NDSU needs farmers for variable-rate study

North Dakota State University put out a call this week for producers to help with a research project to investigate the effects of variable-rate fertilization on crop yields.  John Nowatzki, NDSU agricultural machine systems specialist, leads the study.

"Increasingly, farmers are purchasing equipment capable of applying variable rates of fertilizer, but many farmers are reluctant to incorporate this practice," Nowatzki says. "It could be because there is little whole-field research available to evaluate its effectiveness. The most obvious reason to use variable-rate fertilization is to decrease input costs per unit of harvested crop."

Northern Plains crop producers are invited to participate in the program with up to four fields each. Each field will be analyzed separately, but then combined into a single database to evaluate the effectiveness of variable-rate fertilization.

I asked Nowatzki if Canadian farmers could take part. "I will certainly include Canadian farmers but I need to find a source for free satellite imagery for them," he says. "The ZoneMap site I am using for this study uses the Normalized Difference Vegetation Index (NDVI) derived from Landsat imagery. I could use alternative methods to prepare the zone maps. For example, the farmers could send me previous years' yield data, a topographic map, or even they could prepare their own zones from their knowledge of the field."

If you're interested and you can provide the zone maps, you can email Nowatzki or call 701-231-8213. If you know of other variable-rate research studies that you think Grainews readers would be interested in, please email me. 

More from today's notice:

Project participants will be required to soil test each zone separately. The producer will select the crop and yield goal. To compare the crop yield between variable rate and the normal practice of applying one fertilizer rate across the entire field, random sections of each zone will have fertilizer applied based on a composite soil test from all soil samples.

Nowatzki will use the as-applied fertilizer application maps and crop yield

monitor data from a GIS computer program to analyze the data. Participant requirements include supplying the geographic field description, cropping history, planned crop and yield goal for each field; soil sampling and

testing of each zone; testing a composite soil sample; doing the variable-rate

fertilization; sharing the as-applied map; harvesting the crop with a yield

monitor; and sharing the yield data.

NDSU will prepare zone and fertilizer application maps, provide the maps to the producers in their desired digital format and analyze the data at the end of the growing season.