Forage legumes

Along with ryegrass, the other major component in New Zealand pastures has been clover (and white clover).  Clover is a legume: a plant that is able to fix atmospheric nitrogen through rhizobia in its root nodules.  In plant physiology terms, nitrogen is a growth multiplier – that is (where all other parameters are equal) plants grown with plant available nitrogen will produce a greater bulk of material than plants in situations where nitrogen is lacking or absent.

Clover therefore, prior to the advent of synthetic nitrogenous fertilisers such as urea was the main driver of production in New Zealand’s pastures.  Indeed our fertiliser partner, Ballance Agri-Nutrients advocates the use of nitrogen fertilisers to promote clover growth and thereby pasture growth overall.

Clover has a very high feed value, and thereby compliments ryegrass in pastures.  Stock will preferentially graze clover in a sward and hence careful management can be required to ensure clover is not grazed out.

There are a number of different types of clover – as categorised in the below.  As white and red clover are arguably of the most importance to New Zealand farming systems, they have been described first.
 

White clover

White clover is the base legume of New Zealand’s pastoral system. It is tolerant of and persistent under a wide range of management systems, and has a high feed value.  Its ability to fix atmospheric nitrogen makes a substantial contribution to the growth of companion grasses. It is a perennial clover and has the ability to produce seed and regenerate readily due to its hard seed content and stoloniferous nature (ability to spread).
 

Red clover

Red clover is also a perennial clover but is a relatively short-lived, tap-rooted legume with a high feed value. It has good summer growth and drought tolerance, but little winter growth. Red clover produces hard seed.
 

Sub clover

These are annual clovers that produce seed and thereby regenerate readily due to their hard seed content.
 

Persian clover

These are annual clovers that produce seed, however due to being soft seeded do not regenerate reliably.
 

Bolansa clover

These are annual clovers that produce seed and thereby regenerate readily due to their hard seed content.
 

Strawberry clover

These are perennial clovers and have the ability to produce seed and regenerate readily due to their hard seed content. They possess the ability to tolerate harder grazing and lower fertility than white clover.