Limited food availability

While food security is a major worldwide issue, it is a much more serious problem in Low-Income (LI) and Lower Middle-Income (LMI) countries. Currently, sub-Saharan Africa is the sub-continent with the highest proportion of undernourished people, the largest gap between current and potential yields, and between cereal consumption and production. Looking to the future, population growth and climate change may worsen the situation, particularly in Africa. African countries are still facing rapid population growth with uncertain prospects about the ability of their agriculture to meet growing food demand. In addition, without sufficient adaptation measures, climate change will negatively impact food production in most African regions

Resource over-exploitation and running out

Food systems around the world are highly dependent on both renewable and nonrenewable resources. Drivers such as population growth, urbanisation and climate change put a lot of pressure on resources that have become core issues for the future of food systems. Cropland availability is limited in most parts of the world, adding pressure for cropping intensification. Fossil energy and phosphorus shortages are expected to occur within a few decades, with particular impact in Low-Income (LI) countries where farmers are more vulnerable to volatile prices. The availability of very unevenly distributed freshwater resources shows a similar picture, with an increasing number of regions reaching alarming levels of water scarcity. Some world fish stocks have been overexploited and are now depleted. But the situation is not without hope. While we need to intensify food systems to meet the challenge of a growing population, new ways to produce with less impact on the environment and more resilience to climate change need to be widely adopted

Designing cropping systems from nature

Despite huge gains in productivity, environmental impacts of industrial agriculture based on a few high-yielding crop cultivars and the massive use of chemical fertilisers and pesticides have led to a search for new pathways leading to more sustainable agriculture in both temperate and tropical regions. New strategies incorporating ecological knowledge gained from the observation of natural ecosystems is an alternative to design "ecologically intensive" agroecosystems. Such systems are indeed both ecological and productive. Designing ecologically intensive agroecosystems calls for indepth knowledge of biological regulations in ecosystems, and for the integration of traditional agricultural knowledge held by local farmers. This article reviews the main initiatives underlying ecologically intensive agroecosystems, analyses basic concepts, and proposes a framework for action. The rainforest model, the dry forest model, and the American Prairie are exemplified as three main natural systems at the basis of the mimicry concept. The link between biodiversity and the mimicry hypotheses, and the use of the concepts of productivity, efficiency, stability, and resilience for agroecosystems are discussed. Six main principles for cropping system design based on natural ecosystem mimicry are identified. A three-step framework for action is proposed, including nature observation, experimental design, and participatory design. Although far from being a panacea, the mimicry approach can provide new ways for agroecosystem design both in temperate and tropical countries. (Résumé d'auteur

Underutilized fruits in Africa

The Fruits issue is distributed apart from the annual subscription. It gathers, in the same booklet, fifteen articles already published in Fruits the last years. In this special edition, the articles keep the identification (volume, issue number, pages) which they had at the time of their first publication

Conception and engineering of cropping systems: how to integrate ecological approaches?

The science of agroecology, which is defined as the application of ecological concepts and principles to the design and management of sustainable agroecosystems has known these last years a tremendous renewal of interest among the community of agricultural scientists but also amongst policy makers. This is mainly due to the important ecological disservices and often failure to ensure food security provided by intensive modern agriculture and associated techniques based on the combined use of agrochemicals and high-yielding varieties in monocropped systems. The main principle of agroecology consists in assembling and increasing functional biodiversity in agroecosystems to enhance synergisms in order to provide various categories of ecological services such as the activation of soil biology, the recycling of nutrients, and the enhancement of beneficial arthropods and antagonists. Functional diversity may be enhanced through different practices and strategies which include crop rotations, cover crops, intercrop ping, crop/livestock mixtures, agroforestry mixtures, etc. New strategies incorporating ecological knowledge gained from the observation of natural ecosystems and or traditional agroecosystems may be a credible alternative to design such innovative systems. Designing such novel agricultural systems calls for in-depth knowledge of biological regulations in ecosystems, but also for the integration of traditional agricultural knowledge held by local farmers. Integration of these two aspects is one of the challenges that agricultural science has to deal with today. In addition, although practices are ap plied at the plot and / or farm scale by farmers, their efficiency and associated services are expressed mainly at the landscape scale. This paper reviews the main initiatives that lie behind these trends, analyzes the basic concepts underlying the design of such systems, and suggests new frameworks for action that include Nature observation, experimental and model-based designs and participatory approaches. (Texte intégral

Pour un continuum de l'agronomie au développement local

Au sommaire - L'agronomie : délimitation du champ scientifique, définition, interface avec les sciences humaines pour contribuer au développement local. Les enjeux et les concepts scientifiques. La validité de ces concepts pour les agricultures tropicales. Trois domaines scientifiques complémentaires : l'évolution des états du milieu au sein des écosystèmes cultivés; le fonctionnement des peuplements végétaux au sein des écosystèmes cultivés; la gestion des écosystèmes cultivés. Les méthodes et les outil