Effet de l’inoculum «Compost Plus» Sur le Compostage des Tiges de Cotonnier et les Rendements en Coton au Burkina Faso

Afin de recycler les tiges de cotonnier en compost, l’inoculum «compost plus» comparé au fumier habituellement utilisé comme ferment, a été testé par un groupe de paysans en 2006. La durée de compostage, les consommations d’eau et les caractéristiques chimiques des composts ont été déterminées. Les composts obtenus ont été associés à la fumure minérale vulgarisée, à 5 t ha-1 pour déterminer leur efficacité sur les rendements du cotonnier. La durée moyenne du compostage des tiges de cotonnier a été de 70 et 64 j avec « compost plus » et le fumier, respectivement. Durant le compostage, en saison sèche, les consommations d’eau par tonne de tiges de cotonnier avec «compost plus» (3584 l) ont été plus importantes que celles avec le fumier (2077 l). Ces quantités d’eau ont diminué significativement, en saison pluvieuse, de même que la durée de maturation du compost. Les composts obtenus se sont révélés pauvres en P et riches en N et en K. Ces composts, associés à la fumure minérale vulgarisée, ont amélioré significativement les rendements en coton graine. L’utilisation de « compost plus » pourrait améliorer les rendements à travers un recyclage approprié des tiges de cotonnier.Mots clés : Tiges de cotonnier, compostage, « compost plus », fumier, rendement.The inoculum «compost plus», as compared to manure, usually used as ferment, was used for the composting of cotton straws by farmers in 2006. Composting time, quantities of water used and chemical properties of the compost were determined. The use of the compost, at the rate of 5 t ha-1, associated with conventional mineral fertilizer, was evaluated for cotton seed yield. The results showed that the time for cotton straw composting with «compost plus» and manure was 70 and 64 days, respectively. The quantity of water used, with «compost plus» during the dry season was higher (3584 l t-1) than that of the manure (2077 l t-1). The quantities of water decreased significantly during the rainy season. The same was true for composting time. The composts obtained with «compost plus» and manure, were lower in P and higher in N and K. Seed cotton yield increased significantly with the use of compost associated to mineral fertilizer. Finally the use of the «compost plus» inoculum could be an alternative for the recycling of cotton straws, with an increase in the organic matter content of soil and cotton production.Key words : Cotton straws, composting, «compost plus», manure, yield

Acidification des sols ferrugineux et ferrallitiques dans les systèmes de production cotonnière au Burkina Faso

La productivité des systèmes de culture coton-céréales est menacée par la dégradation et l’acidification des terres. Afin de déterminer les causes de l’acidification des sols dans la zone cotonnière du Burkina Faso, une expérimentation a été conduite pendant deux années, en milieu paysan, sur des sols ferrugineux et ferrallitiques, respectivement sur les sites de Dohoun et Balla. Trois modes d’exploitation des terres, définis par la jachère, la culture attelée et la culture motorisée, ont été comparés pour déterminer leurs effets sur les caractéristiques physico-chimiques des sols étudiés. Par rapport à la jachère, comparée à la culture attelée, la culture motorisée a entraîné, en surface (0-20 cm) des sols ferrugineux et ferrallitiques, une augmentation des teneurs en sable de 8 à 12% et une baisse du taux d’argile de 35% qui expose ces sols à l’acidification. Contrairement à la jachère, la culture motorisée a entraîné des pertes significatives de carbone et d’azote, qui rendent les sols plus sensibles à l’acidification qu’en culture attelée. L’exploitation des terres s’est aussi traduite par une baisse significative des teneurs des cations majeurs du complexe adsorbant (Ca2+ et Mg2+), de la somme des bases échangeables (SBE) et de la capacité d’échange cationique (CEC), accentuant la vulnérabilité à l’acidification sous culture motorisée. La dégradation des sols cultivés a été plus importante pour les sols ferrallitiques qu’au niveau des sols ferrugineux, dont la CEC a été 2 à 3 fois plus élevée. La culture attelée et la culture motorisée, pratiquées, le plus souvent, sans restitution organique, se sont révélées comme étant des causes de l’acidification des sols ferrallitiques, plus accentuée que celle des sols ferrugineux. L’étude recommande d’adopter des techniques adéquates de travail du sol et de procéder à des amendements appropriés pour atténuer l’acidification et garantir la durabilité des systèmes de production.Mots clés: Exploitation des terres, acidification, sol ferrugineux, sol ferrallitique, zone cotonnière

Efficacy of the association of cover crops with maize and direct sowing short-term effect on crops? yields in maize-cotton cropping system in Western Burkina Faso.

To improve the productivity and sustainability of cotton and cereals based system, direct sow ing under mulch was tested for its efficacy on cotton and maize yields on the research station of Farako - Bâ, in Western Burkina Faso. The experimental design was a complete randomized blocks of Fisher with four replications. Conventional tillage by annual moldboard plowing (T7) was compared with direct sowing under mulch -based cropping system (DMC) using maize association with cover crop s defined as: maize without cover crop (T1), maize +Brachiaria ruziziensis(T2), maize + B. ruziziensis+ Mucuna cochinchinensis (T3), maize + B. ruziziensis+ Panicum maximum (T4), maize + B. ruziziensis + Stylosantes hamata (T5), and maize + Crotalaria juncea (T6). Cover crops were planted 21 days after maize emergence between the rows of this main crop. The biomass produced by the cover crops and maize straws were evaluated as well as maize and cotton yields, during the first 6 years of the study, from 2010 to 2015. Results showed that among cover crops, the biomass production was significantly lower with C. juncea. The associations of cover crops with maize increased significantly the production of total dry matter compared to plots without cover crops, in the conventional tillage. Association with cover crops did not influence significantly nitrogen, phosphorus and potassium contents of maize and the maize’s yields even if the depressive effects were recorded. Compared to the conventional tillage, the DMC appeared also effective on seed cotton yields even without a significant improvement during the 6 first years of the study . These promising results, confirm the feasibility in tropical conditions of DMC which must be continued to better analyze its long-term effects on soil properties

"Mango Mango, How to Let The Lettuce Dry Without A Spinner?'': Exploring User Perceptions of Using An LLM-Based Conversational Assistant Toward Cooking Partner

The rapid advancement of the Large Language Model (LLM) has created numerous potentials for integration with conversational assistants (CAs) assisting people in their daily tasks, particularly due to their extensive flexibility. However, users' real-world experiences interacting with these assistants remain unexplored. In this research, we chose cooking, a complex daily task, as a scenario to investigate people's successful and unsatisfactory experiences while receiving assistance from an LLM-based CA, Mango Mango. We discovered that participants value the system's ability to provide extensive information beyond the recipe, offer customized instructions based on context, and assist them in dynamically planning the task. However, they expect the system to be more adaptive to oral conversation and provide more suggestive responses to keep users actively involved. Recognizing that users began treating our LLM-CA as a personal assistant or even a partner rather than just a recipe-reading tool, we propose several design considerations for future development.Comment: Under submission to CHI202

Effets de la valorisation des résidus de récolte sur la nutrition minérale du cotonnier et les rendements d’une rotation coton-maïs-sorgho dans l’Ouest du Burkina Faso

Une étude a été réalisée de 1982 à 2006 pour analyser les effets de la gestion des résidus de récolte sur la nutrition minérale des cotonniers et les rendements d’une rotation coton-maïs-sorgho. Dans un dispositifexpérimental en blocs simples non randomisés, la gestion extensive où les résidus sont exportés (T1) est comparée à la gestion semi-intensive (T2) et à la gestion intensive des résidus de récolte (T3) recyclés encompost et fumier, respectivement. La nutrition minérale des cotonniers et les rendements des cultures ont été évalués. La nutrition des cotonniers en N, P, K et S est satisfaite et n’est pas améliorée par le compost ou lefumier, issu du recyclage des résidus de récolte. On observe au bout de 13 années, de fortes carences en azote (F(N) < 69) et en potassium (F(K) < 80) ainsi qu’une déficience en soufre uniquement sur les cotonniersrecevant la fumure minérale. La durée d’exploitation des terres entraîne des baisses de rendement élevées avec l’exportation résidus de récolte (T1) sur le coton, le maïs et le sorgho. Le recyclage des résidus en compost ou fumier permet de réduire deux à trois fois ces baisses de rendement en 25 ans. L’étude recommande une gestion intégrée des résidus de récolte et l’utilisation du phosphate naturel pour la durabilité des systèmes de culture

Effets de la gestion des résidus de récolte sur les rendements et les bilans culturaux d'une rotation cotonnier-maïs-sorgho au Burkina Faso

Crops Residues Management Effects on Crops Yields and Mineral Balance in a Cotton- Maize- Sorghum Rotation in Burkina Faso. The effect of crop residues management on crops yields and nutrients balances in a cotton-cereals cropping system was studied in a long-term experiment carried out from 1982 to 2006. The experimental design was a simple nonrandomized blocks comparing extensive management of crops residues (T1), semiintensive management of crops residues (T2) and intensive management of crops residues (T3). Crops yields, soil chemical properties and mineral balances were measured. Results showed that after 25 years, soil carbon contents decrease was respectively 44%, 15% and 13%, with an extensive, semi-intensive and intensive management of crops residues. Total phosphorus decrease was 25% in all the treatments. Exchangeable Ca and Mg declined from 2.43 to 1.37 cmol+ kg-1 and 0.9 to 0.29 cmol+ kg-1 respectively while the Sum of Exchangeable Bases declined from 3.79 to 1.79 cmol+ kg-1. Recycling crops residues to compost and manure increased cotton yields from 13 to 22 %, maize yields from 45 to 60 %, and sorghum yields from 19 to 44%. Mineral balance in N, P, K and S was improved after 25 years of continuous cultivation while using compost or manure. At the same time, the decline of soil properties was due to nutrients losses which need to be evaluated. This study recommends integrated crops residues management and the use of rock phosphate to improve sustainability in cottoncereals cropping systems

Effets des amendements locaux sur les rendements, les indices de nutrition et les bilans culturaux dans un système de rotation coton-maïs dans l'ouest du Burkina Faso

ffects of local amendments on yields, nutrition indexes and mineral balances in a cotton-maize rotation system in the west of Burkina Faso. After 20 years of continuous cropping system on a tropical ferruginous soil, the effects of three amendments on crop yield and nutrients uptake were studied for two years in this system. Compost, phosphate rock and dolomite amendments at respectively the rate of 6, 0.3 and 1.5 t.ha-1 were compared to the control soil not amended. The experimental design was a block Fisher with three amendments and four replications. Cotton (Gossypium hirsutum L.) and maize (Zea mays L.) mineral nutrition were determined as well as their yields. These plants dry matter productions were measured after harvesting. Results showed that compost, phosphate rock and dolomite application to soil improved the dry matter production of cotton and maize plants. Soil amendment with 6 t.ha-1 of compost significantly improved cotton seed and maize production. In the same time, the application of 1.5 t.ha-1 of dolomite limestone significantly increased maize yield. The application of phosphate rock (0.3 t.ha-1) had no effect on cotton or maize yields as well as their dry matter production. Compost, phosphate rock and dolomite application to soil had no influence on cotton and maize plants contents in N, P and K. Seventy days after sowing, the amendments did not improve cotton nutrition indexes which revealed a good nutrition for P, K and S. Nutrition indexes indicated that N deficiencies in cotton plants with amended soils (IN < 80) were more important than those observed with cotton plants grown on control soil (IN = 84). The application of mineral fertilizer to the control soil or to amended soils gave positive balances for nutrients like P (45 to 100 kg.ha-1) and S (5 to 24 kg.ha-1), while soils amended with phosphate rock and dolomite showed a high deficit for N and K, compared to the control soil. The study showed that compost combined to mineral manures could improve soil fertility due to the nutrients excess balances in N, P and S