经济学人下载:农业与营养,隐性饥饿

Changing the mix of crops works, too. Many countries’ food policies are essentially about providing cheap grain, which is just a start. When people do not have enough calories, staples such as rice and wheat are vital: they provide the most calories per dollar. But when people have enough calories they need to diversify towards vegetables, pulses and meat. In many places, irrigation and fertiliser subsidies, government marketing and other schemes implicitly or explicitly favour cereal farmers. So poor countries go on encouraging cereals longer than they need to. And plant breeders tend to raise cereals which maximise calories, not nutrients.

另外，改变作物组合的方式也有效。许多国家的食品政策最主要就是提供便宜的谷物，这还仅仅只是开始。当人们摄入的卡路里不足时，大米和小麦等主食便尤为关键：每美元的主食能提供的卡路里最多。但是，当人们卡路里摄入充足时，则需要有蔬菜、豆类和肉类等多样化的饮食。在很多地方，灌溉与施肥补贴、政府营销和其他机制都直接或间接地有利于种植谷物的农户。一些贫穷国家对谷物的鼓励政策甚至有些过头。植物育种者也更倾向于谷物，如此一来虽保证了卡路里摄入，却没有保证营养。

Policymakers can also try to increase women’s control over farming decisions (in some countries, only men may own land or get agricultural credit, for instance). They could boost research into more nutritious non-staple crops; and provide clean water and better transport, which especially benefits kitchen gardeners, because their produce goes off.

政策制定者也可以增加妇女对农业抉择的掌控度（比如，在某些国家，只有男性能够拥有土地和获得农业信贷）。他们还应该投资更多关于非主食营养作物的研究，提供清洁水和更好的交通服务。交通便利对厨房菜园尤为有利，因为食物囤放太久会变质。

But there are limits. Malnutrition does the most damage in the first 1,000 days of life. In those months maternal health, breastfeeding and infant care, not agriculture, matter most. Better farming can mean more calories and higher incomes. But with nutrition, it offers only a few steel bullets, not a silver one.

但光从农业出发收效有限。营养不良对于新生儿的前1000天危害最大。在这段时间里，产妇卫生、哺乳和婴儿健康才是最重要的，农业则不那么重要。农业优化发展能改善人们的卡路里摄入也能提高家庭收入。可说到改善营养，农业虽能加点油，但却不是万金油。