7 practical insights from Happi100 so far
Before we dig into our Happi100 findings, let’s first cover some sub soil agronomy:
- 15% and above for healthy soil oxygen levels
- 10% and below when soil hypoxia begins
- 4 hours for plant root hairs to begin to die
- 10 hours for complete plant root hair die off
- 7 days for oxygen levels to recover in poor draining soils
- 3 days for new root hairs to regenerate when conditions recover
With this in mind, the below findings gathered through collaboration with turf professionals using the Happi100 oxygen sensor, are already helping us to better understand how to maintain optimal turf conditions. Below, we share seven practical lessons learned from the field to support data-driven turf management.
1 - Flood-prone soils hold less water and oxygen
Happi100 data shows that flood-prone soils hold less water - and suffer from depleted oxygen levels – compared to well draining areas. This is because flood-prone areas tend to have smaller pores that restrict water infiltration and gas exchange. In short, it takes less moisture to saturate these areas - and their lack of pore spacing means drainage, evaporation, and oxygen recovery can take up to 1 week to occur.
2 - Well-draining areas recover quickly
Conversely, the larger pore spaces of well draining soil have been observed to have a higher capacity for holding moisture but with quicker rates of drainage and gas exchange. After rain or irrigation, these areas can restore moisture and oxygen levels to healthy levels within hours. These zones can be relied on to bounce back without much intervention, meaning your efforts can be focused on improving other areas.
3 - Recovery of root hairs takes time
Once soil becomes hypoxic – a process that begins after sub soil oxygen levels dip below 10% for 4 hours – plant root hairs begin to die, which impairs nutrient and water absorption. Even when oxygen levels improve, it can take up to 3 days for new root hairs to regenerate. This delayed recovery means extended periods of turf vulnerability, so it is important to prevent placing extra stress on plants where possible and to speed up the turf recovery process.
4 - Oxygen spikes before weather dips
When a significant weather event occurs that quickly introduces moisture into soils that exceeds its holding capacity, we have observed an oxygen spike quickly followed by a drop. This is because a sheet of moisture acts like a hydraulic press, pushing the sub soil oxygen through the turf. An oxygen spike is a clear indicator of saturated soils, indicating now is a good time to work on restoring your turf with timely interventions.
5 - Not all aeration methods improve oxygen levels
Certain aeration practices, such as solid tine aeration or full spoon aeration, make channels that speed up drainage and moisture level recovery, but they may not in fact introduce oxygen into the soil. This is likely because the tine actually compacts the surrounding substrate without removing any matter. This has been observed after full spoon aeration took place, with moisture levels rebounding but oxygen levels remaining unaffected in the short term. Consider which aeration techniques could improve soil gas exchange rather than merely breaking the surface.
6 - Mid-afternoon oxygen dips from root respiration
During the afternoon, plant roots consume more oxygen as they respire at higher rates under the heat and light. This is represented by a small dip in sub soil oxygen levels at mid afternoon. Oxygen levels naturally recover overnight as plants reduce their metabolic activity. This could be something to think about when scheduling irrigation and aeration activities.
7 - Flooding and heavy thatch block gas exchange
Waterlogging and dense thatch layers prevent soil gases from exchanging freely with the atmosphere. And if CO2 cannot escape the soil overnight, with fresh oxygen being introduced, the plant root’s natural respiration pattern will deplete sub soil oxygen every day until the environment becomes hypoxic.
