Tim Wolf: 2023 NutraDrip Field Day
350/150 Yield Group
The 350/150 Yield Group is a small group of farmers that have purchased a drip irrigation system with the goal of breaking through their yield barrier. Most of these have been achieving dry land yields of 200-250 bushels per acre. We want to discover techniques, discover products, discover together and learn together what we can do that will help accomplish 350-bushel corn and 150 bushel soybeans. These growers span a wide geography all the way from Marshall, Minnesota on the north to Southern Missouri on the south, Indiana on the east and western Nebraska on the west side. A lot of geography, a lot of differences, but also a lot of commonalities. One being they’re all drip irrigation growers, maybe at different levels of experience. Some guys have had it for five or more years, some guys are only in their first or second year. The other important characteristic of that grower is they’re not afraid to try new things, and they’re not afraid to express what they’ve learned, both good and bad. We meet yearly to discuss goals for the next year, wins and fails from the last year. In between, we have meetings to go over tissue sampling results, in season soil sampling results, observations, wins and losses of the things that we’re trying.
The overarching goal is to learn what works and what doesn’t. When you purchase an SDI system, we’ll be able to incorporate the learnings and mistakes that we made into leveraging your drip system to deliver as much value as possible. Just because you put in a drip system doesn’t mean you’re going to get to 350-bushel corn. You need to schedule the water correctly, you need to understand what the plant wants, be able to communicate with the plant, ask the plant “what do you need? what do you want?” and be able to deliver it through the delivery system of SDI.
Efficiency, Yield, Profit
How do I get more from my existing acres? When I was a kid on my home farm in Madison, South Dakota, dry land, if we hit 100 bushels, we thought we hung the moon. Now on that very same farm, if we don’t make 200-bushel dry land yield, we’re asking ourselves, what did we do wrong? That evolution will continue. In the next 25 to 30 years, I think it’s very realistic for us to think about 400-bushel dry land yields. We have the genetic potential there. What is the genetic potential? I used to say 600, but some growers broke that, so I moved it to 800. Even if you are currently hitting 400 bushes per acre, that is only HALF the genetic potential! How do we remove the obstacles to getting to that genetic potential? Stress mitigation.
Let’s start with some basics: what does the root see on a corn plant or soybean plant or any plant? Ideally, it sees about 50 percent sand, silt, clay mix and organic matter, and the other half is split between water and air. And if you have too much water, if you’re waterlogged; you’ve got more water than air. If you’re in a drought situation, you’ve got more air than water. But in an ideal scenario at field capacity, we have about half and half, so 25 percent air, 25 percent water. What is field capacity? Field capacity is the point at which the soil is holding the maximum amount of water that it can hold without it either leaching down through the profile and going out the bottom or running off. So it is the maximum point where it holds as much water as possible. On the other end of the spectrum is wilting point. Wilting point is the point at which the plant cannot extract any more water out of the soil. The difference between the two is available water. As irrigators, we get to manage the available water.
It’s not uncommon to have two and a half inches of available water potential at field capacity to work with; the upper half of that is easy water for the plant to extract. As it gets lower, the plant has to expend more energy to extract water from the soil. By watering every day or every other day, we can decrease the amount of stress a plant goes through: minimum stress, maximum genetic potential. How do we monitor where we are in water availability?
I’m a big proponent of soil moisture probes. There are different kinds of soil moisture probes out there; the biggest difference between them is WHO is helping you decipher the information from them and scheduling irrigation and fertigation based on that data.
Another tool we can use for monitoring water availability is imagery. This is something we have been working with for Netafim’s crop advisor tool. This is a global program that is being developed and used around the world. The goal is to help us do a better job of irrigating and fertigating, and then automating that process. Imagery is a big part of what we are learning. Soil moisture probes only show one spot in the field, imagery can give us a bigger picture of the whole. We like to use daily images, and watch for trends. The biggest downfall is the quantification of difference. There aren’t numbers like we get with soil moisture probes. However, using soil moisture probes, plus imagery seems to be a winning combination for monitor crop stress. Ultimately, with Netafim’s Crop Advisor tool, we could have one login and one platform with the ability to run your controller and have all your sensors plugged into it. This allows all the data to be in one spot, and could even allow for autonomous irrigation someday.
