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Détail de l'auteur
Auteur A. Lufafa
Documents disponibles écrits par cet auteur
Affiner la rechercheAgricultural water management, n° 90. Soil water balance of annual crop–native shrub systems in Senegal’s Peanut Basin: The missing link / F. Kizito
Agricultural water management, n° 90. Soil water balance of annual crop–native shrub systems in Senegal’s Peanut Basin: The missing link [texte imprimé] / F. Kizito, Auteur ; M. Sène, Auteur ; M. Dragila, Auteur ; A. Lufafa, Auteur ; I. Diedhiou, Auteur ; E. L Dossa, Auteur ; R. Cuenca, Auteur ; J.S. Selker, Auteur ; Richard P. Dick, Auteur . - [s.d.] . - pp. 137–148.
Langues : Anglais (eng)
Catégories : SCIENCES ET PRODUCTIONS VEGETALES Mots-clés : Hydrologie de la zone vadose, Relations plante-eau, Agro-écosystèmes semi-arides, Humidité du sol, ulture intercalaire, Guiera senegalensis, Piliostigma reticulatum Index. décimale : F610-Physiologie végétale Résumé : Shrubs in the Senegal Peanut basin co-exist with annual food crops in the landscape but are vulnerable to destruction by farmers in a bid to increase agricultural acreage and meet fuel demands. This study determined the impact of two native semi-arid shrub species (Guiera senegalensis and Piliostigma reticulatum) on field water balance components. Soil water fluxes in crop–shrub intercrops and in sole crops were quantified from soil moisture, soil microlysimetery and atmospheric measurements. Up to a depth of 1.10 m, shrubs did not compete with crops for water but preferentially extracted water from the lower portion of the profile below 1.10 m and even beyond the maximum measured depth of 3.5 m. This served as a significant component of the field water balance and was more pronounced at the G. senegalensis site. Shrubs also captured drainage losses beyond the effective root depth of annuals and revealed 25–50% lower deep drainage losses than in sole crop plots. Both shrub species conferred a positive impact on the field moisture regime when intercropped with annuals through enhancing profile recharge in the rainy season. Shrub-mediated effects resulted in 20% higher soil water storage in the upper 1.10 m of the profile in crop–shrub intercrops compared to sole crop control plots. Findings from this study revealed a missing link that deserves special mention. Future work on quantification of water balance in semiarid regions with crop–shrub associations needs to account for shrub contribution to field moisture fluxes through ground water uptake (Gwup), a parameter often ignored, yet serves as a vital component in semi-arid ecosystems.
Exemplaires
Code-barres Cote Support Localisation Section Disponibilité CN1800033 F610-KIZ Publication CNRA/Bambey Rayons Exclu du prêt Documents numériques
Cliquer pour le pdfURL Agriculture Ecosystems and Environment, N° 128. Regional carbon stocks and dynamics in native woody shrub communities of Senegal’s Peanut Basin / A. Lufafa
Agriculture Ecosystems and Environment, N° 128. Regional carbon stocks and dynamics in native woody shrub communities of Senegal’s Peanut Basin [texte imprimé] / A. Lufafa, Auteur ; J. Bolte, Auteur ; D. Wright, Auteur ; Mamadou Khouma, Auteur ; I. Diedhiou, Auteur ; Richard P. Dick, Auteur ; F. Kizito, Auteur ; E. L Dossa, Auteur ; J.S. Noller, Auteur . - [s.d.] . - 11 p.
Langues : Anglais (eng)
Catégories : RESSOURCES NATURELLES ET ENVIRONNEMENT Index. décimale : P340-Biologie et biochimie du sol Résumé : Estimating regional carbon (C) stocks and understanding their dynamics is crucial, both from the perspective of sustainable landscape management and global change feedback. This study combines remote sensing techniques and a coupled GIS-CENTURY model to estimate regional biomass C stocks and SOC dynamics for Guiera senegalensis shrub communities in Senegal’s Peanut Basin. A statistical model relating field-measured shrub aboveground biomass C at training plots to satellite image-derived shrub abundances was developed and used to estimate regional biomass C across a major part of the Basin.Regional SOC dynamics were modeled by coupling the CENTURY model and GIS databases. Significant correlation (r = 0.73; p = 0.05) was observed between aboveground biomass C and satellite imagederived shrub abundance at the training plots. Aboveground biomass C stocks ranged from 0.01 to
0.45 Mg ha1 with an approximate total of 247,000 Mg C for the 3060 km2 study area. CENTURY model predictions indicate that C sequestration in these systems is contingent on long-term effectiveness of non-thermal management of shrub residue and that the actual rates depend strongly on soil type and scenarios of future land management. Compared with the traditional ‘‘pruning-burned’’ management practice, returning prunings for 50 years would increase soil C sequestration by 200–350% without fertilization, and increase soil C sequestration by 270–483% under a low (35 kg ha-1 N yr-1;20 kg ha-1 P yr-1) fertilization regime, depending on soil type and climate conditions. These results
indicate that altered land management could contribute to transforming these degraded semiarid agroecosystems from a source to a sink for atmospheric CO2.Exemplaires
Code-barres Cote Support Localisation Section Disponibilité CN1800031 P340-LUF Publication CNRA/Bambey Rayons Exclu du prêt Documents numériques
Cliquer pour le pdfURL Agronomy journal, Vo l u me 1 0 4 , I s s u e 5. Crop Productivity and Nutrient Dynamics in a Shrub (Guiera senegalensis)–Based Farming System of the Sahel / E. L Dossa
Agronomy journal, Vo l u me 1 0 4 , I s s u e 5. Crop Productivity and Nutrient Dynamics in a Shrub (Guiera senegalensis)–Based Farming System of the Sahel [texte imprimé] / E. L Dossa, Auteur ; I. Diedhiou, Auteur ; Mamadou Khouma, Auteur ; M. Sène, Auteur ; A. Lufafa, Auteur ; F. Kizito, Auteur ; Arona Ndiaye Samba Samba, Auteur ; A. N. Badiane, Auteur ; Richard P. Dick, Auteur . - [s.d.] . - 10 p. (1255-1264).
Langues : Anglais (eng)
Catégories : RESSOURCES NATURELLES ET ENVIRONNEMENT Mots-clés : Guiera senegalensis, Fertilisation, Productivité Index. décimale : P355-Fertilisation du sol. Besoins en engrais et amendement. Alimentation minérale des plantes. Réponse des plantes Résumé : The indigenous shrub, Guiera senegalensis, coexists with crops to varying degrees in farmers’ fields throughout the Sahel, with little known about its biophysical and ecological interactions with soils and crops. Therefore, the objectives were to determine the effect of the presence or absence of shrubs under varying rates of fertilizer on: (i) crop growth and yield, and (ii) soil nutrient dynamics. An experiment from 2004 to 2007 was conducted in northern Senegal where G. senegalensis dominates that had a split-plot factorial design. The presence or absence of G. senegalensis was the main plot and fertilizer rate (0, 0.5, 1 or 1.5 times the recommended N–P–K rate) was the subplot in a peanut (Arachis hypogaea L.)–pearl millet [Pennisetum glaucum (L.) R. Br.] rotation. Averaging over fertilizer rate showed that G. senegalensis had significantly greater crop biomass and yields than no shrub plots (P < 0.05) for all 4 yr. This crop yield response was related to improved nutrient availability (significantly greater for crop N and P uptake in the presence than absence of shrubs in zero fertilizer plots), higher soil quality (elevated particulate organic matter (POM) with shrubs, and a significant correlation of POM with millet yield). Lysimeters below the crop rooting zone had inorganic N levels that were not significantly affected by shrubs compared to no shrub plots, which was attributed to
high variability. Combining the ecological potential to restore degraded landscapes with the agronomic benefits demonstrated here, shows that optimized G. senegalensis–crop systems should be further investigated in farmers’ fields throughout the Sahel.Exemplaires
Code-barres Cote Support Localisation Section Disponibilité CN1800026 P355-DOS Publication CNRA/Bambey Rayons Exclu du prêt Documents numériques
Cliquer pour le pdfURL Agronomy journal, Vo l u me 1 0 5 , I s s u e 4. Crop Productivity and Nutrient Dynamics in a Shrub-Based Farming System of the Sahel / E. L Dossa
Agronomy journal, Vo l u me 1 0 5 , I s s u e 4. Crop Productivity and Nutrient Dynamics in a Shrub-Based Farming System of the Sahel [texte imprimé] / E. L Dossa, Auteur ; I. Diedhiou, Auteur ; Mamadou Khouma, Auteur ; M. Sène, Auteur ; A. N. Badiane, Auteur ; Arona Ndiaye Samba Samba, Auteur ; K. B Assigbetsé, Auteur ; Saidou Sall, Auteur ; A. Lufafa, Auteur ; F. Kizito, Auteur ; Richard P. Dick, Auteur ; Jyotisna Saxena, Auteur . - [s.d.] . - 10 p. (1237-1246).
Langues : Anglais (eng)
Catégories : RESSOURCES NATURELLES ET ENVIRONNEMENT Mots-clés : Guiera senegalensis, Fertilisation, Productivité Index. décimale : P355-Fertilisation du sol. Besoins en engrais et amendement. Alimentation minérale des plantes. Réponse des plantes Résumé : Piliostigma reticulatum (DC.) Hochst., an indigenous shrub, forms an important vegetative component of parkland cropping systems in the Sahel; however, its biophysical interactions with soil and crops are not well understood. Therefore, the objectives were to determine the impact of P. reticulatum, under varying fertilizer rates, on crop yield response and soil nutrient dynamics. The experiment had a split-plot factorial design, where the main plot was shrub (presence or absence) and the subplot was fertilizer rate (0, 0.5, 1.0, or 1.5 times the recommended N–P–K fertilizer rate) applied to a peanut (Arachis hypogaea L.)–pearl millet [Pennisetum glaucum (L.) R. Br.] rotation. In 3 of the 4 yr, P. reticulatum improved or had no effect on crop yields when averaged across fertilizer rates. Overall, millet and peanut biomass and N and P uptake by millet increased in the presence of shrubs and with increasing fertilizer rate. Contrary to P, inorganic N in the soils changed very rapidly, reaching very low levels by the end of the growing season. The N content of soil leachates below the rooting zone was generally lower beneath than outside the shrub canopy, suggesting that the shrub conserves N that is otherwise lost through leaching. Piliostigma reticulatum increased particulate organic matter, indicating that this shrub improved soil quality. These results suggest that P. reticulatum, under nonthermal management and a higher density than typically found in farmers’ fields, has ecological benefits with improved soils and reduced loss of N, which has implications throughout the Sahel. Exemplaires
Code-barres Cote Support Localisation Section Disponibilité CN1800030 P355-DOS Publication CNRA/Bambey Rayons Exclu du prêt Documents numériques
Cliquer pour le pdfURL Geoderma, N° 146. Carbon stocks and patterns in native shrub communities of Senegal's Peanut Basin / A. Lufafa
Geoderma, N° 146. Carbon stocks and patterns in native shrub communities of Senegal's Peanut Basin [texte imprimé] / A. Lufafa, Auteur ; J. Bolte, Auteur ; I. Diedhiou, Auteur ; Arona Ndiaye Samba Samba, Auteur ; M. Sène, Auteur ; Mamadou Khouma, Auteur ; F. Kizito, Auteur ; Richard P. Dick, Auteur ; E. L Dossa, Auteur ; J.S. Noller, Auteur . - [s.d.] . - 8 p.
Langues : Anglais (eng)
Catégories : RESSOURCES NATURELLES ET ENVIRONNEMENT Mots-clés : Equations allométriques, Production de biomasse, Géostatistique, Guiera senegalensis, Piliostigma reticulatum, Carbone organique du sol, Tropique Index. décimale : P340-Biologie et biochimie du sol Résumé : Accurate and reliable estimates of carbon (C) storage in landscapes are critical to the development of effective policies and strategies to mitigate atmospheric and climate change. Carbon stocks of two native woody shrub (Guiera senegalensis J.F. Gmel and Piliostigma reticulatum (DC.) Hochst) communities and associated soils within Senegal's Peanut Basin were determined and the spatial structure of soil C quantified. These shrubs are of interest because they dominate semiarid sub-Sahalien Africa and commonly coexist with rowcrops but have been largely overlooked as a key vegetative component of this landscape. Peak-season shrub biomass C was measured in forty-five 0.81 ha plots at 8 locations using allometric relationships along with soil sampling (0 to 40 cm depth) and analysis for organic C and bulk density. Soil samples to a depth of 20 cm were taken every 2 m in 24×20 m grids and every 0.5 m in four nested 3 m×3 m grids containing at least one shrub or tree canopy, and geostatistical techniques were then used to quantify scale and degree of soil C spatial dependence. Estimates of peak-season biomass C ranged from 0.9 Mg C ha−1 to 1.4 Mg C ha−1 with an overall mean of 1.12 Mg C ha−1 (SEM=0.079) in the G. senegalensis sites and from 1.3 to 2.0 Mg C ha−1 (mean=1.57 Mg C ha−1; SEM=0.18) in the P. reticulatum communities. The overall mean of SOC to 40 cm was 17 and 17.2 Mg C ha−1 respectively, at the G. senegalensis and P. reticulatum sites with 57% of that C residing in the top 20 cm. Semivariograms of soil C showed moderate spatial dependence and spatial autocorrelation at distances of less than 0.56 and 1.34 m at the G. senegalensis and P. reticulatum sites, respectively. Comparison across the different grids showed that the presence of shrub canopies at either site had much closer relationship to soil C levels than trees. Exemplaires
Code-barres Cote Support Localisation Section Disponibilité CN1800032 P340-LUF Publication CNRA/Bambey Rayons Exclu du prêt Documents numériques
Cliquer pour le pdfURL Journal of Arid Environments, n° 67. Seasonal soil water variation and root patterns between two semi-arid shrubs co-existing with Pearl millet in Senegal, West Africa / F. Kizito
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