Microbial functional diversity responses to 2 years since biochar application in silt-loam soils on the Loess Plateau

Li-Xia Zhu; Qian Xiao; Yu-Fang Shen; Shi-Qing Li

doi:10.1016/j.ecoenv.2017.06.075

Microbial functional diversity responses to 2 years since biochar application in silt-loam soils on the Loess Plateau

Ecotoxicol Environ Saf. 2017 Oct:144:578-584. doi: 10.1016/j.ecoenv.2017.06.075. Epub 2017 Jul 5.

Authors

Li-Xia Zhu¹, Qian Xiao², Yu-Fang Shen³, Shi-Qing Li⁴

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China; College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China. Electronic address: justin2118@163.com.
² State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China; College of Forestry, Northwest A&F University, Yangling 712100, China.
³ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China. Electronic address: shenyufang@nwsuaf.edu.cn.
⁴ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China.

PMID: 28688360
DOI: 10.1016/j.ecoenv.2017.06.075

Abstract

The structure and function of soil microbial communities have been widely used as indicators of soil quality and fertility. The effect of biochar application on carbon sequestration has been studied, but the effect on soil microbial functional diversity has received little attention. We evaluated effects of biochar application on the functional diversities of microbes in a loam soil. The effects of biochar on microbial activities and related processes in the 0-10 and 10-20cm soil layers were determined in a two-year experiment in maize field on the Loess Plateau in China. Low-pyrolysis biochar produced from maize straw was applied into soils at rates of 0 (BC0), 10 (BC10) and 30 (BC30)tha^-1. Chemical analysis indicated that the biochar did not change the pH, significantly increased the amounts of organic carbon and nitrogen, and decreased the amount of mineral nitrogen and the microbial quotient. The biochar significantly decreased average well colour development (AWCD) values in Biolog EcoPlates™ for both layers, particularly for the rate of 10tha^-1. Biochar addition significantly decreased substrate richness (S) except for BC30 in the 0-10cm layer. Effects of biochar on the Shannon-Wiener index (H) and Simpson's dominance (D) were not significant, except for a significant increase in evenness index (E) in BC10 in the 10-20cm layer. A principal component analysis clearly differentiated the treatments, and microbial use of six categories of substrates significantly decreased in both layers after biochar addition, although the use of amines and amides did not differ amongst the three treatments in the deeper layer. Maize above ground dry biomass and height did not differ significantly amongst the treatments, and biochar had no significant effect on nitrogen uptake by maize seedlings. H was positively correlated with AWCD, and negatively with pH. AWCD was positively correlated with mineral N and negatively with pH. Our results indicated that shifts in soil microbial functional diversity affected by biochar were not effective indicators of soil quality in earlier maize growth periods in this region.

Keywords: Agroecosystem; Biochar; Biolog EcoPlates™; Functional diversity; Soil microbial community.

MeSH terms

Biomass
Charcoal / chemistry*
China
Nitrogen / metabolism
Principal Component Analysis
Soil / chemistry*
Soil Microbiology / standards*
Zea mays / growth & development*
Zea mays / metabolism

Substances

Soil
biochar
Charcoal
Nitrogen