"Dad, why aren't you cutting your commercial
fertilizer rates this spring to account for the chicken manure you
applied last fall?"
"How do I know how many of those nutrients are still there?"
This excerpt is from a real conversation between an Ohio corn and
soybean producer and his agronomist son just prior to planting in
2006. Dad was worried that the nutrients in the fall-applied
manure may not be there in the amounts predicted by nutrient management
planning. Is he right to be concerned?
Nutrient management planning is a science-based approach built on
multiple-year results from experimental plots and sometimes farm fields
as well. The aim is to optimize returns to farmers over time, so
that on average, more dollars go into the farmer's pocket. Ohio State
University would have recommended a reduction in commercial fertilizer
by 50 lbs. of N and 60 lbs. of P per acre to account for the value of
nutrients in the chicken manure.
Does that mean that each and every year a corn farmer can expect
maximum yields by following university recommendations?
Absolutely not! In any one year, weather conditions can increase
or decrease the amount of nutrient preserved or lost over the long
winter. Errors in calculation, in calibrating manure spreaders or
estimating nutrient content in manures can de-optimize the equation.
However, on average, university recommendations for crediting
nutrients in manure should win out as the most economical. Yields
may suffer in some years, but over time cash returns are higher.
Our results with nearly 100 farmers over the past several
years bear university recommendations out. On average,
university-recommended nutrient rates generate a break-even return -
farmers do just as well financially with university recommendations
than if they had continued to apply extra nutrients. To date,
participating farmers have cut their nitrogen rates by 24% or 41 lbs.
per acre, and earned just as much net income from their corn crop.
As an Extension agent, crop advisor, watershed program manager or
other key influencer of farmer practices, how can you effectively
respond to concerns about yield and economic returns when recommending
Try the BMP CHALLENGE! Designed for farmers who want extra
assurance, the BMP CHALLENGE provides a financial safety
The program is simple. The farmer agrees to follow
university-recommended rates which are calculated by a crop
advisor. The advisor also helps set out a check strip in the
field that will be fertilized at the farmer's traditional rates.
At harvest, the crop advisor works with the farmer to assess yield and
calculate net returns. If net returns are less for the BMP rate,
the farmer receives a cash payment to make up the difference.
Farmers can enroll one or more fields for one or several
seasons to gain familiarity with how university recommendations
perform on their farm. The goal is to give farmers a risk-free
opportunity to experiment in their own fields, on their own farm.
This "trialability" is a key advantage for creating behavior change in
any field, not just agriculture.
Consider adding the BMP CHALLENGE to your toolbox when working
with corn producers to achieve conservation and economic goals.
Great prospects for participation include corn producers who do
not credit nutrients contributed by manure applications, which is about
25% of corn producers, according to a 2005 survey by the University of
The BMP CHALLENGE is available for corn producers using nutrient
management for manure and/or commercial fertilizer, or conservation
tillage. Contact Lori at 608 663-4697 for more information.