Less water, but better grapes on Israeli vines

JERUSALEM－Growing grapes in Israel used to waste a lot of water, an often scarce resource in the country. But thanks to a smart irrigation system, it is now possible to save water and also manage the quality and quantity of grape yields.

In the decades before the invention of the irrigation technology, Israeli farmers used to largely rely on their experience to estimate the conditions and water needs of the grapevines.

But Yishai Netzer, an Israeli agronomist from Ariel University, and his research team did away with this practice by devising a digital-based irrigation system that has been altering the way table and wine grapes are grown.

Based on a large number of sensors that monitor the grape crops, the system lets farmers know how much water is needed for irrigation. The sensors monitor the humidity, radiation and wind speed, in addition to the water being given to the vines.

By using the new drainage lysimeters, a type of measuring device, the amount of transpiration released by the plants is measured. This gives an accurate understanding of how "thirsty" the vines are.

In his experimental greenhouses and vineyard, Netzer is testing five different watering systems to see their effect. The data is then collected by a computer and analyzed by the researchers, together with the farmers who have varying needs.

Different needs require differences in the amount of water irrigated. The less water used, the more stressed the plant is considered. For grapes, however, stress isn't always a bad thing.

"If you want to grow a lot of grapes, the quality will usually be compromised, and then we will irrigate more water," Netzer said.

"In premium wine areas, we do not want a lot of yields. Then we will stress the vine more. The quality of the vine will be increased, but the quantity would be medium, and it won't be the maximum."

Climate change, which has affected rainfall levels, also has an increasing effect on agriculture. Grapes are not exempt from this. The reduced water consumption resulting from the precision irrigation system could mitigate the effects of climate change and global warming, Netzer said.

Netzer said that all this data collected from his research can allow farmers to "cheat the plant".

"You can change the plant physiology with irrigation to the right point," he said. "It depends what the farmer wants. If he wants a lot of yields, we will by irrigation make the vines to be less thirsty and have more yields."

Xinhua