ARS | Publication request: WATER USE AND EVAPOTRANSPIRATION COEFFICIENTS FOR CAMELINA SATIVA

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 17, 2009
Publication Date: May 21, 2009
Citation: Hunsaker, D.J., French, A.N., Clarke, T.R., El-Sheikha, D.M. 2009. Water Use and Evapotranspiration Coefficients for Camelina Sativa. EWRI Proceedings: 3979-3988.

Interpretive Summary: Camelina sativa is an oilseed crop that is currently being marketed in northern and mid-western U.S. regions for its biodiesel potential. Camelina has a number of reported attributes, including drought tolerance. Therefore, camelina could become an attractive alternative crop for growers in the arid-west, where irrigation water availability is becoming increasingly unstable. However, the water use, yield, and management of camelina under irrigation in the arid-west have not yet been sufficiently evaluated. An irrigation experiment was conducted in Arizona to help develop answers for these questions. Findings indicated that camelina seed yields did not increase with irrigation frequency. Thus, camelina appears to be quite tolerant of reduced and delayed irrigation schedules. The study also indicated that the seasonal water requirement of camelina may be much lower than traditional crops produced in the area, such as wheat. A preliminary crop coefficient curve was also developed to help guide camelina growers with irrigation scheduling. This research suggests that camelina and its associated water-savings could create opportunities for irrigation growers in the arid-west with limited cropping alternatives. The paper will be of interest to growers, irrigation consultants, government agencies, and industry.

Technical Abstract: The water use characteristics of Camelina sativa, an oilseed crop, were evaluated in an irrigation experiment in Maricopa, Arizona. Camelina (cv. Robinson) was grown between November 2006 and April 2007 in plots, each 10 by 17 m. Thirty-two of the field plots were replicated in a randomized block design consisting of irrigation treatments of four levels of soil water depletion: 40, 50, 65, and 75%. Six supplemental plots evaluated water stress at 85% soil water depletion. Weekly soil water content measurements were obtained over a soil profile of 1.9 m for all plots using neutron probes. In January 2007, following initial irrigations uniformly applied to all treatments, treatments received one to four additional surface irrigations. The camelina extracted soil water to a depth of 1.5 m. The seasonal evapotranspiration, calculated from soil water balance data, varied from 285 mm for the water stress plots to 371 mm for the 40% treatment. Excluding the water stress plots, seed yields for treatments varied from 950 to 1130 kg ha-1, though differences were not significant. Mid-season camelina crop coefficients were on the order of 1.13 to 1.20. A camelina crop coefficient curve is presented as a function of days after planting.