Fertilization adjustments

Climate based adjustments
Enzymatic activity, which is essential for the assimilation of different ions like nitrate, phosphate, sulphate and ammonium, is largely depended on temperature. Too low or too high temperatures will inhibit these enzymatic activity, this is why the fertilizer recipe is effected by the temperature. High rates of nitrate during low temperature periods, for example, results in dangerous high nitrite levels. Just like temperature, light is also an essential factor for growth, in fact it is necessary for the most important plant growth process known as photosynthesis. During periods of high radiation, it is important to provide sufficient trace elements and nitrogen, because a lack of these elements will inhibit the photosynthesis. Manganese for example is essential for the activity of the enzyme superoxide dismutase, which neutralizes the free radicals, formed during photosynthesis. Without manganese, young cells will get damaged by these free radicals.
Growth stage based adjustments
Plant growth is usually initiated with the development of roots. In contradiction to leaves, roots contain no chlorophyll, hence the energy for growth must be supplied by the ‘green parts’ of the plant. Because the transport of energy to the roots is highly dependent on phosphate, this element is regularly raised during the start of the growth. High rates of nitrate influx, as a result of high vegetative growth, results in a high pH. For this reason, a part of the nitrogen must be supplied by ammonium in stead of nitrate, under high vegetative growth conditions. The acidifying properties of ammonium compensates partly the pH raising effect of nitrate influx. During flower bud or fruit development in the very first stage of growth, it is very important to offer
sufficient calcium to the plant. Calcium is essential for cell division and plays an important role in the strength of the cell wall. During the middle and final stage of flower bud or fruit development, calcium becomes less important, but the demand of potassium is at is height. Potassium is needed to give the flower or fruit cells enough turgor pressure. The more water a plant part contains, the more potassium is needed to keep the water on a certain osmotic level.