Dairy NZ

Kale is normally used as a winter feed crop. It has a deep root system with good drought tolerance. It also has good tolerance to most insect pests and can be used as a second brassica crop, especially after swedes, because of its tolerance to club root and dry rot. Kale is usually sown in November and December to produce large amounts of high quality feed which is carried over for winter grazing.

There are three types of kale:

• Short cultivars - lower potential yields of around 12 tonnes/ha but of good quality with high leaf:stem ratio - suitable for lambs, sheep and young cattle
• Intermediate - good potential yields of up to 15 tonnesDM/ha often with a balanced leaf:stem ratio
• Giant cultivars - potentially highest yielding of up to 17 tonnesDM/ha but often with a large portion of total yield in the stem (lower leaf:stem ratio) which is lower in quality

Good yields can be achieved under good growing conditions but will vary depending on soil type, fertility and available moisture.

Kale grown on light, infertile soils or when water stressed may have lower yields of 6-8 tonnes/ha regardless of cultivar.  Water logged/compacted soils can also severely reduce yield potential. 

Key Points

• Soil moisture is usually the main cause of yield variation.  In some areas it can be the lack of moisture during summer, while water logging can be a problem in wetter areas.
• For good establishment kale needs to be sown early enough to reach its yield potential into a firm fine seedbed with good soil seed contact and a uniform plant population
• Apply appropriate fertiliser to reach a realistic yield potential
• Strategies for weed and pest control should be established before planting
• Feed budget to determine the appropriate area required.  Use realistic yield estimates and allow for utilisation of 80-85% to achieve feed intakes for live weight gain
• A planned approach to growing kale increases the success of the crop and the benefits to the farm as a whole.

Find out more about Kale in the DairyNZ Farmfact: Kale - growing a high yielding crop (1-74)