Comparison of lime- and biochar-mediated pH changes in nitrification and ammonia oxidizers in degraded acid soil
- 773 Downloads
Ca-amendments are recommended for soil fertility enhancement in acid soils. Biochar (Bc) can be used as an alternative for the same purpose. Biochar additions have been reported to alter microbial communities in soils and biogeochemical processes including nitrogen (N) cycling. In a microcosm experiment, we investigated the interactive effects of soil pH, the type of soil amendment (lime or biochar), and the NH4 + supply on net N mineralization and nitrification in degraded acid soil and on the abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA). Soil was incubated under native pH and CaCO3 or biochar-manipulated pH to reach pH 6.2 and 6.8 in the presence or absence of added ammonium for 70 days. Our results showed that Bc had a longer-lasting effect on soil pH than CaCO3, suggesting that Bc could be a preferable liming agent. Increased pH stimulated microbial activity and led to increased N mineralization, which was higher when CaCO3 was applied. Although pH increase and NH4 +-N addition had no immediate effect on nitrification, they synergically enhanced nitrification at the end of the experiment. The amoA gene of AOA consistently outnumbered that of AOB, whereas only AOB amoA gene abundance number was significantly correlated with nitrification and their abundance followed similar trend as NO3 −-N during the incubation. In acid soils where AOB could play a significant role in nitrification, biochar could result in more pronounced changes in N cycle than lime application which could be of especially high interest in intensively managed soils with high N inputs.
KeywordsArchaea Bacteria Liming Net nitrification qPCR
Support for this work was provided by project AGRISOST-CM (S2013/ABI-2717) from the Comunidad de Madrid and cofunded by the ESIF. Dr. Benito acknowledges a grant (PR2015-00046) from the Ministry of Education, Culture and Sport (Spain). Eduardo Vázquez thanks the Ministerio de Economía y Competitividad (Spain) for his FPU fellowship.
- Bremner JM, Mulvaney CS (1982) Nitrogen—total. In: Page AL Miller, RH, DR Keeney (ed) Methods of Soil Analysis. Part 2. Chemical and Microbiological Properties (Agronomy series n 9) ASA. SSSA Madison, Wi, pp 595–624Google Scholar
- Forster JC (1995) Soil nitrogen. In: Alef K NP (ed) Methods in Applied Soil Microbiology and Biochemistry. Academic Press, London, pp 79-87Google Scholar
- Gómez-Paccard C, Mariscal-Sancho I, León P, Benito M, Gonzalez P, Ordonez R, Espejo R, Hontoria C (2013) Ca-amendment and tillage: medium term synergies for improving key soil properties of acid soils. Soil Tillage Res. doi: 10.1016/j.still.2013.08.009
- Okano Y, Hristova KR, Leutenegger CM, Jackson LE, Denison RF, Gebreyesus B, Lebauer D, Scow KM (2004) Application of real-time PCR to study effects of ammonium on population size of ammonia-oxidizing bacteria in soil. Appl Environ Microbiol 70:1008–1016. doi: 10.1128/AEM.70.2.1008-1016.2004 CrossRefPubMedPubMedCentralGoogle Scholar
- Saleh ME, Mahmoud AH, Rashad M (2012) Peanut biochar as a stable adsorbent for removing NH4-N from wastewater: a preliminary study. Adv Environ Biol 6:2170–2176Google Scholar
- Wang Q, Zhang LM, Shen JP, Du S, Han LL, He JZ (2016) Nitrogen fertiliser-induced changes in N2O emissions are attributed more to ammonia-oxidising bacteria rather than archaea as revealed using 1-octyne and acetylene inhibitors in two arable soils. Biol Fertil Soils 52:1163–1171. doi: 10.1007/s00374-016-1151-3 CrossRefGoogle Scholar
- Yao H, Gao Y, Nicol GW, Campbell CD, Prosser JI, Zhang L, Han W, Singh BK (2011b) Links between ammonia oxidizer community structure, abundance, and nitrification potential in acidic soils. Appl Environ Microbiol 77:4618–4625. doi: 10.1128/AEM.00136-11
- Zhang K, Chen L, Li Y, Brookes PC, Xu J, Luo Y (2017) The effects of combination of biochar, lime, and organic fertilizer on nitrification and nitrifiers. Biol Fertil Soils 53:77–87. doi: 10.1007/s00374-016-1154-0