The worldʼs population has grown rapidly in recent years and is predicted to reach 10 billion by 2050. It is feared that in the near future food production will not be able to keep up with this growth, and that humanity will face a serious food crisis. However, the expansion of arable land through deforestation would exacerbate another issue, that of global warming. We have therefore focused on the use of unfavorable soils that at present are not used for agriculture as a means of solving these problems. Such soils, which are unsuitable for cultivation, cover about 70% of the worldʼs land area, and about half (1/3 of the total) are high pH alkaline or calcareous soils (desert soils).1 Were it to become possible to grow crops on these alkaline/calcareous soils, we should be able to expand agricultural land in harmony with the environment and without deforestation.In alkaline soils iron exists as water─ insoluble, trivalent iron hydroxide and hence plants are unable to absorb it through their roots and grow normally. For this reason, chelation agriculture, in which arti cial chelating agents that dissolve iron are applied to a eld, has been intensively researched.2 However, a highly effective iron chelating agent has yet to be found. In addition, there are also concerns about the environmental impact of existing arti cial iron chelators as they persist in the soil.3 On the other hand, we have focused on the iron uptake mechanism of Poaceae plants and planned to use natural iron chelators. The Poaceae plant barley solubilizes iron ions in the soil by secreting a natural iron chelator called mugineic acid (MA) (1) from its roots, and iron ions are taken up by transporters as a mugineic acid─ iron complex (Figure 1). 4 Cereals such as rice and maize are also known to secrete 2 ─ deoxymugineic acid (DMA) (2), a derivative of mugineic acid. 5 However, these cereals cannot grow normally in alkaline soils because they do not secrete suf cient amounts of chelator. 6 We reasoned that using DMA as a fertilizer would compensate for these cereals low secretory ability and allow them to be grown on alkaline soils (Figure 2). At the time this project was planned, more than 30 years had passed since the discovery of mugineic acid, but no attempt had been made to use it as a fertilizer. This was because mugineic acid was extremely dif cult to obtain and DMA was very expensive,