Soil health can be like Human health in many ways
Soil health begins with improving the physical environment in the soil and this brings many important benefits for the gardener.However, it is important to realize that soil health relies on a balance that is actually made up of three components - Structure, Nutrients and Biology. Each of these has its own balance relationship and must also be in balance with the others. One way to look at soil health is in a similar way to that you or I would look at a balanced and healthy lifestyle for ourselves. That is, to have a healthy person, you must first begin with a strong skeleton. To have strong bones you need Calcium, Magnesium and Phosphorus – in the right proportions. Likewise in soil, the proportions of Calcium, Magnesium, Sodium, Potassium and Hydrogen are important for the basic structure or ‘skeleton’ of the soil. But, a human being is more than just a collection of bones. The skeleton supports the body and the development of strong muscles. This process requires Carbohydrate, Protein and Fat in the right proportions, throughout life. Likewise, soil health is built on having Nitrogen, Phosphorus, Potassium and Sulphur available to plants in the right proportion throughout their growing season. In addition, we see the interaction between these two components when we look at people of different sizes. Imagine, for instance, trying to build a 'Schwarzenegger' body on a 'Mr Bean' skeleton. It is just as ludicrous to try and build soil with only fertilizer - the 'body' of the soil must be proportional to its 'skeleton'. Of course, human health relies on more than just carbohydrate, protein and fat; we also have requirements for various vitamins and minerals - in the proper amounts. In similar fashion, productive soils must provide plants with the complete range of Trace elements in suitable quantities. Still, we all realize that healthy people need even more. We need the right balance of ‘good bacteria’ on our skin and in our digestive system to help us take up the nutrients we require and help protect against infection. Soil health is no different and the biological component of the soil also needs to be balanced for similar reasons. And just as the requirements for humans will vary somewhat for each individual and at every stage throughout life, so too, each soil will have its own individual needs and characteristics, while the requirements of plants will alter throughout the growing season. Cation BalanceIn terms how we manage sustainable production, the Albrecht System focuses on cation balance (the soil skeleton)
as the most important step in developing soil health.
This optimizes soil structure and ensures the greatest possible availability of all nutrients. For proper soil health, the desired cation proportions (as percentages of the Cation Exchange Capacity), as well as the Calcium Magnesium ratio
, are as follows: | Calcium | 65% to 70% | | Magnesium | 12% to 15% | | Sodium | <5% | | Potassium | 3% to 5% | | Hydrogen | <10% | | Calcium magnesium ratio | 2:1 to 4:1 | Adjusting these proportions requires the application of materials such as Lime, Dolomite and Gypsum in the appropriate amounts. But how can you work out which material (or combination of them), as well as the 'appropriate' amount to use?
This is where the Hydrogen becomes so important. When the early researchers (like Albrecht) were developing their soil balance systems, there was no test for exchangeable Hydrogen in the soil - only the estimate of total hydrogen expressed as "exchangeable acidity". So these scientists developed a pH-based estimate of the exchangeable Hydrogen that 'Albrecht' laboratories continue to use today. However, a reliable test for exchangeable Hydrogen in soil was developed in 1960 and this showed that in places like Australia, Africa and other countries with very old and fragile soils, the pH estimate simply doesn't work. Once the cation balance has been corrected, providing balanced plant nutrition will mean ensuring the plants you are growing have the necessary amounts of all the nutrients they require (and - ideally - no more) throughout the period of their growing season. Of course, the soil will supply much of this requirement, so the only nutrients needed (as fertilizer) will be those that are in short supply in terms of the existing levels in the soil. Don't rush to put on fertilizer though. Lime, Dolomite and Gypsum need time to improve the soil in ways that assist in making nutrients available to plants. Be sure you allow at least six months between cation balancing and fertilizing.
Soil BiologyNow all that remains for complete soil health is to stimulate the activity of those organisms that are needed to help facilitate the changes we have set in motion.
Soil Biology as an aspect of soil health is a topic that needs a page of its own, so click here for more information.
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