Author
Bryla, David | |
Banuelos, Gary | |
MITCHELL, JEFF - UC |
Submitted to: Irrigation Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/8/2003 Publication Date: 2/26/2003 Citation: BRYLA, D.R., BANUELOS, G.S., MITCHELL, J.P. WATER REQUIREMENTS OF SUBSURFACE DRIP IRRIGATED FABA BEAN (VICIA FABA L.) USED FOR WINTER COVER CROP IN CALIFORNIA.. IRRIGATION SCIENCE. 2003. Interpretive Summary: In California, faba bean is grown for seed production in the Salinas and Northern Sacramento Valleys, but in other parts of the state it is grown mostly as a cover crop or for green manure. It is a cool-season annual usually planted February and March for seed and September to November for cover crops. Vegetative yields typically produce about 20 to 40 tonnes (fresh weight) of forage per hectare and the leguminous nature of the plant can provide considerable amounts of nitrogen to the soil. Once incorporated into the soil, faba bean, as with other cover crops, potentially increase soil organic matter and improve soil structure and tilth over time. A 3-year study was done in central California to determine the water requirements for growing faba bean as a winter cover crop using subsurface drip irrigation (SDI). Water was applied each year at three different rates with drip laterals installed 0.30, 0.45, or 0.60 m deep. Rainfall was above normal the first year and irrigation had no effect on crop production. Irrigation improved production and water use efficiency the following years however. Production was higher when drip laterals were located at 0.30 or 0.45 m than at 0.60 m depth, even though roots tended to be concentrated near the laterals (later in the season) regardless of depth. Overall, well-irrigated faba bean required 231 to 297 mm of water to produce 3.0 to 4.4 tonne ha-1 of dry vegetative biomass. Technical Abstract: A 3-year study was done in central California to determine the water requirements for growing faba bean (Vicia faba L.) as a winter cover crop using subsurface drip irrigation (SDI). Water was applied at 0, 50, and 100% of the estimated crop evapotranspiration (ETc) the first two years and 50, 100, and 150% ETc the third year with drip laterals installed 0.30, 0.45, or 0.60 m deep. Rainfall was above normal the first year (> 330 mm) and irrigation had no effect on crop production. Irrigation improved production and water use efficiency the following years however. Production was higher when drip laterals were located at 0.30 or 0.45 m than at 0.60 m depth, even though roots tended to be concentrated near the laterals (later in the season) regardless of depth. Overall, well-irrigated faba bean required 231 to 297 mm of water to produce 3.0 to 4.4 tonne ha-1 of dry vegetative biomass. |