report
2.2.3.4.2 Nutrients

Nanotechnology applications in enhancing nutrient uptake are largely restricted to crops, i.e. fertilisers (developments in the areas of functional foods and nutriceuticals are described in the report: “Nanotechnology in Food Processing”).

In most cases fertilisers are applied directly to the soil.  The critical factor is that the fertilisers remain available to the crop for a sustained period, not only to limit the number of applications (and therefore cost) but also the levels in run-off (e.g. the WHO recommends that nitrate levels are limited to 50 milligrams per litre).  Promising applications are those that retain fertilisers (or water) in the soil.  Included here are nano-clays which, as already discussed, are highly absorbent and capable of slow release of intercalated chemicals[i]^,[ii].  However, there are other alternatives to soil-based systems- for example one existing patent states that foliar delivery of nutrients to plants is 95% efficient, compared with 10% for soil[iii].