Growing maize silage on-farm gives you the opportunity to renew your pastures.

Modern pasture species¹:
     • produce more drymatter.
     • resist pests and diseases better.
     • are more palatable which makes them easier to manage.
     • have a high feed value (ME) so they deliver higher stock growth or production.
     • offer seasonal benefits (e.g. some varieties are better in summer while others are better in winter).

Successful pasture renewal will increase pasture yield by around 3-6 tonnes of drymatter per year¹.

Because they produce high yields of drymatter, maize silage crops have high requirements for nutrients especially nitrogen, phosphorus and potassium. This high nutrient requirement coupled with the deep rooting structure of maize, makes it an ideal "sink" for dairy shed effluent.

Maize crops can pull nutrients that have dropped out of the root range of shallow rooted crops such as pasture. Maize silage crops grown in long-term pasture paddocks that have been used for effluent disposal may not require any additional fertiliser resulting in significant cost savings per kgDM of maize silage grown on-farm².

To determine the nutrient requirements of on-farm maize silage crops soil test and use AmaizeN (available free from www.far.org.nz).

Growing maize silage on-farm gives you two opportunities to eradicate hard-to-kill weeds and grasses such as kikuyu, mercer grass and paspalum.

By selecting the hybrid and planting date you can determine approximately when your maize silage crop will be harvested and ready to feed.

A Waikato trial showed that yields of almost 39 tDM/ha can be achieved from maize silage followed by a winter crop³. This is more than double the annual pasture yield achieved on most New Zealand farms.

Figure 1: Total annual drymatter yields for maize and a range of winter crop options (two-year average data)³

Buying in maize silage requires minimal dairy farmer input. Once the crop is contracted the farmer can sit back and wait until harvest.

Typically maize silage crops are sold on a c/kgDM basis in the spring. The purchaser pays for the harvesting and all subsequent costs. The stacked price can still vary slightly due to fluctutaions in harvesting, cartage and stacking costs.

Buying in maize silage results in a significant transfer of nutrients onto the milking platform. Each 100 tDM of maize silage contains around 1,300 kg of nitrogen, 220 kg phosphorus, 960 kg potassium and 150 kg sulphur⁵. Where these nutrients end up depends on what percentage of the nutrients is converted into milk or body weight gain, where the maize silage is fed-out (paddock or feed pad) and the effluent system (pond or irrigator).

In farm systems that feed high amounts of maize silage (>1,000 kgDM/cow), the amount of maize silage that is grown on-farm is limited because pasture must still make up at least 65% of the milking cows diet. On these intensive farms, pasture protein harvest on the milking platform is maximised and bought in maize silage provides additional carbohydrates and energy.