Article

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

ABSTRACT

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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    • "In recent years evidence has been accumulated that biochars of various types may reduce N 2 O emissions from soils (Ameloot et al. 2013a; Case et al. 2012; Chintala et al. 2015; Kammann et al. 2012; Spokas and Reicosky 2009; Van Zwieten et al. 2009; Yanai et al. 2007). A number of mechanisms for this N 2 O emission reduction have been proposed, such as the capacity of biochar to shuttle electrons (Cayuela et al. 2013; Kappler et al. 2014), increase the soil pH (Van Zwieten et al. 2009), adsorb denitrification substrates (Clough et al. 2013; LeCroy et al. 2013; Yao et al. 2012) and change the soil structure (Van Zwieten et al. 2009; Yanai et al. 2007), without a clear conclusion to date. The mechanisms investigated in this paper involving a control of biochar over N 2 O emissions are twofold, viz. 1) biochar-induced improvements of soil aeration and 2) the stimulation of the last denitrificaiton step. "
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    Full-text · Article · Apr 2016 · Geoderma
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    • "The high release of cations and anions from BCs, especially those produced at 700 °C, could be related to the presence of soluble salts (as seen in high EC values in Table 2), since they were not subjected to washing after pyrolysis. Therefore, BCs can serve to replenish and retain exchangeable nutrient ions such as Ca, Mg, NO 3 , and PO 4 in the amended soils (Yao et al. 2012). "
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