Learn about the 17 essential plant nutrients and their roles in plant health. All crops must have an adequate supply of each of these 17 nutrients to produce optimum yields. In accordance with The Law of the Minimum, if one or more nutrients are lacking in the soil, crop yields will be reduced, even though an adequate amount of other elements is available. Crop yields may be limited by the element that is in shortest supply, so it helps to understand the key nutrients that are needed to make your crop thrive.