Urban Agriculture: Better Food and Food for Thought *
City farmers and advocates for sustainable food systems champion urban agriculture as a source of better food.
We all strive to be savvy, socially responsible consumers, so it is a good idea to explore this claim in more detail.
How can urban agriculture offer better produce than industrial agriculture? Is time from farm to plate the only difference?
Urban Agriculture & Better Nutrition *
Time has a significant effect on the nutrient value of vegetables. This is an obvious fact, but most of us are so far removed from food production that we don’t think about how long our food has been in transit before it arrives at the grocery store.
The clock starts counting down nutrient value from the moment of harvest. Here is a little reminder from our early school days that explains why industrially produced fruits and veggies are inferior in terms of flavor and nutrition.
Chemical Reaction – Cellular Respiration – Don’t worry this is the simplified version!
Glucose + Oxygen ➞ Carbon Dioxide + Water + Energy
Why does this matter? *
Plants don’t stop breathing just because they have been harvested.
As long as there is sufficient oxygen, plants will use their stores of sugars in this reaction. Without photosynthesis (which, for the most part, does cease at harvest) to replenish the stores there are fewer nutrients available to us relative to time post-harvest.
There is also a corresponding reduction in percentages of minerals, vitamins and non-essential nutrients.
Certain crops have higher respiration rates than others and there are a number of factors that influence respiration, but in the simplest terms this is why truly fresh fruits and vegetables from a garden or a local farm taste so much better than produce from the grocery store.
Better Breeding *
For years industrial agriculture has been breeding nutrition out of our food.
I don’t believe this is a conspiracy. I think it is just a flaw in our approach.
We are seeking ways to provide for the basic needs of our growing global population and in order to produce enough food we have
been breeding crops for a specific set of characteristics, namely high yields, disease/herbicide/pest resistance, and appearance.
Unfortunately, these traits often have a negative correlation with nutrition and flavor.
Studies show that varieties selected for high yields (usually about double that of their unaltered counterparts) are subject to dilution.
There is more produce in total, but the nutritional value is reduced.
A study on broccoli crops found that proteins, amino acids and a variety of minerals decline in crops bred for higher yields. Because of the long journey most of our food has to take, the varieties that we buy in stores have been selected for their thick skins and the ability to maintain a favorable appearance after handling.
Urban Agriculture and Plant Breeding
Urban agriculture gives us the opportunity to modify our approach to plant breeding.
We all want high yields, but taking advantage of vertical growing space and technologies that help us to use resources more efficiently may be a better method than breeding for yield without considering quality.
If we can achieve a little breathing room and security in our food production, we can work toward selecting for traits based on a different set of criteria that includes nutrition and flavor.