Book Chapter
Permanent URI for this collection
Browse
Browsing Book Chapter by Author "Abdoulaye Mando"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- ItemAn Assessment of Inherent Chemical Properties of Soils for Balanced Fertilizer Recommendations for Cocoa in Ghana(2018-04-04) Ekwe L. Dossa; A. Arthur; Wilson Dogbe; Abdoulaye Mando; A. A. Afrifa; S. AcquayeSustainable cocoa production in Ghana would require a shift in fertilizer recommendations from general applications to site-specific recommendations of fertilizers that account for initial fertility status and actual nutrient needs of soils on which cocoa is grown. A soil fertility survey was conducted in the major cocoa regions of Ghana covering the major benchmark soils. Two hundred and twenty four plots were sampled and composite surface soils collected and analyzed for selected fertility characteristics. The results show that most of the cocoa soils have low inherent fertility characterized by low C, N and exchange capacity. All the cocoa soils sorb P, which may limit availability of P in the soil solution. The soils generally are acidic, and soils in Western region, especially the Ferralsols, show the most acidic reaction with substantially measurable exchangeable Al. The results suggest that these differential characteristics of the surveyed soils should be considered in formulating balanced site-specific fertilizer for cocoa in Ghana.
- ItemImproving Fertilizer Recommendations for Cocoa in Ghana Based on Inherent Soil Fertility Characteristics(2018-04-04) Ekwe L. Dossa; A. Arthur; Wilson Dogbe; Abdoulaye Mando; D. Snoeck; A. A. Afrifa; S. AcquayeIn Ghana, cocoa has traditionally been grown as a low input crop, which has caused soil fertility deterioration, and thus, the need to integrate fertilizer use into cocoa agricultural practices. However, fertilizers recommended to farmers are general in nature and do not account for specific crop needs and inherent soil fertility conditions. This study evaluates the use of a soil diagnosis model to determine fertilizer recommendations for cocoa based on inherent soil fertility characteristics in the cocoa growing zones of Ghana. The site-specific fertilizer formulations were tested against blanket recommendations (Asaase Wura and Cocofeed) in farmers’ settings from 2009 to 2011. The results showed that DS-formulated site-specific fertilizer performed better than all blanket fertilizers in Western soils especially on the Ferralsols which are very acidic and depleted of base cations. On the other soil conditions, the site-specific formulations were comparable to the blanket formulations. Trend analysis of cocoa response to applied fertilizer suggests that P is a major determinant of cocoa productivity and that P2O5 rates >120 kg ha−1 would be required, when justified economically, for optimal cocoa yield, while potassium could be kept at around 45 kg K2O ha−1. In view of these results, the cocoa fertilizer formulas proposed for western regions of Ghana could be revised according to the DS model recommendations by taking into consideration the optima presented above. For the other cocoa regions, the DS would not be economic and therefore, proposed formulas should keep P2O5 and K2O around the optima above-presented while compensating for nutrients exported by the crop.
- ItemIntensity Cultivation Induced Effects on Soil Organic Carbon Dynamic in the Western Cotton Area of Burkina Faso(2006-10-13) Badiori Ouattara; Korodjouma Ouattara; Georges Serpantie; Abdoulaye Mando ; Michel P. Sedogo; Andre BationoThe soil organic carbon (SOC) dynamic is a key element of soil fertility in savannah ecosystems that form the key agricultural lands in sub-Saharan Africa. In the western part of Burkina Faso, the land use is mostly linked to cotton-based cropping systems. Use of mechanization, pesticides, and herbicides has induced modifications of the traditional shifting cultivation and increased the need for sustainable soil fertility management. The SOC dynamic was assessed based on a large typology of land cultivation intensity at Bondoukui. Thus, 102 farm plots were sampled at a soil depth of 0–15 cm, considering field–fallow successions, the cultivation phase duration, tillage intensity, and soil texture. Physical fractionation of SOC was carried out by separating the following particle size classes: 2,000–200, 200–50, 50–20, and 0–20 lm. The results exhibited an increase in SOC stock, and a lower depletion rate with increase in clay content. After a long-term fallow period, the land cultivation led to an annual loss of 31.5 g m–2 (2%) of its organic carbon during the first 20 years. The different fractions of SOC content were affected by this depletion depending on cultivation intensity. The coarse SOC fraction (2,000–200 lm) was the most depleted. The ploughing-in of organic matter (manure, crop residues) and the low frequency of the tillage system produced low soil carbon loss compared with annual ploughing. Human-induced disturbances (wildfire, overgrazing, fuel wood collection, decreasing fallow duration, increasing crop duration) in savannah land did not permit the SOC levels to reach those of the shifting cultivation system.
- ItemRestoring Soil Fertility in Semi-Arid West Africa: Assessment of an Indigenous Technology(2006) Abdoulaye Mando; Dougbedji Fatondji; Robert Zougmore ; Lijbert Brussaard; Charles Bielders; Christopher MartiusLow soil fertility and surface sealing, leading to severe water loss through runoff and to a drastic decline in vegetation cover, are major Sahelian agricultural constraints (Casenave and Valentin, 1989; Bationo and Mokwunye, 1991). Owing to lack of financial resources it is often not possible for farmers to utilize external inputs to solve these problems. Increasingly, attention has focused on low-cost but effective alternative solutions. Given the region’s poverty, new innovations will only get adopted if they are cheap, easily accessible, and minimize the use of external inputs. Further, the chances for adoption will be higher if the proposed technology is based on some improvement of traditional practices.
- ItemSocio-economic Determinants and Trends on Fertilizer Use in West Africa(2018-04-04) Amatevi Raoul Klutse; Andre Bationo; Abdoulaye MandoA large number of people in Africa continue to grapple with food and nutrition insecurity largely due to insufficient food availability, inadequate incomes coupled with high rates of unemployment, risk and vulnerability as well as inadequate access to basic services. The situation has been exacerbated by emerging global socio-economic trends, population increase, land degradation, climate change and an undeveloped agricultural sector among many other causes (Bationo and Egulu, Status of implementation of Abuja declaration, 2013). It is estimated that Africa’s 226.4 million people are chronically hungry (FAO 2012). Food security has been threatened in African countries since the past decades due to the decrease in soil fertility, poor use of improved technology and low investment in agriculture. These had impacted negatively on crop yields, overall agricultural production and development of African countries. The situation has been a concern to African leaders who converged to the Africa Fertilizer Summit of Abuja in 2006 to discuss and prescribe some solutions to remedy the issues. At this meeting, it was noted that Africa has the lowest rate of fertilizer application. The continent has a fertilizer application rate of about 8 kilograms per hectare, which is far below the global average of 50 kilograms per hectare. A 12-point resolution was therefore developed at the end of the summit that was aimed at achieving the global average of fertilizer use by 2015. The resolution, which was known as the Abuja Declaration on Fertilizer for an African Green Revolution spells out measures and actions that must be taken to accelerate the accessibility, availability and affordability of fertilizers in the region. On the production side, the average annual increase of cereal yield in Africa is about 10 kg ha−1, corresponding to extensive agriculture neglecting external inputs like improved seeds and plant nutrients (Bationo et al. 2004). Due to a high population growth rate (3%) compared to cereal grain yield (<1%) (Gruhn et al. 2000), cereal production per capita has decreased from 150 kg/person to 130 kg/person over the last 35 years, whereas Asia and Latin America realized per capita food increase from 200 kg/person to 250 kg/ person during the same period. Although some effort are underway to improve agricultural productivity in West Africa through the increased use of improved inputs including fertilizers, it is important to notice that food insecurity is still threatening many African countries. Some scientists support that the increase in yields of the food crops has been largely due to land expansion rather than crop productivity improvement potential. There is ample evidence that increased use of inorganic fertilizers has been responsible for an important share of world-wide agricultural productivity growth. Efficient fertilizer use can stimulate production growth, improve food and nutrition security and reduce poverty through income growth for farmers and lower food costs for consumers. Nevertheless production increase in Africa is mainly attributed to area increase than productivity increase (Table 14.1). Fertilizer was as important as seed in the Green Revolution contributing as much as 50% of the yield growth in Asia (Wigg and Hopper 1993). Several studies have found that one third of the cereal production worldwide is due to the use of fertilizer and related factors of production (Bumb 1995, citing FAO and Van Keulen and Breman 1990). A diagnosis analysis of fertilizer demand in West Africa showed some level of improvement since the Abuja Summit and more specifically after the food crisis of 2008. For instance, fertilizer consumption in the 15 ECOWAS countries was 1,020,000 tons with an average rate of 9 kg/ha in 2006, while it was estimated in the 8 WAEMU countries plus Chad at 1,025,000 tons with an average rate of 15 kg/ha in 2012 (Mando 2013). On 30 June–1 July 2013, the Food and Agriculture Organization in collaboration with the African Union Commission, and the Institute Lula convened a high level meeting in Ethiopia, Addis Ababa. The meeting put together African and International Leaders to deliberate and endorse a radical approach to end hunger in Africa by 2025 building on renewed partnerships within the CAADP Framework. The present paper is an attempt to analyze the socio economic determinants of fertilizer use in West Africa since the declaration of Abuja. It will also point out progress made and their impact on agricultural outputs and people livelihood in West Africa. It will be based on recent studies conducted on fertilizer and agricultural outputs in Africa. Some indicators like fertilizer use rate and consumption, economic return of fertilizer use, effect of fertilizer use on natural resources and livelihood, and new trends in fertilizer use will be developed to show progress achieved since the Abuja Summit.
- ItemThe Lesson of Drente's 'Essen' Soil Nutrient Depletion in Sub-Saharan Africa and Management Strategies for Soil Replenishment(2008-02) Henk Breman; Bidjokazo Fofana; Abdoulaye MandoThe term "replenishment" is used in a misleading way when it is suggested that soils are poor through depletion by farmers and that soils should be restored to their original state for agricultural development. This philosophy created awareness for problems confronted by African farmers. It neglects, however, the heterogeneous redistribution of nutrients that is inherent to agricultural land use. Active and passive transport of organic matter causes centripetal concentration of nutrients around farms and villages and maintains or even improves the soil fertility of crucial fields at the cost of surrounding land. The advice to use fertilizers on bush fields in view of the use of compost and manure on compound fields is like “putting the cart before the horse”; the value: cost ratio of using inorganic fertilizer on compound fields is higher than that on bush fields given their negative organic matter and nutrient balances. The integrated use of inorganic fertilizers and organic forms of manure triggers a positive spiral of improved nutrient use efficiency and improved soil organic matter status. The increasing value: cost ratio of fertilizer use improves the access to this and other external inputs. Where crop-livestock integration is an important component of the intensifying production system, the centripetal concentration (see footnote 1) can even turn into the opposite, a centrifugal transport that replenishes (planned or unplanned) the depleted surroundings of farms and villages. Active replenishment of depleted soils is no requirement for agricultural development; intensification can start on village fields where fertility is maintained or improved. However, public investment in soils, focusing on reinforcement of the positive effects of the centripetal concentration of organic matter and nutrients, is recommended; it enables farmers to start fertilizer use where even the compound fields at present do not allow it.