While the drought is over, thanks to a record setting winter that made up the 11 trillion gallon deficit – many of the urban water restrictions are still in place. I know I shouldn’t turn on the sprinklers when it’s raining but why should I only be able to water two days a week? Groaning aside, the idea is to let people stop and think about watering landscapes only when necessary, rather than out of habit.
Decades ago farmers watered by the calendar. If the ditch company released water on Thursdays, you irrigated on Thursdays. Every Thursday regardless of the moisture level in the ground. It was our habit.
Our approach to irrigation today is completely different. We not only measure water in the soil with all manner of moisture probes, some crops like wine grape actually measure the amount of water in the plant leaf.
We also calculate the amount of water that is used by the plant every day. The statewide CIMIS (California Irrigation Management Information System) has hundreds of weather stations across the state to help farmers know the effect of temperature, wind humidity and soil temperature on the water requirements for their crops.
The final tool we use is close observation of the crop itself. Is it exhibiting water stress? On which soils types on which areas of the farm? Nothing beats going out and looking at the plants – frequently.
What is the result here at Walker Vineyard? Well we have not turned on the irrigation to the older grapevines yet. The data shows we are getting close and some readings say we should be irrigating this week. When Ann goes out and looks at the vines, however, she still sees active growth tips, indicating that the vines still have enough water.
All this to say, drought or not, we all benefit from changing our habits and letting the decisions to irrigate our lawns or crops be based on actual irrigation needs rather than what we have always done.