12.1.7: Summary

Plants require nutrients in simple form. They get their carbon, hydrogen, and oxygen from carbon dioxide and water, their nitrogen from nitrates and ammonia, and their minerals from the soil. Plant growth is limited by the availability of the required nutrients—the quantity of plant produced is reduced, not its quality. Fertilizers provide nutrients that increase crop yield.

Some of the minerals we require (e.g., iodine) aren’t required by plants. But plants can take these in—and also ones we don’t want (e.g., lead)—if they happen to be in the soil. This means the plant content of these “extraneous” minerals vary according to the amount present in the local soil.

Crop yield is also affected by how well we protect our crops from insects and disease. Pesticides are commonly used for this purpose. Alternatively, natural predators of the pests can be used, and plants can be bred to be more pest resistant. Integrated Pest Management customizes pest-control strategies for individual crops and local conditions, using alternatives to pesticides whenever possible—the aim is to minimize the use of pesticides, and to use that which is needed in the safest and most effective way possible.

Plant genes can be altered by biotechnology to create desired characteristics. Biotechnology can be used to transfer desired genes (e.g., ones that provide disease resistance) into a plant or to inactivate undesirable genes (e.g., ones that cause decay) or to edit a plant’s gene.

“Natural” plant substances aren’t inherently better or worse than “man-made” ones. Both the natural and the man-made are important to consider in assessing the safety and adequacy of our agricultural products.

Advances in agriculture and food science have had—and are expected to continue to have—the greatest benefit for the world’s hungry.