Acta Agrestia Sinica ›› 2019, Vol. 27 ›› Issue (4): 1037-1043.DOI: 10.11733/j.issn.1007-0435.2019.04.031

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Dynamic Characteristics of Soil Carbon Accumulation and Mineralization in Rotational Pasture

LIN Dong1,2, ZHANG De-gang1, McCulley Rebecca L.2, ZHOU Sheng-wei3   

  1. 1. College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China;
    2. Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0091, USA;
    3. College of Science, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China
  • Received:2019-05-14 Revised:2019-07-03 Online:2019-08-15 Published:2019-09-26

轮作草地土壤碳蓄积与矿化动态特征

林栋1,2, 张德罡1, McCulley Rebecca L.2, 周生伟3   

  1. 1. 甘肃农业大学草业学院, 甘肃 兰州 730070;
    2. 美国肯塔基大学植物与土壤科学系, 肯塔基 列克星敦 40546-0091;
    3. 甘肃农业大学理学院, 甘肃 兰州 730070
  • 通讯作者: 张德罡
  • 作者简介:林栋(1983-),男,甘肃武威人,助理研究员,博士研究生,主要从事草地土壤生态学研究,E-mail:lind@gsau.edu.cn
  • 基金资助:
    科技部重点研发项目(2016YFC0501900);美国农业部食品与农业孵化项目(1010357);甘肃省高校科研项目(2016A-031)资助

Abstract: In order to explore the dynamic characteristics of soil carbon (C) accumulation and mineralization in crop-pasture rotation system,the changes of soil organic carbon (SOC),particulate organic C (POC) and non-particulate organic C (n-POC) concentrations and the potential soil C mineralization (CM) in a five-year vegetable-pasture rotational agroecosystem in a low-input organic farm in temperate climate area were studied. The results showed that pasture rotational year significantly affected SOC content (P<0.01),but season did not. SOC content increased over 5 years in pasture rotation from 17.31 to 20.88 g kg-1 soil,and was close to that in the permanent pasture. POC content sensitively indicated the change of SOC pool. Time for pasture growing significantly affected SOC fractions (P<0.01),and POC and n-POC increased by 53.5% and 17.6% after 5 years pasture growing. Season did not affect SOC and POC contents. However,n-POC content was significantly affected by season,and it was 18% higher in spring than summer and winter. The soil CM rate significantly increased after 4-year rotation and was close to the average level of permanent pasture. The average soil CM rate in autumn was 5.9 μg·g-1·d-1 in 71-day incubation period,which was significantly lower than those in other seasons. Because the pasture rotation enhanced soil CM potential,promoted C cycling rate and SOC availability,and delayed half-life time of SOC,it played an important role in the capacity increasing and stabilization of soil C pool.

Key words: Carbon accumulation, Particulate organic carbon, Carbon mineralization, Rotational pasture

摘要: 为探明作物-草地轮作系统中草地土壤碳(Carbon,C)蓄积与矿化动态特征,本试验以温带气候区有机农牧场低投入蔬菜生产后的5年草地轮作土壤为研究对象,测定不同轮作年限和季节土壤有机碳(Soil Organic Carbon,SOC)及其颗粒有机碳(Particulate Organic Carbon,POC)和非颗粒有机碳(non-Particulate Organic Carbon,n-POC)组分含量,并对土壤C矿化潜力进行分析。结果表明,草地轮作年限显著影响SOC含量(P<0.01),季节对草地SOC含量无显著影响;SOC含量从草地建植初期的17.31 g·kg-1增加到第5年的20.88 g·kg-1,且接近永久性草地SOC含量;POC敏感指示土壤有机C库变化动态,草地生长年限显著影响土壤POC和n-POC组分变化(P<0.01),草地建植5年POC含量增加了53.5%,n-POC含量增加17.6%,春季草地土壤n-POC含量显著高于夏季和冬季;草地轮作4年后土壤C矿化率显著升高,并接近永久性草地水平;秋季草地土壤在71 d的培养期内平均C矿化速率为5.9 μg·g-1·d-1,显著低于其他季节。草地轮作增强了土壤C矿化潜力,提高了土壤C循环强度和有机C有效性,同时延长了SOC半衰期,对增加土壤C库容量和稳定性具有重要作用。

关键词: 碳蓄积, 颗粒有机碳, 碳矿化, 轮作草地

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