Caractérisation physico-chimique des sols en vue de l’amélioration de la productivité du manioc (Manihot esculenta Crantz) dans la région de Damara au centre-sud de Centrafrique

La présente étude vise à améliorer la productivité du manioc (Manihot esculenta), aliment de base des centrafricains. Plus spécifiquement, il s’agit de (i) caractériser les propriétés physico-chimiques du sol et (ii) déterminer les indicateurs de fertilité des sols étudiés. La collecte des données a consisté à prélever le sol de la couche 0-20 cm, sur les champs de manioc du site expérimental de LaSBAD. Les sols ont été prélevés suivant un dispositif de randomisation, en vue de constituer un échantillon composite de 1 kg par champs. Ils sont séchés, tamisés et analysés au laboratoire de sol du CIRAD-Montpellier-France. Les résultats analytiques de sol ont été comparés à des valeurs de références. Les sols étudiés présentent une texture loameuse et un pH optimal de 5,5, favorable à la culture du manioc, et sont très pourvus en matière organique. Le bilan des éléments nutritifs révèle des carences en calcium et en échangeable. L’analyse en composantes principales a montré une corrélation entre les indicateurs de la fertilité des sols. L’utilisation des légumineuses et la fertilisation organo-minérale à une dose adéquate sont des solutions envisageables pour améliorer la productivité du manioc en Centrafrique.Mots clés: indicateur de fertilité, productivité, manioc, propriété physico-chimique, CentrafriqueEnglish Title: Characterization physicochemical soils to improve productivity of cassava (Manihot esculenta Crantz) in the region of Damara in south-central of Central African RepublicEnglish AbstractThe present study is a contribution to the improvement of cassava (Manihot esculenta) tubers’ productivity in the Republic of Central Africa. Especially it aims to characterize the physicochemical properties of soil and (ii) assess fertility indicators of soil. Data collection was consisted to sample the soil from horizon 0-20 cm in cassava fields of producers and the agricultural site of the LaSBAD. Soils were sampled randomly to form a composite sample of 1 kg per field. Soil samples were dried, sieved, and analysed within the laboratory of soil of CIRAD in Montpellier-France. The analytical results of soils were compared to reference values. The studied soils are in their surface organic loamy texture and optimal of 5.5 pH suitable for the cultivation of cassava. They are well supplied with organic matter. The nutrient balance showed that the most significant deficiencies include calcium and magnesium exchangeable. The principal component analysis showed a best correlation relationship between indicators of soil fertility. The use of legumes, and fertilization organicmineral at one dose adequate were possible conceivable solutions to improve cassava in Central African Republic.Keywords: Diagnosis of deficiency, soils’ fertility, cassava, savannah, Central African Republi

Red wine and pomegranate extracts suppress cured meat promotion of colonic mucin-depleted foci in carcinogen-induced rats

Processed meat intake is carcinogenic to humans. We have shown that intake of a workshop-made cured meat with erythorbate promotes colon carcinogenesis in rats. We speculated that polyphenols could inhibit this effect by limitation of endogenous lipid peroxidation and nitrosation. Polyphenol-rich plant extracts were added to the workshop-made cured meat and given for 14 days to rats and 100 days to azoxymethane-induced rats to evaluate the inhibition of preneoplastic lesions. Colons of 100-d study were scored for precancerous lesions (mucin-depleted foci, MDF), and biochemical end points of peroxidation and nitrosation were measured in urinary and fecal samples. In comparison with cured meat-fed rats, dried red wine, pomegranate extract, α-tocopherol added at one dose to cured meat and withdrawal of erythorbate significantly decreased the number of MDF per colon (but white grape and rosemary extracts did not). This protection was associated with the full suppression of fecal excretion of nitrosyl iron, suggesting that this nitroso compound might be a promoter of carcinogenesis. At optimized concentrations, the incorporation of these plant extracts in cured meat might reduce the risk of colorectal cancer associated with processed meat consumption

Leaf and roots yields responses of three improved cassava (Manihot esculenta Crantz) varieties to organo-mineral fertilizers and leaf harvest in the South-West Nigeria

Open Access Article; Published online: 17 Aug 2020L’étude a été menée dans l’objectif d’évaluer la production de trois variétés améliorées de manioc en réponse à la récolte des feuilles et aux fertilisants NPK, compost et Compost-NPK. L’essai a été fait selon le dispositif en split-split plot, à blocs aléatoires complets à trois facteurs et trois réplications. Les récoltes ont été réalisées à 3 mois et 5 mois après la plantation. La récolte finale a été faite à 12 Mois Après la Plantation (MAP). Le résultat montre qu’une différence non significative (p>0,05) a été observée entre les variétés et entre les traitements fertilisants du rendement en feuilles sèches total. La moyenne totale du rendement en feuilles sèches s'élève à 1454,19 kg/ha au niveau du contrôle. Et ce rendement augmente en moyenne de 10,42% en présence du compost, 39,91% quand le mélange Compost-NPK a été appliqué et de 34, 19% en présence de NPK. Le rendement racinaire varie significativement (p˂0,05) en fonction des variétés et traitement de récolte des feuilles. La perte moyenne de rendement sec due à la récolte des feuilles est de 3,86 t/ha soit 45,77%. La perte du rendement racinaire sec a été compensée en moyenne de 35,59% soit 1,64 t/ha par le mélange Compost-NPK, et 24,05% soit 1,11 t/ha quand le NPK a été appliquée. Parmi les variétés, deux répondent aux fertilisants et sont capables de compenser les pertes. L’IITA-TMS-IBA071393 serait un bon candidat pour les petits exploitants dépourvus de moyen d’intrant. This study was carried out to investigate the leaf and root yield response to leaf harvest and the application of NPK fertilizer, compost and the combination of NPK plus compost of three improved cassava varieties. The experiment was a complete randomised split-split plot design with three factors and three replications. Leaf harvest was at 3 months and 5 months after planting (MAP). The final root harvest was at 12 MAP. The leaf dry matter yield was not significantly (p> 0.05) different between varieties and fertilizer treatments. The average leaf yield was 1454.19 kg/ha DM in control. Leaf yield increased by 10.42% when compost was applied, by 39.91% when compost plus NPK was applied and by 34.19% when only NPK was applied. Root yield was significantly (p˂0.05) affected by cassava variety and leaf harvest. Average root DM yield losses were 3.86 t/ha (45.77%) when leaves were harvested. Root DM yield loss was compensated to 35.59% (1.64 t/ha) when compost plus NPK fertilizer was applied and 24.05% (1.11 t/ha) when NPK was applied. Two varieties responded positively to fertilisers and were able to compensate for root yield losses. IITA-TMS-IBA071393 appears a suitable candidate for cassava farmers with small income because it did not require inputs

Defining common criteria for harmonizing life cycle assessments of livestock systems

Animal production intensification puts pressure on resources, leads to environmental impacts, animal welfare and biodiversity issues. Livestock products provide key components of the human diet and contribute to rural territories through ecosystem services such as nutrient and biomass recycling. Life cycle assessment (LCA) is key to assess environmental impacts in livestock systems and products. A harmonization of LCA methods is necessary to improve evaluations in these areas as LCA still lacks accuracy and robustness in addressing sustainability across livestock systems and products. Here, a participatory harmonization approach was applied to provide a framework to evaluate LCAs of current and future livestock systems. A total of 29 workshops with targeted discussions among 21 LCA experts were organised, together with two anonymous surveys to harmonise evaluation criteria. First, key research topics for improving LCAs of livestock systems were identified as follows: i) Food, feed, fuel and biomaterial competition, crop-livestock interaction and the circular economy; ii) Biodiversity; iii) Animal welfare; iv) Nutrition; v) GHG emissions. Next, general evaluation criteria were identified for livestock focussed LCA methods, considering livestock systems characteristics: Transparency and Reproducibility, Completeness, Fairness and Acceptance, Robustness and Accuracy. Evaluation criteria specific to each key topic were also identified. This participatory method was successful in narrowing down general and specific evaluation criteria through targeted discussion. Moreover, this study provided a holistic participatory framework for the evaluation of LCA methods addressing the impacts of livestock systems across a range of key topics which can be further used for other sectors.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: every author in the author list reports financial support from the PATHWAYS consortium project (Grant Agreement No. 101000395) funded through H2020 research programme on Food Security Sustainable Agriculture and Forestry Marine Maritime and Inland Water Research and the Bioeconomy

Effects of sodium nitrite reduction, removal or replacement on cured and cooked meat for microbiological growth, food safety, colon ecosystem, and colorectal carcinogenesis in Fischer 344 rats

Epidemiological and experimental evidence indicated that processed meat consumption is associated with colorectal cancer risks. Several studies suggest the involvement of nitrite or nitrate additives via N-nitroso-compound formation (NOCs). Compared to the reference level (120 mg/kg of ham), sodium nitrite removal and reduction (90 mg/kg) similarly decreased preneoplastic lesions in F344 rats, but only reduction had an inhibitory effect on Listeria monocytogenes growth comparable to that obtained using the reference nitrite level and an effective lipid peroxidation control. Among the three nitrite salt alternatives tested, none of them led to a significant gain when compared to the reference level: vegetable stock, due to nitrate presence, was very similar to this reference nitrite level, yeast extract induced a strong luminal peroxidation and no decrease in preneoplastic lesions in rats despite the absence of NOCs, and polyphenol rich extract induced the clearest downward trend on preneoplastic lesions in rats but the concomitant presence of nitrosyl iron in feces. Except the vegetable stock, other alternatives were less efficient than sodium nitrite in reducing L. monocytogenes growth