Drip Irrigation Revolution: Closer Emitter Spacing Drives Higher Profitability

The Trend to Closer Drip Emitter Spacing Can Increase Yields and Efficiency for Key Seasonal Crops.

• Optimized Spacing: Closer emitter spacings better distribute the same amount of water in the soil improving water efficiency and reducing deep drainage for densely planted crops.
• Enhanced Germination: Tighter emitter spacing creates a more homogeneous “wet band” in a short time ensuring even moisture, benefiting seed germination.
• Reduced Waste: Lower flow rates and closer emitters improve uniformity and can cut water and fertilizer waste. More drippers encourage a bigger volume of plant-feeding roots, boosting crop quality and yield.

Maximizing water use and crop yields for high-value seasonal, growers have long adhered to a traditional approach of using drip irrigation emitters with spacing between 20 and 30 cm (8 to 12 inches), regardless of the crop. However, recent research and practical grower experience reveal that this “one size fits all” approach may not be the most efficient.

Tailoring Irrigation for Optimal Growth:

“One size does not fit all for high-value seasonal crops,” says Adolfo Levin, Chief Global Agronomist, Rivulis. “Growers must consider various factors to optimize their irrigation strategies and we continue to see innovation in closer distances between drip emitters to achieve the best results.” Three critical situations illustrate the need for emitter spacing of 15 cm (6”) or less:

1. Dense Plant Spacing: For crops planted closer together with very small root areas, such as onions, carrots, strawberries, celery, garlic, and lettuce, using drip tape with emitters spaced 15 cm (6 inches) or less can be more effective. This setup ensures that water reaches all plants in less time by using drippers with lower flowrates at closer density
2. Germination Needs: A solid wetted band can enable seed germination using drip irrigation. Germination is possible with drip tape with closer emitter spacing as the water quickly covers the entire area where the seeds are placed.
3. Deep Drainage Risk: Longer irrigation durations potentially needed in widely spaced emitter to achieve a continuous soil wet band can lead to deep drainage. However, closer emitter spacing better achieves a continuous soil wet band much faster, that in turn minimizes deep drainage, ensuring more efficient water use efficiency.

“Using drip tape with closer emitter spacings allows for shorter irrigation events and in turn reduces the amount of deep drainage,” Levin explains. “This approach can even lead to the ability to use drip for seed germination in some cases.”

Soil type plays a crucial role in determining the effectiveness of irrigation. Depending on how much water is applied, clay soils tend to spread moisture wide but shallow, while sandy soils have a narrower, deeper wetted zone. Loams fall in between. Understanding these soil characteristics helps in selecting the right emitter spacing and flow rate for optimal results.

Reducing Deep Drainage:

While some might think that increasing irrigation duration with wider-spaced emitters could compensate for uneven moisture, this often results in excessive water application and deep drainage.

“Closer drip spacings can promote better water and fertilizer efficiency,” Levin adds. “This not only reduces waste but can also improve crop quality and yield.”

The Bottom Line:

Reducing emitter spacing in horticulture is not just about following traditional methods but adapting to specific crop and soil needs. Careful consideration of emitter spacing, flow rates, and soil type can make a significant difference in achieving excellent crop quality and efficient water use.

“By tailoring irrigation practices to individual situations, growers can achieve superior results and contribute to more sustainable farming practices. Our unique to-market T-Tape drip tape means that farmers do not pay more for closer dripper spacing as the emitter is built into the tape itself. This means the cost is the same regardless of the emitter spacing, enabling the choice of the spacing based on what is best from an agronomic perspective.” Levin concludes.