Cultivated plants require adequate amounts of water, light, carbon dioxide and mineral nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur and microelements) to maximize their full productive potential. Potassium is one of the three main elements for plants. It is involved in the stomata’s functioning and therefore contributes to reducing the plants transpiration, thus increasing the resistance to drought. A higher concentration of potassium in the leaf, increases the water use efficiency (see figure 1).
Crops require high amounts of potassium. Under the assumption that soils contain and provide sufficient potassium, this element has often been neglected by farmers. However, at the current yield levels, soils often do not provide appropriate amounts of potassium.
Numerous experiments have shown that a sufficient supply of potassium, facilitates photosynthesis even in the case of servere drought stress, while photosynthesis stops almost completely in plants poorly supplied with potassium (figure 1).
In addition to potassium supply, soil fertilization with all three main elements N (nitrogen) P (phosphorus) K (potassium) is essential to minimize the effect of drought and to obtain good yields. This is clearly highlighted in results of 7 experiments conducted by Borealis L.A.T on maize at different locations in Central and Eastern Europe including Romania under different climatic conditions (figure 2).