• Macronutrients are C, 0, H, N, S, P, K, Mg, Ca, Fe;
• availability of nutrients is variable and dependent on the original rocks (this determines the texture and the chemical composition), climate (which controls weathering), vegetation (which selectively removes or returns certain elements), and the management of nutrient supply;
• nutrient uptake by plants occurs mainly via the roots. Uptake may also occur via shoots (leaves and bark), which is important for aerial pollutants (see Chap. 18.104.22.168);
• dependent on the availability of nutrients or biotic pests, specific deficiency diseases may occur, that are recognised by specific symptoms in leaves.
needle tip. Necrotic flecks or bands in the middle part of the needle. Buds often die off. Misidentification: damage from road salt, herbicides (see Chap. 1.9).
• Road salt damage: needles of the previous year's growth dark copper-brown in spring, falling in early summer. Buds often fall. Damage along the edge of roads. Misidentification: frost-drought (but here needles light red-brown) or sulfur dioxide.
• phosphorous deficiency: starting with dark, blue-green colour (increased formation of chlorophyll), later violet red to copper brown, yellow colouration (anthocyanin), in parts spotty, starting from the edge of the leaf. Misidentification: K deficiency, drought, salt, but then without the violet-red colour.
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