Archive Article: January, 2010
People commonly ask questions about how to garden in a way that is more harmonious with nature. To help folks get going, we decided that a question-answer approach would be useful.
Assess your growing system: Know where you are starting from
1. What gardening products do you use in your yard now?
a. Have you used pesticides, herbicides or fungicides? When was the last time?
b. Have you used chemical fertilizers? When was the last time?
Answer: a) If pesticides, herbicides or fungicides have been used in the past year, then most likely, residuals of those toxic chemicals are still present in your yard or garden. The fact that these toxic chemicals were used suggests that there are significant problems. Disease, weeds and pests were serious enough that money was invested to alleviate these problems.
Interestingly enough, the situation that caused the weed problem, poor plant growth, excess need to water, wilting problems, fertility problems and disease was, in fact, made even worse by the use of toxic chemicals. Toxic chemicals kill some harmful organisms, but they also impact, and in some cases kill, the very organisms that combat and control diseases, pests and weedy species. Continuous use of toxic chemicals can result in so much loss of soil life that plants can no longer obtain nutrients or water from the soil. When soil life is completely out of balance, the only plants that grow happily are weeds.
The shift from healthy plants to weed systems usually takes some time and is subtle and slow. The natural functions of soil are slowly eroded as the balance of life is lost. Nutrient retention, good water infiltration and provision of nutrients for plants in the right form, at the right time and place, are destroyed.
Have you used chemical fertilizers in your greenhouse?
When was the last time? The ability of the naturally occuring micro-organisms to decompose any toxic chemical addition will be diminished if you have used chemical fertilizers because they will be killed by the salts in the fertilizers.
Recognize that constantly having to use toxic chemicals to control disease, pests, infertility and water movement through the soil is a clear signal that something is terribly wrong. The damage cannot be fixed by using more toxic chemicals. On the other hand, if disease, pests or weeds aren’t routine issues - if they only turn up occasionally, every three or four years, then clearly the underlying problem isn’t as far out of control. There’s still something not quite right, but fixing it will be much easier.
Answer: b) If any chemical synthetic fertilizers have been used within the last year, then many of the soil organisms that were present have been harmed or killed. In addition, residual toxic chemicals will be left, which will have a continuing negative impact until they are decomposed into harmless materials.
All chemical synthetic fertilizers are salts. Table salt is one variety, but there are thousands of other kinds including lime, gypsum and ammonium nitrate, to name a few. Salts hold water, preventing the use of that water by all life in the soil, including the roots of plants. A high salt concentration equals increased difficulty for life to remain functional. In general, significant negative impacts occur above 75 parts per million (ppm) of inorganic fertilizer (salts). That translates into two pounds of inorganic fertilizer on a typical suburban home lot, or 200 pounds of fertilizer per acre. If more than two pounds of inorganic fertilizer are used at a time on a typical home lot, damage will occur.
Check your water source
2. What is the quality of the water that you use?
a. Does your water supply contain chlorine?
b. Does your water supply contain chloramine?
c. Does your water supply salt in your water?
Answer: a) Send a water sample to a laboratory for chlorine testing. Another possible approach is to buy and use a pool chlorine testing kit. If any chlorine is detected, filter your water because chlorine kills the organisms that you want to establish in any natural gardening system. A hose-end carbon-block filter will filter out most of the chlorine. You may need to put a filter at your water source (on the house tap) if you use automatic drip irrigation.
Answer: b) Activated carbon filters or reverse osmosis systems are needed to remove chloramine. Although recent developments have been made in this area, many emerging products have not been time tested, so talk with the manufacturer and run some tests if you are not sure of the product’s quality. Humus, which is most easily obtained from aerobic compost, can also remove chloramine. To obtain liquid humus, run water through dark brown–colored compost.
Answer: c) If the electrical conductivity (EC) of your water is above 10 - 12 microsiemens per centimeter (μS/cm), or 75 ppm salt, you will need to remove the salts with activated carbon and/or a reverse osmosis water filtration system, or complex the salts with humic acid. You can buy inexpensive EC meters at gardening and hydroponic stores or through the Internet.
Buy Environmentally Friendly Products
3. What gardening products will work with nature?
Answer: Compost tea, sea kelp, humic acid, mycorrhizae, compost and worm castings are all examples of products that will work with nature. Look for options that come from a reliable organic source. Use of strong acids or bases or inorganic chemicals will leave chemical residues in the end product, which will harm or destroy any living material the chemicals contact.
Even if a product says that it is organic, you must check that it has been approved for organic production by a certifying agency. A seal and the name of the certifying agency are usually present on the container. Be careful of wording as products used for organic crops are not certified organic, but rather, are approved for organic production by agencies that check the product for compliance with National Organic Program (NOP) standards. Nobody can stop a company from simply writing the word organic on their container, but that is literally just an advertising gimmick.
Even if a product is approved for organic production, it may not be compatible for gardening with nature. For example, some sea kelp may contain salt levels that are over 100 ppm if applied in quantities recommended by the manufacturer.
How does a small-scale grower check this? If the package says, for example, to use 20 ounces in 10 gallons of water (which is the same as two ounces in one gallon), set up a small test. Mix two ounces in one gallon of water. Take your EC meter and test the salt levels. If the levels are over 100 µS/cm, or about 75 ppm, then dilute the kelp even more. Add one ounce in one gallon of water, or one ounce in two gallons of water, until you get EC levels less than 100 µS/cm. Then use that dilution rate for spraying the product on your plants, using it as a soil drench, or incorporating it into your hydro system. Be very careful when looking at EC values because the units µS/cm are different from millisiemens per centimeter (mS/cm) by a factor of one thousand. If you have 100 µS/cm, it would be reported as 0.1 mS/cm (move the decimal point three places left), or as 0.01 centisiemens per centimeter (cS/cm). Sometimes chemical salesmen will disguise extremely high salt materials by reporting the information as decisiemens per centimeter (dS/cm). Scientific units can be confusing if you aren’t familiar with them, so check with someone you trust when these issues come up.
Pesticides, from organophosphates to sulfur, to insecticidal soap, to neem oil, may kill their target disease organisms, but they also kill non-target, beneficial organisms. Think about what a disease organism is: a micro-organism that kills something that humans want to keep living. Why would something that kills a disease organism not also kill beneficial microbes? Whatever means by which a pesticide kills the bad guys, it will also affect the good guys.
All evidence points to the fact that nearly all pesticides kill a broad range of organisms. The only way pesticide companies can try to claim that their chemicals have no effect on non-target organisms is if the methods used do not, in fact, detect non-target organisms. For example, if companies use plate count methods to assess organisms, these methods do not detect non-target organisms. Again, be careful of the so-called science used to demonstrate something. Just because the format looks scientific does not mean that the methods were appropriate for assessing the problem.
If toxic chemicals have been used, no matter how minimal, most likely, beneficial organisms have been reduced. The remedy is really quite simple: replace the missing beneficial microbes through the application of aerobic compost or compost tea. Apply one of these products every few days until the problem (diseases, pests, lack of fertility, weeds) subsides. If, after two weeks of application, the problem is still significant, use an organic pesticide, or if all else fails, a toxic chemical might have to be used. As soon as this material has done its job, add back the beneficial organisms that can sustainably maintain the system for years, without the use of the toxic materials.
The process of returning your system to a condition of health can be rapid but cost a fair amount of money ($100 to $500 per acre, depending on just how bad the soil was to start with). Or it can take additional time but be nearly cost-free. Clearly there is a trade-off between time and money. The cost of rapidly adding the full diversity of organisms, getting them spread throughout the soil and providing them with the food they need to function can cost a significant amount of money, but then, the food you are growing is healthy, with full nutrition, and no surprises with respect to toxic chemical residues.
However, if you can take a few more months, or a few years, to allow the recovery process to happen, there may be no more cost than learning to make good compost, using some appropriate plants to combat weeds and building a compost tea brewer. But in both approaches, if you want to be successful as rapidly as possible, then monitoring the life in your system is necessary.
A word or two needs to be said about residues of toxic chemicals in soil and water. Toxic residues can take a very long time to decompose because the process relies on the actions of living organisms to convert the residues into nontoxic materials. But use of a toxic material kills most, but not all, of the target disease or pest. In the case of inorganic fertilizers, this toxic material adds a high concentration of inorganic salt, which kills the organisms that normally provide plants with available nutrients. Any of these materials kill a range of non-target organisms, most of them actually beneficial organisms. Were the organisms that were killed in fact the organisms that were needed to remediate, break down and detoxify the toxic chemical?
Aerobic conditions are required so that these beneficial organisms can remove the harmful materials. This means not only that the specific microbes that decompose these toxic chemicals must be present, but the entire set of nutrient-cycling, disease-suppressing organisms normally found in growing environments must be present and functioning. This entire food web is necessary to build structure and allow oxygen and water to move normally through the system. Testing is needed to ensure that the organisms and the conditions are right for recovery to occur.
You can do your own testing to adjust EC levels by changing the types, quantities and feeding schedule of nutrients you add. You can send samples of soil or water to testing facilities for microbiological analysis to see if the organisms have been established or you can get a microscope and test your own samples, if you get the proper training to identify the major groups of organisms.
Thus, the time it will take to fix a sick situation depends on just how bad things were to start. How much loss of soil life occurred? How easy will it be to establish the right set of organisms and to replenish the sources of food these organisms need to do their job? If the grower backslides and uses toxic chemicals to give a quick fix, the recovery process will never occur.
Other articles by Dr. Carole Ann Rollins and Dr. Elaine Ingham
