Thursday, May 27, 2010
Modern Hunter-Gatherer, Part 3: Fruits and Vegetables
Part 1; Part 2
This is probably an unnecessary post, given that most folks know you can buy better quality fruits and vegetables at local Farmer’s Markets. Of course, better than buying from farmer's markets is home-grown, even if you only have room for a single pot of tomatoes on your balcony.
While I eat (and grow) organically raised fruits and vegetables, I am not a stickler it be “certified organic”. Organic standards legally govern what farmers may NOT put on their crops/fields or feed to animals (pesticides, herbicides), but they do not govern what IS used to increase the nutrient values. (I have eaten a lot of 'certified organic' foods over the years that were nutritionally poor, before I knew how to tell the difference.) The government regulations for becoming organically certified are long and costly, so many small farmers have switched to saying, “No Chemicals”.
Far more important to me is the nutrient-density of fruits and vegetables, which can be easily detected by taste and measured with a pocket refractometer by placing one drop of the juice on the lens and looking at the scale through the viewfinder. There are free downloadable charts on the internet which list the Brix (nutrient-density) for common fruits and vegetables. The charts will show the Brix numbers by kind in columns for Poor, Average (the best you might be lucky to find in a supermarket), Good, and Excellent. (There is an excellent video explaining how to measure Brix here.)
Three years ago I grew my first tomatoes at this new place, doing everything to insure a healthy organic crop. Well, it was healthy, but to my dismay the Brix barely measured between Poor and Average. Why? Poor existing soil nutrition. On the other hand, my green beans 50 feet away tested Excellent... and so was their taste!
Plants, just like people, need well-balanced nutrition for the best health and productivity. In plants, that is not as simple as just adding NPK willy-nilly. Soils need testing, and the correct nutrients applied accordingly. Additionally, even soils with a great balance of amendments will not produce high Brix fruits and vegetables without sufficient microbial activity in the soil.
Every time you use Round-up, Preen, or any other chemical on or near your garden, you are killing microbes in the soil. Watering and rain readily spread the chemicals, even if you are careful to keep them distant from your food gardens.
If the food you eat is low in Brix, your body will not get all the nutrients those foods should supply. The USDA has data going back to the 1960’s showing significant decrease in nutritional values of common foods over the intervening years, because plants take nutrients (esp. micronutrients) out of the soil and NPK does not put them back. Tomatoes have lost something like 50% of their nutritional value in 50 years.
Today's commercial tomatoes are grown for uniformity in looks, and their ability to be shipped across the country or imported without noticeable damage. Taste is unimportant, and out of over a thousand or more tomato varieties, fewer than half a dozen are grown commercially.
Just because a fruit or vegetable is fresh, locally-grown and chemical-free does not mean it is nutritious. Your taste buds will tell you, and so will a refractometer. I will say that you can bet the local food is safe, though. I cannot remember ever reading about someone getting ill from produce from a well-managed farmer’s market. My local market absolutely forbids anything not grown by the vendor.
Roadside stands could be a different matter, so ask for their sources for the stand owner may not be the grower. There is a produce stand on the old highway near my house, and more than half of what he sells, he did not grow; most is bought by the case just like the grocery stores do, and it could even come from the other coast or be imported.
I’d much rather taste fresh foods before I buy them, and most vendors at the farmer’s markets will let you, especially if it’s something like a green bean or lettuce leaf. In fact, they may be very interested in what a refractometer shows! If it’s tomatoes or melons, they may want you to buy one to test, unless they offer a plate of samples. Still, it’s better to buy just one tomato that may test poor, than a whole sack full before you find out back at home!
Rex Harrill, one of the Brix guru's, said the food quality in grocery stores won't change until a million housewives descend on produce sections armed with refractometers, testing and demanding the 'junk' be returned.
Here are some links to more in-depth articles on obtaining higher nutritional values of fruits and vegetables:
What makes good Brix? Good soil!
The Importance of Microbes in Soil
Understanding Soil Testing
Rock Dust… (mineral amendments)
There are also some articles I wrote on individual plant nutrients and their interactions here. (Scroll down on that page to see the list of articles.)
The bottom line is that I can easily hunt and gather nutritious fruits and vegetables locally if I avoid the grocery stores, taste or measure fruit and vegetables for nutrient density, and grow what I can. There are several fruits and veggies which can be stored in my root cellar over the winter, assuring some fresh items all year. Plus, I have plans to build a cold-frame and have fresh salad greens in winter, a la Eliot Coleman.