Soil texture effect on nitrate leaching in soil percolates
ABSTRACT Nitrate nitrogen (NO3‐N), which is an essential source of nitrogen (N) for plant growth, is now also considered a potential pollutant by the Environmental Protection Agency (EPA). This is because excess applied amounts of NO3‐N can move into streams by run‐off and into ground water by leaching, thereby becoming an environmental hazard. Soils have varied retentive properties depending on their texture, organic matter content, and cation exchange capacity (CEC). The purpose of this study was to determine the effect of soil texture on NO3‐N retention to reduce NO3‐N contamination in the environment. A sand, 85:15 sand:peat Greensmix, a loamy sand, and sandy clay loam soils were placed in 2×3 inch metal cylinders and soaked in a 240 ppm solution of NO3‐N for seven days to saturate the soil with NO3 ions. The columns were leached with water to collect 10 soil percolate samples of 50 mL each until a total volume of 500 mL was collected. Nitrate‐N was measured in each 50‐mL aliquot by automated colorimetry. The results showed that soil texture affected the retention of N03‐N in the sand, which adsorbed the least amount of NO3‐N at 119 ppm, followed by the Greensmix at 125 ppm, loamy sand at 149 ppm, and sandy clay loam at 173 ppm. More NO3‐N was released in the first 50 mL of the sand percolate at 63% followed by the Greensmix, loamy sand, and sandy clay loam at 58,46, and 37% NO3‐N released, respectively. Soils with more silt, clay, and organic matter retained more NO3‐N than the straight sand. Therefore, a straight sand would be the poorest of soil types since NO3‐N retention was low.
- SourceAvailable from: CUNEYT GULERCarpathian journal of earth and environmental sciences 01/2012; 7(4):181-188. · 1.50 Impact Factor
- Communications in Soil Science and Plant Analysis 01/2014; 45(5):680-687. · 0.42 Impact Factor
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ABSTRACT: Nitrogen (N) leaching has become a matter of worldwide concern. The objectives of this study were: (1) to use soil columns to investigate the leaching of nitrate ([Formula: see text]), ammonium ([Formula: see text]), and nitrite ([Formula: see text]) from calcareous soils that had received an average of 200 kg(-1) N ha(-1) year(-1) for the previous 30 years and (2) to determine the relationship between soil properties and [Formula: see text], [Formula: see text], and [Formula: see text] leaching. The soils used in this study ranged in texture from clay to sandy loam. Leaching experiments were conducted under saturation conditions and consisted of the collection of 1,047-2,524 mL of leachate (12 pore volumes (PVs)), which was equivalent to 534-1,286 mm from rainfall or irrigation. Losses of [Formula: see text] ranged from 62 to 437 kg ha(-1), while losses of [Formula: see text] and [Formula: see text] ranged from 2.5 to 19.3 kg ha(-1) and 0.1 to 10.6 kg ha(-1), respectively. Leaching rates differed between soil samples. The initial and secondary rate of [Formula: see text] leaching was determined using an exponential model, and it ranged from 2.8 to 14.7 mg kg(-1) PV(-1) and 0.11 to 0.32 mg kg(-1) PV(-1). Greater leaching rates in the initial period could be due to leaching of [Formula: see text] in solution, while the secondary leaching might be attributable to the diffusion-controlled transfer of [Formula: see text] between mobile and immobile liquid phases. Analysis of variance indicated that the effects of soil type on total [Formula: see text] leaching were highly significant (p < 0.001). The results showed that soil [Formula: see text] concentration was positively correlated with the peak concentration of [Formula: see text] (r = 0.86; p < 0.01) and the total [Formula: see text] leached (r = 0.93; p < 0.01). In addition, the total [Formula: see text] leached was positively correlated with silt (r = 0.67; p < 0.05), clay (r = 0.61; p < 0.05), and pH (r = 0.77; p < 0.01), which suggests that soil parameters might be useful indicators of [Formula: see text] and [Formula: see text] leaching from calcareous soils. Nitrate leaching from soils could threaten groundwater supplies, so possible strategies for minimizing [Formula: see text] leaching losses may need to be considered.Environmental Monitoring and Assessment 02/2012; · 1.68 Impact Factor