Does water quality affect your inoculant? – Jon Urness, Vita Plus

By Jon Urness, Vita Plus national forage specialist

With a few exceptions, the answer is yes, the water doesn’t have enough treatment to reduce inoculant viability.  Lallemand Animal Nutrition, manufacturer of Vita Plus Crop-N-Rich^® Stage 2 and Crop-N-Rich Buchneri forage inoculants, has studied this question in detail and provides us with good insight.

Regarding chlorinated water
Lauren Kasten, a member of Lallemand’s marketing staff, explained that, if the water is potable, then it’s OK for inoculant use.  Most chlorinated water suitable for human consumption is treated to 1 ppm of chlorine or less, and serious viability problems don’t occur until the concentration of chlorine reaches 5 ppm.  At that point, bacterial viability time is cut in half to about 25 hours.  At lower concentrations, viability is at least 48 hours in water with a pH of 7 and a temperature between 77 and 82 degrees F.  A Lallemand technical bulletin stated “products are tolerant of chlorine up to 3 ppm in good quality water at pH 7.”  The bulletin also noted that normal swimming pool water contains 1 to 1.5 ppm of chlorine.

How about acidic or alkaline water?
Acidic and alkaline water can be a problem, and the issue is compounded when chlorine is 3 ppm or higher.  When it comes to pH, you won’t reach the danger zone until water pH is 9 and chlorine is 1 ppm.

Viability problems compound when chlorine is at higher concentrations and the water has an unusually high or low pH.  When water contains 3 ppm or more of chlorine, viability will be reduced considerably with acidic water, and severely reduced with alkaline water.  These situations are quite unusual, but water pH and chlorine concentration should be checked if you have any suspicions.  Test strips for both chlorine and pH are available at pool supply or hardware stores and online.

How about hydrogen-peroxide-treated water?
Lallemand staff have tested their products to be mixed with normal hydrogen peroxide treatment levels at 50 ppm and observed no effects on viability.  A slight reduction in viability was observed when water was overdosed to 100 ppm of hydrogen peroxide.  A recommended practice is to allow water used for mixing inoculants to stand overnight before use.  This will help volatize hydrogen peroxide as well as chlorine.

And high-sulfur water?
Bob Charley, Lallemand forage products manager, also noted water quality can be adversely affected by sulfur levels, and sulfur is very antimicrobial.  Testing is not normally required because the water smells of bad eggs; you’ll know if you have high-sulfur water.  High-sulfur water can be resolved by letting the water “gas off” overnight or by running compressed air through the water.

Poor water quality can indeed negatively affect inoculant viability.  However, if chlorine or hydrogen peroxide treatments are at normal levels (1 ppm for chlorine and 50 ppm for hydrogen peroxide), inoculant viability should not be a concern if the water is within a normal pH range.