By Wayne Nichol, Extension Agronomist & Nutritionist
The Value of legume
On the milking platform our aim is to grow as much high-quality pasture as possible so that it can be harvested and converted into milk. Often, we think of ‘pasture’ as just the grass component, which in most cases is going to be ryegrass, without acknowledging the valuable contribution clover can add to the feed system. Research has shown the higher the white clover content of a pasture the more milk produced, and this is due to its higher nutritive value and dry matter intake relative to ryegrass. What we under value is the ability to fix nitrogen, which is about 25kg N/ha for every 1t DM/ha of clover grown.
Increasing clover content
So, are we missing an opportunity, what if we could increase the clover content in the pasture? In most newly sown pastures, clover is added to the mix, but due to several challenges including shading of clover prior to the first graze, we often don’t see it. Thus, if we made a conscious decision to focus on the clover by changing our soil fertility and grazing management to suit the clover rather than the grass we would likely increase the clover content in the sward.
What if the clover is missing in the sward, can it be reintroduced? The answer is yes, white clover seed can be broadcast over the top (even with the bike spreader) usually with the fertiliser and cows can be used to trample in, it can also be used in conjunction with other species such as ryegrass and the herbs chicory and plantain. The key to success is timing, clover establishment will be most successful when soil temperatures are above 10oC, usually after the first grazing of the round in spring or autumn. This timing is key as it usually means there will be lessened competition from weeds at establishment
When oversowing or adding clover to the pasture mix it is important to use the latest cultivars of white clovers such as Legacy and Quartz to ensure the seed you are using has been bred for higher productivity to compete in pasture swards. Older cultivars like Huia and Kopu were selected from white clover swards, so have not been specifically bred to compete with ryegrass. Recommended rates vary but typically are around 4-6kg/ha which includes seed treatments such as Superstrike® to aid establishment of new seedlings. To support this initiative of introducing more clover into pasture talk to your local seed retailer of PGG Wrightson Seeds regional sales representative about the oversowing campaign for white clovers and other grass species that offers some price specials for this coming spring.