Could someone explain to me the differences between using an organic and an 'inorganic' (such as Miracle Gro) fertilizer? Organic ferts seem to typically have lower NPK ratios (i.e. 2-1-3 vs. 20-10-30). Thanks.
I would try to follow the directions either way, they will have been worked out in field trials to give best results without hurting the plants. It has been stated that many inorganic fertilizers are comparatively inefficient compared to organics, with the majority (?) of dissolved nutrients ending up washed out of the rootzone. Organics would need some soil biology to make them available to the plant, but assuming you've provided for that, the nutrients move from the original form of organic meal and/or rock to being held in the form of various microbes and shouldn't be leached out before the plant can access them. This is why such differing NPK values can provide unexpectedly similar results.
I don't know if the previous response was really answering the question. There are a lot of differences between using organic and inorganic fertilizers, and the relative "strength" of the inorganics is a minor one. Andrea, if you haven't read the threads on the Organics Forum, you might want to take the time to go through it. They'll give you an idea of the breadth, complexity and "voltage" of the issues raised by inorganic vs. organic. The idea that the "dose" is what differentiates organic from chemical really misses the point. It misses the crucial idea that healthy soil is what plants need most (of course, in addition to the requisite sunshine, air and water). Inorganic fertilizers do nothing to promote healthy soil and may actually harm the soil. Organic fertilizers are less likely to damage the soil. Most organic ferts actually build healthy soil, but I don't want to overstate this because soil health is also determined by cultural practices and the absence of pesticides. All fertilizers, even organic ones, can be seen strictly within the chemical paradigm of NPK (the idea that soil is simply a substrate for supporting roots and holding moisture and on-demand nutrients). On the other hand, they can be seen as means to building soil health. The latter is the best way to go, for the long term, in the big picture. I'm not talking about the best method to give you the biggest, reddest, earliest, most perfectly shaped and blemish-free tomatoes this summer. I'm talking about what's best for the long term ability of this planet's soils to sustain agriculture. Organic Ferts: - less danger of over-fertilization and damage to soil or plants - more likely to improve soil structure or tilth - improve the water-holding capacities of sandy soils, an especially distinct advantage in arid climates - more likely to build organic matter which improve long-term soil health - are generally slower to become available to plant roots because they depend on mineralization and other natural soil processes. This means a slow, steady supply of nutrients for the plant, avoiding the treadmill cycle of 'feast or famine' with chemicals - social costs are generally lower, since less indstrial processing is done to arrive at the final "product" - good for local, sustainable economies, since gardeners (or communities) can produce their own organic fertilizers (composts, "green manures") Inorganic Ferts: -commercial fertilizer, especially nitrogen, is easily washed below the level of the plants root system through the leaching of rain or irrigation. - applications which are too heavy or too close to the roots of the plants may cause burning (actually a process of desiccation by the chemical salts in the fertilizer). - Overly heavy applications of commercial fertilizers can build up toxic concentrations of salts in the soil - social costs are, in general, higher. Large scale industrial methods, product trucked long distances - can never be sustainable. Production will inevitably peak and decline due to resource depletion (for example, most chemical N is dependent on natural gas production, which depends on oil production) I've probably missed several points, but I hope this has expanded your viewpoint a bit. (bracing for the onslaught of anti-organic vehemence from the usual suspects...)
No onslaught from me, Bev :-) Seems like you've summarized my views better than I could have. My brief response was trying to focus on Andrea's specific question about the differing NPK concentrations...which do worry a lot of us until we go ahead and try the lower analysis organic solutions and experience satisfactory results (or even better, hmm?) Glen
I've never gardened with chems, so I can't say from experience that the lower NPK values give better results (using the industrial standards I mentioned) than the supercharged chems. I just know that I have a really healthy garden, few pest problems, and the produce is plentiful and delicious. Today I was reading some research about compost tea and the writer was emphasizing the fact that healthy, bio-active soil is necessary for organic fertilizers to "work". Perhaps some of the anti-organic rhetoric stems from a lack of understanding or patience when it comes to making the switch. People expect too much too soon. The soil needs time to recover, build up the organic matter, humus, microherd. As these basics are provided, results will improve. For the past few years I've been making my own "organic mix" using seed meals, greensand, calphos/soft rock phosphate, rock powders, alfalfa fines and kelp. Yummy stuff for the soil. I have a spreadsheet that I can tinker with the NPK, low as the numbers are, to get a relatively balanced mix. But making this stuff is unsustainable. The greensand and kelp are unprocessed but still get trucked from afar. The calphos is pretty highly processed. The seed meals and alfalfa are local, at least. I stocked up last year and I hope I don't need to buy more. Eventually I'll learn and figure out how (whether?) a truly sustainable garden is possible on an acre. So I'm thinking and learning about truly sustainable agriculture, where all "inputs" are produced on site. Fertility is maintained by carefully managed rotations, green manures and composting. Reading Steve Solomon's "Gardening When it Counts" got me really thinking big-picture and thinking critically about this whole bio/french/square foot intensive thing I'd been dabbling in. THEN I read Derrick Jensen and Daniel Quinn and that really changed the entire picture. Added history and anthropology to the mix. Anyway, its good that people are growing stuff, even if they're using the chems. Growing stuff reminds (teaches?) us that food does not come from grocery stores, and that all life depends on soil. It appears that seed houses are doing incredible business this season. Flooded with orders, overwhelming demand from home gardeners. On the one hand, people are starting to "get it"-- peak oil means peak fertilizer means bad news for industrial agriculture and the three-day supply of food at the Loblaws. Even if people believe that this is just another business/energy/climate cycle, there are hard times ahead and growing food makes more sense than ever. The down side of overwhelming demand for vegetable seeds is shortages. I think that home gardeners will have to become self-reliant seed savers. Enough of my rambling. Good luck with the garden Andrea, and thanks for the thoughtful comment, Glen.
Once again, thank you. You have cleared my question, but led to another. So, in regards to my other question ("Oops...now I need help"- the one regarding coir), do you think I should still use a diluted (2-1-3) organic fertilizer? I ask as it will take longer for the fert to be released to the plants. They are in 50-plug trays. Thanks again.
