Maximising white clover

  • White clover is a key component of NZ pastoral systems because of its high feed value, warm season growth and ability to fix
  • Compared to grass, white clover is more difficult to establish in a Care needs to be taken with soil fertility, sowing technique and cultivar choice.
  • Clover content is also greatly influenced by on-going pasture

 

Soil fertility

Correct soil fertility is essential. Clover is sensitive to soil pH, growing best at 5.8-6.2. Ensure that phosphate, sulphur and molybdenum levels are adequate.

 

Establishment

The past 10 years have seen changes in sowing techniques, with greater emphasis on the speed of pasture renewal, often at the expense of its quality. In many cases little thought has been given to white clover.

 

White clover has a small seed, with little energy reserve. Therefore it requires shallow sowing (2-3 mm), and plenty of light and space once emerged. Drilling ryegrass

and clover in the same row through a coulter drill means competition from the faster establishing ryegrass suppresses clover (see graph below). Where possible don’t sow ryegrass and clover together in rows. If cultivating, roller drills are ideal. If your drill (or your contractor's) has a separate small seed box, one option is to order your clover seed separately and sow it through this.

 

Sowing method and clover

In this trial white clover and ryegrass were sown using three widely used methods. Broadcasting white clover seed gave on average 20% more clover in the pasture than drilling with ryegrass in a row, when assessed 9 months after sowing.

 

 

Maintaining good clover 

Once established, white clover will perform best under rotational grazing, with grass kept relatively short, as clover grows close to the ground and doesn’t compete as well for light. White clover is preferentially grazed by stock, so continuous set-stocking often leads to over grazing and reduced clover levels.

Excessive use of N fertiliser (>200kg N/ha/year) will give a competitive advantage to grasses, which may result in less white clover in the pasture. The key is to control the extra grass growth to ensure that white clover is not shaded out.

 

Cultivar choice

This contains cultivars of two leaf sizes to provide greater adaptive capability to variable climate, topography or management.

 

Weka/Apex
This combination is smaller leaved and more tolerant of sheep and deer grazing. In summer dry conditions or under clover root weevil attack, both Weka and Apex show improved tolerance.