The degree of phosphorus saturation of agricultural soils in Germany: Current and future risk of diffuse P loss and implications for soil P management in Europe

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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A comparison of nutrient losses to waters following pasture renewal by cultivation or direct-drilling

Journal of New Zealand Grasslands ◽

10.33584/jnzg.2016.78.524 ◽

2016 ◽

Vol 78 ◽

pp. 93-98

Author(s):

L.C. Smith ◽

R.W. Mcdowell ◽

G.P. Cosgrove

Keyword(s):

Surface Runoff ◽

Agricultural Soils ◽

Bare Soil ◽

Conventional Tillage ◽

Catchment Scale ◽

Buffer Strip ◽

Soil P ◽

P Loss ◽

Direct Drilling ◽

Plough Layer

Agricultural soils enriched in phosphorus (P) have been linked to increases in P losses and declining water quality. Cultivation of pastures near sensitive waterways lowers surface soil P and therefore the concentration of P in surface runoff. However, such a practise can increase the mineralisation of organic nitrogen (N), negating this as a mitigation option for N sensitive catchments. A field trial was set up to compare pasture renewal using either direct-drilling or cultivation (which mixed the plough layer to 150 mm) on hydraulically-isolated runoff plots at Tussock Creek near Invercargill, Southland. The trial ran from March to December 2015. Soil P concentrations (0-150 mm depth) decreased in the cultivated plots by about 20%, 8 months after cultivation. Concentrations of nitrate-N in surface runoff and shallow drainage, and P in shallow drainage only, were not different between directdrilling and cultivation treatments. Cultivation reduced filterable reactive P (FRP) losses in surface runoff by 69% (P=0.047) compared to direct-drilled plots. This study showed that mixing P within the plough layer decreased P loss over the 10 months of measurement. Conventional tillage that inverts the plough layer may result in even larger decreases in soil P concentrations. Tillage can therefore be used as a strategy to decrease P loss in small areas where surface runoff is likely, with little risk of increasing catchment-scale N loss. This includes near stream areas, but care must be taken to leave an adequate buffer strip to prevent sediment (and P) loss via erosion of bare soil. Keywords: phosphorus-enriched soil, cultivation, direct-drilling, runoff, drainage

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Estimation of the degree of soil P saturation from Brazilian Mehlich-1 P data and field investigations on P losses from agricultural sites in Minas Gerais

Water Science & Technology ◽

10.2166/wst.2016.169 ◽

2016 ◽

Vol 74 (3) ◽

pp. 691-697 ◽

Cited By ~ 3

Author(s):

P. Fischer ◽

R. Pöthig ◽

B. Gücker ◽

M. Venohr

Keyword(s):

Risk Assessment ◽

Agricultural Soils ◽

Soil Surface ◽

Minas Gerais ◽

Water Soluble ◽

Soil P ◽

Binding Partners ◽

Field Investigations ◽

Degree Of Phosphorus Saturation ◽

Agricultural Areas

The degree of phosphorus saturation (DPS) of agricultural soils is studied worldwide for risk assessment of phosphorus (P) losses. In previous studies, DPS could be reliably estimated from water-soluble P (WSP) for European and Brazilian soils. In the present study, we correlated measured WSP and Mehlich-1 P (M1P) from soils of Minas Gerais (MG) and Pernambuco (PE) (R2 = 0.94, n = 59) to create a DPS map from monitoring data. The resulting DPS map showed high spatial variability and low values of DPS (54 ± 22%, mean and standard deviation; n = 1,827). Measured soil DPS values amounted to 63 ± 14% and resulted in relatively low dissolved P concentrations measured in a surface runoff study in MG. However, fertilizer grains on the soil surface led to high WSP values (>30 mg/kg) indicating high risks of dissolved P losses. We suppose that small Oxisol particles with Fe and Al hydroxides sorbed most of the dissolved fertilizer P in runoff so that P was mainly exported in particulate form. In soils with lower contents of P sorption and binding partners, e.g. Entisols in PE, this effect may be less dominant. Consequently, superficial fertilizer effects have to be considered in addition to DPS in risk assessment of P losses from agricultural areas in Brazil.

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Changes in degree of phosphorus saturation and risk of P loss upon twelve years of manuring and reduced tillage

Geoderma ◽

10.1016/j.geoderma.2021.115277 ◽

2021 ◽

Vol 404 ◽

pp. 115277

Author(s):

Satya Narayana Pradhan ◽

A.K. Ghosh ◽

Seema ◽

Shankar Ram ◽

Yogesh Pal ◽

...

Keyword(s):

Reduced Tillage ◽

P Loss ◽

Degree Of Phosphorus Saturation ◽

Phosphorus Saturation

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Finnish trends in phosphorus balances and soil test phosphorus

Agricultural and Food Science ◽

10.2137/145960607784125339 ◽

2008 ◽

Vol 16 (4) ◽

pp. 301 ◽

Cited By ~ 18

Author(s):

R. UUSITALO ◽

E. TURTOLA ◽

J. GRÖNROOS

Keyword(s):

Agricultural Soils ◽

Animal Production ◽

Plant Production ◽

Major Influence ◽

Soil Test ◽

P Loss ◽

P Concentration ◽

Soil Test P ◽

Soil Test Phosphorus ◽

Yield Responses

Soil test phosphorus (P) concentration has a major influence on the dissolved P concentration in runoff from agricultural soils. Thus, trends in soil test P partly determine the development of pollution potential of agricultural activities. We reviewed the changes of soil test P and P balances in Finnish agriculture, and assessed the current setting of P loss potential after two Agri-Environmental Programs. Phosphorus balance of the Finnish agriculture has decreased from +35 kg ha1 of the 1980s to about +8 kg P ha1 today. As a consequence, the 50-yr upward trend in soil test P concentrations has probably levelled out in the late 1990s, as suggested by sampling of about 1600 fields and by a modelling exercise. For the majority of our agricultural soils, soil test P concentrations are currently at a level at which annual P fertilization is unlikely to give measurable yield responses. Soils that benefit from annual P applications are more often found in farms specialized in cereal production, whereas farms specialized in non-cereal plant production and animal production have higher soil test P concentrations. An imbalance in P cycling between plant (feed) and animal production is obvious, and regional imbalances are a result of concentration of animal farms in some parts of the country. A major concern in future will be the fate of manure P in those regions where animal production intensity is further increasing.;

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Influence of soil texture on fertilizer and soil phosphorus transformations in Gleysolic soils

Canadian Journal of Soil Science ◽

10.4141/s02-073 ◽

2003 ◽

Vol 83 (4) ◽

pp. 395-403 ◽

Cited By ~ 16

Author(s):

Z. Zheng ◽

L. E. Parent ◽

J. A. MacLeod

Keyword(s):

Soil Texture ◽

Agricultural Soils ◽

Sandy Loam ◽

Clay Content ◽

P Uptake ◽

Hordeum Vulgare L ◽

P Fractionation ◽

Soil P ◽

Plant P Uptake ◽

Heavy Clay

The P dynamics in soils should be quantified in agricultural soils to improve fertilizer P (FP) efficiency while limiting the risk of P transfer from soils to water bodies. This study assessed P transformations following FP addition to Gleysolic soils. A pot experiment was conducted with five soils varying in texture from sandy loam to heavy clay, and receiving four FP rates under barley (Hordeum vulgare L.)-soybean (Glycine max L.) rotations. A modified Hedley procedure was used for soil P fractionation. Soil resin-P and NaHCO3-Pi contents were interactively affected by texture and FP. The NaHCO3-Po, NaOH-Po, HCl-P and H2SO4-P were only affected by soil texture. Proportions of 78 and 90% of the variation in labile and total P were, respectively, related to soil clay content. The FP addition increased resin-P, NaHCO3-Pi and NaOH-Pi and -Po contents in coarse-textured soils, but the amount added was not sufficient to mask the initial influence of soil texture on the sizes of soil P pools. Plant P uptake was proportional to FP rate but less closely linked to clay content. The average increase in labile P per unit of total FP added in excess of plant exports was 0.85, 0.8 2 , 0.73, 0.55 and 0.24 for the sandy loam, loam, clay loam, clay and heavy clay soil, respectively. The results of this study stress the important of considering soil texture in Gleysolic soils when assessing P accumulation and transformations in soils, due to commercial fertilizers applied in excess of crop removal. Key words: P fractions, clay content, fertilizer P, plant P uptake, soil texture

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Development of Pedotransfer Functions to Quantify Phosphorus Saturation of Agricultural Soils

Journal of Environmental Quality ◽

10.2134/jeq1999.00472425002800060044x ◽

1999 ◽

Vol 28 (6) ◽

pp. 2026-2030 ◽

Cited By ~ 36

Author(s):

Peter J. A. Kleinman ◽

R. B. Bryant ◽

W. S. Reid

Keyword(s):

Agricultural Soils ◽

Pedotransfer Functions ◽

Phosphorus Saturation

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Phosphorus forms and their distribution under long-term no tillage systems

Plant Soil and Environment ◽

10.17221/270/2018-pse ◽

2019 ◽

Vol 65 (No. 1) ◽

pp. 35-40

Author(s):

Kai Wei ◽

Zhenhua Chen ◽

Xiaoping Zhang ◽

Lijun Chen

Keyword(s):

Management Practice ◽

Crop Growth ◽

No Tillage ◽

Soil P ◽

P Loss ◽

Phosphorus Forms ◽

Significant Difference ◽

Mouldboard Plough ◽

P Fertilizers

Phosphorus (P) stratification in no-tillage (NT) systems has important implications for crop growth and potential P loss, but little is known about P forms and their distribution when mineral P fertilizers are placed to the depth of 5 cm in NT soil. A 10-year field experiment was used to study the effect of NT and mouldboard plough (MP) on soil P forms at three depths (0–5, 5–10 and 10–20 cm) and their relationship with Fe and Al oxides. The results indicated that stratification of organic P forms occurred under NT treatment, and Fe oxides may have a stronger capacity for adsorbing the P forms. When mineral P fertilizers were placed to the depth of 5 cm under NT treatment, there was no significant difference in P forms or crop yield between NT and MP treatment, and orthophosphate did not show any significant difference under NT treatment between 0–5 cm and 5–10 cm depth. Overall, the agricultural management practice that mineral P fertilizers are placed to the depth of 5 cm under NT treatment could result in stratification of P forms, while the changes in the distribution of P forms in soil profiles might help reduce potential P loss in surface runoff and do not make any difference to crop growth.

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