Asparagus Irrigation Practices in Washington

Soil water, irrigation and rainfall have been system-atically measured on six commercial asparagus fields in south central Washington. Two high frequency center pivot irrigated fields have been studied for 3 years. Four fields irrigated by furrow, solid set sprinkler and wheel-move sprinkler systems have been studied for 2 years. A weekly soil water balance in the top 120 cm (4 ft) of the soil profile was computed for each field and each season. Results are presented which provide estimates of asparagus water use and soil water extraction patterns for the different systems, irrigation regimes and soil types.