Effect of rain drop washes on soil fertility in cotton production zone of Burkina Faso

Crop production in the Sahel is limited by nutrients availability. The study aimed to estimate the contribution of avifauna, crop rotation and trees to soil fertility and crop production improvement. Pot experiment was carried out with soils sampled in Faidherbia albida parklands in cotton production zone of West Burkina Faso. The treatments consisted of two levels of sampling sites (outside and under the crown of Faidherbia albida), three types of previous crop (fallow, maize and sorghum) and two levels of fertilization (normal rain drop and raindrop washes). Results showed that cotton plants height were affected by sampling site and previous crop between 30 and 80 days after sowing. Rain drop washes contained nutrients that can help to improve soil fertility although their nutrients level in the soil is too small to have an impact significant on cotton plant development. No significant difference was observed between factors for the number of nodes and generative branches except for sampling site. Nutrients content in cotton plants was affected by the soil sampling site, the previous crop and the fertilization

Investigating optimal cutting configurations for the contour method of weld residual stress measurement

The present work examines optimal cutting configurations for the measurement of weld residual stresses (WRS) using the contour method. The accuracy of a conventional, single-cut configuration that employs rigid clamping is compared with novel, double-embedded cutting configurations that rely on specimen self-constraint during cutting. Numerical analyses examine the redistribution of WRS and the development of cutting-induced plasticity (CIP) in a three-pass austenitic slot weld (NeT TG4) during the cutting procedure for each configuration. Stress intensity factor (SIF) analyses are first used as a screening tool; these analyses characterise lower stress intensities near the cutting surface when double-embedded cutting configurations are used, relative to SIF profiles from a single-cut process. The lower stress intensities indicate the development of CIP – which will ultimately affect back-calculated WRS – is less likely to occur when using an embedded configuration. The improvements observed for embedded cutting approaches are confirmed using three-dimensional finite element (FE) cutting simulations. The simulations reveal significant localised plasticity that forms in the material ligaments located between the pilot holes and the outer edges of the specimen. This plasticity is caused by WRS redistribution during the cutting process. The compressive plasticity in these material ligaments is shown to reduce the overall tensile WRS near the weld region before this region is sectioned, thereby significantly reducing the amount of CIP when cutting through the weld region at a later stage of the cutting procedure. Further improvements to the embedded cutting configuration are observed when the equilibrating compressive stresses in material ligaments are removed entirely (via sectioning) prior to sectioning of the high WRS region in the vicinity of the weld. All numerical results are validated against a series of WRS measurements performed using the contour method on a set of NeT TG4 benchmark weld specimens

Effect of compost and soil properties on the availability of compost phosphate for white clover ( Trifolium repens L.)

Wide variation in results exists in the literature on the effectiveness of composts to sustain the phosphorus (P) nutrition of crops. The aim of this work was to assess the importance of some soil and composts properties on the utilization of compost-P by white clover (Trifolium repens L.). This study was carried out with samples collected from four composts made from solid kitchen and garden wastes, and with two soil samples taken from the A horizon of a P-rich sandy acidic Dystrochrept and of a P-limited clayey calcareous Eutrochrept. Changes in the amount of inorganic P (Pi) isotopically exchangeable within 1 min (E1min) were measured during 32 weeks in incubated soil-composts or soil-KH2PO4mixtures where P sources had been added at the rate of 50 mg P kg−1 soil. Uptake of compost-P or KH2PO4-P by white clover was measured on the same amended soils during 16 weeks. In both soils, the application of composts resulted after 32 weeks of incubation in E1min values ranging between those observed in the control without P and those observed in the KH2PO4treatment, i.e., in values ranging between 4.2 and 5.9 mg P kg−1 in the sandy acidic soil and between from 1.6 to 4.3 mg P kg−1 in the clayey calcareous soil. The total coefficient of utilization of compost-P (CU-P) by white clover reached values in both soils for the four composts ranging between 6.5% and 11.6% of the added P while in the presence of KH2PO4 the CU-P reached values ranging between 14.5% in the clayey calcareous soil and 18.5% in the sandy acidic soil. Results obtained in the sandy acidic soil suggest, that white clover initially used a fraction of the rapidly exchangeable compost P, while at a latter stage plant roots enhanced the mineralisation of compost organic P and took up a fraction of the mineralized P. These relations were not observed in the clayey calcareous soil probably because of its high sorbing capacity for P. In the sandy acidic soil, composts application increased the uptake of soil P by the plant from 31.4 mg P kg−1 soil in the control without P to values ranging between 37.9 to 42.7 mg P kg−1 soil in the presence of composts. This indirect effect was related to a general improvement of plant growth conditions in this soil induced by compost addition (from 9.9 g DM kg−1 soil in the control without P to values ranging between 14.0 to 16.1 g DM kg−1 soil in the presence of composts) and/or to the release of Al- or Fe bound soil P to the solution due to soil pH increase following compost application. Finally the total coefficient of utilization of P (CU-P) derived from KH2PO4 and composts was related to the total amount of N exported by white clover in the P-limited clayey calcareous soil but not in the P-rich sandy acidic soil. This suggests that in a soil where N2 biological fixation is limited by low P availability, the CU-P of a compost by white clover is not only related to the forms of P present in the compost but also to its effect on N nutrition. However, it is not clear whether this improved N nutrition was due to compost mineralisation, or to an indirect compost effect on the N2 biological fixatio

Effet des pesticides sur l’activité microbienne d’un sol ferrugineux tropical du Burkina Faso

L’effet des pesticides utilisés en culture cotonnière sur l’activité microbienne globale des sols a été étudié sur un sol ferrugineux tropical en zone ouest du Burkina Faso. Des échantillons de sol ont été prélevés à 30, 73, et 119 jours après semis du cotonnier. Les analyses de respirométrie, de détermination de la biomasse microbienne et de l’ammonification ont été réalisées. Les résultats indiquent que les doses de pesticides apportées sont insuffisantes pour affecter les bactéries ammonifiantes. En revanche, ces doses perturbent la vie du sol en affectant l’efficience des microorganismes à utiliser la matière organique, en activant tantôt la respiration et la biomasse microbiennes et tantôt en les inhibant.Mots Clés : Pesticide – Sol – Activité Respiratoire – Biomasse Microbienne – Bactérie AmmonifianteThe effect of pesticides used in cotton cultivation on soil global microbial activity was studied on a tropical ferruginous soil in the west zone of Burkina Faso. The soil samples were took at 30, 73 and 119 days after thecotton seeds. The analyses of respirometry, of microbial biomas  determination and of the ammonification were realized. The results indicate that the doses of pesticides that put aren’t enough to affect ammonificate bacteriums. In return, these doses disrupt soil life by affecting microorganism’s efficiency in using organic matter, by stimulating sometimes microbial’s respiration and biomas, and sometimes inhibiting it.Key words: Pesticide – Soil – Respiratory activity – Microbial biomas – Ammonificate bacteriu

Variabilite spatiale des rendements du riz en systeme de riziculture intensive (SRI) en zone office du Niger au Mali

Une étude exploratoire a été menée de 2009 à 2013 en vue d’évaluer la faisabilité technique du Système de Riziculture Intensive (SRI) dans cinq localités de l’Office du Niger. Le protocole expérimental comprenait 3 traitements : pratique paysanne avec la dose recommandée de fumure minérale (T1) ; méthode SRI avec 10 tonnes de fumier plus la dose d’engrais recommandée (T2) et méthode SRI avec 10 tonnes de fumier et la moitié de la dose vulgarisée de fumure minérale (T3). En plus, deux essais factoriels comprenant les combinaisons fumier X azote et phosphore X azote ont été conduits en station. Durant les 3 années d’étude, les rendements ont varié entre 4,5 et 10 t ha-1 et plus avec la méthode SRI et entre 3 et 8t ha-1 avec la méthode conventionnelle. En outre, une relation positive entre les pratiques de gestion des cultures et les rendements en milieu paysan a été observée. Il en a été de même pour les rendements et les facteurs sol notamment N et P. Dans près de 50 % des cas, la variabilité des rendements pouvait être expliquée par des pratiques culturales, et de gestion de la fertilité et de l’eau.Mots clés : Système de Riziculture Intensive, variabilité spatiale, facteur sol, fertilisation minérale, fumie

Composition chimique d’un extrait aqueux de bridelia ferruginea benth. (euphorbiaceae) et études de ses effets toxicologique et pharmacologique chez les mammifères.

La caractérisation des constituants chimiques de l’extrait aqueux de Bridelia ferruginea (SEA) a révélé la présence de quinones, de tanins catéchiques et galliques, d’alcaloïdes, de stérols, de polyterpènes, de polyphénols, de composés réducteurs, de flavonoïdes et de saponosides.L’étude de la toxicité aiguë de SEA, réalisée sur des souris, a montré que l’extrait aqueux de Bridelia ferruginea administré par voie orale est modérément toxique (DL50 égale à 3568,88 ± 308,45 mg/kg PC). En revanche, la même substance est très toxique (DL50 égale à 111,38 ± 29,3 mg/kg PC) lorsqu’elle est administrée par voie intrapéritonéale. Pour des doses comprises entre 5.10-3 g/kg de PC et 4.10-2 g/kg de PC, SEA provoque une hypotension dose-dépendante chez le lapin. Cette hypotension étant inhibée par l’atropine, l’extrait aqueux de Bridelia ferruginea contiendrait probablement des substances cholinomimétiques de type muscarinique.Mots-clés : Bridelia ferruginea, toxicologie, phytochimie, pharmacologie

Obstetric emergencies in a humanitarian context at the Somine Dolo hospital in Mopti, Mali

Background: Conflicts are a barrier to physical and financial access to health centers. Our objective was to evaluate obstetric emergencies in a humanitarian context at the Sominé DOLO hospital in Mopti.Methods: This was a descriptive and prospective longitudinal study from January to September, 2020 in the obstetrical gynecology department of the Sominé DOLO hospital in Mopti. Our objective was to evaluate obstetric emergencies in the humanitarian context.Results: The frequency of patients evacuated was 30.61%. The average age of the patients was 27 years with extremes of 15 and 49 years. Hemorrhage during pregnancy was the main cause of reference with 23.83%. The ambulance was the most used means of transport with 51%. Delay in evacuation was observed in 31.33 cases. About 73.03% of our patients had given birth by caesarean section. We recorded 64 maternal deaths, a rate of 10.67%. Fetal mortality in our study was 23.28%. Attacks by armed groups had a negative impact on the referral/evacuation system.Conclusions: The health system had experienced severe challenges due to insecurity. Armed conflicts were the cause of evacuation delays. Haemorrhage during pregnancy was the main reference cause. Maternal and perinatal mortality was high

Нацистські окупаційні порядки в українському селі крізь призму народнопісенної сатири

Une étude parasitologique du paludisme a été réalisée dans deux quartiers centraux de la ville de Yaoundé pendant un an. Le quartier Essos borde un bas-fond marécageux et le quartier Obili présente des bassins de pisciculture. Les enquêtes, trimestrielles, ont été réalisées sur un échantillon de 22 et 16 familles à Essos et Obili respectivement. 960 prélèvements sanguins ont été examinés dans les deux quartiers. La prévalence plasmodiale est de 25,4 plus ou moins 2,7%, l'indice gamétocytique de 1,7 plus ou moins 0,8% et la charge parasitaire moyenne de 310 parasites/microlitre de sang. L'indice plasmodique est significativement plus élevé à Essos qu'à Obili : 28,7 plus ou moins 3,6% (n=592) et 20,1 plus ou moins 4,1% (n=368) respectivement (p<0,02). C'est chez les enfants de 6 à 15 ans que l'indice plasmodique est le plus élevé (37,5%) mais ce sont les enfants de 0 à 5 ans qui présentent les charges parasitaires moyennes les plus élevées (1100 parasites/microlitre de sang). La prévalence parasitaire présente des fluctuations saisonnières avec un maximum pendant la petite saison sèche. (Résumé d'auteur

Forms and exchangeability of inorganic phosphate in composted solid organic wastes

Switzerland yearly produces more than 260,000 Mg of compost, two thirds of which is recycled in agriculture and horticulture. This research was undertaken to examine the forms and availability of inorganic P (Pi) in Swiss composts made from solid kitchen and garden wastes using the isotopic exchange kinetic technique, a sequential Pi extraction and magic angle spinning (MAS) solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. The different approaches described in this paper demonstrate the presence of a complex mixture of Pi species in the studied composts. Isotopic exchange experiments and sequential extraction showed that these composts contained relatively large concentrations of rapidly available Pi. Significant correlations were observed between the concentration of water-soluble Pi (Cp), and the total N, C and P content of composts suggesting that organic substances partly controlled the amount of rapidly available Pi. Significant correlations were observed in alkaline composts between the amount of Pi which can not be exchanged within 3 months and the total P and Ca content. In alkaline composts solid-state MAS 31P NMR results suggested the presence of a range of slightly soluble and poorly crystallized Ca-P compounds such as apatites or octacalcium phosphates and of organic P compounds. The slowly or non-exchangeable Pi present in these composts could therefore be bound to Ca in the form of apatites or octacalcium phosphate

Combustibles des ménages et modes d’utilisation à l’échelle du terroir de Vipalogo, en zone nord soudanienne du Burkina Faso

Au Burkina Faso, les besoins en combustibles énergétiques sont satisfaits surtout par le bois d’énergie. En milieu rural, le bois contribue pour 95% à la satisfaction des besoins énergétiques des ménages. Une meilleure connaissance de l’importance du bois et autres combustibles dans la satisfaction des besoins et des modes de consommation du combustible permettraient une meilleure gestion des formations végétales. Pour ce faire, à l’échelle du terroir de Vipalogo, 30 exploitations ont été retenues au hasard, et enquêtées sur les combustibles énergétiques utilisés. Des mesures de consommation de combustibles ont aussi été menées régulièrement à trois périodes de l’année, période froide et sèche, saison sèche et chaude et en saison pluvieuse. A Vipalogo, les ménages utilisent 1129,8 m3 de bois par an. La consommation maximale de bois par personne et par jour atteint 1,12 kg en période froide contre 0,90 kg en période chaude et 0,67 kg en période pluvieuse. En outre, il ressort qu’il y a des espèces préférentielles qui répondent à un certain nombre de critères en fonction de l’usage. Si pour tous les usages, l’aspect abondance est cité, pour le bois de feu, le critère qualité de combustion est le plus signalé. Les ressources ligneuses sont prélevées à 29,6% dans les champs de cases et de brousse et le reste dans les zones non cultivées,  essentiellement les savanes. Les brousses et les jachères apportent la plus grande contribution à la satisfaction des besoins des populations en ressources ligneuses. Il ressort aussi un éloignement progressif des lieux de collecte qui dénote d’une raréfaction du produit.Mots clés : combustibles énergétiques, ménage, bois, résidus de récolte, champ, jachère