At a recent conference, Ward Laboratories president Ray Ward answered farmers’ questions about making the most of soil nutrients in no-till systems.
Among other things, Ward’s lab in Kearney, Neb., recently developed a biological test based on soil phospholipid fatty acid (PLFA) profiles that could help no-tillers determine if they’re making the right management decisions to promote a diverse, active soil-microbial community.
Q: Can both nitrogen and increased microbial activity from cover crops be measured in soils and assigned credit?
RW: “There are tests we use to measure cover-crop nitrogen to know how much to reduce the nitrogen for the following crop. We can also measure microbial life, but I don’t know how you interpret that right now.
“Harvest one square yard of cover crop, stuff it in a plastic garbage bag and send it to us, and we’ll measure the nutrients and calculate it to an acre basis. We’re saying 50% will be available for the next crop.”
Q: If cover crops are fertilized, will they give nutrients back to the crop?
RW: “They will, because it’s going to keep nutrients up top. As that cover crop decomposes, those nutrients are going to be released.
“During summer, the cover crop will be decomposing and releasing nutrients. We want broadleaves in the cover crop because they have a lot more nitrogen. That makes the carbon-to-nitrogen ratio narrow enough to release nitrogen.”
Q: Does your lab test for living organisms in the soil?
RW: “We can do the analysis, but right…