Open Access

ARTICLE

Influence of Biochar on Nitrogen Use Efficiency and Root Morphology of Rice-Seedling in Two Contrasting Paddy Soils

Lei Chu^1,2, Yu Zhang^1,2, Long Qian^1,2, Dandan Zhu^1,2, Haijun Sun^1,2,*

1 Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China
2 Key Laboratory of Soil and Water Conservation and Ecological Restoration of Jiangsu Province, Nanjing Forestry University, Nanjing, 210037, China

* Corresponding Author: Haijun Sun. Email:

Phyton-International Journal of Experimental Botany 2020, 89(4), 1035-1042. https://doi.org/10.32604/phyton.2020.014506

Received 03 October 2020; Accepted 14 October 2020; Issue published 09 November 2020

Abstract

Biochar may affect the root morphology and nitrogen (N) use efficiency (NUE) of rice at seedling stage, which has not been clearly verified until now. To clarify it, we conducted a pot experiment regarding to two soil types (Hydragric Anthrosol and Haplic Acrisol), two biochar application rates (0.5 wt% and 1.5 wt %) and two rice varieties (common rice var. Xiushui134 and hybrid super rice var. Zhongkejiayou12-6) meanwhile. Seedling NUE of common rice Xiuhui134 was significantly increased (p < 0.05) by 78.2% in Hydragric Anthrosol and by 91.4% in Haplic Acrisol following biochar addition with 1.5 wt%. However, biochar addition exerted no influence on seedling NUE of super rice Zhongkejiayou12-6 in both soils. Overall, 0.09–0.10 units higher soil pH and 105– 116% higher soil NH₄⁺ -N were observed in Xiushui134 growing two soils with 1.5 wt% biochar. In addition, improved root morphology (including longer root length, larger root surface area, bigger root volume, and more root tips) contributed to the higher seedling NUE of Xiushui134 in two soils. The soil pH and NH₄⁺ -N content, also the root morphology were influenced by biochar, which though could not thoroughly explained the NUE of Zhongkejiayou12-6. In conclusion, biochar application to paddy soil changed soil pH and NH₄⁺ -N content, root growth, and the consequent seedling NUE of rice, which effects are relative with rice cultivar, biochar addition rate, and soil type.

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