FERTILISER GUIDELINES FOR THE WINE INDUSTRY

at the amounts at which it is applied. The ratios of the elements can be used in the composition of liquid fertiliser, where amounts can be decreased with about 15% due to expected greater efficacy.

TABLE 25: Seasonal guideline amounts N-, P- and K-fertilisation for grapevine nurseries.

ELEMENT

N

P

K

Amount (kg ha -1 )

120

12

55

Ratio

10

1

4.6

Source

LAN(28)

Single supers(10.5)

KCl(50)

This fertiliser can be applied in three or more instalments starting from about 4 weeks after bud break until January/February. There are strong indications that soil choice and management practices are generally greater determinants than fertiliser when it comes to nursery success. Nursery practices are characterised by i.a. intense soil cultivation actions, of which the use of the rotary harrow probably contributes the most to structural and organic material destruction. Great emphasis is justifiably placed on the application of compost and especially chicken manure, but it appears to be uneffective with regard to increasing or even maintaining the organic material content of the soil. In this regard, urgent attention needs to be given to effective cover crops during both the winter, before planting, but also during the sum mer after the grafted vines have been uprooted, in conjuction with minimum cultivation.

8

97