Thought the increasing demand Arachis hypogaea L. (groundnut), its yields remain low with increasingly using chemical fertilizers. To reduce the costs for chemical fertilizers inquisition and their long-term toxic eff...Thought the increasing demand Arachis hypogaea L. (groundnut), its yields remain low with increasingly using chemical fertilizers. To reduce the costs for chemical fertilizers inquisition and their long-term toxic effects on soils, microbial bio-fertilizers could be an accessible alternative to peanut farms. Thus, the aim of this study was to assess the performance of rhizobia strains on peanut varieties production. The experiments were conducted in two agro-ecological zones of Benin, in a peasant environment peasant-researcher control or under peasant and researcher control. The experimental device used was a complete random block with nine repetitions and two factors namely inoculation (with Rhizobium sp and without Rhizobium sp) and mineral fertilizer (with N15P15K15 and without N15P15K15). The effects of these factors divided into four treatments were evaluated on the plants vegetative, symbiotic and production parameters. In addition, an evaluation of each treatments’ comparative advantages was carried out. The results showed that the association Rhizobium sp and N15P15K15 induced groundnut plants best vegetative and productive parameters. The best comparative advantages in economic terms were also recorded with the same combination (Rhizobium sp + N15P15K15). Considering the technical performance, the recorded treatments effects can be classified as follows: Control Rhizobium sp 15P15K15 Rhizobium sp + N15P15K15. Thus, the association Rhizobium sp + N15P15K15 induced both the best plants vegetative and productive parameters and the best comparative advantage from an economic point of view. The results also showed that the plants’ response to inoculation, the application of manure and their combination was more marked in the bar soil zone (Covè) than in the cotton zone (Ouessè). Considering the negative effects linked to the use of chemical fertilizers, the use of Rhizobium sp could be an interesting path to increase the groundnut production.展开更多
ISFM （integrated soil fertility management） involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA （New Rice ...ISFM （integrated soil fertility management） involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA （New Rice for Africa） was evaluated to enhance rice productivity and soil-nitrogen. Five dual-purpose early-maturing cowpea cultivars and local cultivar （Katche） were seeded early in the wet season in five farmers＇ fields at Ouake （9046＇ N, 1°35′ E, highly degraded-savanna）, Benin. After pod harvest, cowpea residues were minimally worked into the soil using minimum tillage with hand-hoe and seeded with early-maturing, resilient NERICA8 rice that received either 20 kg N/ha or zero-N. Cowpea grain yield averaged 0.1-0.3 Mg/ha, and mean aboveground cowpea biomass produced and recycled was 0.54-0.64 Mg/ha among best cultivars （IT97-568-11 and IT89KD-288）. NERICA8 seeded after cowpea cv. IT97-568-11 and supplied with 20N gave the greatest grain yield of about 2.0 Mg/ha, accounting for 500% heavier grains than fallow-rice rotation with zero-N. Mineral-N dynamics monitored under NERICA8 in year 2 showed that previous IT97-568-11 plots had the highest mineral-N at tillering which persisted till panicle initiation stage. The adoption of an ISFM comprising annual cowpea-NERICA sequence by smallholder rice farmers could enhance productivity and improve N-supply in fragile savannas.展开更多
Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing ...Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing areas in Benin. Composite soil samples from 13 production areas at a rate of 04 villages per production areas were collected. A spore trapping device was set up to reveal the diversity of spores. The physical and chemical properties of the soils, the frequency and intensity of mycorrhization of roots, and the diversity of AMF spores were determined in the soil samples following trapping. As result, eight morphotypes belonging to four genera: Glomus, Acaulospora Gigaspora and Disversispora and three families: Diversisporales, Glomérales and Paraglomérales were observed. An important variability of spore densities was observed from one production areas to another with a higher abundance in the production areas of Copargo estimated at 3584 spores/100g soil. The biological diversity indexes as Shannon (0.0311), Simpson (0.0204) and Hill (0.0235), varied significantly (p < 0.05) from one production areas to another. There was significant correlation between the parameters studied, particularly between the physico-chemical parameters of the soils and between the physico-chemical parameters and the biological diversity indexes. For the mycorrhization parameters, the mycorhization frequencies did not vary from one production areas to another, unlike the intensities, which significantly varied from one production areas to another (2.31% to 24.62%). Finally, this study revealed that the physico-chemical parameters of the soils had an influence on the other parameters studied. Moreover, there were an abundance and a significant diversification of AMFs associated with soybean in the different production areas, which are influenced by certain physico-chemical soil parameters.展开更多
Bambara groundnut [Vigna subterranea (L.) Verdc.], as a legume, can establish relationships with nitrogen-fixing bacteria such as Rhizobium. However, Rhizobium efficacy is not always optimal due to the lack or poor ef...Bambara groundnut [Vigna subterranea (L.) Verdc.], as a legume, can establish relationships with nitrogen-fixing bacteria such as Rhizobium. However, Rhizobium efficacy is not always optimal due to the lack or poor efficient strains in the soil. This study aimed to evaluate symbiotic efficiency of endogenous Rhizobia nodulating Bambara groundnut and their resistance to abiotic conditions. Root nodules were randomly sampled from three agroecological zones across the country, surface sterilized, ground and paste plated on YEMA media. After 24 hours, the bacterial colonies were purified. The pure cultures were further characterized using morphological and biochemical methods and their resistance to antibiotics and heavy metals was evaluated. Lastly, the symbiotic efficiency of the isolates was assessed through a greenhouse experiment. A total of eighty-five presumptive strains were isolated from Bambara groundnut roots nodules obtained from the farms. The physiological characterization of the isolated showed a decrease in isolates growth when NaCl concentration was more than 7%. In addition, 47% of the isolates were tolerant to a temperature of 40°C. Most of the isolates were highly resistant to Erythromycin in all its concentration levels and to Kanamycin, Spectinomycin, Neomycin and Ampicillin at 10 μg⋅mL<sup>−1</sup>. Most of them showed resistance to Cu and Zn at 10 μg⋅mL<sup>−1</sup>. Results of the effectiveness test on two Bambara groundnut varieties yielded dry shoot matter varying from 3.33 g⋅plant<sup>−1</sup> to 7.21 g⋅plant<sup>−1</sup> for variety 1 and from 4.38 g⋅plant<sup>−1</sup> to 8.38 g⋅plant<sup>−1</sup> on variety 2. N uptake ranged between 0.09 g⋅plant<sup>−1</sup> and 0.29 g⋅plant<sup>−1</sup> for variety 1 and between 0.12 and 0.29 g⋅plant<sup>−1</sup> for variety 2. The isolates yielding higher shoot dry weight and N uptake were LMSEM312, LMSEM338, LMSEM307, LMSEM351 for variety 1 and LMSEM338, LMSEM309, LMSEM307 for variety 2. The isolates showing better performance can be used to develop bio-fertilizer for sustainable Bambara groundnut production in Benin.展开更多
文摘Thought the increasing demand Arachis hypogaea L. (groundnut), its yields remain low with increasingly using chemical fertilizers. To reduce the costs for chemical fertilizers inquisition and their long-term toxic effects on soils, microbial bio-fertilizers could be an accessible alternative to peanut farms. Thus, the aim of this study was to assess the performance of rhizobia strains on peanut varieties production. The experiments were conducted in two agro-ecological zones of Benin, in a peasant environment peasant-researcher control or under peasant and researcher control. The experimental device used was a complete random block with nine repetitions and two factors namely inoculation (with Rhizobium sp and without Rhizobium sp) and mineral fertilizer (with N15P15K15 and without N15P15K15). The effects of these factors divided into four treatments were evaluated on the plants vegetative, symbiotic and production parameters. In addition, an evaluation of each treatments’ comparative advantages was carried out. The results showed that the association Rhizobium sp and N15P15K15 induced groundnut plants best vegetative and productive parameters. The best comparative advantages in economic terms were also recorded with the same combination (Rhizobium sp + N15P15K15). Considering the technical performance, the recorded treatments effects can be classified as follows: Control Rhizobium sp 15P15K15 Rhizobium sp + N15P15K15. Thus, the association Rhizobium sp + N15P15K15 induced both the best plants vegetative and productive parameters and the best comparative advantage from an economic point of view. The results also showed that the plants’ response to inoculation, the application of manure and their combination was more marked in the bar soil zone (Covè) than in the cotton zone (Ouessè). Considering the negative effects linked to the use of chemical fertilizers, the use of Rhizobium sp could be an interesting path to increase the groundnut production.
文摘ISFM （integrated soil fertility management） involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA （New Rice for Africa） was evaluated to enhance rice productivity and soil-nitrogen. Five dual-purpose early-maturing cowpea cultivars and local cultivar （Katche） were seeded early in the wet season in five farmers＇ fields at Ouake （9046＇ N, 1°35′ E, highly degraded-savanna）, Benin. After pod harvest, cowpea residues were minimally worked into the soil using minimum tillage with hand-hoe and seeded with early-maturing, resilient NERICA8 rice that received either 20 kg N/ha or zero-N. Cowpea grain yield averaged 0.1-0.3 Mg/ha, and mean aboveground cowpea biomass produced and recycled was 0.54-0.64 Mg/ha among best cultivars （IT97-568-11 and IT89KD-288）. NERICA8 seeded after cowpea cv. IT97-568-11 and supplied with 20N gave the greatest grain yield of about 2.0 Mg/ha, accounting for 500% heavier grains than fallow-rice rotation with zero-N. Mineral-N dynamics monitored under NERICA8 in year 2 showed that previous IT97-568-11 plots had the highest mineral-N at tillering which persisted till panicle initiation stage. The adoption of an ISFM comprising annual cowpea-NERICA sequence by smallholder rice farmers could enhance productivity and improve N-supply in fragile savannas.
文摘Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing areas in Benin. Composite soil samples from 13 production areas at a rate of 04 villages per production areas were collected. A spore trapping device was set up to reveal the diversity of spores. The physical and chemical properties of the soils, the frequency and intensity of mycorrhization of roots, and the diversity of AMF spores were determined in the soil samples following trapping. As result, eight morphotypes belonging to four genera: Glomus, Acaulospora Gigaspora and Disversispora and three families: Diversisporales, Glomérales and Paraglomérales were observed. An important variability of spore densities was observed from one production areas to another with a higher abundance in the production areas of Copargo estimated at 3584 spores/100g soil. The biological diversity indexes as Shannon (0.0311), Simpson (0.0204) and Hill (0.0235), varied significantly (p < 0.05) from one production areas to another. There was significant correlation between the parameters studied, particularly between the physico-chemical parameters of the soils and between the physico-chemical parameters and the biological diversity indexes. For the mycorrhization parameters, the mycorhization frequencies did not vary from one production areas to another, unlike the intensities, which significantly varied from one production areas to another (2.31% to 24.62%). Finally, this study revealed that the physico-chemical parameters of the soils had an influence on the other parameters studied. Moreover, there were an abundance and a significant diversification of AMFs associated with soybean in the different production areas, which are influenced by certain physico-chemical soil parameters.
文摘Bambara groundnut [Vigna subterranea (L.) Verdc.], as a legume, can establish relationships with nitrogen-fixing bacteria such as Rhizobium. However, Rhizobium efficacy is not always optimal due to the lack or poor efficient strains in the soil. This study aimed to evaluate symbiotic efficiency of endogenous Rhizobia nodulating Bambara groundnut and their resistance to abiotic conditions. Root nodules were randomly sampled from three agroecological zones across the country, surface sterilized, ground and paste plated on YEMA media. After 24 hours, the bacterial colonies were purified. The pure cultures were further characterized using morphological and biochemical methods and their resistance to antibiotics and heavy metals was evaluated. Lastly, the symbiotic efficiency of the isolates was assessed through a greenhouse experiment. A total of eighty-five presumptive strains were isolated from Bambara groundnut roots nodules obtained from the farms. The physiological characterization of the isolated showed a decrease in isolates growth when NaCl concentration was more than 7%. In addition, 47% of the isolates were tolerant to a temperature of 40°C. Most of the isolates were highly resistant to Erythromycin in all its concentration levels and to Kanamycin, Spectinomycin, Neomycin and Ampicillin at 10 μg⋅mL<sup>−1</sup>. Most of them showed resistance to Cu and Zn at 10 μg⋅mL<sup>−1</sup>. Results of the effectiveness test on two Bambara groundnut varieties yielded dry shoot matter varying from 3.33 g⋅plant<sup>−1</sup> to 7.21 g⋅plant<sup>−1</sup> for variety 1 and from 4.38 g⋅plant<sup>−1</sup> to 8.38 g⋅plant<sup>−1</sup> on variety 2. N uptake ranged between 0.09 g⋅plant<sup>−1</sup> and 0.29 g⋅plant<sup>−1</sup> for variety 1 and between 0.12 and 0.29 g⋅plant<sup>−1</sup> for variety 2. The isolates yielding higher shoot dry weight and N uptake were LMSEM312, LMSEM338, LMSEM307, LMSEM351 for variety 1 and LMSEM338, LMSEM309, LMSEM307 for variety 2. The isolates showing better performance can be used to develop bio-fertilizer for sustainable Bambara groundnut production in Benin.
