Many farms in Northland (and in also in other coastal locations of the Upper North Island) are kikuyu dominant. Kikuyu grows best over summer and autumn, and on farms with kikuyu dominance its growth suppresses ryegrass and clover.
Kikuyu has many advantages over ryegrass-based pastures in the summer – it is more drought tolerant, resistant to pests such as slugs and crickets, and has low facial eczema and grass staggers risk.
It also has some disadvantages over temperate grasses; it can lose feed quality quickly in autumn and winter unless well controlled, and it is highly susceptible to frost damage, contributing to low pasture cover at calving.
Farms with well-managed kikuyu-based pasture can match the profitability of well-managed ryegrass-based farms.
The key to success hinges on changing kikuyu-dominant pastures to ryegrass-dominant pastures in the autumn and winter through a programme of mulching and drilling Italian ryegrass into the kikuyu. This allows the farm to achieve higher growth rates of ryegrass in the winter and spring, followed by the advantage of kikuyu growth over the summer.


Kikuyu in the farm system
There are three key farm policies which are important for aiding successful kikuyu management.
Policy 1. Set stocking rate
Grazing pressure is important for managing kikuyu quality. Maintain a moderate to high stocking pressure between 2.5 and 3.2 cows/ha, depending on soil type and contour.
Kikuyu has a different seasonal production to ryegrass. Manage rotation length and use cost effective supplement to fill feed deficits and maintain pasture quality.
Kikuyu Characteristics for seasonal growth rates.
Policy 2. Maintain some ryegrass dominant pastures
Maintain 20-40% of the pasture area in ryegrass dominant pastures (or other perennial winter active species such as tall fescue if climate permits). Having a component of perennial pasture on the farm can provide better quality feed in summer and helps to increases stocking pressure on kikuyu paddocks in autumn.
Policy 3. Have a mulching and oversowing programme
Mulching kikuyu to ground level and selecting paddocks to undersow is important for ensuring winter feed. Kikuyu declines in quality as it accumulates more dry matter and shading prevents ryegrass plants establishing in pasture. The faster it grows the quicker it loses quality. Old kikuyu needs to be mulched to improve feed quality and allow ryegrass to emerge before winter. The kikuyu management through autumn section (below) will explain this bi-annual cycle using oversowing to increase ryegrass numbers every second-year. where good kikuyu management allows.


Kikuyu Management through the Summer


Kikuyu can grow rapidly in summer when conditions are favourable (warm and wet) and must be managed well to optimise pasture quality.
From December to February the aim is to maintain grazing pressure to keep residuals down; this prevents a mat building up, keeps the kikuyu leafy and maintains clover in the pasture. Through summer kikuyu has a high leaf to stem/stolon ratio and with good management the fast-growing green leaf (10-11 MJME) can be achieved.
- Speed up rotation on kikuyu paddocks to 18-30 days if pasture growth is rapid.
- This can be faster during rapid growth
- Prioritise the grazing of your kikuyu paddocks to maintain good residuals. If needed, leave ryegrass paddocks out of the grazing rotation in order to maintain higher stock pressure on kikuyu dominant paddocks
- From December to March target grazing at the 4-leaf stage.
- Grazing at the 4 to 4.5 leaf stage helps prevent a build-up of stem over time. See kikuyu characteristics for more information on leaf stage and grazing interval.
- Manage the residual height to less than 5cm
- Regular grazing to less than 5cm keeps kikuyu leafy.
- Occasionally mow or mulch some paddocks with higher residuals to prevent a kikuyu mat building up in the base of the pasture over the summer. In January, it’s important to start minimising the trash on paddocks you want to undersow in autumn through mowing or hard grazing.
Kikuyu Management through the Autumn
From March to June the aim is to transition from kikuyu dominant pastures over to ryegrass dominant pasture via a mulching and undersowing programme.
Kikuyu Management through the Winter and Spring
Through winter and early spring, pastures should be ryegrass dominant, switching back to Kikuyu pastures in the early summer. Kikuyu is not frost tolerant so should not be saved for winter feed.