Cornell Researchers Talk Precision Ag at Field Day

AURORA, N.Y. — Attendees of a recent Cornell field day at the Musgrave Research Farm heard from a number of researchers on ways to manage nitrogen inputs and soil health through precision agriculture.

Cornell professor of nutrient management Quirine Ketterings along with her post-doctoral associate Aristotelis Tagarakis, and a number of other researchers from across the state, have been working with GreenSeeker technology.

“GreenSeeker has been used in New York state for a number of seasons,” Tagarakis said.

The GreenSeeker scanner provides data known as Normalized Difference Vegetation Index, or NDVI, which is used to make decisions regarding the amount of fertilizer to be applied to a crop.

Tagarakis said there is still work to do to fine-tune the algorithms growers in New York state are using to convert NDVI values into nitrogen recommendations for corn. He said their data show that the sensor provides good predictions of yield when scanned at the V7-V8 growth stage for corn. For forage sorghum, taking readings at 30 inches plant height was a good time for predicting yield, he said.

Sarah Lyons, doctoral candidate with Ketterings, talked about why they were studying forage sorghum.

“Brachytic dwarf BMR sorghum is, as its name implies, shorter than the standard varieties and is branching, so there is less of an issue with lodging,” Lyons said.

Many believe it is a promising alternative to corn silage as it has good nutritional value and has the potential for earlier harvest, thus allowing for more flexibility in spring planting. Sorghum could fit into a rotation in upstate New York where harvesting the winter cereals in time for corn planting in the spring can sometimes be a challenge.

Lyons said the focus of some of the research has been the nitrogen needs of the crop and to determine the effect of harvest date on yield and quality.

“We’ve seen that harvesting two weeks earlier than normal doesn’t result in yield loss, but how the cows will do when they eat it is yet to be determined,” she said.

A much newer technology used in precision agriculture applications is aerial drones. Lindsay Chamberlain, a student at Cornell who works in Ketterings’ program and with drone expert Elson Shields, talked about some of the work they are doing with drones.

One drone they are using is a quadcopter that Shields modified significantly. The cost of the machine is around $1,500 and uses three different cameras, infrared, NDVI and visual lens.

“We want to determine the right time to fly with respect to plantgrowth stage to allow us to obtain the most reliable yield predictions,” Chamberlain said.

Unlike the GreenSeeker, drone images are affected by atmospheric conditions. Once the images are obtained, processing is time-consuming and requires expert knowledge.

“Each crop has its own signature, and in addition, the current drought in the area is causing the corn to curl and this stress response changes the image obtained with the drone,” she said.

Shields said that even though drones are promising for precision agriculture, there is still a fair amount of research to be done.

Some of the potential advantages drones have are the ability to provide high spatial resolution, the ability to cover large areas of a field in one flight and to acquire crop disease information.

Harold van Es, Cornell professor of crop and soil sciences, talked about Adapt-N, an online tool that can help many crop farmers manage their nitrogen inputs while taking into account numerous agronomic variables such as soil types, nutrient levels, past crops and planting date.

Adapt-N is constantly being updated. Date of emergence has recently been added, and van Es said they are working on a cover crop component, too.

Cornell research support specialist Bob Schindelbeck said “the new Cornell Soil Health Training Manual is now available online.” He said that sample submission and reporting is also online.

“In addition, we have a new reporting format with updated scoring functions based on data analysis from over 7,000 samples,” he said.

Having a standardized soil health test system is something many researchers and growers wish they had. Schindelbeck said that while a national soil health test system is likely way off, it will likely be based on the framework developed at Cornell.

Michael Glos, a research support specialist at Cornell, has been working with van Es to identify groups of farmers in New York state who are using precision agriculture and the tools that are most frequently used.

“Corn and soybean producers are the largest adopter of high-precision GPS services with around 40 percent of the respondents to the online survey saying they used it,” Glos said, adding that they are also the biggest users of yield monitors.

Interestingly, field imagery from satellite, planes or drones was used more by juice and wine grape growers than other farmers.

“From the survey, 81 percent of the corn and soybean producers adopted precision agriculture with the goal of getting higher profits, 60 percent used it to reduce environmental impact and 58 percent were using it to save time,” he said.

Glos said infrastructure, especially communications and access to high-speed internet, needs to improve in the state and nationwide if more widespread adoption of precision agriculture is going to happen.

Those interested in more details of the precision ag survey should contact van Es at hmv1//soilhealth.cals.cornell.edu/training-manual.

Helen Margaret Griffiths is a freelance writer in south-central New York.

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