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Time release fertilizers
In article ,
Tim wrote: lol...Doesn't take much to get you riled, does it? Well, as long as you feel better. Riled? I haven't even dipped into my scatological references yet. I just hope that this chemfert never sees topsoil. Granted you're not distributing this witch's brew over 1000s of acres, but every bit of remaining topsoil is precious. Humankind has not woven the web of life. We are but one thread within it. Whatever we do to the web, we do to ourselves. All things are bound together. All things connect. ~Chief Seattle, 1855 Ah, now that I can agree with...To an extent. I do believe that we are faced with way too many compounds which we don't even know about. From the fluoridated/chlorinated water I drink and water with to the compound that makes plastics soft, to my cell phone looking for the last brain cell to fry. OK Grasshopper, pay attention while ol' Sensei Billy trys to slip this concept into your skull. Teaming with Microbes: A Gardener's Guide to the Soil Food Web Jeff Lowenfels and Wayne Lewis http://www.amazon.com/Teaming-Microb.../dp/0881927775 /ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1206815176&sr= 1-1 pg. 25 Special soil fungi, called mycorrhizal fungi, establish themselves in a symbiotic relationship with roots, providing them not only with-physical protection but with nutrient delivery as well. In return for exudates, these fungi provide water, phosphorus, and other necessary plant nutrients. Soil food web populations must be in balance, or these fungi are eaten and the plant suffers. Bacteria produce exudates of their own, and the slime they use to attach to surfaces traps pathogens. Sometimes, bacteria work in conjunction with fungi to form protective layers, not only around roots in the rhizosphere but on an equivalent area around leaf surfaces, the phyllosphere. Leaves produce exudates that attract microorganisms in exactly the same way roots do; these act as a barrier to invasion, preventing disease-causing organisms from entering the plant's system. Some fungi and bacteria produce inhibitory compounds, things like vitamins and antibiotics, which help maintain or improve plant health; penicillin and streptomycin, for example, are produced by a soil-borne fungus and a soil-borne bacterium, respectively. All nitrogen is not the same Ultimately, from the plant's perspective anyhow, the role of the soil food web is to cycle down nutrients until they become temporarily immobilized in the bodies of bacteria and fungi and then mineralized. The most important of these nutrients is nitrogen‹the basic building block of amino acids and, therefore, life. The biomass of fungi and bacteria (that is, the total amount of each in the soil) determines, for the most part, the amount of nitrogen that is readily available for plant use. It wasn't until the 1980s that soil scientists could accurately measure the amount of bacteria and fungi in soils. Dr. Elaine Ingham at Oregon State University along with others started publishing research that showed the ratio of these two organisms in various types of soil. In general, the least disturbed soils (those that supported old growth timber) had far more fungi than bacteria, while disturbed soils (rototilled soil, for example) had far more bacteria than fungi. These and later studies show that agricultural soils have a fungal to bacterial biomass (F:B ratio) of 1:1 or less, while forest soils have ten times or more fungi than bacteria. Ingham and some of her graduate students at OSU also noticed a correlation between plants and their preference for soils that were fungally dominated versus those that were bacterially dominated or neutral. Since the path from bacterial to fungal domination in soils follows the general course of plant succession, it became easy to predict what type of soil particular plants preferred by noting where they came from. In general, perennials, trees, and shrubs prefer fungally dominated soils, while annuals, grasses, and vegetables prefer soils dominated by bacteria. One implication of these findings, for the gardener, has to do with the nitrogen in bacteria and fungi. Remember, this is what the soil food web means to a plant: when these organisms are eaten, some of the nitrogen is retained by the eater, but much of it is released as waste in the form of plant-available ammonium (NH4). Depending on the soil environment, this can either remain as ammonium or be converted into nitrate (NO,) by special bacteria. When does this conversion occur? When ammonium is released in soils that are dominated by bacteria. This is because such soils generally have an alkaline pH (thanks to bacterial bioslime), which encourages the nitrogen-fixing bacteria to thrive. The acids produced by fungi, as they begin to dominate, lower the pH and greatly reduce the amount of these bacteria. In fungally dominated soils, much of the nitrogen remains in ammonium form. Ah, here is the rub: chemical fertilizers provide plants with nitrogen, but most do so in the form of nitrates (NO,,). An understanding of the soil food web makes it clear, however, that plants that prefer fungally dominated soils ultimately won't flourish on a diet of nitrates. Knowing this can make a great deal of difference in the way you manage your gardens and yard. If you can cause either fungi or bacteria to dominate, or provide an equal mix (and you can - just how is explained in Part 2) , then plants can get the kind of nitrogen they prefer, without chemicals, and thrive. Negative impacts on the soil food web Chemical fertilizers negatively impact the soil food web by killing off entire portions of it. What gardener hasn't seen what table salt does to a slug? Fertilizers are salts; they suck the water out of the bacteria, fungi, protozoa, and nematodes in the soil. Since these microbes are at the very foundation of the soil food web nutrient system, you have to keep adding fertilizer once you start using it regularly. The microbiology is missing and not there to do its job, feeding the plants. It makes sense that once the bacteria, fungi, nematodes, and protozoa are gone, other members of the food web disappear as well. Earthworms, for example, lacking food and irritated by the synthetic nitrates in soluble nitrogen fertilizers, move out. Since they are major shredders of organic material, their absence is a great loss. Without the activity and diversity of a healthy food web, you not only impact the nutrient system but all the other things a healthy soil food web brings. Soil structure deteriorates, watering can become problematic," pathogens and pests establish themselves and, worst of all, gardening becomes a lot more work than it needs to be. If the salt-based chemical fertilizers don't kill portions of the soil food web, rototilling will. This gardening rite of spring breaks up fungal hyphae, decimates worms, and rips and crushes arthropods. It destroys soil structure and eventually saps soil of necessary air. Again, this means more work for you in the end. Air pollution, pesticides, fungicides, and herbicides, too, kill off important members of the food web community or "chase" them away. Any chain is only as strong as its weakest link: if there is a gap in the soil food web, the system will break down and stop functioning properly. Healthy soil food webs benefit you and your plants Why should a gardener be knowledgeable about how soils and soil food webs work? Because then you can manage them so they work for you and your plants. By using techniques that employ soil food web science as you garden, you can at least reduce and at best eliminate the need for fertilizers, herbicides, fungicides, and pesticides (and a lot of accompanying work). You can improve degraded soils and return them to usefulness. Soils will retain nutrients in the bodies of soil food web organisms instead of letting them leach out to God knows where. Your plants will be getting nutrients in the form each particular plant wants and needs so they will be less stressed. You will have natural disease prevention, protection, and suppression. Your soils will hold more water. The organisms in the soil food web will do most of the work of maintain- ing plant health. Billions of living organisms will be continuously at work throughout the year, doing the heavy chores, providing nutrients to plants, building defense systems against pests and diseases, loosening soil and increasing drainage, providing necessary pathways for oxygen and carbon dioxide. You won't have to do these things yourself. Gardening with the soil food web is easy, but you must get the life back in your soils. First, however, you have to know something about the soil in which the soil food web operates; second, you need to know what each of the key members of the food web community does. Both these concerns are taken up in the rest of Part 1. ____ To use chemical fertilizers is to become dependent on them, because they kill the microbes that would otherwise feed your plants, at no cost, for you. As you grow microbes, you grow top soil. As you grow topsoil, you participate in the healing of the planet. Meditate Grasshopper. The system of nature, of which man is a part, tends to be self-balancing, self-adjusting, self-cleansing.* Not so with technology.* ~E.F. Schumacher, Small is Beautiful, 1973 -- - Billy "For the first time in the history of the world, every human being is now subjected to contact with dangerous chemicals, from the moment of conception until death." - Rachel Carson http://www.youtube.com/watch?v=WI29wVQN8Go http://www.haaretz.com/hasen/spages/1072040.html |
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