Quantifying soil carbon stocks and humification through spectroscopic methods: A scoping assessment in EMBU-Kenya

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:234

Article

Segnini, Aline¹  Posadas, Adolfo²  Lopes da Silva, Wilson T.¹  Milori, Debora M. B. P.¹  Gavilan, Carla³  Claessens, Lieven⁴  Quiroz, Roberto⁵ 

[1] Embrapa Instrumentat, Rua 15 Novembro,1452,POB 741, BR-13560970 Sao Carlos, SP, Brazil

[2] AgriEntech Ltda, Rua Oseas Rocha Romalho 110,Parque Fehr, BR-13563753 Sao Carlos, SP, Brazil

[3] Univ Florida, Soil & Water Sci Dept, 2181 McCarty Hall A,POB 110290, Gainesville, FL 32611 USA

[4] Int Crops Res Inst Semi Arid Trop, POB 39063, Nairobi 00623, Kenya

[5] Int Potato Ctr CIP, Av La Molina 1895,POB 1558, Lima 12, Peru

关键词: Agricultural cropping systems;    Mont Kenya;    Andosols;    Nitisols;    Soil carbon stocks;    Carbon humification;    Spectroscopy;   

DOI  :  10.1016/j.jenvman.2018.12.108

来源: Elsevier

【 摘 要 】

A soil carbon assessment was performed comparing agricultural cropping systems with natural vegetation along a sampling transect spanning different agro-ecologies on the eastern foot slopes of Mount Kenya in Embu county, 125 km from Nairobi, Kenya. The aim was to determine differences in soil carbon stocks and carbon recalcitrance and relate these to soil textural class, altitude, climatic parameters and land use. Soils from main agricultural systems as tea, coffee and maize-based intercropping, as well as from natural vegetation cover were sampled in triplicates, in five layers from 0 to 30 cm in depth and processed for total carbon analysis. The whole soil samples were also analysed using Laser-Induced Fluorescence Spectroscopy (LIFS) to assess carbon humification. Prototype portable equipment intended for future in situ analysis was used in the lab to ascertain the structure of the most recalcitrant and stable carbon present in different agro-ecosystems. In addition, Near Infrared Spectroscopy (NIRS) was tested for the quantitative analysis of soil carbon, showing that it is a reproducible and low-cost method that provided satisfactory results under the processing conditions of the samples. Results showed wide variation in the level and quality of carbon stored in the soils, depending on soil texture, land use, elevation, climate, agricultural practices and land use history. Considering the heterogeneous nature of sampled soils and the performance of NIRS and LIFS, these results can be used as a basis for the development of fully portable systems able to provide rapid, clean and potentially cost-effective relevant information for soil management.

【 授权许可】

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