Don Moore
“Nitrogen management is not an exact science,” says Don Moore, an independent crop consultant from North East, Maryland. Moore’s clients are live-
stock and crop producers, located throughout the Mid-Atlantic region.
To help his growers improve their nitrogen management, Moore got involved in a nitrogen use efficiency improvement project in the Upper Chesapeake watershed in 2006. In 2007, the program added guided stalk sampling in coordination with the On-Farm Network®, which en- abled Moore to help his clients add another tool to their nitrogen man- agement arsenal. This program has received funding and support from a variety of sources, including the Natural Resources Conservation Service through the agency’s Con- servation Innovation Grant and Environmental Quality Incentives Programs, the National Fish and Wildlife Foundation’s Targeted Wa- tershed Grant program, the Environ- mental Defense Fund, the Chester County Conservation District, the Pennsylvania State Conservation
Commission, the Philanthropic Collaborative, the Doris Duke Charitable Foundation, and the Keith Campbell Foundation.
“Past nitrogen fertilizer use guidelines were too general- ized and led to overuse in some cases and underuse in oth- ers,” he says. “We’ve been using the pre-sidedress nitrate test (PSNT) for several years to help us come up with a more spe- cific recommendation for each field. Soil testing takes some of the guessing out of it, but even then, it’s been difficult to know whether you used the right amount.”
The end-of-season stalk nitrate test was developed several years ago to help growers assess how well their nitrogen man- agement worked. Moore had used this test with some of his cli- ents prior to their participation in the On-Farm Network pro- gram. What makes this program different from random stalk sampling is the use of aerial imagery to select specific areas of the field for testing. Using images collected in late summer, program technicians select four areas for sampling in each corn field. Two represent typical areas of the field. One point is selected from an area where soil nitrogen may be higher and one from an area that may be deficient. All selections are made based on the crop canopy color.
“We’ve been living with nutrient management regulations for several years and farmers are working at being good envi- ronmental stewards. We’re hopeful that this will give us new tools that help farmers continue in that direction while remain- ing profitable. We’re not intentionally over-applying nutrients. With fertilizer prices as they are now, you can’t afford to do that. There’s a lot of science behind this type of testing, so whatever we can learn from it will only have a positive im- pact,” Moore says. “The more information we have, the better the decisions we can make.”
Dave, Henry and Matt Young:
More than 30 years ago, Henry Young and his sons Matt and Dave started Red Knob Farm in Lancaster County, Pennsyl- vania. This family operation, now in- volving three generations of Youngs and a number of key employees, has grown into a multi-location dairy farm they now call Keystone Dairy Ventures, LLC.
Over the years, they’ve tried a number of practices they hoped would allow them to better manage the manure from their dairy opera- tion and purchased fertilizers to supplement the manure. “All of our crop land (approximately 460 acres) is planted in an annual double crop rotation of corn for silage and rye for silage. We’ve always used the manure to fertilize a portion of our corn, in what we thought was the best manner,” Matt tells.
For the past few years, the Youngs have participated in a program that allows them to use corn stalk samples to see whether their ma- nure and nitrogen fertilizer management have been effective. After harvesting corn silage, they collect stalk samples in various locations across each field and have them analyzed for nitrate concentration.
“We’ve done soil sampling, using the pre-sidedress nitrate test, and tried to adjust nitrogen applications according to what we learned,” he says. “But the stalk nitrate testing we’ve done is the only thing I’ve found that helps us significantly with our nitrogen manage- ment.
“It lets us know if we hit the mark with the amount of nitrogen we
applied. We know that if the nitrate test was too low, we should have applied more nitrogen. And if it’s too high, we applied more than was needed to optimize yields.”
They’ve changed their manage- ment based on the results of these tests. “Because of the cost of hauling to fields farther from the barns, we’d tried to use as much of the manure on closer field tracts to minimize hauling costs, while staying within
the nitrogen application guidelines in our manure management plan. Those fields consistently tested higher in nitrates, according to the stalk tests. As a result, we’re now applying manure to those more distant fields and using it on more acres. At the same time, we’ve been able to get by with less commercial nitrogen fertilizer without hurting our yields.
“The upshot is, we’re using our manure more effectively,” he says.
“What is interesting about this program to practically apply the stalk test at the farm level is that it has been organized by Suzy Friedman from the Environmental Defense Fund, who I believe un- derstands our situation. It is supported by numerous funders inter- ested in water quality. We meet every winter with other growers, our consultants, researchers, and Suzy to discuss the results. The discussions, under the wisdom of Tom Morris, have helped us un- derstand much more about N management. These relationships have benefited us all,” Matt says.
Tom Coleman
As an independent crop consultant in Georgetown, Del- aware, Tom Coleman has tried several things to help his clients improve their nitrogen management. That includes leaf tissue testing and using the pre-sidedress soil nitrate test (PSNT) to guide in-season nitrogen applications and fertigation.
“Many of my clients are in the livestock or poultry busi- ness, so manure is a key part of their fertilizer program. Most are large grain operations, and much of the ground they farm is pivot irrigated,” he says.
Coleman sees a lot of potential for the end-of-season stalk nitrate test. “We need more experience with it, but with today’s nitrogen fertilizer costs and growing scrutiny from regulators and environmentalists, this lets farmers be more proactive in managing their inputs based on performance while keeping their environmental goals in mind,” he says.
“Last year was our first experience with guided stalk sampling and the end-of-season stalk nitrate test. Based on what we saw, we’re probably not far off target in the nitrogen amounts we’re using, for the most part. The initial indication is that we might be able to use less in some cases. We had a drought here last year that may have affected the nitrate concentrations, particularly on dryland fields. But we learned enough that with a couple more years experience, we think we’ll be able to use this information to tailor our nitrogen applications through our irrigation systems so we’re more ef- ficient.”
Included in this project is a group where local growers are presented with stalk sample data from their area. “Of all the grower meetings I’ve been involved in, this one was the most applicable to what farmers are doing. All agreed they wanted to participate in the program again this year, and I had more calls afterwards from growers thanking me for what we’re doing than I’ve ever had before,” Coleman says.
Richard Meinert
Richard Meinert, a University of Connecticut extension educator, has been working with the state’s dairy and crop farmers for many years to help them improve management of manure and nitrogen use for crop production.
“So many times, we can’t see a difference, so we don’t know whether what we’re doing is the right thing,” Meinert says. “I like the end-of-season stalk nitrate test because it’s something
farmers can get a handle on. It gives them a hard number they can use to see whether what they did worked or not.
“And it’s an easy test for grow- ers to do. Most of our corn here is chopped for silage. If they lift the header in a few places as they’re cut- ting the silage, they can leave stalks long enough to do the test. And there’s usually some down time for the truck driver hauling the silage, so it’s easy for him to collect the sam- ples,” he says.
Meinert says it’s important that livestock producers and corn grow- ers adopt stalk nitrate testing as a routine practice, and not just in Connecticut. “All farmers should do this, and not just so they know that what they’re doing is right economically. The environmental police, whoever they are in the different states, are going to want this kind of report card that shows that farmers are justified in using the nutrients they applied for their crops.
“Our state Department of Environmental Protection and NRCS support our program of stalk testing as part of a nutrient management plan. Involving environmental agencies and groups in programs to improve nutrient management is essential for soci- ety to resolve problems with nonpoint pollution,” Meinert says.
Tom Hillyer
“The end-of-season stalk nitrate test lets growers ver- ify how well their nitrogen management program worked,” say Tom Hillyer, a West Liberty, Iowa, crop consultant. Hillyer’s clients use a variety of nitrogen sources, including anhydrous ammonia, UAN, and manure. Most apply their fertilizer preplant. If they suspect that the crop needs additional nitrogen, they’ll use a late-spring soil nitrate test and will sidedress additional nitrogen if the test shows a need for more. “The late-spring soil nitrate test gives us a good in-season picture of the nitrogen avail- ability in some cases, but it’s difficult to get a good read on nitrogen availability when the grower used anhydrous ammonia. When the late spring test comes up with a concentra- tion of 24 or 25 ppm nitrate, growers aren’t always sure if they should apply more or not, but who wants to be on the bubble when corn is $7.00? So there’s a temptation to add a little more,” he says.“By using the end-of-season stalk test, they can see if they made the right decision at sidedressing time.”
He feels the On-Farm Network® guided stalk testing program helps his group of growers improve their nitrogen management by giving them local and statewide information, as well as several years of data to show them what rate of N is optimal for individ- ual fields. “The funding from NRCS and other sponsors makes it possible for us to collect more information from a larger group of farmers. Without the funding, some of my clients would still want the stalk data, but not all farmers would learn the best way to use the data. I might work with a few growers and another consultant might test for a few of his clients. But with the common funding and coordination, we can gather more information and group it together to make comparisons on a larger scale over a larger area. We learn much more this way,” he concludes.