FERTILISER GUIDELINES FOR THE WINE INDUSTRY

CONCENTRATIONS AND NOTATIONS Parts per million (dpm) = mg/kg 10 000 mg/kg = 1% 1% = 10 g/kg

INTERPRETATION OF FERTILISER NOTATION Example 3-1-5(37) 37 = total concentration of plant nutrition in the product, expressed as %

N = 3/(3+1+5) x 37 = 12.3% P = 1/(3+1+5) x 37 = 4.1% K = 5/(3+1+5) x 37 = 20.6% Control = 12.3% + 4.1% + 20.6% = 37%

In the USA and Europe, P and K in fertiliser are expressed as P 2 O 5 and K 2 O respectively. In order to convert this notation to the element notation we use, the following factors must be used: P = 0, 436 x P 2 O 5 K = 0, 83 x K 2 O

6

GRANULAR PRODUCTS Of these products LAN, urea, 1-0-0(40), MAP, KCl, K 2 SO 4 , 1-0-1(36/48) and 3-1-5(37) are most commonly used. As the products are in granular form and convenient to use, they can be applied by hand or using mechanical fertiliser spreaders. The increased use of drip irrigation has lead to a decline in the use of granular fertiliser as fertilisation source during the season, as drip systems are not effective to wash the granular products into the soil. For these systems, water soluble products or liquid fertilisation products are preferred. Micro sprinklers offer the advantage that they are effective for washing in of fertiliser in any form. Granular fertiliser is still the primary product for the fertilisation of cover crops.

78