Sprinkler Spacing Does Not Affect Carrot Yield and Quality

Abstract

Optimal water management is essential in irrigated agricultural regions to sustain productivity, conserve water resources and protect groundwater quality. The southern San Joaquin Valley (SJV) of California is a major irrigated production region in which solid set sprinkler systems are commonly used to grow such crops as carrots (Daucus carota L.), potatoes (Solanum tuberosum L.), garlic (Allium sativum L.) and onions (Allium cepa L.) in predominantly sandy soils. Water and fertilizer use efficiencies are important concerns in this region. In 1996 and 1997, we evaluated the effects of three sprinkler spacings [32.2, 38.6 and 45 ft (9.8, 11.8 and 13.7 m)] and irrigation uniformity within these spacings on carrot yield, quality and nitrogen content. Applied water and soil nitrate and ammonium contents were monitored at four locations within each sprinkler lateral spacing throughout both seasons. Neither sprinkler spacing nor location within a given sprinkler spacing affected carrot production or quality. Distributions of soil nitrate and ammonium resulting from the different sprinkler spacings were also not correlated with carrot yields. These results suggest that any of the three spacings can be used for high carrot quality and productivity.