Status: this preprint is open for discussion and under review for SOIL (SOIL).
Crop fertilization as a key determinant of croplands’ soil carbon stocks
Vincent Chaplotand Pardon Muchaonyerwa
Abstract. Soil organic matter (SOM), which associates organic carbon to key plant nutrients, is a corner stone of soil health, agricultural productivity and ecosystem functioning. While virgin lands (forest or grassland) exhibit the highest SOM stocks, their cultivation leads to their sharp decrease and that of crop yields in the first decade(s), even when zero tillage and cover crops are promoted. The decline in SOM is less acute when crops are fertilized with N, P, K at rates recommended to meet crop needs than when not fertilized, and is often reversed when nutrients are applied above recommendations. This points to the key role of fertilization to manage croplands’ soil carbon that needs to be better understood to mitigate against soil degradation for promoting sustainable agriculture, while minimizing environmental hazards such as water pollution.
Received: 18 Aug 2025 – Discussion started: 17 Sep 2025
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University of KwaZulu-Natal, School of Agricultural, Earth & Environmental Sciences, Scottsville, 3209 Pietermaritzburg, South Africa
Laboratoire d’Océanographie et du Climat: Expérimentations et approches numériques (LOCEAN), UMR 7159, IRD/CNRS/UPMC/MNHN, IPSL, 4, Place Jussieu, 75252 Paris, France
Virgin lands converted to croplands loose staggering amounts of soil organic carbon. The available litterature shows that proper soil fertiliation may allow to revert the decline in SOM which is less acute when crops are fertilized with N, P, K at rates recommended to meet crop needs than when not fertilized. The SOM decline is often reversed when nutrients are applied above recommendations thus pointing to necessary reconsideration of actual soils policies.
Virgin lands converted to croplands loose staggering amounts of soil organic carbon. The...
