Switchgrass Biochar Effects on Plant Biomass and Microbial Dynamics in Two Soils from Different Regions

作     者：Charlene N.KELLY Francisco C.CALDERóN Verónica ACOSTA-MARTíNEZ Maysoon M.MIKHA Joseph BENJAMIN David W.RUTHERFORD Colleen E.ROSTAD 

作者机构：Western Carolina UniversityDepartment of Geosciences and Natural Resources331 Stillwell HallCullowheeNC 28723 (USA) U.S.Geological SurveyDenver CO 80225 (USA) USDA-ARSAkron CO 80720 (USA) USDA-ARSLubbock TX 79403 (USA) 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2015年第25卷第3期

页      面：329-342页

核心收录：

学科分类：0818[工学-地质资源与地质工程] 09[农学] 090101[农学-作物栽培学与耕作学] 0903[农学-农业资源与环境] 0901[农学-作物学] 

主　　题：微生物群落结构 植物生物量 生物炭 柳枝稷 地上部生物量 弗吉尼亚州 土壤功能 土壤类型 

摘      要：Biochar amendments to soils may alter soil function and fertility in various ways, including through induced changes in the microbial community. We assessed microbial activity and community composition of two distinct clayey soil types, an Aridisol from Colorado(CO) in the U.S. Central Great Plains, and an Alfisol from Virginia(VA) in the southeastern USA following the application of switchgrass(Panicum virgatum) biochar. The switchgrass biochar was applied at four levels, 0%, 2.5%, 5%, and 10%, approximately equivalent to biochar additions of 0, 25, 50, and 100 t ha-1, respectively, to the soils grown with wheat(Triticum aestivum) in an eight-week growth chamber experiment. We measured wheat shoot biomass and nitrogen(N) content and soil nutrient availability and N mineralization rates, and characterized the microbial fatty acid methyl ester(FAME) profiles of the soils. Net N mineralization rates decreased in both soils in proportion to an increase in biochar levels, but the effect was more marked in the VA soil, where net N mineralization decreased from-2.1 to-38.4 mg kg-1. The 10% biochar addition increased soil p H, electrical conductivity, Mehlichand bicarbonate-extractable phosphorus(P), and extractable potassium(K) in both soil types. The wheat shoot biomass decreased from 17.7 to 9.1 g with incremental additions of biochar in the CO soil, but no difference was noted in plants grown in the VA soil. The FAME recovery assay indicated that the switchgrass biochar addition could introduce artifacts in analysis, so the results needed to be interpreted with caution. Non-corrected total FAME concentrations indicated a decline by 45% and 34% with 10% biochar addition in the CO and VA soils, respectively, though these differences became nonsignificant when the extraction efficiency correction factor was applied. A significant decline in the fungi:bacteria ratio was still evident upon correction in the CO soil with biochar. Switchgrass biochar had the potential to caus