FRESNO, Calif. -- If they're treated right, eucalyptus trees can grow beautifully in the sticky black soils of the Tulare Lake basin, a fact that fits another piece in the complex jigsaw puzzle that will eventually reveal the sustainable, economically viable long-term farming potential of the San Joaquin Valley's west side, according to UC scientists.
Growing eucalyptus trees could be part of a water reuse scheme for farmers who, to maintain agricultural production well into the future, must consider adopting measures beyond the currently standard evaporation ponds to dispose of drainage water, said Jim Oster, UC Riverside soil scientist.
Sequential water reuse is a system where farmers use ag drainage water from one crop, such as lettuce, to irrigate a more salt-tolerant crop, such as cotton, some forages or eucalyptus trees. The water may be used once again on extremely salt-tolerant crops before the much-reduced volume of water is pumped into a comparatively small evaporation pond.
"We demonstrated that eucalyptus trees can be grown in the Tulare Lake basin with saline drainage water. We believe the same techniques will work with this kind of water at other sites. We know the trees can be part of a sequential reuse system," Oster said. "However, while you wouldn't need as large an evaporation pond, the combination of pond and trees would take more land. That's somewhat discouraging."
Using just the eucalyptus trees for water reduction, the evaporation pond area is reduced by 70%, but the total of tree plus pond area is 1.9 times greater than if all the drainage water is disposed in an evaporation pond.
Nevertheless, Oster said he is encouraged by the results of his study on eucalyptus trees, funded with a $300,000 grant from the United States Bureau of Reclamation and conducted in cooperation with the Tulare Lake Drainage District.
In a remote Kings County site, trees were grown with and without the soil
amendment gypsum. The untreate
Contact: Jeannette Warnert
University of California - Division of Agriculture & Natural Resources