Masso Cargele, Baijukya Fredrick, Ebanyat Peter, Bouaziz Sifi, Wendt John, Bekunda Mateete, Vanlauwe Bernard
International Institute of Tropical Agriculture, PO Box 30772, Kasarani, Nairobi, Kenya.
Africa Regional Center of the International Nitrogen Initiative, PO Box 30772, Kasarani, Nairobi, Kenya.
Soil Res. 2017 Jul 13;55(6):425-434. doi: 10.1071/SR16332.
Food security entails having sufficient, safe, and nutritious food to meet dietary needs. The need to optimise nitrogen (N) use for nutrition security while minimising environmental risks in sub-Saharan Africa (SSA) is overdue. Challenges related to managing N use in SSA can be associated with both insufficient use and excessive loss, and thus the continent must address the 'too little' and 'too much' paradox. Too little N is used in food production (80% of countries have N deficiencies), which has led to chronic food insecurity and malnutrition. Conversely, too much N load in water bodies due mainly to soil erosion, leaching, limited N recovery from wastewater, and atmospheric deposition contributes to eutrophication (152 Gg N year-1 in Lake Victoria, East Africa). Limited research has been conducted to improve N use for food production and adoption remains low, mainly because farming is generally practiced by resource-poor smallholder farmers. In addition, little has been done to effectively address the 'too much' issues, as a consequence of limited research capacity. This research gap must be addressed, and supportive policies operationalised, to maximise N benefits, while also minimising pollution. Innovation platforms involving key stakeholders are required to address N use efficiency along the food supply chain in SSA, as well as other world regions with similar challenges.
粮食安全意味着拥有充足、安全且营养丰富的食物来满足饮食需求。在撒哈拉以南非洲地区（SSA），优化氮（N）的使用以保障营养安全同时将环境风险降至最低的需求早已迫在眉睫。与撒哈拉以南非洲地区氮使用管理相关的挑战既可能与使用不足有关，也可能与过度损失有关，因此该地区必须应对“过少”和“过多”这一矛盾。粮食生产中氮的使用量过少（80%的国家存在氮缺乏问题），这导致了长期的粮食不安全和营养不良。相反，主要由于土壤侵蚀、淋溶、废水氮回收有限以及大气沉降，水体中的氮负荷过高，导致了富营养化（东非维多利亚湖每年有152千兆克氮）。为提高粮食生产中氮的使用效率而开展的研究有限，而且采用率仍然很低，主要原因是农业通常由资源匮乏的小农户进行。此外，由于研究能力有限，在有效解决“过多”问题方面几乎没有取得什么进展。必须填补这一研究空白，并实施支持性政策，以最大限度地提高氮的效益，同时尽量减少污染。需要有涉及关键利益相关者的创新平台来解决撒哈拉以南非洲地区以及其他面临类似挑战的世界地区粮食供应链中的氮使用效率问题。
