4.1.4.2 - When should I irrigate?
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| Ideally, pasture is irrigated just before its growth rate declines as the soil dries out. Many farmers judge this by experience, with varying degrees of success. The recommended best management practice for border-check irrigated pasture is to irrigate after 50 mm of “evaporation less rainfall” (E – R) has occurred since the previous irrigation. This is equivalent to about 40 mm of pasture water use, which is about the maximum that pasture can extract from typical SIR soils before its growth slows due to moisture stress. Extending the irrigation interval as a means of saving water is not recommended. Pasture growth slows with moisture stress, and productivity per megalitre is reduced. For more information on irrigation scheduling, see Step 2.3 - How well is my current irrigation system performing? Bays can be irrigated in any order, but it is practical to irrigate adjacent areas in sequence, depending on the channel system. |
 Evaporation data or evapotranspiration data can help you decide when to irrigate |
© The State of Victoria, 1996 - 2009.
This document was last reviewed on 20/10/2009