Effect of biochar amendment on sorption and leaching of nitrate, ammonium, and phosphate in a sandy soil

Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, United States.
Chemosphere (Impact Factor: 3.34). 07/2012; 89(11):1467-71. DOI: 10.1016/j.chemosphere.2012.06.002
Source: PubMed


When applied to soils, it is unclear whether and how biochar can affect soil nutrients. This has implications both to the availability of nutrients to plants or microbes, as well as to the question of whether biochar soil amendment may enhance or reduce the leaching of nutrients. In this work, a range of laboratory experiments were conducted to determine the effect of biochar amendment on sorption and leaching of nitrate, ammonium, and phosphate in a sandy soil. A total of thirteen biochars were tested in laboratory sorption experiments and most of them showed little/no ability to sorb nitrate or phosphate. However, nine biochars could remove ammonium from aqueous solution. Biochars made from Brazilian pepperwood and peanut hull at 600°C (PH600 and BP600, respectively) were used in a column leaching experiment to assess their ability to hold nutrients in a sandy soil. The BP600 biochar effectively reduced the total amount of nitrate, ammonium, and phosphate in the leachates by 34.0%, 34.7%, and 20.6%, respectively, relative to the soil alone. The PH600 biochar also reduced the leaching of nitrate and ammonium by 34% and 14%, respectively, but caused additional phosphate release from the soil columns. These results indicate that the effect of biochar on the leaching of agricultural nutrients in soils is not uniform and varies by biochar and nutrient type. Therefore, the nutrient sorption characteristics of a biochar should be studied prior to its use in a particular soil amendment project.

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Available from: Andrew R Zimmerman, Aug 29, 2014
    • "Several studies have examined nutrient retention by biochars produced from a range of parent materials (Lehmann et al., 2003; Ding et al., 2010; Laird et al., 2010; Yao et al., 2012). Thirteen different biochars showed little or no absorption of nitrate or phosphate , although nine of those tested removed aqueous ammonium from solution (Yao et al., 2012). "

    Scientia Horticulturae 10/2015; DOI:10.1016/j.scienta.2015.10.021 · 1.37 Impact Factor
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    • "Similarly, biochar application at all the levels of tannery wastes significantly increased soil nitrogen (p<0.05). Some researchers showed that biochar application can increase the uptake and efficiency of nitrogen fertilizers in soil as a result of lowering nitrogen leaching and also by affecting the soil nitrogen cycle (Yao et al., 2012). The positive results of biochar have been described more fully for acidic soils and tropical areas; but there are not many studies done in respect to the biochar effect in alkaline soil and application thereof together with tannery wastes. "
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    ABSTRACT: Tannery wastes can be used in soil as organic manure. The aim of this research was to study the effects of tannery wastes (before a chromium addition step) and biochar on soil chemical and physicochemical properties and radish yield. Treatments included three levels of tannery waste (0, 2.5, and 5%) and two levels of biochar (0 and 2.5 t ha-1) in a completely randomized design (factorial) with three replications. The treated pots were kept under field capacity condition for three months; thereafter, five radish seeds were sown at 1 cm depth in soil of each pot. The results showed that tannery wastes and biochar treatments resulted in an increase in soil nitrogen and phosphorus contents and their concentrations in radish root and above ground biomass, but electrical conductivity of soil was decreased and had no effect on soil potassium content. The tannery waste treatment increased soil pH after plant harvest. It also significantly increased radish fresh and dry matter weight, but the biochar treatment yielded a slight increase. It is concluded that application of tannery wastes and biochar may be useful due to their high nutrient contents in soils lacking organic carbon under arid and semi-arid regions, thereby improving growth and increasing plant yield.
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    • "Ammonium retention by biochar may be readily explained by electrostatic adsorption to negatively charged oxygen-containing surface functional groups (Cheng et al., 2006; Hale et al., 2013). Freshly produced biochars typically have very low ability to adsorb ammonium (Yao et al., 2012). Over time, biochar surfaces are oxidized and cation retention increases (Cheng et al., 2008, 2014), to levels greater than other organic matter in soils (Liang et al., 2006). "
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