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Agricultural soil management is a crucial aspect in agriculture. It is known to influence carbon storage, thus potentially aiding in the mitigation of atmospheric CO2 levels (Martin et al., 2021). The management of crop residues, whether through exportation (e.g., for animal fodder or bioenergy production) or incorporation into the soil, significantly impacts carbon storage (Autret et al., 2016; Hiel et al., 2018). Moreover, soil management practices influence various parameters including soil geochemical dynamics (Hiel et al., 2018), soil microbial communities (Spedding et al., 2004) or weed flora (Nichols et al., 2015).
In Hesbaye region (Belgium) winter wheat is a key component of agricultural rotations. This arable farming region is characterised by a loamy soil and an oceanic temperate climatic condition. In this region, a long-term study of the impact of crop residue management and tillage has been underway since 2008. In 2021-2022, the long-term effect of four soil management on the expressed (in winter wheat) and potential weed flora was examined. Soil management levers were i) the export (OUT) or restitution (IN) of crop residues and ii) the burial of residues by conventional tillage (mouldboard ploughing 25 cm depth, CT) or reduced tillage (cultivator ploughing 10 cm depth, RT). The weed seedbank and expressed flora in winter wheat were characterized. Weed density was monitored during the tillering phases (before weeding) and at wheat flowering. Additionally, at wheat flowering, weed biomass and wheat biomass were collected. Weed diversity was assessed using species richness and the Shannon diversity index. Then, the impact of flora and management on yield were investigated.
The result based on our study (Lacroix et al., 2024) showed that tillage management had little impact on weed diversity with only a slight increase observed in RT. However, RT resulted in a higher weed seedling density in the seedbank compared to CT. A higher weed density was observed in winter wheat crops under RT (+78%) compared to CT. Reduced tillage resulted indirectly to winter wheat yield losses due to the increased of weed pressure. In addition, high density of Alopecurus myosuroides, a very competitive weeds, was present in the trial due to the winter wheat rotation and exacerbated under RT. However, exporting residues had no clear effect on weeds. The lack of effect of maintaining residues could be explained by a dilution of crop residues in the upper soil profile which still occurs in some RT systems (such as the one implemented here), preventing the mulch effect to occur.
In conclusion, within cropping systems based on the cultivation of wheat, reduced tillage practices can pose challenges for the long-term management of the weed flora, necessitating careful attention to management practices.
References
Autret, B., Mary, B., Chenu, C., Balabane, M., Girardin, C., Bertrand, M., Grandeau, G., Beaudoin, N., 2016. Alternative arable cropping systems: A key to increase soil organic carbon storage? Results from a 16 year field experiment. Agric. Ecosyst. Environ. 232, 150–164. https://doi.org/10.1016/j.agee.2016.07.008
Hiel, M.-P., Barbieux, S., Pierreux, J., Olivier, C., Lobet, G., Roisin, C., Garré, S., Colinet, G., Bodson, B., Dumont, B., 2018. Impact of crop residue management on crop production and soil chemistry after seven years of crop rotation in temperate climate, loamy soils. PeerJ 6, e4836. https://doi.org/10.7717/peerj.4836
Lacroix, C., Vandenberghe, C., Monty, A., Dumont, B., 2024. Effect of long-term tillage and residue managements on weed flora and its impact on winter wheat development. Agric. Ecosyst. Environ. 366, 108937. https://doi.org/10.1016/j.agee.2024.108937
Martin, M.P., Dimassi, B., Román Dobarco, M., Guenet, B., Arrouays, D., Angers, D.A., Blache, F., Huard, F., Soussana, J.-F., Pellerin, S., 2021. Feasibility of the 4 per 1000 aspirational target for soil carbon: A case study for France. Glob. Change Biol. 27, 2458–2477. https://doi.org/10.1111/gcb.15547
Nichols, V., Verhulst, N., Cox, R., Govaerts, B., 2015. Weed dynamics and conservation agriculture principles: A review. Field Crops Res. 183, 56–68. https://doi.org/10.1016/j.fcr.2015.07.012
Spedding, T.A., Hamel, C., Mehuys, G.R., Madramootoo, C.A., 2004. Soil microbial dynamics in maize-growing soil under different tillage and residue management systems. Soil Biol. Biochem. 36, 499–512. https://doi.org/10.1016/j.soilbio.2003.10.026
| Keywords | Crop residue; Reduced tillage; Weed flora; Winter wheat |
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