Traditional EDTA chelates have sodium as the “counter ion” whereas Solufeed Sodium Free EDTA chelates are not – they are based on potassium (K) or ammonium (NH4) counter ions. Although sodium (Na) is a so-called functional element for many plants, excess sodium can be problematic. Very high levels can be directly toxic while more moderate levels reduce the ability for plant roots to absorb water leading to stress. Sodium also influences soil physics and is responsible for ‘slumping’ where in severe cases the open, healthy soil structure is effectively destroyed.
The amount of sodium applied to soil by the use of most fertilizers is extremely small and has insignificant consequences in normal agricultural situations. However, there is some concern being shown especially in areas where saline and sodic soils are present. A trend towards reducing the sodium content of fertilizers is therefore being seen. In modern closed hydroponics systems great care is needed to ensure that the circulating nutrient solution remains balanced. Sodium is an element that can build up to harmful levels, and again selecting low sodium or sodium free nutrient sources can be advantageous.
Solufeed Sodium Free EDTA chelates are new EDTA formulations of copper, iron, manganese and zinc. A reformulated Solufeed Sodium Free TEC™, a balanced mixture of all six micronutrients is also available. These are companion products to other Solufeed chelates and suitable for use where excess sodium is a concern.