Soil nitrification and nitrogen mineralization responded non-linearly to the addition of wood biochar produced under different pyrolysis temperatures

Autor: Zakaria Karim, Juan Zhan, Dianjie Wang, Ashrafun Nessa, Zhihong Xu, Shahla Hosseini Bai, Negar Omidvar
Rok vydání: 2021
Předmět:
Zdroj: Journal of Soils and Sediments. 21:3813-3824
ISSN: 1614-7480
1439-0108
DOI: 10.1007/s11368-021-03077-9
Popis: Purpose: Nitrogen (N) cycle is one of the key biogeochemical cycles in terrestrial ecosystems. Global climate change and soil management practices have disrupted the soil N cycling processes due to increased water and N limitations. Biochar is a soil amendment and improves soil–plant water and N retentions. However, it is uncertain to what extent biochar pyrolysis temperature would affect soil N transformations under two soil moisture regimes. This study aimed to explore how pyrolysis temperature would affect biochar properties and subsequently soil N transformations through a short-term laboratory incubation study at two moisture levels. Materials and methods: An incubation study was carried out for 5 days. Biochar added to the soil at a rate of 5% (w/w) was produced under six different pyrolysis temperatures (e.g., 500, 600, 650, 700, 750, and 850 °C). We used 15N natural abundance (δ15N) of inorganic N (NH4+-N and NO3−-N) to assess the potential of biochar materials in facilitating forest soil N transformations at two different soil moisture levels of 50% and 65% water holding capacity (WHC). Results and discussion: Pyrolysis temperature significantly increased cumulative nitrification and N mineralization initially, peaked between 600 and 700 °C and decreased thereafter. However, both cumulative nitrification and N mineralization were significantly lower in the biochar-amended soils than those of the control soil, with significantly lower δ15N of NH4+-N and δ15N of NO3−-N. The 65% WHC had higher cumulative nitrification and N mineralization compared with those in 50% WHC. This study highlights that application of biochar would reduce N losses and improve soil N retention particularly for forest soil. Conclusions: The present study highlights the importance of biochar pyrolysis temperatures for their use as soil conditioner to increase soil N retention. An optimum pyrolysis temperature range of 600–700 °C was identified for improving soil nitrification and N mineralization under the laboratory incubation conditions.
Databáze: OpenAIRE
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