Does biochar affect the availability and chemical fractionation of phosphate in soils?
Biochar as a soil amendment has been reported to affect the content and availability of soil nutrients. In this study, we aimed to test whether the biochar addition to soils would change the availability and chemical fractionation of phosphate in soils. Two soils (Ultisol and Alfisol) were amended with five kinds of biochars at application rate of 0, 1, and 2% (w/w). After 3-month incubation, availability and chemical forms of P were measured to investigate the potential effect and role of biochar in improving P availability in soils. The biochars used here had a lager variation of P content, depending on their feedstocks. Compared to the untreated soils, application of biochars derived from deciduous tree leaves (DLB), reed (RB), and rice straw (RSB) significantly increased the pH of two soils. The total P content of biochar-amended soils was increased with the addition of biochars. However, only RSB exhibited a significant increase (p < 0.05) of total P content. Application of biochars significantly increased the NH4Cl-extractable P content of two soils, indicating that biochars were able to increase the availability of phosphate in soils, but the amount of available P was dependent on biochar types. Ultisol and Alfisol amended with RSB (2% w/w) showed an increase in the P availability (0.5 M NaHCO3-extractable P) by 46 and 39%, respectively. For strongly acidic Ultisol, addition of biochar significantly increased Al-P and Ca-P content, as well as decreased Fe-P content. The P desorption test indicated the release of P from soils increased with the addition of biochar. Results suggested that biochar would change the P sorption affinity of the soil and help to increase the availability of fixed P. The increase of P availability with biochar application was due to the pH change and direct P contribution from biochar. Our results concluded that biochar affected the availability, chemical forms, and sorption capability of phosphate in soil. The extent of biochar effects on soil P varied greatly with the type of feedstock of biochar and soil type.
KeywordsBiochar Phosphate Olsen-P Chemical form Soil pH
This research was supported by the National Key Research & Development Program of China (2016YFD0200302).
- Agbenin JO (1995) Phosphorus sorption by three cultivated savanna Alfisols as influenced by pH. Nutr Cycl Agroecosyst 44:107–112Google Scholar
- Bao SD (2000) Soil and agricultural chemistry analysis (in Chinese). China Agricultural Press, BeijingGoogle Scholar
- Chintala R, Schumacher TE, McDonald LM, Clay DE, Malo DD, Papiernik SK, Clay SA, Julson JL (2014) Phosphorus sorption and availability from biochars and soil/biochar mixtures. Clean: Soil Air Water 42:626–634Google Scholar
- DeLuca TH, Mackenzie MD, Gundale MJ (2009) Biochar effects on soil nutrient transformations. In: Lehmann J, Joseph S (eds) Biochar for environmental management: science and technology. Earthscan, London, pp 250–270Google Scholar
- Kloss S, Zehetner F, Dellantonio A, Hamid R, Ottner F, Liedtke V, Schwanninger M, Gerzabek MH, Soja G (2012) Characterization of slow pyrolysis biochars: effects of feedstocks and pyrolysis temperature on biochar properties. J Environ Qual 41(4):990–1000. https://doi.org/10.2134/jeq2011.0070 CrossRefGoogle Scholar
- Kumari K, Moldrup P, Paradelo M, Elsgaard L, Hauggaard-Nielsen H, de Jonge LW (2014) Effects of biochar on air and water permeability and colloid and phosphorus leaching in soils from a natural calcium carbonate gradient. J Environ Qual 43(2):647–657. https://doi.org/10.2134/jeq2013.08.0334 CrossRefGoogle Scholar
- Lu RK (1999) Analytical methods of soil agrochemistry (in Chinese). China Agricultural Science and Technology Publishing House, BeijingGoogle Scholar
- Nelson NO, Agudelo SC, Yuan W, Gan J (2011) Nitrogen and phosphorus availability in biochar-amended soils. Soil Sci 176:218–226Google Scholar
- Peng F, He PW, Luo Y, Lu X, Liang Y, Fu J (2012) Adsorption of phosphate by biomass char deriving from fast pyrolysis of biomass waste. Clean: Soil Air Water 40:493–498Google Scholar
- Soil Survey Staff (2010) Keys to soil taxonomy, 11th edn. USDA Natural Resources Conservation Service, Washington, DCGoogle Scholar
- Uzoma KC, Inoue M, Andry H, Zahoor A, Nishihara E (2011) Influence of biochar application on sandy soil hydraulic properties and nutrient retention. J Food Agric Environ 9:1137–1143Google Scholar