Crop sequence intensification: Meta-analysis of soil organic carbon and aggregate stability in Argentina

GIUSTINIANI, EMILIA; BEHRENDS KRAEMER, FILIPE; GARIBALDI, LUCAS A.

EUROPEAN JOURNAL OF SOIL SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2024 vol. 75

1351-0754

Intensification of crop sequence (ICS) has been proposed as a key field practice to preservesoil health and achieve more sustainable agricultural systems. However, the effects of ICSare site-specific and vary according to soil characteristics, climatic conditions, the duration ofthe crop sequencing and the types of crop involved. Soil aggregate stability (AS) and organiccarbon (SOC) stock are useful indicators of soil health as they are closely linked to diversesoil services and functions and are sensitive to management practices. We performed ameta-analysis of 33 studies to analyse the impact of ICS on SOC stock and AS in fieldexperiments in the central-eastern region of Argentina. Our results showed that ICSincreased SOC stock and AS, with an overall mean change of 7% and 22% respectively.Fine-textured soils showed the greatest SOC stock increase (12%), comparable to theincrease observed in coarse-textured soils (11%); in medium-textured soils this increase wasless than half (5%). Coarse-textured soils had the greatest increase in AS (32%), followed bymedium-textured and fine-textured soils, which also showed notable improvements (25%and 19% respectively). Greater diversity of crops resulted in higher increases in both AS andSOC. ICS generated a larger increase of SOC stock in the soil surface (0-10 cm) than in thesubsurface (10-20 cm), whereas the opposite was found for AS. Long term studies (≥ 9years) had the greatest effect on AS and SOC stock. Regression analysis revealed that theinitial carbon stock influenced SOC stock results following ICS, increases being greaterwhen initial carbon stock contents were lower. Introducing gramineous species into the cropsequence was associated with a greater improvement of AS and SOC stock. Finally, themean rate of carbon sequestration from ICS in all the studies amounted to 0.28 Mg ha -1 yr -1 .Overall, ICS is a useful strategy for improving SOC storage and AS in this region, thoughresults may vary according to soil characteristics and management practices.