Dealing with Drought Part 3
After heat and drought, the effect on unirrigated turfgrass can look quite devastating. However, as the plants can go dormant to protect the growing point in the crown it is possible that much of the surface will recover naturally. Before acting, take stock and assess what is likely to recover and what will need assistance in order to recover.
Rewetting and Initial Recovery
Droughted soils can be difficult to rewet once hydrophobicity has developed. Wetting agents can assist with this situation, improving turf recovery and establishment conditions.
Repairing Damaged Areas
In the most affected areas where recovery is unlikely to occur, removal of the dead turf followed by ground preparation and re-seeding will be necessary. Other areas which experience less extreme thinning may be revitalised by overseeding to improve sward health and density.
For either activity, choose a suitable seed mix depending on the use of the area and existing species.
Fescues can be a good choice for drought resilience because they are naturally drought resistant due to a deep rooting system and creeping growth habit which increases recovery ability.
For speed of establishment, ryegrass is a clear winner with germination occurring in as little as 3-7 days. Although less able to repair itself, it tends to be wear resistant.
Autumn is an excellent time of year to sow grass seed as there is usually both warmth and moisture which improve establishment success.
Supporting Recovery with Nutrition
As soil moisture improves and good growing conditions return, fertiliser will assist with healthy recovery growth.
In addition to nitrogen, apply potassium if required to support cell strength, water regulation and stress tolerance. Phosphorus can be useful for energy transfer.
Again, an understanding of soil properties, and turf can help to narrow down what ratio of NPK is required but fertilisers that are high in nitrogen will help with leaf turgor and water management.
Where growth is needed, nitrogen will always be required.
Enhancing Recovery with Biostimulants
Biostimulants such as seaweeds and humates can help to further stimulate root development and increase both water and nutrient use efficiency.
Finally, it is always helpful to review the season, particularly if there have been issues.
- Which measures helped with drought and heat stress management?
- Were there actions that could have been taken earlier to reduce the impact of drought?
- Were there actions that could have been taken later to reduce costs?
- Were the priority zones successful or should the boundaries be changed?
Asking yourself these kinds of questions will help to ensure you repeat your successes next year whilst improving on any shortfalls.