1.College of Agriculture, Henan University of Science and Technology, Luoyang;2.Chongqing Branch of China Tobacco Corporation;3.China Tobacco Chongqing Industrial Co, Ltd
Supported by the National Natural Science Foundation of China (No. 41601309) and the Natural Science Foundation of Henan Province of China (No. 182300410163)
采用室内培养结合同位素13C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（Cs）和秸秆源性碳（Cstr）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Cs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Cs损失率由2.83%增加至5.53%（P<0.05），使褐土闭蓄态组分中Cs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Cstr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，Cstr总残留率在黑土与褐土之间无显著差异，轻组中Cstr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Cstr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 (Cs) and straw-derived carbon (Cstr) 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, 8 580 kg?hm-2), RN (soil with nitrogen fertilizer 170 kg?hm-2 and straw addition 8 580 kg?hm-2). The wheat straw used was isotope 13C 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 Cs loss in the two soils were ranked as HF>OPOC>LF. Straw application increased the percentage of Cs loss in HF from 2.83% to 5.53% (P<0.05) in black soil and decreased the percentage of Cs loss in OPOC from 1.86% to 0.82% (P<0.01) in cinnamon soil. Importantly, the Cstr 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 Cstr in cinnamon soil showed no significant difference compared to that in black soil. The residual rate of Cstr 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 Cstr in LF of cinnamon soil. 【Conclusion】 The HF was the main source of Cs loss. Nitrogen fertilization inhibited carbon mineralization in the two soils. Straw addition exhibited a positive priming effect on the carbon mineralization of HF in black soil and an inhibitory effect on the mineralization of OPOC in cinnamon soil. The degradation degree of LF-Cstr in cinnamon soil was lower than that in black soil and could be limited by nitrogen application.
陈鲜妮,吴姗薇,寇太记,徐鹏飞,谭晓华,郭大勇.秸秆源性碳在黑土和褐土中的转运及其对氮肥的响应[J].土壤学报,2022,59(5). DOI:10.11766/trxb202105210059 CHEN Xianni, WU Shanwei, KOU Taiji, XU Pengfei, TAN Xiaohua, GUO Dayong. Transport of Straw-derived Carbon in Black Soil and Cinnamon Soil and its Response to Nitrogen Fertilization[J]. Acta Pedologica Sinica,2022,59(5).复制