Feeding the plants that feed people
Nutrients are the substances that living organisms need to fuel growth and to ensure the functioning of their metabolisms. In the case of plants, nutrients are generally defined as the mineral elements that plants require, with substances like water included in a broader group called “growth factors”. Few minerals are absorbed by plants in their elemental forms; most plant-available forms of minerals are inorganic compounds.
Depending on how much of a given nutrient is required by plants, scientists classify them as primary, secondary or micronutrients .
Manufactured fertilizers are needed because organic sources of nutrients are not plentiful enough to produce enough crops for today’s population . Manufactured fertilizers, which provide crop nutrients in the forms that plants can absorb, will be even more critical as the demand for agricultural output increases in coming decades. Most organic sources of nutrients have to be mineralized to these forms before plants can use them.
The nutrients that we ingest enter the food chain through plants. The availability of plant nutrients is a necessary precondition for crops to provide the minerals we need. In addition, the genetic makeup of each plant variety affects its capacity to absorb and store nutrients. Plant breeding and crop nutrition are therefore inextricably linked for producing the most nutritious crops possible. The forms of nutrients in plants and derived foods are generally the most easily absorbed by our bodies.
In addition to adequate nutrition of improved crops, other methods for increasing the nutritional profile of our diets include enhancing animal feed, fortifying specific food products (e.g. iodized salt or enriched cereals), cultivating “nutraceutical” crops (with enhanced nutritional attributes such as a high level of anti-oxidants) and taking dietary supplements.