Assessing Smallholder Farmers’ Perception on Climate Variability in Relation to Climatological Evidence: A Case Study of Benguene in the Sudanian Zone of Mali

Sudanian zone is one of the regions in West Africa most confronted with high climate variability, challenging agricultural sustainability and rural livelihoods. Despite multiple research efforts devoted to exploring how farmers in this region perceive climate variability and how perceptions relate to adaptive responses, much remains to be done. This study examined farmers’ perception of climate variability compared with scientific evidence in the terroir of Benguene, between 1983 and 2018. Data was collected from twenty-nine (29) farmland heads (representing 49% of the total farmland heads in the village) through a survey conducted in October 2019. Monthly temperature data from ground measurement and daily rainfall data extracted from the gridded African Rainfall Climatology version 2 (ARC-2) time series was used. Descriptive statistic was used to analyse survey data. Climate data analysis included Mann Kendall trend analysis and computation of growing season parameters (Onset, Duration and Cessation) and its trend. In the end, a conformity index was used to compare farmers’ perceptions to climatological evidence. Conformity graph showed that apart from temperature, the farmers have low, to a weak perception of the other variables used to assess their perception. Results showed that many smallholder farmers have observed a rise in temperature (90%), delay onset (93%) and early cessation (93%) of rainfall. The analysis of the climate data showed high variability in the climate during the study period as observed in the increasing trends in temperature (p-value of 0.0007) and in the rainfall (p-value of 0.0001). Concerning the season parameters, the results show increasingly early-onset (June 1st ± 22 days) increasingly late cessation (October 09th ± 14 days) and consequently a long duration of the rainy season (130 ± 27 days). Conversely, farmers thought the opposite. These results imply the urgent need to increase smallholder farmers awareness of climate variability and change by providing climate information for better adaptation

Mycorrhizal Status of Natural Stands of Pterocarpus erinaceus Poir. (Fabaceae) in Sudanian and Guinean Zones of West Africa

Background and Aims: The sylviculture of Pterocarpus erinaceus is still in its infancy due to lack of information on its biology. The aim of this study is to investigate its mycorrhizal status in order to better address its sylviculture. Place and Duration of Study: The study was performed on the field from May 2019 to December 2020 and data were analyzed at the laboratory from January to March 2021. Methodology: The frequency and intensity of mycorrhization were determined under a microscope after staining with trypan blue of fine roots collected at a depth of 20 cm under adult plants at 5 sites, 3 in the Guinean zone and 2 in the Sudanian zone in Togo. The spore density was obtained on soil samples taken at the same depth under the same trees. Results: Results indicate, without significant differences (P value = 0.166) among sites, and show that P. erinaceus is frequently mycorrhized (88% to 94%). However, there were significant differences (P value = 0.001) in spore densities between sites located in the Sudanian zone (16.53 ± 1.25 and 10.66 ± 0.71 spores per gram of soil – SPGS – respectively for the Fazao-Malfakassa and Oti-Kéran-Mandouri) and those located in the Guinean zone (4.54 ± 0.3, 2.93 ± 0.43 and 3.76 ± 1.01 SPGS respectively at Abdoulaye, Hahomegbe and Togodo). There are significant differences between mycorrhization intensities Togodo which has a mycorhization intensity of 33.52 ± 2.54 and other sites. The redundancy analysis carried out by taking into account substrates’ chemical characteristics shows that spore density remains low when phosphorus and nitrogen are important in the rhizosphere whereas the intensity of mycorhizations is low when PHKCl is high. Conclusion: This study provided evidence of mycorrhizal symbiosis in Pterocarpus erinaceus whether in the Sudanian or Guinean zone. Chemical quality of the growing substrate has an influence on parameters of mychorization. Further studies should therefore allow an assessment of the degree of dependence of this species with respect to the possible benefits associated with this symbiosis.

Improvement of sorghum productivity through introducing integrated soil fertility management options in the Northern Sudanian zone of Burkina Faso

Agricultural intensification is a necessity to ensure food security in the Sahel countries. This study aimed at assessing the effects of technological packages of integrated soil fertility management on sorghum productivity. An experiment was set up in dispersed blocks design where each producer constituted a repetition. Fertilizers were applied using the microdose technique. The results showed that the best grain yields of sorghum are obtained with the technology combining stone bunds + zaï + NPK + urea with respectively 1428.70 kg / ha in 2018 and 1158.40 kg / ha in 2019. The grain yield gaps between the current farmers’ practice under stone bunds and ISFM packages varied from 5.66% to 44.45% in 2018 and from 25.15% to 53.80% in 2019. In the context of climate variability and climate change, these results show that water harvesting techniques such as stone bunds and the zaï, associated with microdose are viable and sustainable alternative for improving agricultural productivity. L’intensification agricole est une nécessité pour assurer la sécurité alimentaire dans les pays du sahel. Cette étude avait pour objectif d’évaluer les effets de paquets technologiques de gestion intégrée de la fertilité des sols sur la productivité du sorgho. Pour ce faire, un dispositif en blocs dispersés a été mis en place en milieu paysan où chaque producteur constituait une répétition. Les paquets technologiques se composent des formules de fumures et/ou des techniques de conservation des eaux et des sols (CES). Les engrais ont été apportés selon la technique de la microdose. Les résultats ont montré que les meilleurs rendements grains du sorgho ont été obtenus avec la technologie cordons pierreux + zaï + NPK + urée avec respectivement 1428,70 kg/ha en 2018 et 1158,40 kg/ha en 2019. Les gaps de rendement grains entre la pratique actuelle des producteurs sous cordons pierreux et les paquets technologiques ont varié de 5,66% à 44,45% en 2018 et de 25,15% à 53,80% en 2019. Dans le contexte de la variabilité et des changements climatiques, ces résultats montrent que la collecte et la valorisation de l’eau à la parcelle à travers les cordons pierreux et le zaï, associée à la microdose est une alternative viable et durable d’amélioration de la productivité agricole.

Decomposition and nutrient release from the mixed leaf litter of three agroforestry species in the Sudanian zone of West Africa

This study was carried out to determine the rates of decomposition and nutrient release from pure and mixed leaf litter samples of three agroforestry species (Azolla africana Desv., Detarium microcarpum Guill. and Perr. and Vitellaria paradoxa C.F.Gaertn.) that have potential use as green manure. Litterbags containing a total of 5 g of pure and mixed leaf litter of different quality levels were incubated under field conditions from July to November in 2017. Litter decomposition and nutrient release (N, P, and K) rates were assessed in each litterbag. The decomposition rate (k) indicated that pure A. africana litter decomposed faster (k = 0.406 week−1) than its mixture with V. paradoxa (k = 0.114 week−1) and D. microcarpum (k = 0.103 week−1). The slowest decomposition rates were found for the pure D. microcarpum (k = 0.075 week−1) and V. paradoxa (k = 0.071 week−1) leaf litters. Mixing with A. africana litter increased the decomposition rate of both D. microcarpum and V. paradoxa leaf litter. We conclude that mixing litter of different quality can accelerate the decomposition of pure litter with poor quality and represents a practical biomass management option for farmers to improve nutrient cycling in agroforestry systems.

Relations between the ecological conditions and the properties of Pterocarpus erinaceus Poir. wood from the Guinean-Sudanian and Sahelian zones of West Africa

Pterocarpus erinaceus (Poir) is currently the most exploited and threatened spontaneous tree species in the Guinean-Sudanian and Sudano-Sahelian zones in West Africa. This work analyzed the density and color parameters of P. erinaceus wood in the phytogeographic zones (Sudanian, Guinean and Sahelian) in three countries in West Africa (Togo, Burkina Faso and Niger). The results obtained by studying 451 specimens taken from 95 trees showed significant differences in basic density and color parameter values (P < 0.001) based on phytogeographic zones. Individual tree samples from the Sahelian zone were denser (780 ± 63 kg · m − 3), darker (L* = 48.3 ± 0.6) and redder (a* = 8.2 ± 2) than those in the Guinean zone (basic density = 684 ± 53 kg · m−3; L* = 59.7 ± 0.5; a* = 6 ± 0.2) and the Sudanian zone (basic density = 725 ± 70 kg · m−3; L* = 53.7 ± 0.40; a* = 7.30 ± 0.2). At intra-tree scale, the results did not show a significant variation of basic density according to the number of rings counted from the pith (P > 0.05). This indicated that the age of the trees has little influence on the basic density of P. erinaceus wood.

On-farm management and participatory evaluation of pigeonpea (Cajanus cajan [L.] Millspaugh) diversity across the agro-ecological zones of the Republic of Benin

Background: Pigeonpea is a multipurpose food legume crop that contributes to food security in the Republic of Benin. For the establishment of conservation and breeding programs, previous ethnobotanical surveys on pigeonpea were done in Benin but restricted to south and central regions. In previous years, pigeonpea landraces were introduced in northern Benin for soil fertility management; it is therefore important to evaluate the diversity in this legume in this region. Exhaustive documentation of pigeonpea diversity grown in the Republic of Benin will be necessary for effective breeding and conservation programs. Therefore, the aim of this study was to document genetic diversity of pigeonpea, across the agro-ecological zones of the Republic of Benin for its promotion and valorization.Methods: A total of 500 pigeonpea farmers representing thirteen sociolinguistic groups were selected from 50 villages. The data were collected using methods and tools of participatory research appraisal. Folk nomenclatures, taxonomy of pigeonpea and seed system were investigated. The distribution and extent of pigeonpea landraces were evaluated using the Four Square Analysis method. A comparative analysis of pigeonpea use categories production systems, production constraints, famers’ preference criteria and participative evaluation for existing landraces across agro-ecological zones was done.Result: Folk nomenclature and taxonomy were mainly based on seed coat colour and size. Seven pigeonpea use categories were recorded including sacrifice, grain processing and fertilization. The results showed that the pigeonpea seed system is informal. Based on seed characteristics, fifteen landraces were recorded including seven new landraces. The Sudano-Guinean zone contained the highest number (11) of landraces. The average number of landraces per village was 2.7. A high rate of landraces facing threat of disappearance was observed across the ecological zones. Ten constraints are known to affect pigeonpea production in Benin, with pests and diseases as the most critical in all agro-ecological zones. This study revealed that pigeonpea cultivation is increasing in the Sudanian zone. Varieties to be produced must be selected based on 11 criteria which included precocity and resistance to pests and diseases in the three ecological zones and adaptability to any type of soil in the Sudanian zone. The participatory evaluation revealed the existence of a few performing cultivars.Conclusions: Our results revealed that implementation of a pigeonpea genetic conservation program in Benin must take into account the diversity, production constraints and varietal preference, which varied according to agro-ecological zones. In situ and ex situ conservation strategies are important to preserve pigeonpea landraces. Morphological and molecular characterizations of identified cultivars are highly recommended to help select suitable varieties for breeding programs.

On-farm management and participatory evaluation of pigeonpea (Cajanus cajan [L.] Millspaugh) diversity across the agro-ecological zones of the Republic of Benin

Background: Pigeonpea is a multipurpose food legume that contributes to food security in Benin. However, its production declined and some landraces are being threatened to disappear. For establishment of conservation and breeding programs previous ethnobotanical surveys on pigeonpea were done in Benin but restricted to south and central regions. Knowing that in past years, pigeonpea landraces were introduced in northern Benin for soil fertility management, it is therefore important to evaluate the diversity of this legume in this region. Exhaustive documentation of pigeonpea diversity grown in the Republic of Benin is necessary for effective breeding and conservation programs. Therefore, this study aimed to document genetic diversity of pigeonpea, across the agro-ecological zones of the Republic of Benin for its promotion and valorization.Methods: 500 producers of pigeonpea belonging to thirteen sociolinguistic groups were selected through 50 villages. Data were collected using methods and tools of participatory research appraisal. Folk nomenclatures, taxonomy of pigeonpea and seed system were investigated. The distribution and extent of pigeonpea landraces were evaluated using the Four Square Analysis method. A comparative analysis of pigeonpea uses categories, production systems, pigeonpea production constraints, famers’ preference criteria and participative evaluation for existing landraces across agro-ecological zones was done.Result: Folk nomenclature and taxonomy were mainly based on seed coat colour and size. Seven pigeonpea use categories were recorded including sacrifice, grain processing and fertilization. The results showed that the pigeonpea seed system is informal. Based on seed characteristics, fifteen landraces were recorded with seven new landraces. The Sudano-Guinean zone contained the highest number (11) of landraces. The average number of landraces per village was 2.7. A high rate of landraces threatened to disappear was observed across the ecological zones. Ten constraints are known affecting pigeonpea production in Benin with pests and diseases as the most important in all agro-ecological zones. This study revealed that pigeonpea cultivation is increasing in the Sudanian zone. Varieties to be produced must be selected on the basis of 11 criteria among them precocity and resistance to pests and diseases, in the three ecological zones and adaptability to any type of soil in the Sudanian zone were the most important. The participatory evaluation revealed the existence of a few performing cultivars.Conclusions: Our results showed that to implement a pigeonpea genetic conservation program in Benin, it would be necessary to take into account the diversity, production constraints and criteria of varietal preference, which varied according to agro-ecological zones. In situ and ex situ conservation strategies are important to preserve pigeonpea landraces. Morphological and molecular characterizations of identified cultivars are highly recommended to help select suitable varieties for breeding programs.