Soya growing does not require permanent irrigation. However, in certain climates, one or more top-up irrigations during critical growth periods increase yield considerably. The most critical period is during the late flowering stage, when small pods start to appear. If 2 applications can be provided, it is generally a good idea to give the first application on pre-emergence to help the plant take root quickly. A third application, where necessary, will provide the best results if it is given as the pods start filling out.
In regions where soya is irrigated, spray irrigation is used as part of large crop rotation.