Sprinkler irrigation versus furrow irrigation for emergence and yield in the Imperial Valley of California.

Abstract

Establishing an adequate sugar beet population is one of the first challenges of sugar beet production. Sugar beet is planted in the Imperial Valley of California during September and early October. Daily high temperatures often exceed 100 degrees F in the first half of September. In addition, soils in the Imperial Valley often have significant salt content. This combination creates a harsh environment for sugar beet emergence. Fields are furrow irrigated in the Imperial Valley; however, installing sprinkler irrigation during the sugar beet emergence period is being considered by growers to increase sugar beet emergence in their fields.  After the emergence period, the sprinkler pipe is removed, and the fields are furrow irrigated for the remainder of the season. Two projects were developed to quantify potential emergence and yield differences between sprinkler and furrow irrigation during the sugar beet emergence period. A field survey of sprinkler and furrow irrigated production fields planted during September was conducted by the Spreckels Sugar Agricultural Staff during the 2020-2021 and 2021-2022 growing seasons. The field survey showed a 6.3% increase in emergence with sprinkler irrigation in 2020-2021 and an 8.0% increase with sprinkler irrigation in 2021-2022 compared to furrow irrigation. Sprinkler irrigation during emergence averaged 1,119 lbs. of extractable sugar per acre greater than furrow irrigation in 2020-2021 during the first seven weeks of harvest and 312 lbs. of extractable sugar per acre greater than furrow irrigation in 2021-2022 during the first five weeks of harvest.  A replicated trial was conducted at the Imperial Valley Research Center during the 2021-2022 season, looking at sprinkler versus furrow irrigation for emergence and yield. The trial was conducted as a randomized complete block with a split plot arrangement. In this trial, the sprinkler irrigated treatment emergence was 23.6% greater than the furrow irrigated treatment at the initial emergence count. The sprinkler irrigated treatment yielded 312 lbs. of extractable sugar per acre greater than the furrow irrigated treatment. The field survey and the trial at the Imperial Valley Research Center will be repeated for the 2022-2023 growing season.