When it comes to precision ag, Chad Godsey says one of the best pieces of advice is, "You've got to figure things out on your own." On-farm research is more important now than ever.
In recent years, Godsey, former associate professor and cropping systems specialist at Oklahoma State University and founder of Godsey Precision Ag near Eckley, Colorado says with the turnover of faculty at various land grant universities, there has been less collaboration between universities and industry. "Ultimately what this leads to is a lack of unbiased research," he says. "That's why on-farm research is so important. In my opinion, with all these precision ag technologies, you've got to figure out how to use them on your own and incorporate them into your management skillset."
In some cases, he adds, this may be why adoption of certain technology is hindered – every farm is different. "We've seen some instances where companies develop precision ag programs that are tailored to Iowa, Illinois, Ohio and places like that. It gets brought out here to Kansas, Oklahoma, Colorado, or western Nebraska, and it's different enough to not be a good fit out here. It's been a real hindrance to our adoption," he says. "Each plan has got to be tailor-made for that individual, that farmer, or that operation."
Do it yourself
Godsey prefers to start with creating management zones using yield history and multiple years' worth of analysis before implementing variable rate technologies, whether seeding rates, fertilizer, or water, and at the end of the year, analyzing data to incorporate into next year's decisions. This way, producers can delineate management zones based on yield potential and where to emphasize higher management.
However, without a check strip, there's no way to quantify the benefits. "We always have a check strip or multiple check strips not only for nitrogen but for seeding," he says. "Always incorporating those check strips and fine-tuning those management zones is often something that doesn't get done enough."
Management zones are dynamic. Things change throughout the growing season and from one part of a zone to another, which Godsey says makes it difficult for technology like variable rate irrigation to meet the needs of a zone consistently. "We've got to take into account different seeding rates when we've got 38,000 plants per acre in one area versus 26,000 in another. So, crop water use is different," he says. "We're pretty naïve if we think we can make a prescription in April and just move the application rates up and down uniformly."
On the other hand, soil type and fertility doesn't fluctuate like soil moisture does, and Godsey says it's more practical to set management zones to match seeding rate and fertilizer to yield potential and soil test data.
Focus on efficiency
Godsey says nitrogen applications have seen the biggest efficiency boost from variable rate technology. "We've gone away from a uniform rate and increased the number of split applications of nitrogen we apply on corn," he says. His nitrogen applications on corn range from 160 to 270 pounds per acre for the entire season, including starter, sidedress, and sprinkler applications. These rates are based on historic yield potential and using a one-pound of nitrogen per bushel factor. "One of the things that's led to increased efficiency is matching nitrogen rates with yield potential, not putting as much on hill tops and putting more on more productive parts of the field."
In one 125-acre field example from 2010 to 2014, Godsey saved on average $11.07 per acre per season on variable rate sidedress, from 30 to 100 pounds per acre, and $1.75 per acre per season with variable rate seeding, from 27,000 to 34,000 seeds per acre. Over the five-year period, the overall savings for the 125 acres was $6,919.
But it isn't just about savings – it's about efficiency. By intensifying management and increasing rates in productive areas, these 125 acres saw a 5% average yield increase, producing more with less. "Cutting inputs when you can is part of efficiency, but sometimes we focus too much on just saving money," Godsey says. "By conducting on-farm research and improving efficiency by adjusting optimum seeding and nitrogen rates, you're optimizing efficiency for your own production practices on your own soils."