Production et Stockage

Le champ «Production et stockage» met l’accent sur l’amélioration de la sécurité alimentaire par l’intensification durable de la production agricole et la réduction des pertes après récolte.

La production agricole et la gestion après récolte sont deux piliers importants qui soutiennent la sécurité alimentaire car elles peuvent assurer un approvisionnement constant en matières premières. Compte tenu de la pression démographique croissante et des ressources limitées, notamment en Afrique, il est indispensable de mener des activités de recherche et de sensibilisation sur la manière d’améliorer la sécurité alimentaire au cours des prochaines décennies, parallèlement à une utilisation plus durable des ressources naturelles. Les facteurs importants à prendre en compte sont l’utilisation efficace de l’eau et des engrais, la gestion adéquate des ravageurs et des maladies et les moyens de réduire les pertes après récolte, représentant 30 à 50% des pertes de production alimentaire dans le monde. Par conséquent, il faut une perspective systémique solide sur la production agricole qui tienne compte des problèmes de ressources et de consommation, tels que le potentiel de changements dans l’alimentation humaine ou la réduction des déchets et des pertes alimentaires.

Ce champ thématique comporte des contributions associées à:

  • Quantifier et combler les écarts de rendement et de biomasse
  • Améliorer l’efficacité de l’utilisation des ressources (intensification durable)
  • Réduire les pertes après récolte

Coordinateur de thème: Amit Kumar Srivastava

Srivastava Amit Kumar, Mboh Cho Miltin, Gaiser Thomas, Ewert Frank. 2016. Impact of climatic variables on the spatial and temporal variability ofcrop yield and biomass gap in Sub-Saharan Africa- a case study inCentral Ghana. Elsevier

We investigated the impact of climate variables on yield and biomass gap variability in two humid topi-cal regions, Brong-Ahafo and Ashanti region, of central Ghana using the crop model LINTUL5 embedded into a general modeling framework, SIMPLACE (Scientific Impact Assessment and Modelling Platform for Advanced Crop and Ecosystem Management). The simulations were run using a late maturity maize variety (Obatanpa) and historical weather data (1992–2007) across the 18 districts of the regions studied. The simulated maize yield and biomass production under water-limited conditions varied spatially which was significantly correlated with the solar radiation and precipitation in the crop growing period , whereas, associated temporal variability in the simulated maize yield was significantly correlated with the radiation in the crop growing period.

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Akinwale T E, Niniola D M, Abass A B, Shittu T A, Adebowale A A, Awoyale W, Awonorin S O, Adewuyi S, Eromosele C O. 2017. Screening of some cassava starches for their potential applications in custard and salad cream productions. Journal of Food Measurement and Characterization

Custard powder and salad cream are two food products commercially manufactured using different quantities of corn starch. This study aimed at determining the physicochemical properties of some starches extracted from some white and yellow root cassava varieties. The
prospective applicability of the cassava starches in custard powder and salad cream production was also determined. The physical, chemical and functional properties of eight cassava starches were determined using standard analytical procedures. Sensory acceptability of the products was also determined using untrained consumer group. Products made from corn starch were used as the reference samples. The physical, chemical and functional properties of the cassava
starches varied significantly (p < 0.05). The results of multivariate data analysis (principal component and cluster analyses) showed that it was difficult to completely discriminate starches from the yellow fleshed and white fleshed cassava roots. Texture was the most important sensory attribute determining the two products’ acceptability. Starch powder dispersibility was found to have significant influence (p < 0.05) on the sensory acceptability of the two
products. However, starch from a yellow fleshed root (TMS 01/1368) was the most preferred for salad cream making while starch from a white fleshed root (TMS 30572) was the most preferred for making custard powder. The starches showed high potential to replace corn starch for the respective product manufacture.

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Christine B. Schmitt, Daniel Kisangau and Kennedy W. Matheka. 2019. Tree diversity in a human modified riparian forest landscape in semi-arid Kenya. Forest Ecology and Management (433): 645-655 pp.

Riparian forests in tropical drylands support high biodiversity and provide crucial ecosystem services. Yet, fertile soil, water availability and trees as a source of charcoal and timber make them a favourable place for settlements and subsistence agriculture. The present study aimed at evaluating the floristic diversity of riparian forest remnants in semi-arid Kenya as a basis for developing conservation and management strategies. Plant diversity was assessed along the Nzeeu and Kalundu rivers in Kitui County, Eastern Province, where riparian forest patches were intermingled with agricultural and grazing lands and invasive thickets dominated by Lantana camara. Diameter at breast height (DBH) and height of woody species (DBH > 5 cm) were recorded in a total of 74 transects (50m×10 m) laid out perpendicular to the rivers on both sides at 300m intervals. In each transect, the distribution of six land cover types was mapped out and the distance of each plant individual from the river bank was noted. Overall, 631 individuals were recorded representing 85 woody species, of which 12 were exotic timber and fruit trees. The study highlights that the area still supports viable remnants of indigenous riparian vegetation, whereas tree diversity on agricultural land is strongly shaped by human preferences and shows lack of recruitment. Targeted management interventions could support the maintenance of indigenous tree diversity with positive effects for overall biodiversity, soil protection and livelihood diversification. For instance, it is recommended to facilitate natural tree regeneration and to plant a variety of indigenous tree species, especially on the river banks. Further research is necessary to assess the status of riparian vegetation along similar dryland rivers in Kenya and Africa to adequately manage these important areas for biodiversity and ecosystem services.
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West Paul C, Gerber James S, Engstrom Peder M, Mueller Nathaniel D, Brauman Kate A, Carlson Kimberly M, Cassidy Emily S, Johnston Matt, MacDonald Graham K, Ray Deepak K, Siebert Stefan. 2014. Leverage points for improving global food security and the environment. Science

Achieving sustainable global food security is one of humanity’s contemporary challenges. Here we present an analysis identifying key “global leverage points” that offer the best opportunities to improve both global food security and environmental sustainability. We find that a relatively small set of places and actions could provide enough new calories to meet the basic needs for more than 3 billion people, address many environmental impacts with global consequences, and focus food waste reduction on the commodities with the greatest impact on food security. These leverage points in the global food system can help guide how nongovernmental organizations, foundations, governments, citizens’ groups, and businesses prioritize actions.

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Trawally D.M.A, Webber H, Agyare W A, Fosu M, Naab J, Gaiser Thomas. 2015. Modelling heat stress effect on two maize varieties in Northern Region of Ghana. Global Advanced Research Journal of Agricultural Science

Agriculture in Ghana accounts for more than 30% of GDP and three-quarters of export earnings. In Sub-Saharan Africa, climate change is predicted to affect the agricultural sector most. The objectives of this study were: to use the SIMPLACE (Scientific Impact assessment and Modelling Platform for Advanced Crop and Ecosystem management) to simulate maize yield under heat stress. To compare SIMPLACE model output with heat stress, and without heat stress. Finally simulate the effect of heat stress on maize yield depending on the sowing date. The study collected and analysed data from field experiments during the 2012/2013 dry season and repeated in 2014 at Botanga irrigation site and the 2014 rainy season at Gbulahagu farming community based on three (3) sowing dates (SD). Comparing the SIMPLACE model output to the observed field data, the duration of development phases were predicted with acceptable accuracy among the three sowing dates. Simulated and observed showed good agreement for maize biomass at several growth stages of the maize. The heat stress component of SIMPLACE gave a good prediction for yield under heat stress when no other stress (water, nutrients) occurred. The estimations of the final yield showed an over estimation when the model was run with no heat stress condition in the rainy season experiment in particular under nutrient stress. The model was successfully parameterized and evaluated for simulating the effect of heat stress on maize yield under no nutrient and drought stress and can therefore be used as a research tool in the study area.

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Siebert Stefan, Ewert Frank. 2014. Future crop production threatened by extreme heat. Environmental Research Letters

Heat is considered to be a major stress limiting crop growth and yields. While important findings on the impact of heat on crop yield have been made based on experiments in controlled environments, little is known about the effects under field conditions at larger scales. The study of Deryng et al (2014 Global crop yield response to extreme heat stress under multiple climate change futures Environ. Res. Lett. 9 034011), analysing the impact of heat stress on maize, spring wheat and soya bean under climate change, represents an important contribution to this emerging research field. Uncertainties in the occurrence of heat stress under field conditions, plant responses to heat and appropriate adaptation measures still need further investigation.

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Porkka Miina, Kummu Matti, Siebert Stefan, Varis Olli. 2013. From food insufficiency towards trade dependency: a historical analysis of global food availability. PLoS One

Achieving global food security is one of the major challenges of the coming decades. In order to tackle future food security challenges we must understand the past. This study presents a historical analysis of global food availability, one of the key elements of food security. By calculating national level dietary energy supply and production for nine time steps during 1965–2005 we classify countries based on their food availability, food self-sufficiency and food trade. We also look at how diets have changed during this period with regard to supply of animal based calories. Our results show that food availability has increased substantially both in absolute and relative terms. The percentage of population living in countries with sufficient food supply (>2500 kcal/cap/d) has almost doubled from 33% in 1965 to 61% in 2005. The population living with critically low food supply (<2000 kcal/cap/d) has dropped from 52% to 3%. Largest improvements are seen in the MENA region, Latin America, China and Southeast Asia. Besides, the composition of diets has changed considerably within the study period: the world population living with high supply of animal source food (>15% of dietary energy supply) increased from 33% to over 50%. While food supply has increased globally, food self-sufficiency (domestic production>2500 kcal/cap/d) has not changed remarkably. In the beginning of the study period insufficient domestic production meant insufficient food supply, but in recent years the deficit has been increasingly compensated by rising food imports. This highlights the growing importance of food trade, either for food supply in importing countries or as a source of income for exporters. Our results provide a basis for understanding past global food system dynamics which, in turn, can benefit research on future food security.

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