10 years of monitoring recycled water: what we have learned
Adoption of recycled water is an important tool in water conservation, and there continues to be greater use of this resource with every year that goes by. That said, there are some management challenges posed by the use of recycled water. None are insurmountable, but being prepared and aware will help you to use recycled water as effectively as possible.
Starting in 1999, we had a great opportunity to initiate a long-term study on the effects of recycled water on turf health and management. Thanks to PACE Turf member Jeff Beardsley of Big Canyon Country Club, we were able to study changes in soil chemistry in 14 fairways that were irrigated with recycled water, and 4 fairways that were irrigated with domestic water. The results of this study were covered in a poster presentation that we made at Crop Science Society of America meetings. You can view and print the poster here, though it is a fairly large (528 KB) pdf document. Some of the key points from the study include:
- Significant increases in soil salinity, nitrogen and organic matter were the most important trends observed in areas irrigated with recycled water.
- To reverse these trends, these management practices were instituted:
- Periodic leaching to limit soil salts to less than 6 dS/m
- Switch to higher quality domestic water during the summer months to mitigate build-up of salts and nitrogen
- Aerification and sand topdressing to dilute organic matter and to allow increased leaching without loss of soil integrity
- Re-surfacing of fairways to remove excess organic matter
- Decreased rates of nitrogen fertilizer to accommodate the high levels of N delivered in irrigation water
- Although the focus is frequently on the quality of the recycled water, it turns out that soil chemistry, soil physical characteristics and rainfall patterns were equally important in the successful use of recycled water on golf courses.
- A contract with the water provider should define water quality limits and delivery guarantees, and should cover the cost of management programs (cultivation, amendments, monitoring programs) adopted to prevent soil and plant damage from long-term use of recycled water.
Irrigation audit spreadsheet
We have designed an Irrigation audit calculator spreadsheet that will perform the necessary calculations for determining the precipitation volume and precipitation rate of your irrigation heads. This spreadsheet should be used in conjunction with the procedure described in this this PACE Update.
Got gray leaf spot? Then you can help
Gray leaf spot is a devastating summer disease of reygrass, fescue St. Augustine and kikuyugrass in many parts of the U.S. It's hard to think of anyone who might want to actually see it in action, but there are indeed a few dedicated scientists at the USDA and Kansas State University who would be glad to receive samples of this dread disease.
It's all because gray leaf spot, which is caused by the fungus Magnaporthe grisea (also known as Pyricularia grisea) is closely related to a serious disease of rice and wheat known as rice blast or wheat blast, and caused by the fungus Magnaporthe oryzae. Your samples of gray leaf spot-infested turf will help plant breeders to develop new strains of wheat that are resistant to the disease.
If you'd like to help out in this project, please consider sending turf samples (a cup cutter sample placed inside a securely closed zip-lock plastic bag, and then placed in a sturdy box) that are infested with gray leaf spot to: Dr. Gary Peterson, USDA ARS, 1301 Ditto Ave., Frederick, MD 21702. You can contact Dr. Peterson here.
It's very important to enclose this permit with your shipment. Please print it out and include it with your sample in the shipment.
We encourage you to participate in this important project. It would be nice to know that there's some good associated with this awful pathogen...
