Changes in abundance and composition of nitrifying communities in barley (Hordeum vulgare L.) rhizosphere and bulk soils over the growth period following combined biochar and urea amendment
- 90 Downloads
To understand the effects of biochar and urea on soil N availability and plant growth, we conducted a pot experiment growing barley (Hordeum vulgare L.) under six treatments: control (N0), soil with 30 g kg−1 biochar (N0B), soil with 0.23 g kg−1 urea (N1), soil with 0.23 g kg−1 urea and 30 g kg−1 biochar (N1B), soil with 0.46 g kg−1 urea (N2), and soil with 0.46 g kg−1 urea and 30 g kg−1 biochar (N2B). The nitrifying community abundance and compositions in rhizosphere and bulk soils were analyzed using quantitative polymerase chain reaction (qPCR) and amplicon-based Illumina Hiseq sequencing. Adding urea with biochar (N1B) produced the greatest increase in above- and belowground plant biomass, followed by doubling the amount of urea with biochar (N2B); both treatments raised pH (p < 0.001) and lowered extractable N in the rhizosphere (p < 0.05). N1B treatment produced the greatest increase in ammonia-oxidizing bacteria (AOB) amoA gene copies, presumably because the combined amendment raised soil pH, which favored AOB access to NH4+. Nitrifier sequences were selected after blasting with reported nitrifiers in NCBI (similarity ≥ 97%). Nitrosospira dominated AOB communities during the plant seedling stage; however, during the mature stage, Nitrosomonas dominated over Nitrosospira and the nitrite-oxidizing bacteria (NOB) community became diverse. Redundancy analysis indicated that nitrifying community composition was affected by multiple soil properties, including N availability (i.e., exchangeable NH4+ and NO3−) and soil chemistry (i.e., pH, dissolved organic C, and exchangeable base cations). Our research suggests a positive application of combining biochar with urea in improving N bioavailability and promoting plant growth in the acidic soil.
KeywordsSoil acidity Plant growth Ammonia-oxidizing bacteria (AOB) Nitrite-oxidizing bacteria (NOB) Nitrosospira Nitrosomonas
We are grateful to Prof. Guoping Zhang and his group members Fei Dai and Shengguan Cai (College of Agriculture and Biotechnology, Zhejiang University, China) for donating barley seeds and providing plant technical guidance.
This work was funded by the National Key Research and Development Program of China (2016YFD0200302), the National Natural Science Foundation of China (41520104001), the 111 Project (B17039), and the Fundamental Research Funds for the Central Universities.
- DeLuca TH, Gundale MJ, MacKenzie MD, Jones DL (2015) Biochar effects on soil nutrient transformations. In: Lehmann J, Joseph S (eds) Biochar for environmental management: science, technology and implementation, 2nd edn. Routledge, London, pp 421–454Google Scholar
- Glaser K, Hackl E, Inselsbacher E, Strauss J, Wanek W, Zechmeister-Boltenstern S, Sessitsch A (2010) Dynamics of ammonia-oxidizing communities in barley-planted bulk soil and rhizosphere following nitrate and ammonium fertilizer amendment. FEMS Microbiol Ecol 74:575–591PubMedCrossRefPubMedCentralGoogle Scholar
- Major J, Steiner C, Downie A, Lehmann J (2012) Biochar effects on nutrient leaching. In: Lehmann J, Joseph S (eds) Biochar for environmental management. Routledge, London, pp 303–320Google Scholar
- Okamura K, Takanashi A, Yamada T, Hiraishi A (2012) Ammonia-oxidizing activity and microbial community structure in acid tea (Camellia sinensis) orchard soil. In Journal of Physics: Conference Series 352, 012052. IOP PublishingGoogle Scholar
- Oksanen J, Blanchet FG, Kindt R, Legendre P, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H (2013) Package ‘Vegan’. Community ecology package, version 2Google Scholar
- Paradis E (2011) Analysis of phylogenetics and evolution with R. Springer Science & Business MediaGoogle Scholar
- Subbarao GV, Nakahara K, Hurtado MP, Ono H, Moreta DE, Salcedo AF, Yoshihashi AT, Ishikawa T, Ishitani M, Ohnishi-Kameyama M, Yoshida M, Rondon M, Rao IM, Lascano CE, Berry WL, Ito O (2009) Evidence for biological nitrification inhibition in brachiaria pastures. Proc Natl Acad Sci 106:17302–17307PubMedCrossRefPubMedCentralGoogle Scholar
- Xu X, Liu X, Li Y, Ran Y, Liu Y, Zhang Q, Li Z, He Y, Xu J, Di H (2017) High temperatures inhibited the growth of soil bacteria and archaea but not that of fungi and altered nitrous oxide production mechanisms from different nitrogen sources in an acidic soil. Soil Biol Biochem 107:168–179CrossRefGoogle Scholar
- Yu L, Yu M, Lu X, Tang C, Liu X, Brookes PC, Xu J (2018) Combined application of biochar and nitrogen fertilizer benefits nitrogen retention in the rhizosphere of soybean by increasing microbial biomass but not altering microbial community structure. Sci Total Environ 640:1221–1230PubMedCrossRefPubMedCentralGoogle Scholar