I spent several evenings this month reading scientific papers published in the Proceedings of the Second Scientific Conference of the International Society of Organic Agriculture Research. The conference was held in Modena, Italy in June of 2008. The Proceedings include over 400 papers. These are science based papers and include every kind of agriculture topic, coming from all over the world.
Many scientists from the United States had papers in the Proceedings and I was interested in those with long-term results. Iowa State University scientists reported on their 9-year corn and soybean tests, comparing conventional and organic systems. Here are their conclusions: (1) No differences in production figures between organic and conventional. (2) Costs of production were lower for organics. (3) Revenues for organic corn were 1.67 times greater than for conventional. (4) Revenues for organic soybeans were 2.32 times greater than for conventional. (5) Soil organic carbon and mineralizable nitrogen were greater in the organic tests.
The Proceedings included a lot of papers on soil development, plant nutrients, and beneficial micro-organisms. The conclusions or themes that are revealed include: (1) organic systems are better than conventional systems for building soil organic matter and fertility; (2) there is less leaching of nutrients, especially nitrogen, from organic systems, and (3) organic systems with good microbial populations utilize nutrients more effectively and also increase production. In a different vein, one study in Italy showed that residue from transgenic (Genetically Modified Organism) corn (with the Bt gene) reduced the establishment of beneficial mycorrhizal fungi. It's another reason why "certified organic" growers in the US are not allowed to use GMO seeds.
In another recent publication, ACRES USA, there are several articles on compost. The authors, with many years of personal experience dealing with farmers and gardeners, quote long standing research studies dealing with soil fertility and compost. I am a firm believer that compost is a key element as you garden, whether it is a conventional or an organic approach; but, with the following qualification…the amount of compost to use must be considered in light of soil nutrient availability. If used wisely, compost is a great product for many soils and it will pay great dividends. Compost provides nutrients, aids in promoting life in the soil and neutralizing toxins, improves soil water holding capacity, and improves soil tilth (structure and workability). As with any soil amendment or process, there are some misconceptions and cautions about the use of compost.
The misconceptions about compost, are as follows: (1) All compost is alike. In fact, the quality of compost depends on the composting process and what special products have been added. (2) The more compost you use, the better. You can't add too much. In fact, the amount to apply should be dependent on the soil nutrient analysis. There are times, e.g. when K levels are high and Ca is low, you should probably not be adding any compost. Remember, if a soil has too much of something, it will always have too little of something else. Nutrient-dense foods do not come from soils that are excessive in any of the required nutrients. (3) Compost should be applied regularly. In fact, compost should be applied when the soil analysis calls for it. (4) For good fertility, compost is all the gardener needs. In fact, soils often need some nutrients beyond what compost provides. It is entirely possible for a soil to already have too much of what compost provides. (5) Compost is far superior to all other fertilizers and soil amendments. In fact, compost is a tool for a specific job, and not an either/or decision.
If you are new at gardening, by all means become familiar and committed to composting. You can compost essentially all of your yard, garden, and kitchen wastes. It can be applied to the trees, bushes, vegetables, and flowers. Using compost moves you closer to becoming sustainable. As the price of fertilizers rise, and the economy weakens, compost becomes more and more important and valuable. Use it wisely.