Harnessing the benefits of African leafy vegetables for smallholder farmers and their households

南非是世界上最不平等的国家之一；55%的人口生活在贫困中，25%的人口生活在极端贫困中。食物短缺和营养不良影响着许多家庭，24%的五岁以下儿童发育不良。营养不良不仅是缺乏大量营养素，而且是缺乏对健康有影响的微量营养素、矿物质和维生素。南非17%的儿童和19%的孕妇缺乏维生素A。200万个农场，其中大多数位于土壤退化和降雨量少的土地上；这些地区的贫困率最高，粮食和营养问题最严重。生产率很低。南非大部分地区容易发生干旱，自1970年以来，9个省中有8个省的降雨量逐渐减少。降雨量不足导致产量下降，特别是在农民负担不起灌溉费用的小农农业部门。因此，迫切需要制定战略，以可持续的方式确保这些农民及其家庭有足够的营养食品和收入来源，即以一种对环境波动有弹性、不会耗尽自然资源的方式生产。尽管被忽视和利用不足，但非洲叶蔬菜提供了独特的机会，使耕作系统多样化，有助于适应气候变化，确保粮食安全，减轻贫困，增加收入，改善人类健康(特别是营养不良和缺乏微量营养素)。大多数受贫困和营养不良影响的社区生活在生物多样性丰富的地区，包括ALV。ALV的一个关键属性是其高营养含量，许多研究表明，与种植的蔬菜(如卷心菜和菠菜)相比，ALV含有更高水平的维生素和矿物质。在许多农村社区，ALV的消费量正在下降，这导致饮食质量差，营养不良的发生率增加。目前，ALV是从野外收获的，而不是种植的。这是不可持续的，据报道，由于过度捕捞和缺乏种子生产，ALV的野生数量已经下降。ALV很好地适应了当地的生长条件。ALV生长在边际土地上，几乎没有投入。它们很耐寒，在干旱和洪水时期都能茁壮成长。因此，在大多数种植作物都会歉收的恶劣环境条件下，ALV是可用的，而且在干旱时期，农村地区从野外收获和消费ALV的数量确实增加了，以帮助解决粮食短缺问题。ALV的种植将在增加农业生物多样性方面发挥作用，这有助于抑制病虫害，并防止气候变化的影响。由于ALV的价值相对较高，它们也有可能为家庭收入做出贡献。随着供应可靠性的提高，将有可能开发新的价值链，如通过超市销售。因此，增加ALV的种植和使用将改善营养，提供应对气候变化的粮食供应弹性，改善小农农业的环境可持续性，并使收入机会多样化。然而，为了帮助增加ALV的种植和利用，有必要培育出在低投入和气候波动的情况下保持其生长能力的品系，并保持其营养价值但增加产量。在这项提案中，我们将结合分子分析、营养成分代谢图谱、基因组学、小农户的参与性育种以及对害虫的易感性分析，为南部非洲最常见的ALV--苋菜--开发这样的品种。我们将提供改进后的路线，然后由南非农业研究理事会推广，以改善小农家庭的营养、生计和环境可持续性。

South Africa is one of the most unequal countries in the world; 55% of the population live in poverty with 25% in extreme poverty. Food shortages and poor nutrition affect many households, with 24% of under-fives stunted. Poor nutrition is not just a lack of macronutrients but of micronutrients, minerals and vitamins which have an impact on health. 17% of children and 19% of pregnant women in South Africa are deficient in vitamin A. The smallholder sector comprises approx. 2 million farms most of which are on land with degraded soil and low rainfall; these areas have the highest prevalence of poverty and food and nutrition problems. Productivity is low. Most areas in South Africa are prone to drought and 8 out of 9 provinces have received progressively less rainfall since 1970. Inadequate rainfall causes reduced yields, especially in the smallholder farming sector where farmers cannot afford irrigation. Hence, there is an urgent need to develop strategies to ensure sufficient nutritional food and a source of income for these farmers and their households in a sustainable manner, i.e. produced in a way that is resilient to environmental fluctuation and does not deplete natural resources.Although neglected and underutilised, African leafy vegetables (ALVs) offer unique opportunities to diversify farming systems, contribute to climate change adaptation, ensure food security, alleviate poverty, increase income and improve human health (particularly malnutrition and lack of micronutrients). Most communities affected by poverty and undernutrition live in areas rich in biodiversity, including ALVs. A key attribute of ALVs is their high nutritional content with many studies indicating higher levels of vitamins and minerals compared to cultivated vegetables, such as cabbage and spinach. The consumption of ALVs is in decline in many rural communities which has contributed to poor diets and increased incidence of nutritional deficiencies. Currently, ALVs are harvested from the wild rather than cultivated. This is unsustainable and already a decline in the wild population of ALVs has been reported due to over-harvesting and lack of seed production.ALVs are well-adapted to local growing conditions. ALVs grow on marginal land with little input. They are hardy and able to thrive in both drought and flood times. As a result ALVs are available during harsh environmental conditions when most cultivated crops would have failed, and indeed harvesting and consumption of ALVs from the wild increases in rural regions during times of drought to help meet food shortages. The cultivation of ALVs would play a role in increasing agro-biodiversity which helps suppress pests and disease, as well as protect against the effects of climate variability. ALVs also have the potential to contribute to household income because of their relatively high value. With increased reliability of supply, it would be possible to develop new value chains such as selling through supermarkets.Thus increased cultivation and utilisation of ALVs would improve nutrition, provide resilience of food supply in the face of climate change, improve the environmental sustainability of smallholder agriculture and diversify income opportunities. However, to help increase cultivation and utilisation of ALVs it is necessary to develop lines which maintain their ability to grow with low inputs and under fluctuating climate, and maintain their nutritional benefits but have increased yield. In this proposal we will develop such varieties for the most common ALV in Southern Africa, Amaranthus, using a combination of molecular analysis, metabolic profiling of nutrient content, genomics, participatory breeding with smallholder farmers, and analysis of susceptibility to pests. We will deliver improved lines which can then be promoted by the Agricultural Research Council in South Africa to improve the nutrition, livelihoods and environmental sustainability of smallholder households.