Skip Navigation


Agricultural Review

Time is good to test source water for tobacco float beds

Agriculture Commissioner Steve Troxler reminds producers of tobacco transplants that January is a good time to check the quality of their float-bed source water by collecting samples and sending them to the N.C. Department of Agriculture and Consumer Services agronomic lab for analysis.

Being proactive now allows growers to take necessary corrective action before filling beds and adding fertilizers. After fertilizer is mixed into float beds, it is also a good idea to submit sam-ples to verify appropriate nutrient concentrations.

Solution analysis provides information important to uniform seedling growth, such as alkalinity, pH, electrical conductivity (soluble salts) and nutrient concentrations. The laboratory report also provides recommendations for corrective action, when necessary. "Following these recommen-dations can reduce prod-uction costs, disease pressure and other environmental and cultural problems," Troxler said.

Nearly half of the source water samples taken from tobacco float-bed operations in North Carolina, and about one in five nutrient solution samples, have high alkalinity, sometimes known as total carbonates. Alkalinity values greater than or equal to 100 contribute to high pH and soluble-salt problems. The solution analysis report can provide recommendations for reducing alkalinity by 80 percent. If needed, alkalinity neutralization should be performed before trays are floated. The recommendations from the analysis should be followed carefully, as too much acid application can lead to undesirably low pH and possible root damage.

To collect and submit a solution sample, growers should follow these procedures:

  1. Collect eight ounces of solution in a clean, plastic bottle. Small soda bottles are about the right size, but should be triple rinsed with plain water (no soap). Remove or mark out any original product labeling. Make sure the sample represents the total solution. For example, for a source water sample, let the tap run for a few minutes before collecting it. For a nutrient solution sample, mix the fertilizer thoroughly and combine samples from several areas of the float bed to make one composite sample.

  2. Complete the Solution Analysis Information sheet (form AD7). Select the appropriate solution code. "ST" is the code for float-bed source water. "NT" is for a nutrient solution, or one that contains fertilizer.

  3. Send solution samples, a completed sample information sheet and the $5 fee per sample to the NCDA&CS Agronomic Division. For fastest results, be sure the package is addressed to the Plant/Waste/Solution Section.

For more information on Agronomic Division services go to or call (919) 733-2655.

NCDA&CS Public Affairs Division, Andrea Ashby, Director
Mailing Address:1001 Mail Service Center, Raleigh NC 27699-1001
Physical Address: 2 West Edenton Street, Raleigh NC 27601
Phone: (919) 707-3001; FAX: (919) 733-5047

How can we make this page better for you?
Contact the NCDA&CS

Found a bug? Have a suggestion? Fill out the form below and we'll take a look!

Your Name:
Your E-mail:
Question or Comments:

Back to top

Get Email Alerts

Stay up to date with NCDA&CS. Sign up to receive the latest news and upcoming events via email.