摘要
采用室内培养结合同位素^(13)C标记技术,探讨了添加小麦秸秆和氮肥后黑土和褐土的碳素矿化特征,分析了土壤原有碳(C_(s))和秸秆源性碳(C_(str))在土壤不同有机碳组分(轻组、闭蓄态组分、重组)中的转运特征。结果表明:土壤培养过程是碳矿化损失的过程,施氮肥对黑土和褐土中碳矿化均有一定的抑制效应,褐土中该抑制效应在施秸秆时较不施秸秆时更显著。土壤有机碳组分中C_(s)损失率表现为由高到低依次为重组、闭蓄态组分、轻组,施秸秆使黑土重组C_(s)损失率由2.83%增加至5.53%(P<0.05),使褐土闭蓄态组分中C_(s)损失率由1.86%减少至0.82%(P<0.01)。随培养时间的进行,土壤轻组中C_(str)经降解逐渐向闭蓄态组分和重组中转移,180 d后转移缓慢;至培养结束(300 d)时,C_(str)总残留率在黑土与褐土之间无显著差异,轻组中C_(str)残留率为褐土(4.98%~8.52%)显著高于黑土(1.71%~2.47%)。与不施氮相比,施氮处理使褐土轻组的C_(str)残留率增加了近一倍。综上,施氮肥对黑土和褐土中碳矿化均有一定的抑制效应,重组是土壤碳损失的主要来源,添加秸秆对黑土重组的碳矿化有激发效应,而对褐土闭蓄态组分的碳矿化有抑制作用。褐土轻组中外源秸秆的降解程度低于黑土,并且施氮肥抑制其降解。
【Objective】A laboratory incubation was conducted to study the transport characteristics of soil native carbon(C_(s))and straw-derived carbon(C_(str))after adding wheat straw and nitrogen fertilizer in black soil and cinnamon soil.【Method】There are four treatments:Control(soil only,no straw or nitrogen added),N(soil with nitrogen fertilization,170 kg·hm^(-2)),R(soil with straw addition,8580 kg·hm^(-2)),RN(soil with nitrogen fertilizer 170 kg·hm^(-2) and straw addition 8580 kg·hm^(-2)).The wheat straw used was isotope ^(13)C labeled.Soil samples were collected and fractionated into three different soil organic carbon fractions(light fraction-LF,occluded particulate organic carbon-OPOC,heavy fraction-HF)at 0,180,300 days.【Result】The results showed that the soil incubation was a carbon loss process of soil carbon mineralization.Nitrogen fertilization showed an inhibitory effect on carbon mineralization in both soils,and the effect in cinnamon soil was more significant in straw-added treatments compared to no straw-added treatments.The percentages of C_(s) loss in the two soils were ranked as HF>OPOC>LF.Straw application increased the percentage of C_(s) loss in HF from 2.83%to 5.53%(P<0.05)in black soil and decreased the percentage of C_(s) loss in OPOC from 1.86%to 0.82%(P<0.01)in cinnamon soil.Importantly,the C_(str) in LF was gradually transferred to OPOC and HF,and the transfer became slower after 180 days.By the end of incubation(300 days),the total residual rate of C_(str) in cinnamon soil showed no significant difference compared to that in black soil.The residual rate of C_(str) in LF was 4.98%-8.52%in cinnamon soil and was significantly higher than that in black soil(1.71%-2.47%).Compared to R treatment,RN treatment almost doubled the residual rate of C_(str) in LF of cinnamon soil.【Conclusion】The HF was the main source of C_(s) loss.Nitrogen fertilization inhibited carbon mineralization in the two soils.Straw addition exhibited a positive priming effect on the carbon mineralization of HF
作者
陈鲜妮
吴姗薇
寇太记
徐鹏飞
谭晓华
郭大勇
CHEN Xianni;WU Shanwei;KOU Taiji;XU Pengfei;TAN Xiaohua;GUO Dayong(College of Agriculture,Henan University of Science and Technology,Luoyang,Henan 471000,China;Chongqing Branch of China Tobacco Corporation,Chongqing 404100,China;China Tobacco Chongqing Industrial Co.,Ltd.,Chongqing 404100,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2022年第5期1248-1257,共10页
Acta Pedologica Sinica
基金
国家自然科学基金项目(41601309)
河南省自然科学基金项目(182300410163)共同资助。
关键词
碳矿化
秸秆碳残留率
土壤原有碳
闭蓄态组分
重组
Carbon mineralization
Residual rate of straw carbon
Soil native carbon
Occluded particulate organic carbon
Heavy fraction
