Studies show farmland in Africa is often lacking in important nutrients. But researchers say a combination of farming methods may help. Since the world food crisis several years ago, researchers have directed more of their attention to small farms. 研究显示非洲的农田通常缺少重要养分,但研究者称一种联合农业方法可以起到作用.自从7年前发生粮食危机以来,研究者更多地关注小型农场.
_________________________________________________________.
most farms in areas south of the ... are only about one or two... one of the goals is to increase production without necessarily clearing more land to grow additional crops
Most farm in this areas .......have disert are only about .. to .. . what the goals is to increase production without necessary clearing more the land to grow addational crops.