Location: Horticultural Crops Production and Genetic Improvement Research Unit
2024 Annual Report
Objectives
Irrigation and nutrient management are key factors that impact sustainable and profitable production of high-quality small fruit and nursery crops. The goal of this project is to develop new approaches that integrate water and nutrient management methods with other environmental and cultural constraints to improve the quantity and quality of berry, wine grape, and nursery crops grown in the Pacific Northwest (PNW) while protecting the environment.
Objective 1: Determine requirements for high-quality berry crop production through monitoring and management of water, nutrients, and soil. [NP 305, Component 1, Problem Statement 1B]
• Subobjective 1A: Adapt and refine remote sensing technology to monitor water and nutrient deficits and determine irrigation and fertilizer needs in berry crops.
• Subobjective 1B: Assess the feasibility of using deficit or pulsed-drip irrigation to increase water use efficiency and protect regional water quality in berry crops.
• Subobjective 1C: Develop new fertigation and soil management practices to increase production and fruit quality in blueberry.
Objective 2: Develop approaches to manage vineyard canopies, soils, and nutrients for improved grape production, plant health, and fruit quality. [NP 305, Component 1, Problem Statement 1B]
• Subobjective 2A: Develop an integrated nitrogen (N) management approach encompassing N use in both the vineyard and winery to identify the most effective and efficient manner to manage N inputs to improve wine quality and protect water quality.
• Subobjective 2B: Examine how canopy architecture, vine density, and crop load interact to identify the most efficient use of sunlight and soil water resources to improve production efficiency of Pinot noir.
• Subobjective 2C: Understand how N management practices influence beneficial arbuscular mycorrhizal fungi (AMF) in grapevines to develop more sustainable methods for farming grapes.
• Subobjective 2D: Determine the impact of rootstocks on root development and AMF colonization when challenged by the northern root knot nematode.
Objective 3: Evaluate the impact of management practices for water and nutrients on tolerance to abiotic and biotic stress in specialty crops. [NP 305, Component 1, Problem Statement 1C]
• Subobjective 3A: Develop new management practices and disease control measures to minimize pathogen damage and losses for woody nursery plants.
• Subobjective 3B: Define salinity thresholds for specialty crops so growers can reduce losses of planting stock, mitigate salinity impacts on quality, and broaden the use of more salt tolerant species in systems considered marginal for production of other crops.
• Subobjective 3C: Develop and evaluate water and nutrient management practices for specialty crops grown in soilless substrates.
Approach
Experiments will be conducted in the greenhouse and field on small fruit (blueberry, raspberry, strawberry, grapevines) and other specialty crops including nursery crops (Rhododendron, Vaccinium, Basil), and in growth chambers on root pathogens. For Obj. 1 we will develop remote sensing based crop coefficients and water stress indices for irrigation of blueberry and raspberry, and will test the following hypotheses: Deficit irrigation will reduce water use but have no effect on yield or fruit quality when it is applied at early stages of fruit development or after harvest in blueberry or raspberry; Pulsed-drip irrigation will reduce water use and increase yield and production relative to conventional irrigation in blueberry and raspberry; Application of P and B by fertigation will result in greater yield and fruit quality than granular or foliar fertilizers in blueberry; Biostimulants are most effective when applied at low rates and during peaks in root production. For Obj. 2 we will test these hypotheses: Maintaining low N status in the vineyard will enhance wine composition as compared to boosting N supply in the vineyard; Varying N supply to Pinot noir alters berry and wine phenolic composition to a greater extent than P or K; Altering the VSP trellis to increase canopy solar exposure at midday will increase productivity but not alter ripening or fruit quality in Pinot noir; Soil and foliar applied N in vineyards reduces AMF colonization and P uptake; Nitrogen inhibition of AMF colonization in grape roots increases with N dose; Nitrogen is a more potent inhibitor of AMF as vine P increases; Root development and AMF colonization differ among rootstock genotypes when northern root knot nematode is present. We will test the following hypotheses for Obj. 3: Critical temperatures for vegetative growth and zoospore formation of Phytophthora isolates will be similar within a species; fungicide sensitivity of Phytophthora is greatest at the optimal temperature for growth; Root rot induced by flooding is more severe than rot under moisture conditions common in nurseries; Reducing water availability minimizes root damage caused by Phytophthora in rhododendron; Increasing N increases root damage caused by Phytophthora in rhododendron; Crop tolerance to salinity will differ among production systems; Southern highbush blueberry plants have different substrate needs than northern highbush blueberry; Strategies to improve water distribution in substrates will increase growth and production in blueberry. Measurements and techniques used in these studies will include standard approaches to measure plant growth, biomass, and yield, plant water status (pressure chamber, porometer), photosynthesis (gas-exchange), fruit quality (refractometry, titratation, HPLC, sensory perception), root production and mycorrhizal colonization (soil cores, microscopy), soil pH and EC, soil water content (TDR, tensiometers), plant and soil nutrients (CNS analyzer, ICP), and pathogen growth (microbiological media) and root damage (visual ratings). We will also utilize multi-spectral cameras and drones to develop new methods to measure plant water status.
Progress Report
This report documents FY 2024 progress for project 2072-21000-055-000D, “Water and Nutrient Management for Sustainable Production of Small Fruit and Nursery Crops”, which began in April 2020.
In support of Sub-objective 1.A, ARS researchers in Corvallis, Oregon, collected multispectral and thermal images from blueberry, blackberry, and raspberry fields using a small unoccupied aerial system (drone). The images were processed and analyzed for normalized difference vegetation index (NDVI) and canopy temperature. The NDVI images provided clear information on canopy development and the amount of irrigation required at each site. Thermal images were also useful, particularly for assessing spatial variability in water status of the fields and determining whether the plants are irrigated sufficiently. Additional trials were initiated with large weighing lysimeters (devices used to measure plant water use) to validate the relationships between canopy cover and irrigation water requirements in blueberry and blackberry.
For Sub-objective 1.B.1, results were published on using deficit irrigation in blueberries, and with support from the industry, a new trial was initiated in blackberries rather than raspberries. The plants were managed with or without irrigation after harvest and measured for water status during postharvest water deficits, cold hardiness over the winter, and yield and fruit quality in the following summer. The data from the first two years of the study were analyzed. The final year of data on yield and fruit quality will be collected this summer.
Under Sub-objective 1.B.2, field trials evaluating the benefits of pulse drip irrigation were completed in commercial blueberry and raspberry fields located in Washington state. Soil water content, yield, fruit quality, plant water status, leaf and soil nutrients, and canopy development were measured for two years at each site. Data were analyzed from both trials, and the results were published in two manuscripts.
For Sub-objective 1.C.2, ARS researchers conducted a trial on the use of biostimulants in raspberries. Plants were treated with commercial biostimulants containing glycine betaine, silicone, or kelp extract and exposed to temperatures greater than 95 degrees F for 28 days. Measurements on the plants included photosynthesis, transpiration, and water use efficiency; leaf florescence and anthocyanins; and total dry weight of the roots and shoots. Analysis of the data indicated that glycine betaine and kelp extract increased growth and photosynthesis in the plants and enhanced their tolerance to heat stress. A manuscript was written and submitted for publication. Additional trials with both biostimulants were initiated this spring in experimental field plots of blueberry and blackberry.
In support of Sub-objective 3.C.2, a two-year trial was completed to evaluate irrigation methods for growing potted blueberry plants in soilless substrate. The plants were harvested destructively and analyzed for growth, root development, and nutrients in the leaves and stems. Fruit was also harvested and analyzed for size, firmness, sugar content, and acidity. Analysis of the data indicated that growth and yield were greatest when irrigation was triggered frequently and applied using a new type of multi-outlet drip emitter that was designed to apply water evenly over the surface of the substrate and prevent dry spots in the pots. A manuscript is partially written and will be submitted for publication.
Accomplishments
1. Pulse irrigation increases fruit production in blueberries and raspberries. Pulse irrigation is the practice of applying water in cycles of 20-60 minutes every day until the total amount required by a crop is added. If managed correctly, the practice can prevent water limitations, particularly on sandy or silty soils, which are commonly used for many berry crops. In conjunction with grower collaborators, ARS scientists in Corvallis, Oregon, tested the feasibility of using pulse irrigation in commercial blueberry and raspberry fields. Relative to the conventional practice of irrigating continuously for 12-13 hours every two days, pulse irrigation increased yield by as much as 3,000 pounds of fruit per acre within the first year of application, which based on market prices was equivalent to $8,560/acre. Pulsing also increased yield by an average of 1,100 pounds or $980/acre in raspberry. As a result of this research, growers in Oregon and Washington state are beginning to use pulse irrigation in their berry fields.
2. Water requirements for irrigating blackberries. Irrigation scheduling requires knowledge of several factors, including rooting depth and the daily water requirements of the crop. ARS researchers in Corvallis, Oregon, used large underground weighing devices called “lysimeters” to accurately measure daily water use in trailing blackberries, which are grown on roughly 6,200 acres in the United States. At full production, the plants required nearly a half-gallon of water from either rain or irrigation to produce just one blackberry and over 12.5 gallons of water to produce enough berries to fill a six-ounce clamshell. Additional measurements indicated that the plants extracted water primarily from the top two feet of soil on cooler days and up to four feet deep on warmer days. This information will enable blackberry growers to make informed decisions on how much water to apply and determine how frequently irrigation is needed to avoid water limitations to fruit production.
3. Best way to apply boron fertilizer to blueberries. Boron (B) is essential for flowering and fruit development but is often deficient in many crops, including blueberries. ARS researchers in Corvallis, Oregon, investigated different methods of applying B in a mature blueberry field irrigated by drip, including soil applications, foliar applications, and fertigation, which is the practice of applying liquid fertilizer through the irrigation water. Foliar application was the most effective method for increasing the concentration of B in the leaves, roots, and fruit, followed by fertigation with B fertilizer. Soil application of B, on the other hand, was ineffective and resulted in less sugar in the fruit than fertigation or foliar applications. Findings from this work provides valuable new information for improving nutrient management in blueberry.
4. A new process for recovering nutrients and clean irrigation water from municipal wastes. With increasing water shortages, irrigation with reclaimed water is becoming necessary for securing agricultural production in many regions. In collaboration with Oregon State University, an ARS researcher in Corvallis, Oregon, investigated the feasibility of using a novel hybrid electrodialysis-forward osmosis (ED-FO) process, designed for simultaneous recovery of nutrients and clean water from municipal wastewater, as a means for safe production of food crops. The final product water from the process was tested and evaluated for hydroponic production of lettuce and kale. The process recovered 84-96% of the nutrients from the effluent and reclaimed up to 74% of the clean water. Both ED and FO had low-fouling potential, and plants grown in nutrient water recovered from the process had a similar amount of growth as those grown with conventional fertilizers. According to an economic analysis, the hybrid ED-FO process is promising for scalable implementation and highly attractive in terms of resource recovery, waste footprint reduction, and water quality enhancement.
5. Nitrogen fertilizer requirements are lower than expected in mature blueberry fields. Most crops require nitrogen (N) fertilizer, but multiple studies over the past four decades have shown that insufficient or excessive use of N fertilizer can negatively affect both yield and fruit quality in blueberries. A portion of the N required for plant growth is often available from soil organic matter, but the amount released is difficult to predict and usually not considered in N fertility programs. In collaboration with Washington State University, an ARS researcher in Corvallis, Oregon, conducted a series of laboratory and field experiments to identify when and how much N is available from soil organic matter. The amount released ranged from 15 to 110 pounds of N per acre in soils collected from mature commercial blueberry fields. Availability peaked in June, which is when the plants take up most of their N during the growing season. Consequently, fertilizer rates as low as 30-45 pounds of N per acre were sufficient to sustain production for three years at sites with 3% to 28% soil organic matter. This combined with longer-term observations from other studies suggests that N fertilizer rates could be reduced to lower input costs with no consequences to fruit production.
6. Heatwave causes excessive nutrient losses from potted nursery plants. Controlled-release fertilizers (CRFs) are water-soluble pellets that slowly release essential nutrients into soil or soilless potting media. In collaboration with Oregon State University, an ARS researcher in Corvallis, Oregon, carried out an experiment with CRFs that were designed to supply nutrients for six to seven months in several important nursery crops, including roses and maple trees. During the experiment, the region experienced a series of heatwaves in June that caused unanticipated and excessive release of nutrients from the fertilizers. As a result, the nutrients were leached from the pots, and extra fertilizer had to be added. These results indicate that new climate-ready practices are needed to sustain nursery production under extreme heat.
Review Publications
Sloan, C., DeVetter, L.W., Griffin-Lahue, D., Benedict, C., Bryla, D.R., Lahue, G. 2024. Nitrogen supply from soil organic matter: Predictors and implications for recommended nitrogen application rates in northern highbush blueberry. HortScience. 59(6):725-735. https://doi.org/10.21273/HORTSCI17632-23.
Leon-Chang, D.P., Bryla, D.R. 2024. Applying boron by fertigation or as a foliar fertilizer is more effective than soil applications in northern highbush blueberry. HortScience. 59(5):565-570. https://doi.org/10.21273/HORTSCI17461-23.
Nackley, L., Mccauley, D., Scagel, C.F. 2023. Hot mess: Heatwave effects on controlled-release fertilizer. HortScience. 58(11):1459-1460. https://doi.org/10.21273/HORTSCI17325-23.
Caroll, J.L., Orr, S.T., Davis, A.J., Strik, B.C., Bryla, D.R. 2024. Water use by ‘Columbia Star’ trailing blackberry in western Oregon. Irrigation Science. https://doi.org/10.1007/s00271-023-00912-4.
Carroll, J.L., Orr, S.T., Benedict, C.A., DeVetter, L.W., Bryla, D.R. 2024. Feasibility of using pulse drip irrigation for increasing growth, yield, and water productivity of red raspberry. HortScience. 59(3):332-339. https://doi.org/10.21273/HORTSCI17467-23.
Tran, Q., Garcia-Jaramillo, M., Schindler, J., Eness, A., Bryla, D.R., Patel, H., Navab-Daneshmand, T., Jin, X. 2024. Sustainable nutrient water recovery by a hybrid electrodialysis (ED) - forward osmosis (FO) process for agricultural application. Journal of Environmental Chemical Engineering. 12(2). Article 112091. https://doi.org/10.1016/j.jece.2024.112091.
Carroll, J.L., Orr, S.T., Retano, A., Gregory, A.D., Lukas, S.B., Bryla, D.R. 2024. Weather-based scheduling and pulse drip irrigation increase growth and production of northern highbush blueberry. HortScience. 59(5):571-577. https://doi.org/10.21273/HORTSCI17527-23.