On and about Bonsai

måndag 10 maj 2010

Intressant text - kolets användbarhet.

Hittade denna text på engelska om att använda kol, som jordförbättrare för bonsairötter:

"Analysis has shown that charcoal possesses a remarkable ability to hold nutrients in the soil, thanks to the cation-exchange capacity (CEC), resulting in improved soil fertility.
-Retains Nitrogen.
-Retains moisture.
-Increases number of mycorhizae.
-Moderates soil acidity.
-Avoids roots to rotten.
-Acts as a natural fungicide.

Cation-Exchange Capacity (CEC)

In order for a plant to absorb nutrients, the nutrients must be dissolved. When nutrients are dissolved, they are in a form called "ions". This simply means that they have electrical charges. As an example table salt is sodium chloride (NaCl), when it dissolves it becomes two ions; one of sodium (Na+) and one of chloride (Cl-). The small + and - signs with the Na and the Cl indicate the type of electrical charges associated with these ions. In this example, the sodium has a plus charge and is called a "cation". The chloride has a negative charge is called an "anion". Since, in soil chemistry "opposites attract" and "likes repel", nutrients in the ionic form can be attracted to any opposite charges present in soil.

Cation-exchange capacity is defined as the degree to which a soil can adsorb and exchange cations.
Cation-a positively charged ion (NH4+, K+, Ca2+, Fe2+, etc...)
Anion-a negatively charged ion (NO3-, PO42-, SO42-, etc...)
Soil particles and organic matter have negative charges on their surfaces. Mineral cations can adsorb to the negative surface charges or the inorganic and organic soil particles. Once adsorbed, these minerals are not easily lost when the soil is leached by water and they also provide a nutrient reserve available to plant roots.
These minerals can then be replaced or exchanged by other cations (i.e., cation exchange)
CEC and Availability of Nutrients
Exchangeable cations, as mentioned above, may become available to plants. Plant roots also possess cation exchange capacity. Hydrogen ions from the root hairs and microorganisms may replace nutrient cations from the exchange complex on soil colloids. The nutrient cations are then released into the soil solution where they can be taken up by the adsorptive surfaces of roots and soil organisms. They may however, be lost from the system by drainage water. Additionally, high levels of one nutrient may influence uptake of another (antagonistic relationship). For example, K uptake by plants is limited by high levels of Ca in some soils. High levels of K can in turn, limit Mg uptake even if Mg levels in soil are high.

I have been using all these years the charcoal left after a barbecue, with out knowing it I was eliminating chemicals which are harmful to plants as it seems that certain charcoals are treated with chemicals. So just in case don’t use the charcoal that you have just pulled out of a bag. What I have also discovered recently is that you can buy Bamboo charcoal which is even better and safer. So after reading all the benefits of charcoal, I think you will start using it from now on."

Källa: http://yamadori-passion.blogspot.com/