COVER CROPS in South African Vineyards

trol

COVER CROPS IN SOUTH AFRICAN VINEYARDS

rol

3000

2500

2000

1500

1000

500 Nitrogen in milligram per kilogram

0

Sown Sown 1995 Sown Sown two- Mechanical control annually annually yearly

Chemical

Slashed

control

Grazing vetch

Oats

No cover crop

Dwarf fescue

FIGURE 8.18. Average nitrogen measured as nitrates in the leaf petioles of grapevines from 1995 to 1999 in cover-crop treatments compared to a control in the Lower Orange River region. Box indicates acceptable range. Fourie, unpublished data.

JOHAN FOURIE

157