Scientific animation

2024

The group in charge of this Aïda event is made up of : David Berre, André Chabanne and Mathias Christina. You can follow the events remotely on Teams. Don't hesitate to suggest themes for events (contact opposite)...

Programme of events

Thursday 16 May 2024 - Understanding and evaluating the effects of agroecological innovations (agroforestry and CA) in cotton/maize systems in the face of climate change in North Cameroon

Teams virtual room at 11:00 (CEST) by Carmel FOULNA

Abstract: Initial results from monitoring the state of the environment, stands and yields of maize/cotton systems in three agroforestry parks (diversified and with Acacia) and under conservation agriculture.

Thursday 4 April 2024 - Presentation of the results of the consultation on assignment conditions - mobility

Teams virtual room at 11:00 (CEST) by Valérie SOTI & Coralie SIMEON

Abstract: Historical background. Debriefing of the investigation carried out in the unit. Understand the issues. Recognise the actions that can be taken in the unit.

Thursday 28 March 2024 - Evaluation of innovations compatible with organic cotton production in the management of cotton pests and their beneficials in Benin

Teams virtual room at 11:00 (CEST) by Saturnin AZONKPIN (IRC, Benin), Ana LOPEZ LLANDRES & Janine JEAN (Prose team)

Abstract: Cotton occupies a very important place in the socio-economic development of producing countries, but the chemical inputs are proving harmful to the environment and human health. Organic cotton production therefore appears to be an alternative way of cotton production and is carried out using various agro-ecological practices which effects on pests remain unexplored. In Benin, organic cotton production is already being carried out in several localities with various production systems. The objective of this study is to evaluate the effectiveness of different innovative practices that aim to contribute to an increase in organic cotton yield through integrated pest management. Specifically, the study aims to evaluate the effectiveness of agroecological practices using biopesticides for pest management an intercropping system of cotton and soybean as a legume, on the abundance of pests and natural enemies and on crop damage. Overall, the results showed that the cotton-soybean intercropping sytems had a significant effect on pest control for several pest species, with the exception of Bemisia tabaci. The biopesticides were very effective against Haritalodes derogata but had no significant effects on the other pests: Jacobiella fascialis, Bemisia tabaci, Aphis gossypii, Earias spp, Pectinophora gossypiella and Cryptophlebia leucotreta. In addition, biopesticides application and intercropping practices, showed a lower proportion of abscised cotton squares and bolls throughout the cropping season, and a lower proportion of rotten cotton collected from harvested bolls. Cotton–soybean intercropping and cotton monocropping organic systems showed lower yield of cotton (776 Kg/hectare for cotton monocropping and 412 Kg/hectare for cotton–soybean) comparatively to conventional cotton (1597 Kg/hectare). Nevertheless, the gross gain due to soybean yield obtained in intercropping (1612 Kg/hectare) compensated the loss in yield obtained in organic plots which shows the potential interest of intercropping cotton and soybean for Beninese cotton organic producers. Regarding the impact of biopesticide application and intercropping on natural enemies, the results revealed that contrarily to synthetic pesticides, biopesticides did not have a negative impact on natural enemies. In addition, the intercropping systems showed marginally significant higher abundances of natural enemies collected from pit-fall traps. Finally, further studies should be conducted on soybean sowing date and plant density and on biopesticide selection for an improved pest control.

Thursday 21 March 2024 - Publishing research results in a context of open science and scientific integrity

Teams virtual room at 11:00 (CEST) by Laurence DEDIEU & Christine RAWSKI (Dist)

Abstract: The global movement for open science has resulted in an obligation to make publications available, as required by funding bodies (Europe, ANR) and by the law for a digital republic. CIRAD has also included the principle of open access in its institutional strategy. The aim of this presentation is to help you meet this requirement, while avoiding publishing with an increasing number of dubious publishers whose primary aim is commercial, to the detriment of scientific quality and integrity.

Thursday 14 March 2024 - Performance of conservation agriculture systems and impact of soil health and macrofauna in cotton based cropping system in Benin

Teams virtual room at 11:00 (CEST) by Lionel YEMADJE (Aïda)

Abstract: Soil degradation is one of the greatest challenges facing humanity. It particularly affects food security in sub-Saharan Africa. Our research comprehensively investigated the agronomic and economic differences between Conservation Agriculture (CA) practices and conventional tillage in cotton-based cropping system.

Through a long-term experiment, our results showed that the maintaining of crop residues with ploughing of weed biomass into the soil help to maintain crops yields over time but could not maintain SOC stock in a Ferralsol in Benin. A combined approach of minimum tillage or even no tillage and the addition of larger organic matter inputs (or even manure) and legumes in intercropping or in association must be studied in the long term. However, transitioning towards minimum or no tillage is challenging for smallholder farmers in Sub-Saharan Africa (SSA), due to the possible yield penalties during the initial years of a transition. Conventional tillage, strip tillage, direct seeding and direct mulch-based cropping systems (DMC) were tested in different cotton growing regions of Benin. Understanding the early impacts of such transitions is crucial in a cash crop such as cotton, on which farmers rely for their income, and necessary to inform agroecological strategies to cope with both these challenges. At all sites, direct seeding led to lower below ground biomass growth and seed cotton yields compared to conventional tillage in an early transition to conservation agriculture starting from degraded soils (2 to 25%). Weak rooting under direct seeding resulted in lower cotton yields compared to tillage (-12%) and strip tillage (-15%). Fertilizer regimes affected seed cotton yields differently across sites and treatments, with marginal responses within soil preparation methods, but they contributed to increase yield differences between conventional and no tillage. Strip tillage, appears as a reasonable compromise to minimize yield penalties in an early transition to CA.

After 2-3 years of direct mulch-based cropping systems (DMC), the cotton yield advantage with respect to CT grew from 5% to 7%. However, cotton yield penalties of respectively 11% and 26% were found for DS. ST treatment went from a yield advantage of 8% with respect to CT in the first year, to a yield penalty of 20%. The DMC and CT treatments gave similar and highest boll weights compared to the ST and DS treatments. Water storage and water use efficiency were higher in the direct mulch-based cropping systems. The parameters were the main drivers of significantly higher cotton yields after three years of transition to CA. An experiment with strip-till plus hoeing and ridging (STSB) showed that STSB treatment resulted in higher grain yields (2207 kg ha-1 cotton and 5446 kg ha-1 maize) in 2022, while CT recorded the highest values (2308 kg ha-1 cotton and 3870 kg ha-1 maize) in 2023. ST showed high work productivity and monetary profit per labor day despite its low gross margin and net gross return.

After 4 years of agroecological transition, DMC improves soil health (POXC, water infiltration and SituResp) and macrofauna in cotton-based cropping system. Moving forward, continued research efforts and extension initiatives are essential to refine CA practices in cotton-based cropping system in Benin.

Thursday 7 March 2024 - A long-term multi-criteria analysis of sugarcane intercropping compared to conventional cropping systems

Teams virtual room at 11:00 (CEST) by Mathias CHRISTINA (Aïda)

Abstract: To develop sustainable intercropping agroecosystems, multi-criteria approaches are needed to integrate their agronomic, environmental, and socio-economic performances. Nonetheless, the temporal dynamics of intercropping agrosystems is still poorly understood, particularly in tropical sugarcane systems. This study provides the first long-term multi-criteria analysis of sugarcane intercropping systems to assess how temporal changes will determine the long-term sustainability of this practice. In an experimental trial in Reunion Island, six sugarcane x companion crop intercropping systems were compared to a conventional and a low weed control cropping system over seven years. In intercropping systems, weed cover increased over time, associated with an increase in weed species richness and manual weeding. In the conventional system, herbicide application increased over time, reducing weed pressure. In terms of biodiversity, the intercropping system only modified the weed community in the first three years, compared with the conventional or low-weed control system, before the communities homogenized under sugarcane pressure and climate. Over seven years, the intercropping system reduced herbicide application by 51% and increased soil cover by 144%, with no significant impact on yield or sucrose content. Nevertheless, this practice led to an increase of 85% in costs and 162% in working hours, mainly due to the companion crop sowing. Finally, no difference in soil chemical and biological fertility was observed between cropping systems but the physical fertility increased with the companion crop and weeds development in the inter-row after seven years. This study illustrates the need to consider the dynamics of intercropping systems performances over the long term. It highlights the limits of this system for weed control in sugarcane, notably through an increase in weed pressure over time, but also ways of improving it regarding costs (particularly sowing). Finally, cropping systems with spontaneous flora in the inter-row should be studied further to reduce herbicides with a limited impact on production.

Thursday 29 February 2024 - Intensifying sorghum and pearl millet crops in the SAT. Tolerance to high sowing densities: from ecophysiology to farmers' fields

Teams virtual room at 11:00 (CEST) by Raphaël PILLONI (Aïda)

Abstract: Sorghum and pearl millet are staple food millions inhabitants in the world and particularly important in food security in the Sahel region. In Senegal and India where they are massively grown, the yield are low and the planting density are considered as very low (around three plants per m² in the Sahel for example). Increasing the density of sowing may so allow a sustainable intensification of both crops. The main questions this work aimed to answer was then to evaluate the potential of this change in crop management to increase yield. However, trade off, particularly regarding the water budget of the crops, can accompany such an intensification. Also, farm reality can differs from research stations. Based on that, this work decipher the crops response to increased density using different tools and platform, from automated and field-like lysimetry to quantify the water use and ecophysiological process associated, to field trials in research stations to assess the agronomical response of different cultivars and finally to on-farm trials to validate the method in a smallholders farming system context.

Thursday 8 February 2024 - CIO2 - carbon assessment of our activities.

Virtual Teams Room at 11:00 (CEST) by J. DEMENOIS, K. NAUDIN (Aïda), G. CAROFF & E. VROT

Abstract: -

Thursday 25 January 2024 - Targeting and prioritising agricultural interventions using an approach combining statistical typology and frontier analysis: an example of application to mixed farming-livestock farms in the semi-arid regions of Zimbabwe.

Teams virtual room at 11:00 (CEST) by Frédéric BAUDRON (Estime team)

Abstract: Most food in the Global South is produced in mixed crop-livestock smallholder farms. Similarly, these farms dominate in semi-arid areas of Zimbabwe, which cover two thirds of the country. It is thus of strategic importance to better understand the diversity of mixed crop-livestock systems in these areas, in order to tailor interventions that support them. Using semi-arid Zimbabwe as a case, this study aimed to describe the diversity of mixed crop-livestock farms, and to unravel the determinants of cereal and livestock production for different farm types and contexts in order to prioritize interventions supporting their productivity. An innovative methodological approach combining statistical typologies and stochastic frontier analysis was applied to data collected from 1840 households in six districts of Zimbabwe, representative of semi-arid areas of the country. Farms in the study area were found to be small, cultivating on average 2.20 ± 2.41 ha, including 1.74 ± 2.20 ha of cereals, and owning on average 4.61 ± 6.42 cattle and 7.86 ± 9.30 sheep and goats. The average annual cereal production was 362 kg farm-1 and the average annual livestock offtake 0.64 ± 1.32 Tropical Livestock Units (TLU) farm-1. Our results demonstrate there is scope to increase cereal and livestock production by 90.7% and 111.9% relative to current production levels, respectively, with more efficient use of existing resources and technologies. Rainfall was found to have a strong effect on cereal production, highlighting the need for climate-smart practices. Livestock mortality (0.59 ± 1.62 TLU farm-1) was found to be in the same order of magnitude as livestock offtake (0.64 ± 1.32 TLU farm-1). Cereal production was also supported by livestock, demonstrating the importance of crop-livestock interactions in these mixed farming systems. Three farm types were identified in our analysis. Mixed farms dependent on off-farm activities (36% of the sample) may not be the primary target of crop and livestock performance-enhancing interventions. Crop-oriented mixed farms (31%) are likely to be the ones most responsive to crop-specific interventions e.g., crop rotation and integrated pest management. Livestock-oriented mixed farms (34%) are likely to benefit the most from livestock-specific interventions, e.g., home feed and deworming. Reducing cattle mortality is a priority for all three farm types. Mixed crop-livestock farming systems will continue to play an important role in most of the Global South, including semi-arid Zimbabwe, calling for approaches to identify tailored solutions, as proposed in this study.

Thursday 18 January 2024 - Biofunctool, two web and mobile applications for producing nine soil health indicators as soon as field data is entered.

Virtual Teams Room at 11:00 (CEST) by Thibault SOIRAT (UMR Absys), Alexandre THOUMAZEAU (eTumba) & Agnès TENDERO (Estime team)

Abstract: -