Paddock selection and Crop sequence
Historically wheat was grown in a rotation with pastures and a period of fallow, often bare cultivated. The advent of a range of pulse and oilseed crops, favourable economic outcomes from cropping and with a deeper understanding of management of disease and fertility issues, crops are normally sown every year in the same paddock.
Rotation is now rarely used to describe cropping systems as flexibility is the key to success. Changes in crop choice can be made at sowing time based on several factors.
Pulses, oilseed crops and barley offer disease breaks for many wheat diseases and indeed differing genetic backgrounds of wheat varieties sometimes allow wheat to be sown in consecutive years. Incorporation of disease resistances into wheat has also virtually eliminated some diseases, such as cereal cyst nematode, and allowed more frequent sowing of wheat.
Wide row sowing with precision guidance techniques, where crops are sown in the gaps between the crop rows from the previous season, can also allow wheat to be sown more frequently.
Choice of paddock to sow wheat is therefore based on a range of issues. Economics, risk of production due to disease or weed pressures, herbicide options, seasonal forecasts, stored soil water and achieving a balance of risk with other crop types are some of the considerations which form choice of crop.
Seedbed preparation
Preparation of a seedbed to ensure good seed soil contact was an important element in successful crop establishment. Minimum and no till crop production systems have however proved that a fine tilth for a seedbed is not so critical.
Advances in equipment for minimum and no till systems has incorporated sowing implements with tynes and press wheels that create furrows. The furrow harvests water into the seed row and the press wheels ensure good seed soil contact.
Shared knowledge within farmer groups has led to many of the changes in farming systems and these groups are a good source of advice relevant to a particular district.
Sowing
Timeliness of operations is a gift that farmers owe themselves. Seasonal variability always modifies a calendar decision, but whether the season breaks early or late, farmers need to be prepared. Every year there is a weather limit on the window of opportunity for sowing. Sowing requisites and equipment need to be ready to exploit that window.
A season which breaks in April is ideal because of the opportunity to use all options. Long season (winter) wheat varieties are sown first at the optimum time of mid-late April through to mid May (SW and NE Victoria), and mid season varieties follow in May/June. If the ‘break’ is later, the same principle applies except that in an extremely late season farmers would forego sowing long season wheats.
Recent experience has demonstrated the benefit of sowing a portion of the crop dry if a seasonal break has not been received by late April. These crops germinate rapidly when rain falls and generally make the best use of limited growing season rainfall.
