et al. (2022) found that the spring injected method of applying P fertilizer decreased both total P and dissolved reactive P (DRP) concentrations and loads in runoff water compared to the fall broadcast treatment during the 2016 through 2019 cropping years. Further, they showed relatively consistent trends over time. After 5 years of treatment implementation, we found that the PEx fraction in source soil showed a significant difference by P treatment (Figure 2a) and in sediments by both P treatment and cover crop in all three time periods (Figure 2b,c). In both source soil and sediments, fall broadcast had the greatest PEx (Figure 2a,b). Differences in the application methods are the likely cause of this result. Fall broadcast was a surface broadcast application as granular diammonium phosphate, and the spring injected was a below‐surface band application as liquid ammonium polyphosphate. Surface application of fluid polyphosphate has been shown to decrease soluble P losses by 98% when compared to application of both granular monoammonium phosphate and diammonium phosphate fertilizers (Smith et al., 2016). The fall broadcast granules most likely did not react much. They were at the surface and reduced diffusion when granules started dissolving, likely causing P saturation and high PEx. In spring injected, fertilizer P would potentially interact with a larger soil mass than a broadcast P fertilizer. Liquid forms facilitate P diffusion into a larger soil volume and, therefore, stronger retention in soil (i.e., longer time to saturate sorption sites with high energy in the P‐enriched soil volume). Higher exchangeable P in the soil increases the risk of P loss from the field in surface runoff, which helps explain the increased DRP losses by treatments with fall broadcast fertilizer observed by Carver et al. (2022) for this study. In literature, it is well documented that the application of P‐containing fertilizers increases P loss compared to no‐P fertilizer controls depending on the timing of runoff and soil conditions at the time of fertilizer application (Y. Li et al., 2020; Smith, Moore, Maxwell, et al., 2004; Smith, Moore, Miles, et al., 2004; Smith et al., 2007; Torbert et al., 1999). In no‐till management, P fertilizer is often broadcast on the soil surface, concentrating the nutrient in the top few mm of soil due to the lack of mechanical incorporation, where surface water interacts most (Sims et al., 2000). Subsurface placement of P fertilizer is a well‐recognized management practice that can reduce the risk of P loss in runoff and minimize nutrient loss (Pote et al., 1999; Sharpley et al., 1992; Smith et al., 2016). Smith et al. (2016) also found that injecting liquid polyphosphate fertilizer had less soluble and total P loss than annual and biannual surface broadcasting in no‐till fields. Incorporating P fertilizer decreased the average total P concentration in the runoff between 90 and 99% compared to surface‐broadcast P fertilizer application (Pote et al., 1999). Smith et al. (2016) further found that the subsurface placement of P fertilizer also decreased the total P load in the runoff by approximately 97% compared to surface‐broadcast P fertilizer application.

FIGURE 2.

FIGURE 2

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(a) The exchangeable phosphorus (PEx) fraction in source soil by P treatment. (b) The PEx fraction in sediments by P treatment in all three time periods. (c) The PEx fraction in sediments by cover crop in all three time periods. Means within a treatment containing the same letter are not significantly different at p = 0.05 according to Tukey's pairwise method. CC, with cover crop; CN, control; FB, fall broadcast; NC, no cover crop; SI, spring injected.

The PEx fraction was greater in the cover crop treatment than in the no cover crop in sediments (Figure 2c). Cover crops can modify P forms in the soil and may lead to competitive adsorption (Violante & Gianfreda, 1993). Root exudates/organic acids such as citric, malic, malonic, oxalic, succinic, and tartaric from the roots of cover crops may alter soil P sorption capacity by ligand‐promoted dissolution or enhanced dissolution via complexation and organic acid competition for adsorption sites and ultimately lessen or weaken sorption of P in soils (Johnson & Loeppert, 2006). Cover crops have shown the capability to access and solubilize more recalcitrant forms of soil P through the exudation of P solubilizing compounds, the release of organic P mineralizing compounds, and by modifying the rhizospheric microbial population (Hallama et al., 2019). Furthermore, cover crops have access to traditionally non‐available P fractions via the establishment of symbiotic relationships with mycorrhizal fungi and secretion of P solubilizing root exudates or alteration of root architecture. Cover crop uptake of these less available forms of P could result in P translocation to the soil surface, thereby increasing the PEx (Hallama et al., 2019). Dube et al. (2017) and Wang et al. (2021) found that adding a cover crop increases the concentration of total P in surface soils. The increased PEx we observed for sediments originating from cover crop treatments indicates that cover crop effects on P speciation may contribute to the increased DRP losses observed by Carver et al. (2022) in this same study field. They found cover crops consistently increased DRP concentrations in the runoff each year and increased DRP loss in three out of 4 years of the study.

Only the P treatments showed a significant difference in PHum fraction in sediments in all three time periods. There was clear separation between fall broadcast and spring injected in the PHum fraction, with no difference between control and fall broadcast or control and spring injected (Figure 3). The differences in the source of P (i.e., diammonium phosphate vs. ammonium polyphosphate) may have caused this. Besides, given that PHum is estimated in the second step, part of the loosely bound organic matter associated P could have already been extracted in Step 1. Whereas each subsequent extraction in this series is intended to target specific and increasingly recalcitrant P species, these fractions are operationally defined by the reagents used. Each fraction may represent several P chemical forms that all happen to be extracted by the same procedural steps, which makes interpretation challenging. This fraction is a modification of the SEDEX extraction scheme Baldwin (1996) proposed to differentiate organic matter‐associated P, which may otherwise be co‐extracted during the PFe step.

FIGURE 3.

FIGURE 3

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The organic matter associated P (PHum) fraction in sediments by P treatment in all three time periods. Means within a treatment containing the same letter are not significantly different at p = 0.05 according to Tukey's pairwise method. CN, control; FB, fall broadcast; SI, spring injected.

The third step in this sequential extraction was intended to extract P co‐precipitated with iron (III) oxyhydroxides through reductive dissolution by dithionite, referred to as PFe (Ruttenberg, 1992). The extent of dissolution of Fe (III) minerals depends on the redox condition, sediment composition (phyllosilicates vs. oxides), and degree of crystallinity (amorphous vs. crystalline), among other factors (W. Li et al., 2015). The PFe fraction in sediments showed a significant difference only by the P treatment in time period 1. Iron‐bound P was affected differently in control versus P treatments (Figure 4). It showed an increase in control with cover crops compared to no cover crops and a decrease in fall broadcast with cover crops compared to no cover crops. That suggests that the reaction pathways for native P and the added P are different in these sediments, and cover crops trigger the transformation of Fe‐bound P to other P. This difference could be due to the fact that in control soil, it was a reflection of cover crop effects on native soil P, whereas in spring injected and fall broadcast it reflected cover crop effects on added fertilizer P.

FIGURE 4.

FIGURE 4

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The iron‐bound phosphorus (PFe) fraction in sediments by P treatment in all three time periods. Only time period 1 showed significant interaction between P treatment and cover crop at p = 0.05. CC, with cover crop; CN, control; FB, fall broadcast; NC, no cover crop; SI, spring injected.

Adding P fertilizer in both fall broadcast and spring injected treatments increased PRes and total P concentrations near the soil surface compared to control, but no significant differences were observed between the fall broadcast and spring injected treatments (Figure 5), and a similar trend was observed when PRes fraction was presented as a percentage of total P (Figure S3). It was surprising to find no significant difference between the fall broadcast and spring injected treatments. The spring injected treatment involves placing P below the surface, but because P tends to stay immobile within the soil system, it suggests that subsurface placement may not effectively reduce potentially high concentrations of P on the surface in the no‐till system. The lack of difference in PRes and total P between the fall broadcast and spring injected treatment could be attributed to inconsistencies in the placement depth of P fertilizer applied in the spring injected treatment. The spring injected treatment may not always be placed at the same depth, 5 cm below, and to the side of the seed at planting, leading to variability in results. Additionally, plant uptake followed by deposition and decomposition of residue could lead to rapid cycling of P to the soil surface and contribute to this lack of difference (Bourns et al., 2024). Insufficient vertical mixing of soil and crop residue may lead to higher concentrations of dissolved P in surface runoff in the control treatment (Bordoli & Mallarino, 1998). Daryanto et al. (2017) found that dissolved P in surface runoff in no‐till systems is 35% greater than in conventionally tilled systems.

FIGURE 5.

FIGURE 5

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(a) The residual phosphorus (PRes) fraction in source soil by P treatment. (b) The total P in source soil by P treatment. Means within a treatment containing the same letter are not significantly different at p = 0.05 according to Tukey's pairwise method. CN, control; FB, fall broadcast; SI, spring injected.

3.2. Phosphorus XANES‐soils and sediments

The control soil was dominated by Fe‐associated P (Fe‐adsorbed P and Fe‐precipitated P) species followed by apatite‐like P and clay‐Al‐adsorbed P species, whereas the P‐added soils (fall broadcast and spring injected) were dominated by clay‐Al‐adsorbed P species (Figure 6). This suggests that the added P has contributed to the change in overall P speciation in P added soils compared to control soil. Total P differences obtained by the sequential extraction for source soil also showed the difference between control and P‐added soils. In addition, when comparing the soil without cover crop treatment, it was dominated by Fe‐associated P species, whereas the cover crop treatments were dominated by the clay‐Al‐absorbed P species (Figure 6). This suggests that the cover crop treatment enhanced the clay‐Al‐adsorbed P at the expense of the Fe‐associated P. In sediments, a similar trend was observed in cover and no cover crop treatments where the Fe‐associated P species dominated no cover crop treatment, and clay‐Al‐absorbed P species dominated the cover crop treatment (Figures 7 and 8). This also suggests that cover crop treatment induced the transformation of Fe‐associated P to other P. In other words, cover crop treatment redistributed the P species in these cropping systems. This could be due to cover crops changing the Fe chemistry in surface soil via ligand‐promoted dissolution by root exudates, competitive adsorption by organic acids (Johnson & Loeppert, 2006; Owen et al., 2015), and redistribution of residual P in soil. The sequential extraction PFe results also showed a similar trend. In sediments, spring injected treatment showed higher Fe‐associated P species than the fall broadcast treatment (Figures 7 and 8), which could have led to less exchangeable P in the spring injected treatment, as was observed in the sequential extraction.

FIGURE 6.

FIGURE 6

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Normalized P K‐edge X‐ray absorption near edge structure spectra of source soil with linear combination fitting (LCF) results as percent distribution of P species. CN‐CC, control‐with cover crops; CN‐NC, control‐no cover crops; FB‐CC, fall broadcast‐with cover crops; FB‐NC, fall broadcast‐no cover crops; SI‐CC, spring injected‐with cover crops; SI‐NC, spring injected‐no cover crops.

FIGURE 7.

FIGURE 7

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Normalized P K‐edge X‐ray absorption near edge structure spectra of sediment time period 1 with linear combination fitting (LCF) results as percent distribution of P species. CN‐CC, control‐with cover crops; CN‐NC, control‐no cover crops; FB‐CC, fall broadcast‐with cover crops; FB‐NC, fall broadcast‐no cover crops; SI‐CC, spring injected‐with cover crops; SI‐NC, spring injected‐no cover crops.

FIGURE 8.

FIGURE 8

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Normalized P K‐edge X‐ray absorption near edge structure spectra of sediment time period 3 with linear combination fitting (LCF) results as percent distribution of P species. CN‐CC, control‐with cover crop; CN‐NC, control‐no cover crops; FB‐CC, fall broadcast‐with cover crops; FB‐NC, fall broadcast‐no cover crops; SI‐CC, spring injected‐with cover crops; SI‐NC, spring injected‐no cover crop.

4. CONCLUSIONS

The findings from the sequential chemical extraction showed that P and cover crop management affected the exchangeable, organic matter‐associated, and iron‐bound P fractions in sediments and exchangeable and residual fractions in source soil. The XANES analysis showed that cover crop treatment decreased Fe‐associated P in soil and sediments. The results suggest that the Fe‐associated P was more vulnerable to transformations due to cover crops. The root exudates and organic acids from cover crops significantly impact the soil's ability to retain P, likely via ligand‐promoted dissolution or enhanced dissolution via complexation of Fe minerals and organic acid competition for adsorption sites in soils. Reduced Fe‐associated P in cover crop systems likely resulted in more labile P, which could increase the potential risk of P loss from the field, subsequently reducing the surface water quality. Changed P speciation in soil and sediments could be the reason for increased DRP and total P losses, suggesting that the changes in P speciation play a crucial role in the solubility of P in different P and cover crop management systems. The findings of this study also have implications for soil fertility. When cover crops increase soluble and/or potentially soluble P in soil, it could require adjusting P rates for systems with cover crops. However, it is essential to acknowledge that the impact could vary on different soils, leading to different effects of cover crops on P loss. Further research on changes in iron chemistry in soil with cover crops will help understand P speciation changes. The study emphasizes the importance of selecting the most effective P management practices to protect surface water quality, even when implementing other conservation practices.

AUTHOR CONTRIBUTIONS

Kasuni H. H. Gamage: Conceptualization; data curation; formal analysis; investigation; methodology; validation; visualization; writing—original draft; writing—review and editing. Ganga M. Hettiarachchi: Conceptualization; data curation; formal analysis; funding acquisition; investigation; methodology; project administration; resources; supervision; validation; visualization; writing—original draft; writing—review and editing. Nathan O. Nelson: Conceptualization; investigation; methodology; project administration; resources; supervision; writing—review and editing. Kraig L. Roozeboom: Conceptualization; funding acquisition; resources; writing—review and editing. Gerard J. Kluitenberg: Conceptualization; funding acquisition; resources; writing—review and editing. Peter J. Tomlinson: Conceptualization; funding acquisition; resources; writing—review and editing. DeAnn R. Presley: Conceptualization; funding acquisition; resources; writing—review and editing.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.

Supporting information

The supplemental material contains two tables that provide summary statistics for the sediments and soils. It also contains three figures showing the cumulative precipitation for the experimental site during the study period compared to the 30‐year average cumulative precipitation with the dates of precipitation events that generated runoff used for the current study, cropping system timeline and runoff events in 2020, and different P fractions as a % of total P in source soil.

JEQ2-54-382-s001.docx (137.6KB, docx)

ACKNOWLEDGMENTS

We acknowledge the funding support of this study by FFAR Grant # CA19‐SS‐0000000022, Kansas Department of Agriculture and Kansas Soybean Commission; NRCS KAW water quality grant. This research used resources of the Advanced Photon Source; a U.S. Department of Energy (DOE) Office of Science user facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE‐AC02‐06CH11357. Special thanks to the beamline scientists Tianpin Wu and George Sterbinsky at Sector 9 BM‐B for their support during the data collection. The authors also wish to acknowledge the contributions of Cassandra Schnarr and Sarah Raugewitz. Contribution no. 25‐113‐J from the Kansas Agricultural Experiment Station.

Gamage, K. H. H. , Hettiarachchi, G. M. , Nelson, N. O. , Roozeboom, K. L. , Kluitenberg, G. J. , Tomlinson, P. J. , & Presley, D. R. (2025). Phosphorus and cover crop management practices affect phosphorus speciation in soils and eroded sediments. Journal of Environmental Quality, 54, 382–396. 10.1002/jeq2.20677

Assigned to Associate Editor Tyler Groh.

REFERENCES

  1. Adler, R. L. , Singh, G. , Nelson, K. A. , Weirich, J. , Motavalli, P. P. , & Miles, R. J. (2020). Cover crop impact on crop production and nutrient loss in a no‐till terrace topography. Journal of Soil and Water Conservation, 75(2), 153–165. 10.2489/jswc.75.2.153 [DOI] [Google Scholar]
  2. Baldwin, D. S. (1996). The phosphorus composition of a diverse series of Australian sediments. Hydrobiologia, 335, 63–73. 10.1007/BF00013684 [DOI] [Google Scholar]
  3. Blanco‐Canqui, H. , Mikha, M. M. , Presley, D. R. , & Claassen, M. M. (2011). Addition of cover crops enhances no‐till potential for improving soil physical properties. Soil Science Society of America Journal, 75(4), 1471–1482. 10.2136/sssaj2010.0430 [DOI] [Google Scholar]
  4. Blanco‐Canqui, H. , & Ruis, S. J. (2020). Cover crop impacts on soil physical properties: A review. Soil Science Society of America Journal, 84(5), 1527–1576. 10.1002/saj2.20129 [DOI] [Google Scholar]
  5. Bordoli, J. M. , & Mallarino, A. P. (1998). Deep and shallow banding of phosphorus and potassium as alternatives to broadcast fertilizer for no‐till corn. Agronomy Journal, 90(1), 27–33. 10.2134/agronj1998.00021962009000010006x [DOI] [Google Scholar]
  6. Bourns, M. A. , Nelson, N. O. , Carver, R. E. , Roozeboom, K. L. , Kluitenberg, G. J. , Tomlinson, P. J. , Kang, Q. , & Hettiarachchi, G. M. (2024). Cover crops impact phosphorus cycling and environmental efficiency in a corn–soybean system. Agronomy Journal, 116(1), 109–120. 10.1002/agj2.21498 [DOI] [Google Scholar]
  7. Bremner, J. M. , & Mulvaney, C. S. (1982). Salicylic acid thiosulfate modification of the Kjeldhal method to include nitrate and nitrite. In A. L. Page , Miller R. H., & Keeney D. R. (Eds.), Methods of soil analysis: Part 2. Chemical and microbiological properties (pp. 621). American Society Agronomy, Inc. [Google Scholar]
  8. Carver, R. E. , Nelson, N. O. , Roozeboom, K. L. , Kluitenberg, G. J. , Tomlinson, P. J. , Kang, Q. , & Abel, D. S. (2022). Cover crop and phosphorus fertilizer management impacts on surface water quality from A no‐till corn‐soybean rotation. Journal of Environmental Management, 301, 113818. 10.1016/j.jenvman.2021.113818 [DOI] [PubMed] [Google Scholar]
  9. Christianson, R. , Fox, J. , Wong, C. , Caraco, D. , Daniels, A. , Law, N. , & Stack, B. (2017). Literature review and synthesis of the effectiveness of cover crops for water quality management in the Upper Mississippi River Basin (white paper). Center for Watershed Protection, Inc. [Google Scholar]
  10. Coelho, J. P. , Flindt, M. R. , Jensen, H. S. , Lillebø, A. I. , & Pardal, M. A. (2004). Phosphorus speciation and availability in intertidal sediments of a temperate estuary: Relation to eutrophication and annual P‐fluxes. Estuarine, Coastal and Shelf Science, 61, 583–590. 10.1016/j.ecss.2004.07.001 [DOI] [Google Scholar]
  11. Daryanto, S. , Wang, L. , & Jacinthe, P. A. (2017). Meta‐analysis of phosphorus loss from no‐till soils. Journal of Environmental Quality, 46(5), 1028–1037. 10.2134/jeq2017.03.0121 [DOI] [PubMed] [Google Scholar]
  12. Dodds, W. K. , Bouska, W. W. , Eitzmann, J. L. , Pilger, T. J. , Pitts, K. L. , Riley, A. J. , Schloesser, J. T. , & Thornburgh, D. J. (2009). Eutrophication of U.S. freshwaters: Analysis of potential economic damages. Environmental Science & Technology, 43(1), 12–19. https://doi/10.1021/es801217q [DOI] [PubMed] [Google Scholar]
  13. Dube, E. , Chiduza, C. , & Muchaonyerwa, P. (2017). High biomass yielding cover crops can improve soil phosphorus availability in soil. South African Journal of Science, 110(3/4), 1–4. 10.1590/sajs.2014/20130135 [DOI] [Google Scholar]
  14. Eichler‐Löbermann, B. , Köhne, S. , Kowalski, B. , & Schnug, E. (2008). Effect of catch cropping on phosphorus bioavailability in comparison to organic and inorganic fertilization. Journal of Plant Nutrition, 31(4), 659–676. 10.1080/01904160801926517 [DOI] [Google Scholar]
  15. Frank, K. , Beegle, D. , & Denning, J. (1998). Phosphorus. In Brown J. R. (Ed.), Recommended chemical soil test procedures for the north central region (pp. 21–30). Missouri Agricultural Experiment Station, University of Missouri. [Google Scholar]
  16. Hallama, M. , Pekrun, C. , Lambers, H. , & Kandeler, E. (2019). Hidden miners–the roles of cover crops and soil microorganisms in phosphorus cycling through agroecosystems. Plant and Soil, 434, 7–45. 10.1007/s11104-018-3810-7 [DOI] [Google Scholar]
  17. Hettiarachchi, G. M. , Lombi, E. , McLaughlin, M. , Chittleborough, D. , & Johnston, C. (2010). Chemical behavior of fluid and granular Mn and Zn fertilisers in alkaline soils. Australian Journal of Soil Research, 48(3), 238–247. 10.1071/SR09051 [DOI] [Google Scholar]
  18. Hudnell, H. K. (2010). The state of U.S. freshwater harmful algal blooms assessments, policy and legislation. Toxicon, 55(5), 1024–1034. 10.1016/j.toxicon.2009.07.021 [DOI] [PubMed] [Google Scholar]
  19. Johnson, S. E. , & Loeppert, R. H. (2006). Role of organic acids in phosphate mobilization from iron oxide. Soil Science Society of America Journal, 70(1), 222–234. 10.2136/sssaj2005.0012 [DOI] [Google Scholar]
  20. Kar, G. , Hundal, L. S. , Schoenau, J. J. , & Peak, D. (2011). Direct chemical speciation of P in sequential chemical extraction residues using P K edge X‐ray absorption near‐edge structure spectroscopy. Soil Science, 176(11), 589–595. 10.1097/SS.0b013e31823939a3 [DOI] [Google Scholar]
  21. Khatiwada, R. , Hettiarachchi, G. M. , Mengel, D. , & Fei, M. (2012). Speciation of phosphorus in a fertilized reduced till soil system: in‐field treatment incubation study. Soil Science Society of America Journal, 76(6), 2006–2018. 10.2136/sssaj2011.0299 [DOI] [Google Scholar]
  22. Kizewski, F. , Liu, Y. T. , Morris, A. , & Hesterberg, D. (2011). Spectroscopic approaches for phosphorus speciation in soils and other environmental systems. Journal of Environmental Quality, 40(3), 751–766. 10.2134/jeq2010.0169 [DOI] [PubMed] [Google Scholar]
  23. Leikam, D. F. , Lamond, R. E. , & Mengel, D. B. (2003). Soil test interpretations and fertilizer recommendations (Pub. MF‐2586) . Kansas State University, Agricultural Experiment Station and Cooperative Extension Service. [Google Scholar]
  24. Li, W. , Joshi, S. R. , Hou, S. , Burdige, D. J. , Sparks, D. L. , & Jaisi, D. P. (2015). Characterizing phosphorus speciation of chesapeake bay sediments using chemical extraction, 31P NMR, and X‐ray absorption fine structure spectroscopy. Environmental Science & Technology, 49(1), 203–211. 10.1021/es504648d [DOI] [PubMed] [Google Scholar]
  25. Li, Y. , Abegunrin, T. P. , Guo, H. , Huang, Z. , Are, K. S. , Wang, H. , Gu, M. , & Wei, L. (2020). Variation in dissolved nutrient exports by surface runoff from sugarcane watershed is controlled by fertilizer application and ground cover. Agriculture, Ecosystems & Environment, 303, 107121. 10.1016/j.agee.2020.107121 [DOI] [Google Scholar]
  26. Liu, J. , Macrae, M. L. , Elliott, J. A. , Baulch, H. M. , Wilson, H. F. , & Kleinman, J. A. (2019). Impacts of cover crops and crop residues on phosphorus losses in cold climates: A review. Journal of Environmental Quality, 48(4), 850–868. 10.2134/jeq2019.03.0119 [DOI] [PubMed] [Google Scholar]
  27. Liu, J. , Yang, J. , Cade‐Menun, B. J. , Liang, X. , Hu, Y. , Liu, C. W. , Zhao, Y. , Li, L. , & Shi, J. (2013). Complementary phosphorus speciation in agricultural soils by sequential fractionation, solution 31P nuclear magnetic resonance, and phosphorus K‐edge X‐ray absorption near edge structure spectroscopy. Journal of Environmental Quality, 42(6), 1763–1770. 10.2134/jeq2013.04.0127 [DOI] [PubMed] [Google Scholar]
  28. Lombi, E. , Hettiarachchi, G. M. , & Scheckel, K. G. (2011). Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: Introduction to the special section. Journal of Environmental Quality, 40(3), 659–666. 10.2134/jeq2010.0542 [DOI] [PubMed] [Google Scholar]
  29. Loss, A. , Brass, A. , Oliveira, B. S. , Koucher, L. P. , Oliveiria, R. A. , Kurtz, C. , Lovato, P. E. , Curmi, P. , Brunetto, G. , & Comim, J. J. (2015). Total organic carbon and soil aggregation under a no‐tillage agroecological system and conventional tillage system for onion. Revista Brasileira de Ciência do Solo, 39(4), 1212–1224. 10.1590/01000683rbcs20140718 [DOI] [Google Scholar]
  30. Machesky, M. L. , Holm, T. R. , & Slowikowski, J. A. (2010). Phosphorus speciation in stream bed sediments from an agricultural watershed: Solid‐phase associations and sorption behavior. Aquatic Geochemistry, 16, 639–662. 10.1007/s10498-010-9103-2 [DOI] [Google Scholar]
  31. Macrae, M. , Jarvie, H. , Brouwer, R. , Gunn, G. , Reid, K. , Joose, P. , King, K. , Kleinman, P. , Smith, D. , Williams, M. , & Zwonitzer, M. (2021). One size does not fit all: Toward regional conservation practice guidance to reduce phosphorus risk loss in the Lake Erie watershed. Journal of Environmental Quality, 50(3), 529–546. 10.1002/jeq2.20218 [DOI] [PubMed] [Google Scholar]
  32. Milani, N. , Hettiarachchi, G. M. , Beak, D. G. , McLaughlin, M. J. , Kirby, J. K. , & Stacey, S. P. (2015). Fate of zinc oxide nanoparticles coated onto macronutrient fertilizers in an alkaline calcareous soil. PLoS One, 10(5), e0126275. 10.1371/journal.pone.0126275 [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Moody, P. W. (2011). Environmental risk indicators for soil phosphorus status. Soil Research, 49(3), 247–252. 10.1071/SR10140 [DOI] [Google Scholar]
  34. Murphy, J. , & Riley, J. P. (1962). A modified single solution method for the determination of phosphate in natural waters. Analytica Chimica Acta, 27, 31–36. 10.1016/S0003-2670(00)88444-5 [DOI] [Google Scholar]
  35. Nelson, N. O. , Roozeboom, K. L. , Yeager, E. A. , Williams, J. R. , Zerger, S. E. , Kluitenberg, G. J. , Tomlinson, P. J. , Abel, D. S. , & Carver, R. E. (2023). Agronomic and economic implications of cover crop and phosphorus fertilizer management practices for water quality improvement. Journal of Environmental Quality, 52(1), 113–125. 10.1002/jeq2.20427 [DOI] [PubMed] [Google Scholar]
  36. NRCS . (2015). Soil Health literature summary–effects of conservation practices on soil properties in areas of crop land . Natural Resources Conservation Service, National Soil Survey Center, United States Department of Agriculture. [Google Scholar]
  37. Owen, D. , Williams, A. P. , Griffith, G. W. , & Withers, P. J. A. (2015). Use of commercial bio‐inoculants to increase agricultural production through improved phosphorous acquisition. Applied Soil Ecology, 86, 41–54. 10.1016/j.apsoil.2014.09.012 [DOI] [Google Scholar]
  38. Peak, D. , Sims, J. T. , & Sparks, D. L. (2002). Solid‐state speciation of natural and alum‐amended poultry litter using XANES spectroscopy. Environmental Science & Technology, 36, 4253–4261. 10.1021/es025660d [DOI] [PubMed] [Google Scholar]
  39. Pote, D. H. , Daniel, T. C. , Nichols, D. J. , Sharpley, A. N. , Moore, P. A., Jr. , Miller, D. M. , & Edwards, D. R. (1999). Relationship between phosphorus levels in three ultisols and phosphorus concentration in runoff. Journal of Environmental Quality, 28(1), 170–175. 10.2134/jeq1999.00472425002800010020x [DOI] [Google Scholar]
  40. Ravel, B. , & Newville, M. (2005). Athena, artemis, hephaestus: Data analysis for X‐ray absorption spectroscopy using IFEFFIT. Journal of Synchrotron Radiation, 12, 537–541. 10.1107/S0909049505012719 [DOI] [PubMed] [Google Scholar]
  41. Ruffatti, M. D. , Roth, R. T. , Lacey, C. G. , & Armstrong, S. D. (2019). Impacts of nitrogen application timing and cover crop inclusion on subsurface drainage water quality. Agricultural Water Management, 211, 84–88. 10.1016/j.agwat.2018.09.016 [DOI] [Google Scholar]
  42. Ruttenberg, K. C. (1992). Development of a sequential extraction method for different forms of phosphorus in marine sediments. Limnology and Oceanography, 37(7), 1460–1482. 10.4319/lo.1992.37.7.1460 [DOI] [Google Scholar]
  43. SAS Institute . (2011). The SAS system for windows version 9.1.3 . SAS Institute. [Google Scholar]
  44. Sharpley, A. , & Tunney, H. (2000). Phosphorus research strategies to meet agricultural and environmental challenges of the 21st century. Journal of Environmental Quality, 29(1), 176–181. 10.2134/jeq2000.00472425002900010022x [DOI] [Google Scholar]
  45. Sharpley, A. N. , Smith, S. J. , Jones, O. R. , Berg, W. A. , & Coleman, G. A. (1992). The transport of bioavailable phosphorus in agricultural runoff. Journal of Environmental Quality, 21(1), 30–35. 10.2134/jeq1992.00472425002100010003x [DOI] [Google Scholar]
  46. Sims, J. T. , Edwards, A. C. , Schoumans, O. F. , & Simard, R. R. (2000). Integrating soil phosphorus testing into environmentally based agriculture management practices. Journal of Environmental Quality, 29(1), 60–71. 10.2134/jeq2000.00472425002900010008x [DOI] [Google Scholar]
  47. Smith, D. , Owens, P. , Leytem, A. , & Warnemuende, E. (2007). Nutrient losses from manure and fertilizer applications as impacted by time to first runoff event. Environmental Pollution, 147(1), 131–137. 10.1016/j.envpol.2006.08.021 [DOI] [PubMed] [Google Scholar]
  48. Smith, D. R. , Francesconi, W. , & Livingston, S. J. (2015). Phosphorus losses from monitored fields with conservation practices in the Lake Erie Basin, USA. AMBIO, 44, 319–331. 10.1007/s13280-014-0624-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Smith, D. R. , Harmel, R. D. , Williams, M. , Haney, R. , & King, K. W. (2016). Managing acute phosphorus loss with fertilizer source and placement: Proof of concept. Agricultural & Environmental Letters, 1(1), 150015. 10.2134/ael2015.12.0015 [DOI] [Google Scholar]
  50. Smith, D. R. , Moore, P. A. , Maxwell, C. V. , Haggard, B. E. , & Daniel, T. C. (2004). Reducing phosphorus runoff from swine manure with dietary phytase and aluminum chloride. Journal of Environmental Quality, 33(3), 1048–1054. 10.2134/jeq2004.1048 [DOI] [PubMed] [Google Scholar]
  51. Smith, D. R. , Moore, P. A. , Miles, D. M. , Haggard, B. E. , & Daniel, T. C. (2004). Decreasing phosphorus runoff losses from land‐applied poultry litter with dietary modifications and alum addition. Journal of Environmental Quality, 33(6), 2210–2216. 10.2134/jeq2004.2210 [DOI] [PubMed] [Google Scholar]
  52. Spears, B. M. , Carvalho, L. , Perkins, R. , Kirika, A. , & Paterson, D. M. (2006). Spatial and historical variation in sediment phosphorus fractions and mobility in a large shallow lake. Water Research, 40, 383–391. 10.1016/j.watres.2005.11.013 [DOI] [PubMed] [Google Scholar]
  53. TerAvest, D. , Carpenter‐Boggs, L. , Thierfelder, C. , & Reganold, J. P. (2015). Crop production and soil water management in conservation agriculture, no‐till, and conventional tillage systems in Malawi. Agriculture, Ecosystems & Environment, 212, 285–296. 10.1016/j.agee.2015.07.011 [DOI] [Google Scholar]
  54. Torbert, H. A. , Potter, K. N. , Hoffman, D. W. , Gerik, T. J. , & Richardson, C. W. (1999). Surface residue and soil moisture affect fertilizer loss in simulated runoff on a heavy clay soil. Agronomy Journal, 91(4), 606–612. 10.2134/agronj1999.914606x [DOI] [Google Scholar]
  55. Trentman, M. T. , Tank, J. L. , Royer, T. V. , Speir, S. L. , Mahl, U. H. , & Sethna, L. R. (2020). Cover crops and precipitation influence soluble reactive phosphorus losses via tile drain discharge in an agricultural watershed. Hydrological Processes, 34(23), 4446–4458. 10.1002/hyp.13870 [DOI] [Google Scholar]
  56. Violante, A. , & Gianfreda, L. (1993). Competitive adsorption between phosphate and oxalate on an aluminum hydroxide montmorillonite complex. Soil Science Society of America Journal, 57(5), 1235–1241. 10.2136/sssaj1993.03615995005700050013x [DOI] [Google Scholar]
  57. Wang, Y. , Huang, Q. , Gao, H. , Zhang, R. , Yang, L. , Guo, Y. , Li, H. , Awasthi, M. K. , & Li, G. (2021). Long‐term cover crops improved soil phosphorus availability in a rain‐fed apple orchard. Chemosphere, 275, 130093. 10.1016/j.chemosphere.2021.130093 [DOI] [PubMed] [Google Scholar]
  58. Watson, M. E. , & Brown, J. R. (1998). pH and lime requirement. In Brown J. R. (Ed.), Recommended chemical soil test procedures for the north central region (pp. 13–16). Missouri Agricultural Experiment Station. University of Missouri. [Google Scholar]
  59. Weeks, J. J. , & Hettiarachchi, G. M. (2020). Source and formulation matter: New insights into phosphorus fertilizer fate and transport in mildly calcareous soils. Soil Science Society of America Journal, 84(3), 731–746. 10.1002/saj2.20054 [DOI] [Google Scholar]
  60. Werner, F. , & Prietzel, J. (2015). Standard protocol and quality assessment of soil phosphorus speciation by P K‐edge XANES spectroscopy. Environmental Science & Technology, 49(17), 10521–10528. 10.1021/acs.est.5b03096 [DOI] [PubMed] [Google Scholar]
  61. Zhang, Q. , Wieler, M. , O'Connell, D. , Gill, L. , Xiao, Q. , & Hu, Y. (2020). Speciation of phosphorus from suspended sediment studied by bulk and micro‐XANES. Soil Systems, 4(3), 51. 10.3390/soilsystems4030051 [DOI] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

The supplemental material contains two tables that provide summary statistics for the sediments and soils. It also contains three figures showing the cumulative precipitation for the experimental site during the study period compared to the 30‐year average cumulative precipitation with the dates of precipitation events that generated runoff used for the current study, cropping system timeline and runoff events in 2020, and different P fractions as a % of total P in source soil.

JEQ2-54-382-s001.docx (137.6KB, docx)

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