Blueberry drip irrigation on hilly terrain: Case study and essential guide

Modern blueberry irrigation and fertigation systems enable farmers to significantly increase yields even under suboptimal field conditions. BB Crown Agro Group, a family-owned enterprise in Serbia, has become a profitable and recognized blueberry grower, despite their fields having clay soil and a 17% inclination.

A semi-automatic pressure-compensated drip irrigation system designed by Pipelife has helped coin the farm’s success. This article explores the semi-automated irrigation setup used on the farm as well as provides an overview of the best irrigation, fertigation and soil acidity control practices in commercial blueberry production.

_{Case study: Starting a blueberry farm from scratch}

Andrija Becin is a blueberry farmer living in Obrenovac, Serbia. Eight years ago, he decided to step away from safe employment in the power supply industry to follow his dream of having a family farm. This was the beginning of BB Crown Agro Group — an agricultural company which has now grown to 3.8 hectares and 17,000 blueberry plants, providing living and employment to the whole Becin family.

The growing export demand for blueberries in Serbia inspired Andrija to specialize in this crop; yet, blueberry farming turned out to be far from simple.

The clay soils in the Becin orchard were not optimal for blueberries due to poor water permeability and the risk of waterlogging. Furthermore, the fields are located on a steep hillside with an inclination reaching 17%, which complicates irrigation and fertigation of the blueberry plants.

“Blueberry farming is different from any other fruit,” Andrija admits. “To have maximum yields, everything must be taken care of, especially irrigation. The most important factor in blueberry farming is water, then everything else.”

_{End-to-end drip irrigation solution: Design, installation, customer support}

While commercial blueberry production is considered highly profitable, establishing a successful farm requires time and skill. Aware of the complex field conditions at their farm, the Becin family was looking for a tailored drip irrigation solution that would entail comprehensive technical support. They became interested in Pipelife’s irrigation services, covering system design, delivery, installation, and after-sales support.

After consulting with Pipelife’s Irrigation Category Manager, Dusan Jankovic, the Becins opted for a pressure-compensated no-drain drip irrigation system. The chosen setup guarantees uniform water distribution to every plant despite the uneven terrain. The system comprises 940 meters of PE water supply pipes, over 7,000 meters of lateral lines, an acid injection system for regulating soil pH levels, and almost 9,000 PCND (pressure-compensated no-drain) drippers.

_{Drip irrigation scheduling and control for blueberry crops}

The irrigation season in the Becin orchard lasts for six months. The plants are grown in bags filled with a special substrate and irrigated 3-4 times per day for a period of 15 minutes. During heatwaves, the irrigation frequency can be increased to 6 times per day.

“Under these conditions and slope, I don’t think modern blueberry production would be even possible without pressure-compensated and no-drain drippers,” Andrija says. “We are using spider drippers, which are the latest trend in blueberry farming.”

Moreover, the system is equipped with a modern MINIAGG 6 control unit. Blueberries require a substrate pH between 4 and 5.5, and the optimal electrical conductivity of irrigation water should be ~1mS/cm. Reliance on semi-automation allows for quick setup and modification of a highly accurate dosing schedule, including the desired supply of water, fertilizers and acid injection.

“Since blueberry farming is so intricate, a semi-automatic control system made it easier for me to experiment and learn what works best for my fields,” Andrija explains. “What I particularly appreciate is that Dusan has always been one call away. Especially while I was learning to operate the system, I could always reach out to him, and together, we resolved any issues. With the knowledge I have acquired now, I feel confident to modernize my farm further and move to a fully automatic setup.”

_{Supporting new blueberry growers}

Due to the many challenges blueberry farmers in Serbia face, they often keep in touch and exchange knowledge. Andrija believes that such close cooperation is key to securing and strengthening their position in export markets.

As BB Crown Agro Group has become a profitable and well-known blueberry producer in the area, Andrija now plans to further expand his own orchard as well as offer consultations and advice to blueberry farmers who might still be struggling to achieve high yields:

 “I believe that blueberry farmers have to support each other — we are all partners, not competitors.”

_{Blueberry irrigation guide: Overview, challenges and best practices}

The blueberry is a perennial shrub and typically begins producing small yields 2-3 years after planting. The maximum yields are usually reached when plants are 5-8 years old, but well-maintained blueberry bushes remain productive for 10-20 years or even more.

When it comes to irrigation, the blueberry crop is vulnerable to both over- and underwatering due to a shallow root system. Experiencing water stress even for one season may negatively affect yields in the coming years. On the other hand, excessive soil moisture and waterlogging lead to rot and root diseases.

Commercially, blueberries are typically grown in raised beds or bags to prevent waterlogging, ensure adequate drainage, and maintain constant soil moisture and alkalinity. Minimizing plant stress is critical, especially during the first years, as well as the blooming and fruit stages; therefore, blueberry growers must pay close attention to precise irrigation scheduling.

Short, frequent irrigation cycles (sometimes called pulse irrigation) are optimal, as they keep the soil surface layer damp but not wet, ensuring ideal conditions for blueberry plants. A common schedule is 15-minute cycles applied 4-8 times per day, depending on soil type and local climate conditions.

_{Best blueberry irrigation method: Overhead sprinkler systems vs. drip irrigation}

While both overhead sprinkler and drip irrigation systems can be used in blueberry farming, most commercial producers nowadays rely on drip irrigation.

• The main advantage of overhead irrigation is that it offers frost protection in spring. Overhead sprinklers are also relatively easy to install and maintain. However, sprinkler systems have higher water and energy consumption, and they offer less precise distribution of water and nutrients. Regular wetting of leaves can also lead to fungal diseases in blueberry plants.
• Drip or precision irrigation is the preferred water-application technology for blueberry production. Drip irrigation systems boast very high water use efficiency and provide consistent, low-volume watering, which is ideal for blueberry root development. Furthermore, drip emitters deliver water directly to the root zone, avoiding wetting of leaves and stems and minimizing the risk of fungal disease development. In commercial blueberry farms, drip irrigation is typically combined with fertigation and acid injection systems, offering growers nuanced control over soil moisture, acidity and nutrient levels within a single setup. 

_{Pressure-compensated drip irrigation for blueberries}

On sloping or uneven fields, using non-pressure-compensating drip systems may lead to insufficient irrigation in some areas and excess water accumulating in others. Therefore, pressure-compensated (PC) drip irrigation systems are commonly used in blueberry farms with long rows and/or uneven terrain.

Pressure-compensated (PC) drip irrigation systems rely on specially engineered emitters that maintain a constant flow rate regardless of water pressure fluctuations, ensuring uniform delivery of water and nutrients to all crops. Furthermore, pressure-compensated emitters often have a self-cleaning design, making them resistant to clogging and simplifying overall system maintenance.

_{Automated and semi-automated irrigation systems}

In large-scale agricultural irrigation setups, constant monitoring and control of soil moisture and pH levels can become highly labor-intensive. Automated precision irrigation systems rely on sensor technology and automation, reducing or even eliminating the need for manual monitoring, pump and valve operation.

Smart irrigation controllers are commonly used by blueberry growers due to the crop's sensitivity. Relying on data obtained from pH-, EC and soil moisture sensors, local weather stations and flow meters, the system can automatically adjust irrigation, fertigation and acid injection schedules, maintaining consistent growth conditions for plants.

The level of automation can be tailored to individual preferences, ranging from simplifying some laborious tasks to providing complete remote control via a customized computer and mobile interface.

_{Soil acidity control for blueberry crops}

Blueberries require acidic, well-drained soil with a pH between 4.0 and 5.5 in order to thrive. Lower-acidity soils with higher pH negatively affect plant development, manifesting as yellowing leaves and poor yields, while extremely low pH levels below 4.0 can be toxic to blueberry plants and damage their root systems.

Adding controlled doses of phosphoric or sulfuric acid to the irrigation water enables precise pH control, regardless of the growing medium. Therefore, acid injection systems have become integral to the overall blueberry irrigation setup.

_{Blueberry fertilization: Do's and dont's}

Careful fertilizer dosing allows farmers to maximize their field capacity and obtain the highest yields. Still, blueberry plants evolved to thrive in sandy soils low in organic matter, and plants are vulnerable to overfertilization.

The optimal dosing depends on plant age — it is often recommended to avoid fertilizing during the first few years altogether to avoid damaging young, sensitive blueberry roots. Once the plants have established (years 3-4), fertilizers are used during early blooming and fruit stages as well as post-harvest to ensure shrubs fully recover for the next season.

Blueberry fertilization goes hand in hand with soil pH control, and fertigation systems are commonly used to ensure precise dosing and prevent root burn. It is crucial to use ammonia- or urea-based fertilizers and avoid nitrate-based ones, as the latter raise soil pH and can be toxic to blueberry roots.