Agriculture is harming its own future through soil degradation and pollution of the water that it generates. The different chemical analyses carried out on surface waters and the land surveys carried out in the Nakanb...Agriculture is harming its own future through soil degradation and pollution of the water that it generates. The different chemical analyses carried out on surface waters and the land surveys carried out in the Nakanbé basin have shown that agricultural practices contribute to water pollution. The monitoring of nitrate, orthophosphate and BOD5 levels in the dams of Goinré, Ziga and Bagré during the period from August to December revealed that agricultural practices lead to variation in these parameters. The average values for nitrates are 0.833 mg/L in the Goinré fresh waterbody, 1.372 mg/L in the Ziga reservoir, and 1.267 mg/L in the Bagré fresh waterbody. As for ortho phosphate, mean values are 0.357 mg/L in the Goinré reservoir, 0.157 mg/L in the Ziga reservoir and 0.123 mg/L in the Bagré reservoir. These average values are higher than the norms established by Nisbet and Vernaux (1970) for eutrophication. Nitrates and orthophosphate are the elements that contribute to the eutrophication of water surfaces in the Nakanbé basin, although this eutrophication is of low intensity. Of all pesticides encountered in our study sites, 45% are registered by the Sahelian Pesticides Committee (CSP): 35% are non-accredited and 20% are unknown in the global list authorized by the CSP in 2010.展开更多
A French programme, “Réseau de mesure de la qualité des sols: biodiversité des organismes” (RMQS BioDiv) was developed in Brittany (27,000 km2 in the western part of France) as an initial assessment o...A French programme, “Réseau de mesure de la qualité des sols: biodiversité des organismes” (RMQS BioDiv) was developed in Brittany (27,000 km2 in the western part of France) as an initial assessment of soil biodiversity on a regional scale in relation to land use and pedoclimatic parameters. The nematode community assemblages were compared among the land use categories. Crops were characterised by a high abundance of bacterial-feeders, particularly opportunistic bacterial-feeders belonging to Rhabditidae. Meadows presented a higher total abundance of nematodes than did crops (20.6 ind·g-1 dry soil vs. 13.1 ind·g-1 dry soil), and they were mainly linked to the great abundance of plant-parasitic nematodes, particularly Meloidogyne, but with a very high heterogeneity between sampled plots. The nematodes were most abundant in forests (23.7 ind·g-1 dry soil) and presented the most structured community (SI = 82.2 in forests vs. 58.6 and 55.5 in crops and meadows, respectively). Forests had also the higher fungal component (fungal-feeders and facultative plant-feeders belonging to the Tylenchidae) leading to a significant higher part of the fungal decomposition pathway in forests than in crops. The ability of different taxonomic levels of nematode identifica- tion to discriminate among different cropping systems (i.e., continuous cropping system, crop with meadow in the rota- tion, meadow with crop in the rotation and permanent meadow) was also tested. The family level (48 families identified in these samples) was more efficient than the other taxonomic levels (86 taxa, 17 functional guilds and 6 trophic groups): best statistical significant discrimination for time spent in identification. The relation between the nematode ecological indices, the abundance of nematode trophic groups and the crop management practices were studied. The effects of fertilization, ploughing frequency, use of pesticides and management systems on ecological indices, particu- larly on the Maturity Indices, were observed.展开更多
Agriculture practices have been widely proposed as the major cause of amphibian population decline. However, the majority of these results have been based on laboratory experiments. The present study was conducted to ...Agriculture practices have been widely proposed as the major cause of amphibian population decline. However, the majority of these results have been based on laboratory experiments. The present study was conducted to test the repercussion of wetland sediment provenance on amphibian larval development.Bufo bufo larvae were used in two dif ferent treatments in an outdoor experiment, the ?rst one using sediment from one wetland surrounded by intensive agricultural practices, and the second using sediment with no record of agrochemical uses. A negative ef fect was observed in the agricultural treatment, from subcellular to individual level. The results showed that the sediment from agricultural practices watershed generates a reduction in survival. Furthermore, individuals that developed under this treatment showed a lower total length and a delay in the time necessary to complete metamorphosis; these features are connected with recruitment success. In the same way, biochemical analysis showed high values of lipid peroxidation in metamorphs developing in sediments from an agricultural area. Finally, the results obtained highlight the importance of considering the sediments, not only the water, as origin treatment, allowing us to understand the consequences on amphibian populations that inhabit areas af fected by intensive agriculture.展开更多
Bananas and plantains production is an important income source for millions of small farmers. The increased demand for bananas and plantains on national and international market would justify its value chain developme...Bananas and plantains production is an important income source for millions of small farmers. The increased demand for bananas and plantains on national and international market would justify its value chain development. However, its value chain faces several constraints, of which production and marketing turn out to be the most important. This study aimed at determining and analyzing the constraints related to Bananas and Plantains value chain and showing the gaps between agroecological and agricultural practices used by farmers in southern Benin. Characterization was carried out on the seed production systems, agricultural practices, bananas and plantains production, fruit availability and commercialization constraints with farmers using individual and focus groups surveys. Bananas and plantains seedlings production and acquisition varied according to production areas. Their seedlings self-production was widespread in production areas and 26 cultivars have been identified as major. The availability of these cultivars varied across time and production areas. There were significant negative effects of agricultural practices on major banana pest’s presence. Bananas and plantains production was limited by 12 factors, from which banana plants fall related to the wind, lack of financial support to irrigate banana fields, climate changes, no availability of cultivable lands and low rainfall are revealed to be the most important. Regarding commercialization constraints, low sale prices and difficult access to markets were the most important. Better knowledge of bananas and plantains production systems would help to develop sustainable organic farming strategies to reduce the constraints identified.展开更多
文摘Agriculture is harming its own future through soil degradation and pollution of the water that it generates. The different chemical analyses carried out on surface waters and the land surveys carried out in the Nakanbé basin have shown that agricultural practices contribute to water pollution. The monitoring of nitrate, orthophosphate and BOD5 levels in the dams of Goinré, Ziga and Bagré during the period from August to December revealed that agricultural practices lead to variation in these parameters. The average values for nitrates are 0.833 mg/L in the Goinré fresh waterbody, 1.372 mg/L in the Ziga reservoir, and 1.267 mg/L in the Bagré fresh waterbody. As for ortho phosphate, mean values are 0.357 mg/L in the Goinré reservoir, 0.157 mg/L in the Ziga reservoir and 0.123 mg/L in the Bagré reservoir. These average values are higher than the norms established by Nisbet and Vernaux (1970) for eutrophication. Nitrates and orthophosphate are the elements that contribute to the eutrophication of water surfaces in the Nakanbé basin, although this eutrophication is of low intensity. Of all pesticides encountered in our study sites, 45% are registered by the Sahelian Pesticides Committee (CSP): 35% are non-accredited and 20% are unknown in the global list authorized by the CSP in 2010.
文摘A French programme, “Réseau de mesure de la qualité des sols: biodiversité des organismes” (RMQS BioDiv) was developed in Brittany (27,000 km2 in the western part of France) as an initial assessment of soil biodiversity on a regional scale in relation to land use and pedoclimatic parameters. The nematode community assemblages were compared among the land use categories. Crops were characterised by a high abundance of bacterial-feeders, particularly opportunistic bacterial-feeders belonging to Rhabditidae. Meadows presented a higher total abundance of nematodes than did crops (20.6 ind·g-1 dry soil vs. 13.1 ind·g-1 dry soil), and they were mainly linked to the great abundance of plant-parasitic nematodes, particularly Meloidogyne, but with a very high heterogeneity between sampled plots. The nematodes were most abundant in forests (23.7 ind·g-1 dry soil) and presented the most structured community (SI = 82.2 in forests vs. 58.6 and 55.5 in crops and meadows, respectively). Forests had also the higher fungal component (fungal-feeders and facultative plant-feeders belonging to the Tylenchidae) leading to a significant higher part of the fungal decomposition pathway in forests than in crops. The ability of different taxonomic levels of nematode identifica- tion to discriminate among different cropping systems (i.e., continuous cropping system, crop with meadow in the rota- tion, meadow with crop in the rotation and permanent meadow) was also tested. The family level (48 families identified in these samples) was more efficient than the other taxonomic levels (86 taxa, 17 functional guilds and 6 trophic groups): best statistical significant discrimination for time spent in identification. The relation between the nematode ecological indices, the abundance of nematode trophic groups and the crop management practices were studied. The effects of fertilization, ploughing frequency, use of pesticides and management systems on ecological indices, particu- larly on the Maturity Indices, were observed.
基金Supported by the Ministerio de Educación y Ciencia(Spain)Project(No.CGL2007-61482co-funded by the European Regional Development Fund)
文摘Agriculture practices have been widely proposed as the major cause of amphibian population decline. However, the majority of these results have been based on laboratory experiments. The present study was conducted to test the repercussion of wetland sediment provenance on amphibian larval development.Bufo bufo larvae were used in two dif ferent treatments in an outdoor experiment, the ?rst one using sediment from one wetland surrounded by intensive agricultural practices, and the second using sediment with no record of agrochemical uses. A negative ef fect was observed in the agricultural treatment, from subcellular to individual level. The results showed that the sediment from agricultural practices watershed generates a reduction in survival. Furthermore, individuals that developed under this treatment showed a lower total length and a delay in the time necessary to complete metamorphosis; these features are connected with recruitment success. In the same way, biochemical analysis showed high values of lipid peroxidation in metamorphs developing in sediments from an agricultural area. Finally, the results obtained highlight the importance of considering the sediments, not only the water, as origin treatment, allowing us to understand the consequences on amphibian populations that inhabit areas af fected by intensive agriculture.
文摘Bananas and plantains production is an important income source for millions of small farmers. The increased demand for bananas and plantains on national and international market would justify its value chain development. However, its value chain faces several constraints, of which production and marketing turn out to be the most important. This study aimed at determining and analyzing the constraints related to Bananas and Plantains value chain and showing the gaps between agroecological and agricultural practices used by farmers in southern Benin. Characterization was carried out on the seed production systems, agricultural practices, bananas and plantains production, fruit availability and commercialization constraints with farmers using individual and focus groups surveys. Bananas and plantains seedlings production and acquisition varied according to production areas. Their seedlings self-production was widespread in production areas and 26 cultivars have been identified as major. The availability of these cultivars varied across time and production areas. There were significant negative effects of agricultural practices on major banana pest’s presence. Bananas and plantains production was limited by 12 factors, from which banana plants fall related to the wind, lack of financial support to irrigate banana fields, climate changes, no availability of cultivable lands and low rainfall are revealed to be the most important. Regarding commercialization constraints, low sale prices and difficult access to markets were the most important. Better knowledge of bananas and plantains production systems would help to develop sustainable organic farming strategies to reduce the constraints identified.
