New Jersey Ag News
Grantham delivers soil expertise for attendees
By RICHARD SKELLY
LINCROFT (Feb. 15, 2015) — Soil testing for proper pH and careful addition of soil amendments were just a few of the pointers offered up by Allison Grantham, who has spent many years studying soil composition and soil health at Penn State.
She discussed these topics at a seminar held at the annual Northeast Organic Farming Association-New Jersey chapter conference.
Organic soil health, she said, is based on a complex but necessary inter-relationship of components. “It’s a whole system, and organic is about taking a systemic approach to food production, not a command-and-control approach,” Grantham said.
Organic farmers and gardeners want to make sure the makeup of their soil can provide enough nitrogen, potassium and phosphorus to their vegetable plants, she said, and that entails “making sure your plant community and microbial community are actually retaining that within your soil system and not allowing it to escape.”
“The first rule is to get thorough soil tests. You need to know what your baseline is before you make any management decisions, you need to know whether the biologicals you’re trying to use will be able to thrive and provided the services that you need,” Grantham said, “pH is really the linchpin of things,” she added, noting a 6.5-to-7.5 range is where organic enthusiasts will have the highest nutrient availability.
“Too many nutrients can create an imbalance, so knowing your excesses is just as important as knowing your deficiencies,” she argued, drawing an analogy with antibiotics, where too many antibiotics in a human being with an infection that needs clearing up is not necessarily a good thing.
“You don’t want to have too much of one thing, ‘cause then your plants are not going to be as healthy,” she said, adding, “Manure, I think, is over-relied upon, because it’s inexpensive and has all the nutrients in it, nitrogen, phosphorus and potassium.”
She urged seminar attendees to take a close look at plant roots as well, noting you can detect pathogen overload by looking at roots.
“A big part of soil health is pathogen load: often times you have pathogens that get out of whack, and a lot of times it’s not a chemical or physical problem, but a biological imbalance,” Grantham said, adding that growers should also want to look at how well your soil holds water, so that “even when your soil gets drenched it’s not going to all run off into the stream.”
Other components of maintaining soil health include rotating crops wisely on a grower’s respective parcel farm land and planting cover crops to contain the nutrients in soil over the long winters we often get here in the Northeast.
“Once you know the status of your soil health and where the deficiencies are, then you can make good decisions about how best to feed your soil,” she said.
Grantham pointed to a quote displayed on her video screen: “The soil is like the farmer’s bank: you’ve got to be making deposits all the time, if you keep withdrawing from it until it’s empty, you’ll be out of business.”
Grantham recommended a number of books that are available for hard copy purchase but also available free online by visiting http://www.sare.org/Learning-Center/Books.
“In summing up,” she added, “test your soil, adjust accordingly, try to use a diverse selection of organic plant foods or soil foods, and rotate your crops.
“If you have an emerging pathogen problem, you can adjust your whole system based on simple crop rotations.”