Phosphorus saturation and superficial fertilizer application as key parameters to assess the risk of diffuse phosphorus losses from agricultural soils in Brazil

ABSTRACTNaturally occurring radionuclides can also end up in soils and groundwater due to human practices, such as application of certain fertilizers in agriculture. Many mineral fertilizers, particularly (super)phosphates, contain small amounts of 238U and 230Th which eventually may be leached from agricultural soils to underlying water resources. Field soils that receive P-fertilizers accumulate U and Th and their daughter nuclides, which eventually may leach to groundwater. Our objective was to numerically assess U migration in soils. Calculations were based on a new reactive transport model, HP1, which accounts for interactions between U and organic matter, phosphate, and carbonate. Solid phase interactions were simulated using a surface complexation module. Furthermore, all geochemical processes were coupled with a model accounting for dynamic changes in the soil water content and the water flux. The capabilities of the code in calculating natural U fluxes to groundwater were illustrated using a semi-synthetic 200-year long time series of climatological data for Belgium. Based on an average fertilizer application, the input of phosphate and uranium in the soil was defined. This paper discusses calculated U distributions in the soil profile as well as calculated U fluxes leached from a 100-cm deep soil profile. The calculated long-term leaching rates originating from fertilization are significantly higher after 200 years than estimated release rates from lowlevel nuclear waste repositories.

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Influence of long-term mineral fertilization on metal contents and properties of soil samples taken from different locations in Hesse, Germany

SOIL ◽

10.5194/soil-1-23-2015 ◽

2015 ◽

Vol 1 (1) ◽

pp. 23-33 ◽

Cited By ~ 40

Author(s):

S. Czarnecki ◽

R.-A. Düring

Keyword(s):

Cation Exchange ◽

Cation Exchange Capacity ◽

Agricultural Soils ◽

Mineral Fertilizer ◽

Fertilizer Application ◽

Exchange Capacity ◽

Soil Samples ◽

Residual Effects ◽

Metal Contents

Abstract. Essential and non-essential metals occur in soils as a result of weathering, industrial processes, fertilization, and atmospheric deposition. Badly adapted cultivation of agricultural soils (declining pH value, application of unsuitable fertilizers) can enhance the mobility of metals and thereby increase their concentrations in agricultural products. As the enrichment of metals in soils occurs over long time periods, monitoring of the long-term impact of fertilization is necessary to assess metal accumulation in agricultural soils. The main objective of this study was to test the effects of different mineral fertilizer variations on soil properties (pH, Corg, and cation exchange capacity (CEC)) and pseudo-total and mobile metal contents of soils after 14 years of fertilizer application and to determine residual effects of the fertilization 8 years after cessation of fertilizer treatment. Soil samples were taken from a field experiment which was carried out at four different locations (210, 260, 360, and 620 m above sea level) in Hesse, Germany. During the study, a significant decrease in soil pH and an evident increase in soil carbon content and cation exchange capacity with fertilization were determined. The CEC of the soils was closely related to their organic C contents. Moreover, pseudo- and mobile metal (Cd, Cu, Mn, Pb, Zn) contents in the soils increased due to application of 14 years of mineral fertilizer treatments (N, P, NP, and NPK) when compared to control plots. Eight years after termination of the fertilization in the soil samples taken from soil profiles of the fertilized plots (NPK) for monitoring the residual effects of the fertilizer application, a decrease of 82.6, 54.2, 48.5, 74.4, and 56.9% in pseudo-total Cd, Cu, Mn, Pb, and Zn contents, respectively, was determined.

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Modelling Phosphorus Losses from Tropical Agricultural Soils in Gilgel Gibe Watershed, Ethiopia

Journal of Pollution Effects & Control ◽

10.4172/2375-4397.1000141 ◽

2015 ◽

Vol 03 (02) ◽

Cited By ~ 1

Author(s):

Yalemsew Adela

Keyword(s):

Agricultural Soils ◽

Phosphorus Losses

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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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IMPACT OF ELEMENTAL SULFUR FERTILIZATION ON AGRICULTURAL SOILS. I. EFFECTS ON MICROBIAL BIOMASS AND ENZYME ACTIVITIES

Canadian Journal of Soil Science ◽

10.4141/cjss88-045 ◽

1988 ◽

Vol 68 (3) ◽

pp. 463-473 ◽

Cited By ~ 30

Author(s):

V. V. S. R. GUPTA ◽

J. R. LAWRENCE ◽

J. J. GERMIDA

Keyword(s):

Microbial Biomass ◽

Elemental Sulfur ◽

Agricultural Soils ◽

Microbial Biomass Carbon ◽

Fertilizer Application ◽

Biomass Carbon ◽

Repeated Application ◽

Organic C ◽

The Impact ◽

Sulfur Fertilization

This study investigated the impact of repeated application of S° fertilizer on microbial and biochemical characteristics of two Grey Luvisolic soils. The Waitville pasture plots received Agri-Sul at a rate of 22 or 44 kg S° ha−1 yr−1 for 5 yr, whereas the Loon River canola-summerfallow plots received single or double applications of Flow-able Sulfur (50 kg S° ha−1) or Agri-Sul (100 kg S° ha−1). Application of S° fertilizer significantly decreased the pH in both soils. Organic C declined in S°-treated plots of the Waitville soil, and there was a narrowing of C:N:S ratios in both soils. Application of S° fertilizer significantly increased the total S, HI-S and sulfate sulfur levels of both soils. There was a 29–45% and 2–51% decline in microbial biomass carbon content due to S° fertilizer application in Waitville and Loon River soils, respectively. Repeated application of S° also resulted in a decline in respiration, dehydrogenase, urease, alkaline phosphatase and arylsulfatase activities, along with populations of protozoa, algae and nitrifiers in both soils. Significant correlations observed among related characteristics further emphasized the treatment effects. These results indicate that the impact of repeated application of S° fertilizer on microbial biomass and activity should be considered when recommending S° as a fertilizer for sulfur-deficient soils. Key words: Sulfur (elemental), microbial biomass, dehydrogenase, urea, phosphomonoesterases, arylsulfatase

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Simulated effects of gypsum amendment on phosphorus losses from agricultural soils

Agricultural and Food Science ◽

10.23986/afsci.6773 ◽

2012 ◽

Vol 21 (3) ◽

pp. 292-306 ◽

Cited By ~ 8

Author(s):

Elina Jaakkola ◽

Sirkka Tattari ◽

Petri Ekholm ◽

Liisa Pietola ◽

Maximilian Posch ◽

...

Keyword(s):

Field Experiments ◽

Clayey Soil ◽

Agricultural Soils ◽

Macropore Flow ◽

Modified Model ◽

Four Seasons ◽

Complex Process ◽

Phosphorus Losses ◽

The Impact ◽

Total P

Our objective was to incorporate the effects of gypsum on phosphorus (P) losses into the field-scale ICECREAM model and to simulate the treatment of 93 ha of clayey soil with gypsum in a catchment located in southern Finland. In addition to the gypsum effects, a macropore flow description was added to ICECREAM. First, a sensitivity analysis was performed for the new macropore parameters, retrieved from a literature survey. After this, the model was calibrated for a reference period by setting of the macropore parameters to correspond to the P losses observed in the catchment experiment. Next, the effect of gypsum was added to the model in line with laboratory and field experiments that suggested decreased P losses and changed hydraulic properties of the soil. Finally, the modified model was verified for four seasons after the gypsum amendment in the catchment experiment. The model was able to simulate the P losses in three out of the four seasons. According to the simulations, gypsum reduced total P losses by 44%. Although the effect of gypsum on P and erosion is a complex process, our relatively simple modifications to the ICECREAM model described the impact with reasonable accuracy. However, to increase confidence in the performance of the model, it should be tested under other environmental conditions.

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