According to Bill Wolf, founder and president of the Necessary Trading Company in New Castle, Virginia, finding the answer is not that easy. His firm specializes in agricultural consulting, and the
distribution of biologically safe farm and garden supplies. The basic principle to natural/organic fertilizing is this: feed the soil and let the soil feed the plants.
Wolf knows that soil is the source of essential nutrients such as nitrogen, potassium and phosphorus that plants need for growth and development. ?Plants also absorb water from the soil and draw physical support for their growth by spreading their roots through the soil,? he says. ?The challenge for the landscape contractor using only natural/organic fertilizers is to balance the soil so that it provides all the conditions plants need to thrive. Adding organic matter ? various forms of living or dead plant and animal material ? to the soil is the keystone to soil fertility.?
Peter Tompkins, author of the book ?Secrets of the Soil,? feels chemical fertilizers cannot restore soil fertility. ?Only organic humus makes for life. Chemical fertilizers can neither add to the humus content of soil nor replace it. When chemical fertilizers are put into the soil they dissolve and seek natural combination with minerals already present. Chemical fertilizers do not work on the soil but are enforcedly imbibed by plants,? Tompkins explains.
Like all business people, professional landscape contractors want repeat customers, and to do this they must continue to provide quality service. So keeping an eye on long-term results is important. Tompkins adds that chemically-fertilized plants may look lush, but lush growth produces watery tissues, which become more susceptible to disease.
Wolf says organic matter supplies raw materials to earthworms and naturally occurring bacteria, fungi, and other microorganisms in the soil. These organisms digest organic matter in a process known as the decay cycle. ?The decay cycle breaks down the complex compounds in the plant material into forms that can be absorbed by plant roots, creating a natural recycling process,? Tompkins explains. ?Enriching the soil with organic matter also improves soil structure. This in turn improves the soil?s capacity to hold water and nutrients, and to release them to plant roots as needed.?
Another element in organic fertilizers is carbon. ?Organic fertility provides a carbon source for the soil, which is the key food for soil microorganisms. By creating an available carbon source for the soil, the microorganism populations increase, transpiring a fertilizer factory effect,? said Rick Geise, branch manager of Nature Safe, a manufacturer of organic fertilizers.
How do professional landscape contractors feel about these ideas? According to John D. Hickey, a registered landscape architect/contractor and owner of Maple Shade Landscaping, based in Effort, Pennsylvania, using natural/organic fertilizers works best for him on a limited basis. ?I prefer to use natural/organic fertilizers for shrubs and trees, which is our primary business,? says Hickey, who has worked in the field professionally for 15 years.
?The things we use are the holly tones and the plant tones, which are basically organic in nature. We found that they give us reliable growth, and we rarely have any problems with over-fertilizing, burning, or causing any type of harm to the new plants. We?ve had a lot of success with them and are happy using them.?
Hickey says the primary difference between synthetics and natural fertilizers is that synthetics are easy to overuse. ?You have to be very careful in the handling of synthetic fertilizers, not getting too much on the plants because they have a tendency to burn. The leaves would scorch, or it would put out a bolt of new growth that it can?t support. It doesn?t always kill the plants, but it can. It?s much harder to overuse organics.
A landscape contractor can make money using organic/natural fertilizers, especially for shrubs and trees, but in terms of lawns, I?m not sure how it would work.?
According to Pacific Organics, a consulting firm in Salem, Oregon, that works with companies to turn their wastes into assets and specializes in the development and marketing of organic fertilizers, there are two types of lawn fertilizer: water-soluble and water insoluble. ?Synthetic fertilizers are mostly water-soluble, which means they dissolve and release their entire nutrient quickly,? Pacific Organics says on its Web site. ?This gives very fast results. However, the roots can only take up a small amount of these nutrients at any one time, and the remaining nutrients leach below the root zone or into the gutter. Most lawns only require two to five pounds of actual nitrogen per thousand square feet per year. Synthetic fertilizers can also be high in salts that destroy beneficial soil microorganisms.?
Natural fertilizers are mostly water insoluble, Pacific Organics notes, and they are derived from organic materials that break down and release their nutrients slowly. Although initially more expensive, organic fertilizers ? since they are mostly water insoluble ? tend to remain where they are applied, and the effects last much longer. They also provide some organic matter to the soil. This helps hold soil moisture and breaks up hard soils. ?Lawns stay naturally green rather than the green and yellow cycle of synthetically fertilized lawns,? Pacific Organics concludes. ?Natural fertilizers are generally applied only two to three times a year, as oppos Building overall
fertility increases plant yields during the first season and for years
thereafter ed to double that for synthetics.?
Tina Peterson, vice president of Hendrikus Schraven Landscape Construction and Design, Inc., Seattle, Washington, feels the choice between organic and synthetic fertilizers depends on the type of client. Although more and more people are expressing interest in organics, organic fertilizers cost more than synthetics. Some clients won?t want to spend the money, due to budget constraints.
?We specialize in rock work, water features and in the use of organic fertilizers and sprays,? Peterson said. ?Almost all of our customers are residential clients. Our landscape installation jobs have ranged from $20,000 to $1 million. A homeowner is looking for artistry while most commercial clients are mainly concerned with the bottom line.?
The real bottom line is this: lawns can be lush without the use of synthetic fertilizers, if you consider the combined effect of organics and other factors, such as exposure to light, air, moisture and nutrients.
Providing good surface and subsurface drainage when establishing a lawn, filling in low spots where water may stand, thinning or removing surrounding shrubs and trees that restrict air movement to increase air flow and allow more sunlight to penetrate ? these factors can aid contractors using natural/organic fertilizers on lawns.
Roger B. Yepsen, Jr., author of the book ?Organic Plant Protection,? wrote, ?...while many of the highly acidic chemical fertilizers increase the need for lime, organic fertilizers seldom lead to overacidity. In addition,? Yepsen states, ?organics are long-lasting and don?t burn grass. Cottonseed meal, soybean meal, screened compost, and well-decayed animal manures are the most common organic fertilizers used. Dried blood or blood meal is also an excellent choice. It has a high (8?14%) nitrogen content, plus other elements necessary for grass growth.?
Yepsen adds that sludge has proven to be another excellent organic fertilizer for turf and, he says, it can be mixed with the soil when starting a new seedbed in September. ?Open the soil to a depth of five or six inches,? he advises, ?and thoroughly mix sludge and compost in with the topsoil. After seeding, top-dress with more sludge, topsoil, and compost and cover with a thin straw mulch. For well-established lawns, sludge may be applied in a 1/2-inch deep layer during winter when the ground is frozen. Not only is it a luxuriant plant food, but the sludge cover will insulate the grass roots from alternate thaws and freezes.?
?Landscape contractors clearly have a potential advantage, marketing wise, when they use natural/organic fertilizers,? says Simmons. ?The public is looking for contractors who use natural/ organic products. It?s a challenge; still, a number of contractors are succeeding with natural/organic fertilizers, and they?re doing it very effectively.?
How can landscape contractors make the transition from using synthetics to using natural/organic fertilizers? According to Zach J. Finger, vice-president of Nicron Industries Inc., Fayetteville, Arkansas, a company specializing in organic fertilizers and soil amendments, ?You can turn your lawn into a chemical-free environment by following these three steps:?
1. Soil detoxification.
3. Balancing the soil?s nutrient and mineral needs with the plants.
The basic objective in soil fertility management is to feed the soil, not merely apply minimum nutrients for a single season. Building overall fertility increases plant yields during the first season and for years thereafter. The microorganisms in a living soil break down minerals and nutrients, making them available in a form plants can use. As the microorganisms release nutrients, the flow of food to the plants becomes regulated, creating sustained fertility.?
When buying organic products, remember that any fertilizer described on the package as ?organic? must be derived from the decomposing remains of animals and plants. A material can be described as ?organic-based? if it is only 15% organic matter or more, and an ?organic-based? fertilizer can contain synthetic products.
A good soil, enriched by an organic/natural fertilizer like compost, is key to avoiding many disease problems. Some disease organisms live in the soil but when
compost is applied, it heats up considerably as it forms and is free of most soil-borne diseases, according to Hamilton Tyler, author of the book ?Organic Gardening Without Poisons.?
After the first heat, even earthworms are unharmed. What is left is available plant food. The heat of composting will not have killed all weed seeds, plant diseases and pests, but it will have
attained a balance. There will not be perfection, but nature tends to create a balance.?
Some landscape contractors are reluctant to use organic/natural fertilizers; however, the time may be coming when they may have to use them out of sheer necessity. According to a U.S. Bureau of Mines report published in 1969 (that?s right, more than 30 years ago!), native sources of commercial fertilizers are diminishing rapidly. The report said the supply of the basic fertilizing elements ? phosphate, rock, potash and nitrogen ? may soon be exhausted. ?There are mineable supplies of phosphate rock in only four states in the Northwest and three in the East, and estimates are that they will be exhausted in about fifty years,? the report stated. u
Editor?s Note: There?s a growing interest in organic landscaping. We?ve tried to give you a basic understanding of organic fertilizers. The challenge for the landscape contractor using only natural/organic
fertilizers is to balance the soil so that it
provides all the
conditions plants need to thrive by Rob Gluck Enriching the soil with organic matter also improves soil structure A good soil, enriched by an organic/natural fertilizer, like compost, is key to avoiding