Effet du biochar et de la poudre des balles de riz sur la productivité du maïs (zea mays) et les sols au Nord Cameroun

The objective of this study is to evaluate the effects of the application of biochar and rice husk powder combined with mineral fertilizer on the yield of the CMS-9015 variety of maize (Zea mays) and fertility. soils. The field experiment with three replicates covered 18 plots of 2.5 m × 2 m each arranged in a randomized random block design. The base treatment in all plots excepted null control T0 (without fertilizer or amendment) was the fertilizer dose NPK + Urea in full dose and half dose: T1: 100 kg NPK ha-1 + 50 kg N ha-1 (advisable treatment); T2 = 15 t (biochar) ha-1 + 100 kg NPK ha-1 + 50 kg N ha-1; T3 = 15 t (powder) ha- 1 + 100 kg NPK ha-1 + 50 kg N ha-1; T4 = 15 t (biochar) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1 and T5 = 15 t (powder) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1. The agronomic parameters of maize and its yield as well as the physico-chemical properties of the soils after harvest were measured in these plots. The results were analyzed by STATGRAPHICS followed by the Fisher multiple comparison test (α = 0.05). The application of biochar and powder on this soil resulted in an increase in maize yield of +54.64%, +38.46% and +45.88% respectively with treatments T2, T3 and T4 compared to the recommended treatment (T1). The same positive effect was observed on the soil after harvest compared to the recommended treatment for available phosphorus: 8.67 ± 0.19 mg/kg (with biochar) and 6.34 ± 0.21 mg/kg (with the powder) together with the CEC: 22 ± 4.94 meq/100 g with the powder. Biochar and rice husk powder help rehabilitate soil fertility and increase agricultural productivity when combined with chemical fertilizers. They can ensure sustainable agricultural production.L'objectif de cette étude est d’évaluer les effets de l'application du biochar et de la poudre des balles de riz combiné à l’engrais minéral sur le rendement de la variété CMS-9015 du maïs (Zea mays) et la fertilité des sols. L’expérience en champ avec trois répétitions couvrait 18 parcelles de 2,5 m × 2 m chacune disposées suivant un plan en blocs aléatoires randomisés. Le traitement de base dans toutes les parcelles exceptée le témoin nul T0 (sans engrais, ni amendement) était l’engrais NPK + Urée (N) en dose complète et demi-dose : (T1) : 100 kg NPK ha-1 + 50 kg N ha-1 (traitement recommandé) ; T2 = 15 t (biochar) ha-1 + 100 kg NPK ha-1 + 50 kg N ha-1 ; T3 = 15 t (poudre) ha-1 + 100 kg NPK ha-1 + 50 kg N ha-1 ; T4 = 15 t (biochar) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1 et T5 = 15 t (poudre) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1. Les paramètres agronomiques du maïs et son rendement ainsi que les propriétés physico-chimiques des sols après la récolte ont été mesurés dans ces parcelles. Les résultats ont été analysés par STATGRAPHICS suivi du test de comparaison multiple Fisher (α = 0,05). L’application du biochar et de la poudre sur ce sol a entrainé une augmentation du rendement de maïs de +54,64 %, +38,46 % et +45,88 % respectivement avec les traitements T2, T3 et T4 comparé au traitement recommandé (T1). Le même effet positif a été observé sur le sol après la récolte par rapport au traitement recommandé pour le phosphore assimilable : 8,67 ± 0,19 mg/kg (avec le biochar) et 6,34 ± 0,21 mg/kg (avec la poudre) ainsi que la CEC : 22 ± 4,94 méq/100 g avec la poudre. Le biochar et la poudre des balles de riz contribuent à réhabiliter la fertilité des sols et à accroître la productivité agricole lorsqu’ils sont combinés aux engrais chimiques. Ils peuvent assurer une production agricole durable

Mount Cameroon - ein natürliches Freilandlabor zur systematischen Analyse des Einflusses von Zeit, Niederschlag und Temperatur auf die Pedogenese aus vulkanischen Gesteinen

Die Genese von Böden aus vulkanischen Gesteinen ist nicht nur wegen der spezifischen chemischen und mineralogischen Prozesse besonders interessant; mit Blick darauf, dass diese Böden oft außerordentlich hohe Gehalte an organischem Kohlenstoff (Corg) enthalten, ist sie auch hochrelevant. Die hier vorgestellte Studie zielt auf eine quantitative Analyse des Einflusses der Faktoren Zeit (t), mittlerer Jahresniederschlag (MAP) und Jahresmitteltemperatur (MAT) auf die Pedogenese aus basaltischen Pyroklastika unter feucht-tropischen Bedingungen ab. Mount Cameroon bietet optimale Voraussetzungen dazu, den Einfluss dieser Faktoren auf die Pedogenese unabhängig voneinander zu quantifizieren. Der Einfluss des Faktors t wird an Bodenbildungsstadien auf Basaltströmen unterschiedlichen Alters quantifiziert, vom jüngsten Basaltstrom aus dem Jahr 2000 bis zu einige Tausend Jahre alten Basaltströmen. Der Einfluss des Faktors MAP wird entlang eines MAP-Gradienten von >9000 mm a-1 im Westen (an der Küste) bis 2000 mm a-1 im Osten erfasst, der des Faktors MAT entlang des vertikalen MAT-Gradienten von 26-29 °C am Fuß des Mount Cameroon bis 0 °C auf dem Gipfel in 4095 m ü. NN. Die Pedogenese führt überwiegend zu Silandic Andosols, die sich später zu Nitisols weiterentwickeln. Erste Daten von Böden mit bekannter Faktorenkombination geben Hinweise darauf, wie schnell mit zunehmendem Bodenalter die Fed/Fet-Verhältnisse, die Gehalte an Ton und Corg sowie Sio, Alo und Feo zunehmen. Gesamt- und Tonmineralanalysen stützen die Interpretation dieser Daten im Hinblick auf die Bildung von short-range order minerals. Die Röntgendiffraktogramme zeigen jedoch auch erhebliche Gehalte an Magnetit und Gibbsit an, sodass bei der Interpretation der Feo- und Alo-Werte Vorsicht geboten ist. Die Abnahme der molaren (Ca+Mg+K+Na)/Al- und Si/Al-Verhältnisse aufgrund fortschreitender Verwitterung, Entbasung und Desilifizierung unter dem Einfluss des Faktors t wird ebenso quantifiziert. Diese Indices werden zusätzlich durch die Faktoren MAP und MAT beeinflusst. Mit fortschreitendem Bodenalter sind zudem zunehmende Quarzgehalte in den Böden zu beobachten. Da das Ausgangsgestein quarzfrei ist, ist dies ein Hinweis auf Eintrag von Saharastaub, der für Böden des Mount Cameroon in der Literatur bereits beschrieben wurde. Sowohl die Magnetit- und Gibbsitgehalte als auch der Staubeintrag sind daher bei der Beurteilung der Indices im Hinblick auf fortschreitende Bodenentwicklung zu berücksichtigen

Morphological, mineralogical and geochemical characterization of the Danfili-Mambal duricrust formations (Adamawa-Cameroon)

In the present study, duricrust formations of Danfili-Mambal are characterized on morphological, mineralogical and geochemical point of view, in order to identify the different facies and to determine their potential mining. To this end, four hills were explored and samples collected for analysis. The morphological characterization allows to distinguish four facies : massive to sub-nodular, nodular massive, massive and vacuolar. These facies show a spatial distribution : the massive and vacuolar facies occupy the top and the upper slope of the hills, the nodular facies are found at the mid-slope and the sub-nodular facies at the down slope. The mineralogical analysis revealed that all these facies include gibbsite, kaolinite, goethite, quartz, hematite, magnetite and anatase. Gibbsite appears as the most dominant mineral. Geochemically, aluminum oxides (Al2O3) and iron oxides (Fe2O3) are the most abundant (Al2O3 : 29.92% - 56.59%; Fe2O3% : 8.87% - 46.55%). The SiO2 contents as well as Alkali and alkali earth elements were very low. The most represented trace elements are Ba, Sr, V and Zr. Light rare earths were more concentrated than heavy rare earths respectively: 629.66 ppm and 8.30 ppm. The high values of CIA and MIA (> 99.94) associated to the low content of alkali and alkali earth elements supported an intense weathering origin of duricrust. The presence of gibbsite and kaolinite suggested that the main cristallochemical mecanisms are allitisation and monsiallitisation. The average Al2O3 contents (>40%) associated to low content in SiO2 indicates that they are bauxites

Study of the Effect of Biochar Incubation on Some Physico-Chemical Properties of a Tropical Leached Soil from South-West Chad

Soils in the Sudanian zone of Chad, and more specifically leached tropical soils, were subject to physical and chemical degradation phenomena that hamper crop production. Solving this problem requires solutions for the rational improvement of fertility. The aim of this study, conducted in a controlled environment, was to assess the fertilising potential of biochar on impoverished soil by monitoring the kinetics of the evolution and release of chemical elements that improve the physico-chemical quality of the soil. Four treatments were carried out: control soil (T0), treatment 1B: 100g soil + 0.225g biochar (i.e. 5 t/ha), treatment 2B: 100g soil + 0.3375g biochar (i.e. 7.5 t/ha) and treatment 3B: 100g soil + 0.450g biochar (i.e. 10 t/ha). Each treatment was repeated four times. Four main parameters were measured during the trial period: pH, assimilable phosphorus, exchangeable bases and their sums (Ca, Mg, K, Na and SBE) and cation exchange capacity. These different parameters showed that the biochar treatments significantly improved soil quality, whatever the dose and incubation time, compared with the T0 control. Treatment 1B (5t/ha biochar application) increased pH by an average of 6.5%, phosphorus by 132.5%, SBE by 406.1% and CEC by 43.4%. Treatment 2B (application of 7.5 t/ha of biochar) improved pH by an average of 8.5%, phosphorus by 155.1%, SBE by 207.6% and CEC by 46.2%. Treatment 3B (application of 10t/ha of biochar) produced a marked improvement, increasing pH by 11.2%, phosphorus by 198.7%, SBE by 457.6% and CEC by 29.9%. These results further confirm the vital importance of biochar in fertilising impoverished tropical soils. Based on pH, sum of bases and phosphorus, treatment 3B gave better results by considerably increasing the initial chemical element content of the control soil than the other biochar treatments

Effet du biochar et de la poudre des balles de riz sur la productivité du maïs (zea mays) et les sols au Nord Cameroun

The objective of this study is to evaluate the effects of the application of biochar and rice husk powder combined with mineral fertilizer on the yield of the CMS-9015 variety of maize (Zea mays) and fertility. soils. The field experiment with three replicates covered 18 plots of 2.5 m × 2 m each arranged in a randomized random block design. The base treatment in all plots excepted null control T0 (without fertilizer or amendment) was the fertilizer dose NPK + Urea in full dose and half dose: T1: 100 kg NPK ha-1 + 50 kg N ha-1 (advisable treatment); T2 = 15 t (biochar) ha-1 + 100 kg NPK ha-1 + 50 kg N ha-1; T3 = 15 t (powder) ha- 1 + 100 kg NPK ha-1 + 50 kg N ha-1; T4 = 15 t (biochar) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1 and T5 = 15 t (powder) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1. The agronomic parameters of maize and its yield as well as the physico-chemical properties of the soils after harvest were measured in these plots. The results were analyzed by STATGRAPHICS followed by the Fisher multiple comparison test (α = 0.05). The application of biochar and powder on this soil resulted in an increase in maize yield of +54.64%, +38.46% and +45.88% respectively with treatments T2, T3 and T4 compared to the recommended treatment (T1). The same positive effect was observed on the soil after harvest compared to the recommended treatment for available phosphorus: 8.67 ± 0.19 mg/kg (with biochar) and 6.34 ± 0.21 mg/kg (with the powder) together with the CEC: 22 ± 4.94 meq/100 g with the powder. Biochar and rice husk powder help rehabilitate soil fertility and increase agricultural productivity when combined with chemical fertilizers. They can ensure sustainable agricultural production.L'objectif de cette étude est d’évaluer les effets de l'application du biochar et de la poudre des balles de riz combiné à l’engrais minéral sur le rendement de la variété CMS-9015 du maïs (Zea mays) et la fertilité des sols. L’expérience en champ avec trois répétitions couvrait 18 parcelles de 2,5 m × 2 m chacune disposées suivant un plan en blocs aléatoires randomisés. Le traitement de base dans toutes les parcelles exceptée le témoin nul T0 (sans engrais, ni amendement) était l’engrais NPK + Urée (N) en dose complète et demi-dose : (T1) : 100 kg NPK ha-1 + 50 kg N ha-1 (traitement recommandé) ; T2 = 15 t (biochar) ha-1 + 100 kg NPK ha-1 + 50 kg N ha-1 ; T3 = 15 t (poudre) ha-1 + 100 kg NPK ha-1 + 50 kg N ha-1 ; T4 = 15 t (biochar) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1 et T5 = 15 t (poudre) ha-1 + 50 kg NPK ha-1 + 25 kg N ha-1. Les paramètres agronomiques du maïs et son rendement ainsi que les propriétés physico-chimiques des sols après la récolte ont été mesurés dans ces parcelles. Les résultats ont été analysés par STATGRAPHICS suivi du test de comparaison multiple Fisher (α = 0,05). L’application du biochar et de la poudre sur ce sol a entrainé une augmentation du rendement de maïs de +54,64 %, +38,46 % et +45,88 % respectivement avec les traitements T2, T3 et T4 comparé au traitement recommandé (T1). Le même effet positif a été observé sur le sol après la récolte par rapport au traitement recommandé pour le phosphore assimilable : 8,67 ± 0,19 mg/kg (avec le biochar) et 6,34 ± 0,21 mg/kg (avec la poudre) ainsi que la CEC : 22 ± 4,94 méq/100 g avec la poudre. Le biochar et la poudre des balles de riz contribuent à réhabiliter la fertilité des sols et à accroître la productivité agricole lorsqu’ils sont combinés aux engrais chimiques. Ils peuvent assurer une production agricole durable

The Influence of Basalt Powder on the Physicochemical Properties of Impoverished Oxisoils from Ngaoundéré (Adamawa - Cameroon)

The present study aims at assessing the fertilizing potential of basalts on impoverished oxisoils from Ngaoundéré (Adamawa, Cameroon). This specifically involves the application of finely ground basalts on impoverished oxisoils and monitoring changes in physicochemical properties during six months. An experimental design which consisted in a randomized complete block design is constituted of three series of four treatments each one: the control (ST), the control soil mixed with 100 g of finely ground basalt (T0 + BA_10), the control soil mixed with 200 g of finely ground basalt (T0 + BA_20), the control soil mixed with 300 g of finely ground basalt (T0 + BA_30). Each treatment was replicated ten times in every serie. The control treatment is only soils of Ng, collected at the top soil and without any basalt application. They are clayey, acid and display an average CEC. The basalt is rich in silica (47.52%), Calcium (8.22%), Magnesium (4.03%), sodium (4.01%), potassium (2.42%) and displays average content in alumina (16.54%) and iron (11.1%). The experiment was carried out in pots, and the incubated soil samples were analyzed after 0, 1, 2, 4 and 6 months. The analyzes mainly focused on the physicochemical parameters (Grain size analysis, pH, Cation exchange capacity (CEC), the sum of exchangeable bases (SBE) and the saturation rate (V). Obtained results indicated that the application of basalt greatly improved the chemical properties of oxisoils from Ngaoundéré: the pH changes from acidic (5.5) to weakly acidic (6.5); the saturation rate, as well as the sum of exchangeable bases and the cation exchange capacity increased. Physicochemical properties of the soil are closely accompanied by an increase in fertility. It appears that 10 and 20% treatments are the most efficient treatments. Thus, the basalts from Manwi can be recommended as petrofertilizer to improve the chemical properties of impoverished soils and especially for plants requiring alkalis and alkaline earth