Modeling soil organic carbon dynamics in Oxisols of Ibiruba (Brazil) with the Century Model
Modeling soil organic carbon dynamics in Oxisols of Ibiruba (Brazil) with the Century Model
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DOI：
10.1016/j.still.2009.05.005
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发表时间：
2009-09-01
影响因子：
6.5
通讯作者：
Pellegrino Cerri, Carlos Eduardo
中科院分区：
文献类型：
--
作者：
Tornquist, Carlos Gustavo;Mielniczuk, Joao;Pellegrino Cerri, Carlos Eduardo
在退化的农业土地上采用养护做法，一般会恢复土壤质量，特别是通过增加土壤有机质。这方面的土壤有机碳（SOC）动态在不同的种植和管理制度下，可以方便地分析生态系统模型，如世纪模型。在这项研究中，世纪被用来模拟SOC股票在农场领域的Ibiruba地区的北中南里奥格兰德州在巴西南部。该地区的土壤主要是氧化土，最初覆盖着亚热带林地和草地。SOC动态模拟与土壤管理和耕作制度的历史数据，从1900年开始的农业发展的一般情况。从1993年到2050年，两个对比方案的基础上免耕土壤管理建立：“现状”的情况下，作物和农业投入，目前在该地区和“高生物量”的情况下，种植系统中玉米的频率增加，导致约80%的生物量增加到土壤。世纪的模拟与SOC股票在2005年测量的Oxisols与纹理较细的表面层最初在林地。然而，在林地和草原土壤下具有肥沃表面层的Oxisols中的模拟并不那么准确。土壤有机碳储量下降，从44%到50%，在原来的林地和草地下的领域从20%到27%，引进密集的一年生粮食作物与密集的耕作和耙操作。在20世纪80年代通过的保护措施，导致SOC股票的稳定，其次是本地股票的部分恢复。到2050年的模拟表明，维持“现状”将使SOC储量从林地的81%恢复到86%，从草地的80%恢复到91%。如果采用“高生物量”设想，到2050年，林地的种群将占原始种群的75%至95%，草原的种群将占89%至102%。这些模拟结果强调了种植系统产生更高的生物量，以进一步增加这些氧化土中的SOC含量的重要性。这种应用的世纪模型可以再现的总趋势的SOC损失和恢复的Oxisols的伊比鲁巴地区。在推荐广泛使用世纪作为该地区和其他地区土壤固碳项目的支持工具之前，应进行额外的校准和验证。(C)2009爱思唯尔有限公司版权所有。
introduction of conservation practices in degraded agricultural land will generally recuperate soil quality, especially by increasing soil organic matter. This aspect of soil organic C (SOC) dynamics under distinct cropping and management systems can be conveniently analyzed with ecosystem models such as the Century Model. In this study, Century was used to simulate SOC stocks in farm fields of the Ibiruba region of north central Rio Grande do Sul state in Southern Brazil. The region, where soils are predominantly Oxisols, was originally covered with subtropical woodlands and grasslands. SOC dynamics was simulated with a general scenario developed with historical data on soil management and cropping systems beginning with the onset of agriculture in 1900. From 1993 to 2050, two contrasting scenarios based on no-tillage soil management were established: the "status quo" scenario, with crops and agricultural inputs as currently practiced in the region and the "high biomass" scenario with increased frequency of corn in the cropping system, resulting in about 80% higher biomass addition to soils. Century simulations were in close agreement with SOC stocks measured in 2005 in the Oxisols with finer texture surface horizon originally under woodlands. However, simulations in the Oxisols with loamy surface horizon under woodlands and in the grassland soils were not as accurate. SOC stock decreased from 44% to 50% in fields originally under woodland and from 20% to 27% in fields under grasslands with the introduction of intensive annual grain crops with intensive tillage and harrowing operations. The adoption of conservation practices in the 1980s led to a stabilization of SOC stocks followed by a partial recovery of native stocks. Simulations to 2050 indicate that maintaining "status quo" would allow SOC stocks to recover from 81% to 86% of the native stocks under woodland and from 80% to 91 % of the native stocks under grasslands. Adoption of a "high biomass" scenario would result in stocks from 75% to 95% of the original stocks under woodlands and from 89% to 102% in the grasslands by 2050. These simulations outcomes underline the importance of cropping system yielding higher biomass to further increase SOC content in these Oxisols. This application of the Century Model could reproduce general trends of SOC loss and recovery in the Oxisols of the Ibiruba region. Additional calibration and validation should be conducted before extensive usage of Century as a support tool for soil carbon sequestration projects in this and other regions can be recommended. (C) 2009 Elsevier B.V. All rights reserved.