Macronutrients (calcium and magnesium) and micronutrients (iron, zinc, manganese, copper, boron and molybdenum) are essential nutrient elements absorbed by the plant (the latter in smaller proportions) which are necessary to its development.
Microelements are almost entirely absorbed by the roots. If these elements are not available in sufficient concentrations, they should be incorporated into the cropland for a correct development of the plant. For this purpose, microelements have to soluble, interchangeable or chelated/complexed in order to be assimilated by the plant.
In the case of hydroponic crops, these elements must be available to the plant in the nutrient solution.
To avoid the blockade of these macro/micronutrients into the ground, complexing/chelating agents have to be used to support the metal in the most adverse conditions (limestone soils, high pH, etc.) allowing the micronutrients to gain access to the plant’s vascular system.
The efficacy of a chelate/complex depends on its ability to facilitate the processes of dissolution, transport and transfer of the element to the plant and to withstand inhibiting factors like high pH, competition form other metals, adsorption over materials in the ground and resistance to degradation of the organic molecule.
The complexing and chelating agents incorporate the metal in their structure, preventing its precipitation in form of oxide or hydroxide in the soil and keeping the metal available for the plant.
While traditionally it has been extensively used chelates like EDTA, DTPA, EDDHA, etc., the use of sodium heptagluconate (HGA)-based complexes offers an eco-friendlier alternative than, other traditional chelates and represents an advance in preventing contamination of crop soils and groundwater reserves, due to its high biodegradability.
HGA-complexed Fe, Mn, Zn and Cu and also Ca and Mg are used in farming, as:
- Deficiency correctors
- Contribution of macro and/or microelements in
fertirrigation (improving productivity)
- Salinity correctors
HGA complexes are particulary indicated for foliar application due to the absence of phytotoxicity.
Moreover, the high stability of these complexes in alkaline environments makes them highly suitable for use for radicular application, achieving a very good effectiveness/cost ratio.
In both traditional soil-based crops and hydroponics, the solubility of the complexed macro/microelements is of great importance, because if the product is not totally dissolved microelements supply becomes inadequate, losing those nutrients that has not been solubilised. In addition, there’s a risk of spray nozzles becoming blocked, which can cause severe problems in the irrigation system. HGA forms extremely soluble complexes which are therefore ideal to avoid problems of this kind.
S.A. DABEER has been producing sodium heptagluconate (HGA) for over 50 years, and recently developed the DABQUEL COMPLEX range, which includes a wide selection of micronutrients in both liquid (aqueous solution) and solid (micro-granules) form
The HGA complexes in the DABQUEL COMPLEX range are designed to maximise the features mentioned above.
All the products in the range are therefore highly stable, the solid products are also highly soluble (around >500 g/l), and can easily be dispersed in water due to their microgranular structure.
Spanish RD 824/2005 (concerning fertilizers and related products) has already been included sodium heptagluconate (HGA) as authorized complexing agent.
The recent publication of (EC) Regulation 2016/1618 also confirms the inclusion of HGA as complexing agent, and therefore, the HGA metal complexes have become regarded as EC Fertilizers.
Inorganic fertiliser for foliar application fertirrigation and incorporation into the soil hydrosoluble fertiliser