学术论文

      不同温度制备的生物质炭对土壤有机碳及其组分的影响:对土壤活性有机碳的影响

      Effects of Biochar Pyrolyzed at Varying Temperatures on Soil Organic Carbon and Its Components:Influence on the Soil Active Organic Carbon

      摘要:
      土壤活性有机碳作为土壤有机碳中活跃的化学组分,在全球碳循环中起着非常重要的作用.为了探究生物质炭输入对土壤活性有机碳的影响,以苹果枝条为原料,在300~ 600℃条件下制备生物质炭,在研究生物质炭基本理化性质的基础上,通过室内培养试验研究生物质炭输入对土壤活性有机碳的影响.结果表明:高温制备的生物质炭碳(C)的质量分数增加,而氢(H)和氧(O)质量分数下降,H/C及O/C比下降;生物质炭的脂肪族结构减弱,芳香性增强,稳定性升高;生物质炭输入可以显著增加土壤有机碳(SOC)含量(P<0.05),且随着添加比例的增加而增加,其中以500℃制备的生物质炭对土壤有机碳库的提升效果最为明显;与对照相比,低温(≤400℃)制备的生物质炭在培养期间增加了土壤微生物量碳(MBC)、水溶性有机碳(WSOC)以及易氧化有机碳(ROC)的含量,且随着添加比例的增加而增加,培养360 d后,BC300处理平均分别增加了38.25%、82.09%和63.53%;BC400处理平均分别增加了26.07%、65.61%和48.09%,且差异均达到显著水平(P<0.05);高温(> 400℃)制备的生物质炭在培养初期(<40 ~60 d)增加了土壤MBC、WSOC及ROC含量,且随着添加比例的增加而增加,而在培养后期则减少了土壤MBC、WSOC、ROC含量,且随着添加比例的增加而减少,培养360 d后,BC500处理平均分别减少了0.27%、13.48%和14.67%,BC600处理平均减少7.80%、14.66%和15.79%,且差异达到显著水平(BC500处理MBC含量除外)(P<0.05);生物质炭输入降低了土壤有机碳中ROC的比例,并且随着热解温度的升高以及添加比例的增加而降低.从提升土壤有机碳库及生物活性等方面考虑,在黄土高原(搂)土地区,500℃条件下制备生物质炭,既能保证有机碳具有较高的稳定性,又不至于引起土壤活性碳库的过度降低,是生物质炭在农田土壤利用的最佳制备温度.
      Abstract:
      Soil active organic carbon is the most important carbon pool and a good indicator in ecosystem management due to its great significance in soil carbon cycling and soil quality.In order to investigate the effect of biochar(BC) addition on soil organic matter fractions,apple tree twigs were used to produce BC at 300,400,500 and 600℃,respectively.Elemental analysis and Fourier transform infrared (FTIR) spectroscopy were used to determine the characteristics of BC.Four kinds of BC were added into soils at five application rates(0,0.5%,1%,2% and 3%) and incubated at 25℃ in lab for over 360 days.Soil organic carbon (SOC),microbial biomass carbon (MBC),water soluble organic carbon (WSOC) and readily oxidized organic carbon (ROC) were measured during the incubation.The mass fraction of carbon (C) in the generated BC ranged from 62.20%-80.01%,while hydrogen (H) ranged from 2.72%-5.18% and Oxygen (O) ranged from 15.98%-30.92%.The increasing temperature increased the mass fraction of C,while decreased the O and H mass content,as well as the ratio of H/C and O/C.The addition of BC significantly increased SOC,and the treatments amended with BC500 had the highest increments.Compared with the control treatment (CK),the addition of BC produced at temperatures below 400℃ increased the contents of MBC,WSOC and ROC during the incubation,at the end of the incubation,BC300 treatments significantly increased the contents by 38.25%,82.09% and 63.53% (P < 0.05),respectively;BC400 treatments significantly increased the contents by 26.07%,65.61% and 48.09% (P < 0.05),respectively;while lower contents of MBC,WSOC and ROC were found in the treatments amended with BC produced at temperatures above 400℃ after 40-60 d incubation.After 360 d of incubation,the contents of MBC,WSOC and ROC were significantly decreased by 0.27%,13,48% and 14.67% in BC500 treatments and 7.80%,14.66% and 15.79% in BC600 treatments (except for the MBC in BC500 treatment) (P <0.05).The relative contents of ROC ranged from 3.39% to 15.65%,BC application decreased the relative content of ROC,suggesting that the increase was in proportion to the stability of organic carbon in the soil.Considering the content and quality of SOC,when the BC products were applied to the Loutu soil,500℃ was the optimal temperature for preparing apple-derived BC due to its significant increase of the soil organic carbon and a slight decrease of the relative content of soil active organic carbon.
      作者: 赵世翔 [1] 于小玲 [1] 李忠徽 [1] 杨艳 [1] 刘丹 [1] 王旭东 [2] 张阿凤 [1]
      Author: ZHAO Shi-xiang [1] YU Xiao-ling [1] LI Zhong-hui [1] YANG Yan [1] LIU Dan [1] WANG Xu-dong [2] ZHANG A-feng [1]
      作者单位: 西北农林科技大学资源环境学院,杨凌,712100 西北农林科技大学资源环境学院,杨凌712100;农业部西北植物营养与农业环境重点实验室,杨凌712100
      刊 名: 环境科学 ISTICPKU
      年,卷(期): 2017, 38(1)
      分类号: X144
      在线出版日期: 2017年9月28日
      基金项目: “十二五”国家科技支撑计划项目,农业部公益性行业科研专项,国家自然科学基金项目,西北农林科技大学基本科研业务费专项