Measuring the stability of soil organic carbon in Arenosols in the Senegalese Groundnut Basin
Item
-
Title
Measuring the stability of soil organic carbon in Arenosols in the Senegalese Groundnut Basin
Journal of Arid Environments
-
Creator
Oscar Pascal Malou
Tiphaine Chevallier
Patricia Moulin
David Sebag
Murielle Nancy Rakotondrazafy
Ndeye Yacine Badiane-Ndour
Abou Thiam
Lydie Chapuis-Lardy
-
Subject
Agricultural practices
Mineralized carbon
Particulate organic matter
Permanganate-oxidizable carbon
Rock-Eval® thermal analysis
Tropical sandy soils
-
doi
10.1016/j.jaridenv.2023.104978
-
Abstract
Soil organic carbon (SOC) contributes to agrosystem productivity. Understanding how farming practices implemented by smallholders affect the levels and distribution of SOC in carbon (C) pools with different stabilities is essential in sub-Saharan Arenosols where SOC mineralization is intense. The stability of SOC was studied by thermal (Therm-C), physical (particulate organic matter >50 μm, POM-C and fine soil fractions <50 μm, FF-C), chemical (permanganate-oxidizable carbon, POX-C) and biological (mineralizable C, Min-C) approaches. Soil samples were collected at depths of 0–10 and 10–30 cm in cultivated fields (out- or home-fields) without any input, with millet residues, amended with manure, or with household organic wastes. Globally, average SOC contents were low (<6 g C kg-1). The variability in SOC and C pool contents was sensitive to field management. The different approaches to measuring the stability of SOC did not measure the same fraction of SOC. POM-C and Therm-C were correlated and both explained Min-C similarly, thus suggesting that in these sandy soils, POM-C or Therm-C probably measured comparable properties of the stability of C. The lack of relationships between POX-C and other pools suggested that POX-C encompassed a different nature of SOC while providing complementary information on the biogeochemical stability of SOC.
