Friday, August 24, 2012

Fall Gardening and Fertilizer Cost Calculations

More On Fall Crop Selection
Yesterday we transplanted our 30-day old starts of fall brassicas:

 Bak Choy, Baby Choy—a dwarf cultivar from the Burpee seed rack at Lowe’s
 Broccoli, Thompson—a variety developed specifically for fall culture, from Southern Exposure
Brussels Sprouts, Catskill—an old standby from the Burpee seed rack
 Cabbage, Early Flat Dutch—starts from a gardening friend
Cabbage, Savoy Perfection—also from Southern Exposure, recommended for fall growing
Chinese Cabbage, Michihili—the standard “napa” type, from Mayo Garden Seeds
We had previously transplanted cauliflower ‘Frosty’ from the same July 21 sowing, and those plants are now almost a foot tall. All of our brassicas receive a dusting of Dipel weekly. Today, I fed each transplant about two tablespoons of cottonseed meal, working it into the soil at the base of the plant.
We also started five Romaine lettuce cultivars:
·         Anuenue—developed for Hawaiian heat, our seeds came from Southern Exposure
·         Freckles—from the Burpee seed rack
·         Forellenschluss—also from Burpee
·         Jericho—originally from Israel, another one from Southern Exposure
·         Generic-- a green variety that grows well here, purchased from Mayo Garden Seeds
We expect these plants to be ready to go into the ground in three weeks. Romaine lettuces are more heat tolerant, and so will perform well despite the unusually warm early autumn days we are likely to experience.
A Note on Amy’s Sugar Gem
We purchased the seeds of this “patio” size tomato from Southern Exposure on the basis of their glowing catalog entry. We have not been disappointed. Besides abundant fruit production despite the unseasonably hot, humid summer, the plants have remained free of common problems. The fruits resist cracking, even with the boom-and-bust rainfall distribution we had this year. The flavor is superb, they keep a week or so after picking. If you are inclined to canning, Amy’s Sugar Gem is a cinch to peel after 30 seconds in a boiling water bath. Cut a tiny slit in the blossom end with a serrated knife, plop them in rapidly boiling water for no more than half a minute, and transfer to a sink full of cold water with a slotted spoon. After another half minute, the peels can be slipped off easily with your fingers, and the fruit will remain whole and undamaged.
Determining Fertilizer Costs
I covered this topic in The New American Homestead. Here is how to compare the cost of different brands and types of fertilizers. Nitrogen, phosphorus and potassium percentages by weight are printed on every fertilizer package. Phosphorus and potassium are abundant and cheap, but nitrogen, in a form that plants can use, is not. Natural sources include volcanoes and lightning, but by far the majority of natural nitrogen comes from the activities of beneficial bacteria. Organic nitrogen sources consist of the tissues of plants or animals that have been concentrated in some way to render them effective as fertilizer. Cottonseed meal is one example. It contains about 6% nitrogen, and is a good source for the home vegetable gardener. A three pound bag costs $8.72, including tax, at my local garden center. Since six percent of the contents of the bag is nitrogen, the weight of the nitrogen is 0.18 pounds. (.06 X 3) Dividing the cost by the weight of nitrogen yields a value of $48.45 per pound of nitrogen.
We can use this same method to calculate the relative cost of any nitrogen source. Earthworm castings were on offer at another store I frequent. The best price was $43.69, including tax, for a 30-pound bag. The label says it is 1% nitrogen, so the bag contains 0.3 pounds of nitrogen, at a cost of $145.63 per pound!
Bear in mind that in both cases, nitrogen fixed by soil bacteria was taken up by plants that were in turn processed (either by worms or a cotton gin) into a usable material. This material then had to be packaged and transported, all at additional cost. The less concentrated the nitrogen source, the more transportation costs add up. At one percent nitrogen, you have to ship 99 pounds of inert material for every pound of nitrogen. Understanding this, you can begin to understand the costs.
Now let’s calculate the cost for artificially-fixed nitrogen. This is what is added to chemical fertilizer mix. A 40-pound bag of 10% nitrogen fertilizer at Lowe’s is $18 with tax. If you do the math, you will find the cost per pound of nitrogen is $4.50. Unfortunately, the external costs of producing this nitrogen by artificial means are not taken into account. The energy required to produce ammonia or other forms of nitrogen that can be utilized by crops is produced at the cost of large amounts of carbon dioxide and other kinds of pollution, because natural gas is both the feedstock and the energy source for the process.
Due to the consumption of natural gas as an energy source and as feedstock in ammonia produc­tion, the price of N fertilizer is typically related to supply and price of natural gas. A modern ammonia production plant requires net energy consumption of approximately 29.7 million BTUs per ton of N (Kongshaug and Jenssen). Upgrading ammonia to other N fertilizers requires even more energy: 35.9 million and 31.4 million BTUs per ton for urea and urea/ammonium nitrate manufacture, respectively. “
This is equivalent to burning a gallon of diesel fuel for every 10 pounds of fixed nitrogen thus obtained, in terms of the energy needed. But how much diesel fuel was needed to move the earthworm castings from their source to Knoxville? Ten pounds of nitrogen would be half a ton of bagged worm poo. Calculations far more complex than the ones above would be needed to accurately compare the overall environmental cost of various forms of fertilizer. How much energy was expended, for example, to grow the cotton that ended up in my cottonseed meal? Were pesticides involved? No labeling requirement, to my knowledge, exists for soil amendments.
Conscientious gardeners everywhere might benefit from having this knowledge, but it is not easy to obtain.

Saturday, August 18, 2012

Planting a Fall Garden

Somehow I managed to delete last week's post on planting fall root vegetables. Sorry about that! In that post, I offered some tips for gardeners who like to plant by the moon, along with some suggestions for fall growing. To summarize, in August and September you still have plenty of gardening opportunities. Root crops for fall planting include beets, carrots, scallions and turnips. According to the moon, the next good planting time is between September 1 and September 14. Leeks for overwintering should go in the ground right away, however, if you have not already started plants. They can take a long time to mature.

Perennial onions, shallots and garlic should all be planted during the first two weeks of September, also. Choose the best bulbs from this summer's garlic harvest and replant the cloves for next year. Find starts for perennial onions and shallots online, or ask your gardening friends if they are willing to share.
From now until the end of August is a good time to transplant bak choy, broccoli, Brussels sprouts, cabbages, and cauliflower, along with parsley, cilantro and Swiss chard. If you did not start seeds last month, you can find plenty at the local garden centers. I am seeing more offerings of fall vegetable starts and seeds this year than ever before.
From now until the end of August is a good time to plant some favorite fall green crops. Lettuces, kale, Asian mustards, corn salad, spinach and chervil are all great choices for a fall garden. Along with late tomatoes, their tender greens make tasty, nutritious salads.
Sweeten the pot with peas, either English (shelling), snap or snow. All varieties tend to perform better as a fall crop in the Tennessee Valley region. Now is the perfect time to plant, as the weather begins to moderate and rainfall returns. We have grown many varieties, but the original 'Sugar Snap' remains our favorite for an edible podded pea. Among snow pea varieties, 'Dwarf Gray Sugar' abundantly yields pods only an inch and a half long from lovely bi-color pink flowers. 'Mammoth Melting Sugar' produces huge pods, and is a reliable cultivar. Most peas will do best if given some support. These three demand it, as they all can grow to six feet. If you bother with shelling peas, old stand-bys like 'Lincoln' and 'Green Arrow' still perform.
Plant fall lettuce cultivars in the opposite order that you followed in spring.  Start with heat tolerant Romaines, and follow in succession with increasingly cold tolerant varieties. Looseleaf, then butterhead, is my preference. It is worth noting that red coloration and a savoyed (frilly) leaf texture usually indicate cold tolerance. Flat, green leaves do better in warmer temperatures. Here in the Tennessee Valley, any lettuce is worth a try between now and the onset of freezing temperatures.
A classic Romaine lettuce that has been offered by our local seed company for many years is a dependable performer. Another good Romaine to plant now is ‘Rouge d’Hiver.’ Both mature in about 70 days or a little less. Some other possibilities that we have tried include ‘Forellenschluss’ and ‘Freckles’ both of which have green leaves with reddish brown markings, and a sharper flavor than plain green Romaine. Burpee touted a dwarf variety, ‘Little Ceasar’ this year, but we did not have room to try it.
Kale is a dependable and super-nutritious fall crop. By choosing more than one cultivar and planting in succession, you can have fresh kale all winter long here in Zone 6b.
Kale is classified by its leaf shape into several types. All are varieties of wild cabbage, Brassica oleracea Acephala Group. Scotch Kale is characterized by its extremely curly leaves. Popular cultivars include:
·         Dwarf Blue Curled Scotch—good for containers because of its smaller size, this kale matures in only 55 days, but can be used when younger for salad greens.
·         Redbor and Winterbor—cold hardy types, maturing in 55-60 days; Redbor has deep red-purple leaves. Very young leaves are tender enough for salads.
Russian Kale has flat leaves, often with ragged edges. ‘Vates’ is the cultivar most often seen in seed racks, but ‘White Russian’ and ‘Red Russian’ are other good choices. Red kales tend to mature a little earlier than their white counterparts. In this case, the difference is about a week. All three of these can be eaten within a month of sowing as salad greens.
For maximum cold tolerance, consider ‘Lacinato’ kale for a later crop. This one spent last winter in my coldframe and produced plenty of delicious leaves. It is almost black in color, because of its dark blue-green pigmentation. The leaves are long, straplike, and crinkled like seersucker. Maturing at about 65 days, it is at its most flavorful after a frost.  A late August planting should be ready by Halloween.
Mature kale is delicious stir fried with a little garlic and soy sauce. You can also coat the leaves lightly with oil and soy sauce and place on a sheet pan in a 200 degree oven until they are crisp, for a healthy snack. Around here, the traditional way to enjoy kale or other cooking greens is to simmer them a long time in a little water with a ham hock or pieces of bacon or fatback tossed in, then serve them with cornbread to sop up the delicious juices, or "pot likker." If you want to come close to the traditional taste without the meat, try this approach:
New-Fashioned Greens with Pot Likker
Wash 1 pound fresh kale, turnip, or mustard greens, or a combination. Pat dry with kitchen towels. Stack the leaves and cut them into ribbons about an inch wide. Bring a large pot of water to a boil. Drop in the greens and simmer 1 minute. Drain in a colander and immediately rinse in cold water to set the color. Return the greens to the pot and add 1 cup vegetable stock, 1 small onion, chopped, and a pinch of salt. Simmer until the greens are meltingly tender, about half an hour. Taste carefully and correct the seasoning. Serve over cornbread, garnished with a little grated cheese, if you prefer.

Wednesday, August 1, 2012

Food Fight

The Irish are fighting, and I am not referring to the Notre Dame football team.  At odds, according to the BBC, are organic farmers and government agriculture officials who want to field test genetically modified (GM) potatoes. Organic farmers, concerned about unleashing harmful genes into the environment, and the potential for “contamination” of their organic crops with GM ones, have launched a firestorm of angry rhetoric.
What the government scientists want to do is grow a small plot of potatoes that have received genes from a wild potato variety in an attempt to confer resistance to late blight, arguably the most destructive potato disease, and one that is beginning to develop resistance to existing control methods. Because the genetic manipulation was done in a few weeks in the laboratory, rather than over a period of two decades of traditional plant breeding, GM opponents are upset.
The debate in Ireland offers an all-too-common example of politics trumping science. The type of genetic manipulation being done with potatoes is known as “cis-genic,” meaning a transfer of genes between species that are closely related to each other. This is essentially traditional agricultural breeding, speeded up via modern technology. It is a technique unlikey to produce “Frankenfood.”
It is ironic that much of the concern over GM varieties and organic agriculture represents unintended consequences of government regulation that was initially requested by farmers themselves. Organic farming was well out of the mainstream 40 years ago when I first started learning about it. As the 60s generation grew up, the market for organic foods grew also. Advertisers began throwing around health and nutritional claims related to “organic” foods, and soon the organic farmers began clamoring to have their brand (which at the time could command a 50% premium over market prices) protected. So the USDA finally came up with a program for organic food certification. In the intervening years, this has had the opposite of its intended effect. Instead of supporting the small farmers who were producing artisanal products, the rules began shutting them out of the market and favoring big companies who could afford not only the high cost of certification, but also the  futures contracting power necessary to arrange for, say, 50 tons of organic wheat flour.
If you go to the farmer’s market, you are likely to find only one or two certified organic farmers. Most vendors are advertising themselves as “pesticide free” (= we sometimes use chemical fertilizer), “naturally farmed”(=we try to be as conscientious as possible), “biodynamic” (=naturally farmed, rama dama ding dong), and so forth. It costs several thousand dollars to certify a farm, and sweet corn is $5 a dozen ears. Do the math.
One of the tenets of organic production is a prohibition on GM crop varieties. No distinction is made between cis-genic modifications (equivalent to modern plant breeding on fast forward) versus trans-genic modifications (putting bacterial genes into corn plants).   Let us note, further, that the Ireland dust-up is over a carefully planned trial on a relatively minuscule acreage. The potato is self-fertile, so the wind cannot carry pollen from the fields. Upon rare occasion, members of the potato family are pollinated by flying insects, but separating the fields by a couple of miles solves that tiny concern. Yet, this experiment will have “grave consequences” for Irish agriculture, according to some.
With all that in mind, take a look, please, at the image at right. This is a tetra, Hyphessobrycon eques, a South American fish that has been in the aquarium trade for decades. It happens also to be albino. This particular fish, however, has had a bacterial gene for bioluminescence spliced in, and therefore it glows in the dark. I shot this photo at a local aquarium store. They have a tank full, along with albino zebra danio fish that also carry the bacterial glow-gene. Cute, huh? They sell like hotcakes, too, according to the store manager.
These fish are typically produced in Asia, shipped as small fry to Florida, grown to market size in outdoor ponds, and shipped to stores all over the country. During that entire cycle, no regulation, other than the strictly routine fish import permit, affects who may handle these fish and what they may do with them. Should a flood happen in east-central Florida (perhaps due to excessive rain from a hurricane), these fish could easily enter a river system and establish themselves. Although they would have nothing to interbreed with, as there are no tetras native to North America, their potential ecological impact is unknown. Numerous other species of tropical fish have established themselves in Florida waters, both fresh and marine, and some have caused serious problems.
One concern with all genetic modification is that it is difficult, although not impossible, to know if additional genes, of unknown effect, are present on the piece of DNA spliced in. Probably not, but still…you would need a complete DNA sequence of both this fish and a normal one for comparison. Given that two genes can be adjacent to each other and have wildly different biological effects, there is potential for harm. I’m willing to bet no such study has ever been done on these fish. I have no data for the tetra, but human beings share 85% of their genes in common with the zebra danio fish, so in the case of the tetra it should be similar. No apparent concern exists about importing thousands of these fish for pet stores everywhere, either.
I find it ironic that people get emotional about cis-genic potatoes, and think nothing of moving trans-genic animals all over the world, willy-nilly. Trans-genic plants are everywhere, too. The noteworthy “Mosquito Plant” which turns up in garden centers every spring, is a trans-genic variety. It is a geranium with citronella genes stitched in. Although there is no evidence the plant does anything to repel mosquitoes, people buy them. No outcry over “Frankenplants.”
In the United States, almost everyone eats GM foods without knowing it. If you consume French fries, corn chips and just about anything fried in a restaurant, you have very likely consumed GM corn, potatoes, and soybean oil. There is no requirement for food producers to label foods as containing GM ingredients. This, it seems to me, errs too far in the direction opposite an outright ban on GM foods.
There are some serious questions regarding the wisdom of allowing trans-genic hybrids into the environment, despite the fact that the horses are already out of the barn in many cases. We need more public discourse on the whole issue of GM organisms in food, what “organic” should really mean, and what regulatory structures might be most appropriate. People also need a better understanding, in general, of what GM actually invovles, on a species by species basis. And all of this needs to be approached without hysteria about “grave consequences” from either side.
Please add your comments to the discussion. What do you think about GM foods?