In New Zealand arable crops are generally grown on mixed-cropping farms. As well as producing grains, these farms may grow peas, corn, potatoes, beans and carrots, which will be sold to companies for freezing or canning.
Mixed-cropping farms may also have significant areas of pasture, which are initially used to produce herbage seeds, and are then grazed by animals such as sheep, cattle or deer. Forage crops may also be grown, particularly to feed stock in the winter when pasture grows slowly.
Arable farms generally develop a crop rotation system, which:
- helps to control specific weeds, pests and diseases that are associated with particular crops
- provides environmental benefits, such as improving the structure of the soil by sowing pasture, or increasing soil nitrogen levels by growing legume crops
- means that not all crops will need to be irrigated or harvested at the same time.
A major factor determining the crops used in a rotation are the relative economic returns (gross margins) of each crop.
The scientists at Crop & Food Research, a Crown research institute, are recognised worldwide for their research into plant breeding, disease and pest control, development of new agronomic practices and soil science. Some of their research is commissioned by the Foundation for Arable Research, which is primarily funded from a levy on growers.
Although crop rotations vary considerably, a typical rotation might be from pasture to autumn-harvested wheat for milling, followed by barley and then peas. This may be followed by a ryegrass seed crop, spring-feed wheat and then potatoes, before being returned to pasture.
A farm that had more animals might have a shorter arable crop phase, with its main purpose being to improve the pasture crop. For example, a weedy pasture could be cultivated and sown in wheat for animal feed, followed by barley or peas, then a winter-forage brassica crop and back to pasture in the spring.