Effets de la fertilisation des sols à l'aide des déchets ménagers solides compostés dans les décharges sur le rendement et la qualité chimique de la laitue (Lactuca sativa L.

Une étude a été conduite sur une période de deux ans, à la station de recherche sur le cacao du Centre National de Recherche Agronomique (CNRA) à Divo, en vue d'étudier les effets de la fertilisation organophosphatée sur la fertilité et la microvariabilité verticale de la matière organique, du complexe adsorbant et de quelques équilibres chimiques d'un ferralsol sous cacaoyers en replantation dans la région de Divo. Le dispositif expérimental était un bloc de Fisher à 4 répétitions avec 6 traitements : T 0 (témoin), T 1 (5t.ha-1 de compost), T 2 (5t.ha-1 compost + 184 kg.ha-1 P 2 O 5), T 3 (5t.ha-1 compost + 122,6 kg.ha-1 P 2 O 5), T 4 (5t.ha-1 compost + 92 kg.ha-1 P 2 O 5) et T 5 (184 kg.ha-1 P 2 O 5). La dynamique verticale du complexe adsorbant, de la matière organique et de quelques équilibres chimiques dans les sols sous cacaoyers ont été évaluées par les évolutions de ces paramètres en fonction des traitements et par horizons. Les résultats obtenus ont montré que la fertilisation mixte (organique et minérale) était meilleure que l'amendement organique ou la fertilisation minérale exclusive vis-à-vis du complexe, de la matière organique et des équilibres chimiques. Les traitements T2, T3, T4 et T1 ont amélioré les caractéristiques étudiées. Cependant, le traitement T2 s'est révélé meilleur pour l'amélioration des caractéristiques étudiées par rapport aux autres traitements (T1, T3, T4). La matière organique tout en se minéralisant a aussi permis l'accumulation des éléments nutritifs en surface surtout pour les régimes de fertilisation mixte, pool de l'absorption racinaire chez le cacaoyer. Cette étude a montré que la nutrition phosphatée des cacaoyers replantés peut être assurée convenablement avec une fertilisation organophosphatée à base de compost et d'une faible dose de TSP. Ces résultats pourraient être utilisés par les producteurs de cacao pour une replantation réussie durable, respectant l'environnement.

Photo 4 e de couverture © IRD/T. Chevallier -Culture de haricots amendée par du fumier de ferme à Madagascar.

In Côte d’Ivoire, the sweet potato is little cultivated but stays however a culture of pension and a food mattering in certain regions. This study was conducted to assess the effect of the application of mineral (NPK 15-15-15, NPK 12-22-22) and organic (poultry manure) fertilizers on yield components of sweet potato (Ipomoea batatas (L) Lam). The experiment was conducted over two years (2016 to 2017) in experimental station of National Center of Agronomic Research (CNRA) of Bouaké in the centre of Côte d'Ivoire. The experiment was conducted following a split plot with 2 factors (variety and fertilizers) and 3 replicates. The main factor was variety with 2 levels (variety Irene and variety TIB-440060) and the subplot was fertilizers application consisted 13 levels (200, 300, 400, 500 kg ha-1 of NPK fertilizers combined 5, 10, 15 t ha-1 of organic fertilizer). Thirteen treatments based on poultry manure (T6, T7), chemical fertilizer NPK 15 15 15 (T1, T3, T4, T5) and NPK 12 22 22 (T8, T10, T11, T12) and their combination (T2 and T9) were tested. The experimental results revealed that that the effects of chemical fertilizer treatments, manure and their combination with mineral fertilizers did not influence the measured parameters. The results also showed that fertilizers improved all the agronomic parameters of sweet potato compared to the control treatment during two years of experiment. However, the Irene variety with a mean weight of 180 g tuberous roots was significantly different from the TIB variety with a mean weight of 138.73 g. In the conditions of our study and over the two-year period, producers of sweet potatoes would benefit from using organic fertilizers with the Irene variety.

Objective: The objective of this study was to assess the fertilizing properties of two organic fertilizers (chicken droppings and coprah meal) on the growth parameters of the plantain banana tree (Musa paradisiaca) grown on quaternary sands of the Ivorian coast. Methodology and results: The study was conducted at the Marc Delorme research station of the National Centre for Agronomic Research (CNRA) in southern Côte d'Ivoire on the quaternary sands of the Ivorian coast with the PITA 3 variety of plantain banana tree with chicken droppings and coprah meal. The test was conducted using an experimental device in randomized random blocks with three replicates. Banana tree plants of PITA 3 have been subjected to eight treatments for ten weeks with three chicken dung treatments: T2 (500g/plant), T3 (750g/plant) and T4 (1000g/plant), three coprah meal treatments: T5 (500g/plant), T6 (750g/plant) and T7 (1000g/plant) and a control treatment (without fertilizers). Observations included collar circumference, banana plant size, leaf surface and mean number of live leaves. The results obtained showed that on the quaternary sands of the Ivorian coast, banana plants treated with 750 g/plant of chicken droppings or coprah meal have generated the best growth. However, chicken dung at the 750 g/plant dose yielded the best mean values of plant height (58.24+9.26), collar circumference (17.119 + 2.77), foliar surface (1534.452 cm2) and living leaves (9.16 + 1.46) during the study. Conclusion and application: Soil fertilization in plantain banana cultivation can be adequately ensured in coastal sandy soils by fertilization based on chicken droppings that are relatively accessible to producers with generally very low economic incomes, at a dose of 750 g/plant to ensure the proper growth of plants for a successful, sustainable plantain cultivation that respects the environment. However, in the absence of chicken droppings, the coprah meal also at the dose of 750 g/plant, could be an alternative for fertilization of soils in plantain banana tree culture on the quaternary sands of the Ivorian coast.