If the management of photosynthesis is seen as a central goal in crop production, it is important to understand the relationship between the above-ground and below-ground portions of the plant. The plant roots and the micro-organisms, which live on or around them in the root-zone (or rhizosphere), are completely dependent on the above-ground plant to supply the sugar for their energy needs. There is no root growth without sugar, and there is no sugar production without the necessary minerals provided by the roots and nutrient-solubilising micro-organisms. In recognition of this synergy, the above ground plant translocates 60% of its total glucose production to the roots, and the roots release 50% of this sugar shipment into the surrounding soil to feed the root-zone microbes.
The mineral management priority involves the supply of the right starter nutrients to ensure the initial supply to the leaves of the minerals needed to build chlorophyll and produce sugar. Nitrogen and magnesium are essentials, as they are the core elements in each chloroplast. These major elements should be present in a planting blend or pre-plant mix if a soil test confirms their requirement. The trace elements, which are required in much smaller amounts initially, can be covered by a seed treatment or liquid injection at planting. Phosphate is the absolute priority at planting, because there is no sugar production and no associated early root growth without this element.