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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Production and Genetic Improvement Research Unit » Research » Publications at this Location » Publication #413257
Research Project: Water and Nutrient Management for Sustainable Production of Small Fruit and Nursery Crops

Location: Horticultural Crops Production and Genetic Improvement Research Unit

Title: Weighing lysimeters for measuring evapotranspiration and developing crop coefficients for trailing blackberry

Author
item CARROLL, JESSE - Missouri State University
item Orr, Scott
item DAVIS, AMANDA - Oregon State University
item STRIK, BERNADINE - Oregon State University
item Bryla, David

Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 3/15/2024
Publication Date: 4/12/2024
Citation: Carroll, J., Orr, S.T., Davis, A.J., Strik, B.C., Bryla, D.R. 2024. Weighing lysimeters for measuring evapotranspiration and developing crop coefficients for trailing blackberry. Acta Horticulturae. 1388:191-196. https://doi.org/10.17660/ActaHortic.2024.1388.29.
DOI: https://doi.org/10.17660/ActaHortic.2024.1388.29

Interpretive Summary: Information on how much water is required by most berry crops, including blackberries, is limited or unavailable. ARS researchers in Corvallis, Oregon, installed large underground weighing devices called “lysimeters” to measure daily water use in trailing blackberries. This type of blackberry is grown on roughly 6,200 acres in the United States and is used primarily for the processed market (frozen fruit, juice, and jams). Data was collected each year from planting to full production and used to develop numerical figures called “crop coefficients” for calculating blackberry water use based on the weather conditions (temperature, solar radiation, wind, and humidity). These figures are available on-line and used by farmers to accurately schedule irrigation in commercial blackberry fields.

Technical Abstract: Precision weighing lysimeters are expensive but invaluable tools for measuring crop evapotranspiration (ETc) and developing crop coefficients (Kc). We installed two of this type in Oregon, USA and planted them and the surrounding field with ‘Columbia Star’ trailing blackberry (Rubus L. subgenus Rubus Watson). The lysimeters were constructed from steel and included an inner tank (1.0-m wide x 1.5-m long x 1.7-m deep), resting on four shear-beam load cells, inside an outer tank. During the first year after planting (primocanes only), ETc totaled 120 mm, or 18% of total potential evapotranspiration (ETo). That year, Kc, calculated by dividing ETc by ETo, was 0.24 when the measurements were initiated in early July and increased to 0.81 before leaf fall in early October. The following year, ETc doubled due to floricane and primocane growth, reaching a total of 275 mm, or 34% of total ETo. At that point, Kc increased from 0.30 at budbreak to 0.48 before it dropped to 0.27 due to leaf damage that occurred due to record-breaking heat in late June. Afterwards, Kc slowly increased with primocane development until it reached 0.85. By the third year, the plants reached full production, and ETc doubled again, reaching a total of 511 mm, or 71% of total ETo. Weekly Kc in year 3 increased from 0.55 in late June to 0.88 in mid-August, where it remained until the plants were pruned and trained in late September. At full production, the plants required an average of 2 L of water (rain or irrigation) to produce each individual fruit and over 48 L of water to produce enough berries to fill a 170-g clamshell. The plants extracted water as deep as 1.2 m, indicating that it is important to maintain adequate soil moisture to at least this depth in trailing blackberry.