Subsurface Drip & Buried Where Roots Drink
Designs laterals
Enter your field size, lateral spacing and emitter spacing to get the total buried lateral length, the number of emitters and a suggested burial depth for the crop's root zone.
Design your SDI system
Next: order about 4,047 m of dripline and plan for 10,117 emitters buried 20 cm deep.
Burial depth, lateral spacing and emitter discharge are set by crop root zone and soil type; SDI also needs good filtration, flushing and root-intrusion protection.
Subsurface drip (SDI) — key facts
- Lateral length
- area ÷ lateral spacing
- Emitters
- lateral length ÷ emitter spacing
- Burial depth
- match the crop root zone
- Veg / row crop
- ≈ 10–20 cm / 20–40 cm
- Surface stays dry
- less evaporation & fewer weeds
- Service life
- many years, protected pipe
- Needs
- good filtration & flushing
- Privacy
- Runs in your browser; nothing uploaded
Put the water where the roots are
Subsurface drip irrigation buries the laterals in the crop's root zone instead of laying them on the soil surface. Because the top of the soil stays dry, evaporation losses and weed germination both fall, and a buried line protected from sun and machinery can last many years. From your lateral spacing you get the total length of pipe, and from the emitter spacing you get the number of emitters — the two numbers that drive your flow, filtration and budget.
This tool turns a field size into a buildable plan: the total lateral length, the emitter count, the wetted area, and a suggested burial depth matched to the crop's roots. Use it to lay out the block before you order pipe. Pair it with the Drip System Flow, Emitter Spacing and Lateral Length tools to complete a precise, water-efficient design.
Dry surface, fewer weeds
Buried lines cut evaporation and weed germination.
Order the right pipe
Total lateral length straight from your field size.
Size the emitters
Emitter count drives flow, filtration and budget.
Bury to the roots
Suggested depth matched to the crop's root zone.
Frequently Asked Questions
What is subsurface drip irrigation (SDI)?+
SDI buries the drip laterals a few centimetres below the surface, in or just above the crop's root zone, instead of laying them on top of the soil. Water is delivered directly where the roots take it up. Because the surface stays dry, evaporation losses and weed germination both fall, and a buried system protected from sun and machinery can last many years.
How is the total lateral length calculated?+
Total lateral length = field area ÷ lateral spacing. Closer rows of buried laterals mean more length and more uniform wetting; wider spacing uses less pipe but suits crops on wider rows. The tool multiplies your field's dimensions by the lateral spacing you choose to give the metres of buried line you need.
How many emitters will my field need?+
The number of emitters = total lateral length ÷ emitter spacing. Closer emitter spacing creates a continuous wetted strip along the root zone; wider spacing gives discrete wetted bulbs and uses fewer emitters. The tool reports the emitter count so you can size flow, filtration and budget for the whole field.
How deep should I bury the laterals?+
Burial depth should match the crop's main root zone — typically shallow (around 10–20 cm) for vegetables and shallow-rooted crops, and deeper (20–40 cm or more) for row crops and perennials. Bury deep enough to stay below tillage and clear of machinery, but shallow enough that young roots can reach the wetted zone.
Why choose subsurface over surface drip?+
Keeping the laterals and the soil surface dry cuts evaporation, suppresses weeds that need surface moisture to germinate, and avoids tripping or sun damage to the pipe. SDI also lets you cultivate and harvest over the lines. The trade-off is higher install cost and the need for good filtration and flushing to keep buried emitters clear.
What is the wetted area for SDI?+
The wetted area is the field footprint the laterals cover — area = lateral length × lateral spacing, which equals your field area for a fully laid-out block. Within that footprint, water spreads outward and upward from each buried emitter; spacing the laterals and emitters to the soil type keeps the wetted bulbs overlapping into a continuous root-zone band.
How do I stop buried emitters from clogging?+
Filtration is essential — pair SDI with a screen or disc filter fine enough for the emitter, flush the laterals regularly, and consider periodic chlorination or acid treatment to clear biological and mineral build-up. Root intrusion is managed with anti-siphon design and, where used, treated emitters. See the Drip Filter Sizing and Flushing tools.
Does SDI really last longer?+
Yes — protected from ultraviolet light, foot traffic, machinery and temperature swings, buried laterals commonly last well over a decade when filtration and flushing are maintained. The longer service life and lower labour to move pipe each season help offset the higher up-front cost compared with surface drip or sprinkler systems.
Can I use this for any crop?+
The design logic — lateral spacing, emitter spacing and burial depth from your field size and crop roots — applies to vegetables, row crops, orchards and forage. Match the spacing to the crop geometry and the burial depth to the root zone. Use the tool to plan the layout, then confirm flow and filtration with the related drip tools.