Latest / The Illinois Nutrient Loss Reduction Podcast / Episode 05 | Fall Tillage and Fertilization Do's and Don'ts
Transcript
- Episode 05 | Fall Tillage and Fertilization Do's and Don'ts 00:00:05:26 - 00:00:27:29 Todd Gleason This is the Illinois Nutrient Loss Reduction podcast. Episode five, fall Tillage and Fertilization. Do's and don'ts. I'm extensions Todd Gleason. We're now joined by Doug Gooker and Jennifer Woodyard, both from the University of Illinois extension, to talk about water quality and nutrient loss. Doug, let's start with you. What impact does fall tillage have on water quality? 00:00:28:01 - 00:00:34:18 Doug Gooker Well, fall tillage, anytime we do tillage, it disrupts soil structure. 00:00:34:21 - 00:01:02:14 Doug Gooker And when we disrupt soil structure, then it's much easier for rainfall freeze thaw cycle to make that soil able to move. And whether it's move by the wind or by the rain. And so even out where, I live on the flat prairies, we have water movement even out on the flat prairies, and we see erosion not near like you do on sloping fields. 00:01:02:14 - 00:01:55:16 Doug Gooker Sloping fields we see lots of erosion. And if farmers are doing tillage in the fall and they're doing it up and down slopes with no regard, and they're using disc rippers that are leaving less than 10% residue cover. There's very little difference between that and the moldboard plow. The term conservation tillage with a disc ripper. Is awfully hard to for soil people to come to grips with, because we have less than 30% residue cover, and that is a minimum we need if we're going to have any type of tillage and not have significant soil movement, we'll still have soil movement with 30% residue cover. 00:01:55:22 - 00:02:03:02 Doug Gooker And the best would be not to do any tillage in the fall or if you do tillage, use cover crops immediately thereafter. 00:02:03:04 - 00:02:08:19 Todd Gleason And Jennifer, you have, some more information, kind of data about this. What do you know? 00:02:08:22 - 00:02:18:12 Jennifer Woodyard So when we think about tillage and soil erosion, there is a value use called T, which is considered the maximum rate of erosion that does not damage the productive potential of the soil. 00:02:18:15 - 00:02:42:14 Jennifer Woodyard So depending on your soils characteristics, T can be anywhere from 1 to 5 tons per acre per year. So in the nutrient loss reduction strategy, one scenario shows that if 1.8 million acres of conventional tilled ground, that is eroding at a rate greater than that T value, or to be converted to reduced mulch or no till, we would see the amount of total phosphorus loss on those acres reduced by 50%. 00:02:42:17 - 00:03:03:04 Jennifer Woodyard So and then another scenario in the nutrient loss direction strategy shows that if cover crops were put on 1.6 million acres that are currently using reduced or no till, but they're still eroding at a rate greater than T, we would see total phosphorus loss from those acres also reduced by 50%. Some of these practices that are listed in the nutrient loss reduction strategy are really going to help us reach those goals. 00:03:03:05 - 00:03:22:21 Jennifer Woodyard We have an interim goal by 2025 to reduce phosphorus loss by 25%, and we want to reduce nitrogen loss by 15%. So I encourage all the producers out there, if they haven't had a chance to take a look at this nutrient loss reduction strategy, to really look at it and consider how some of these factors might practices might fit in on their, operation. 00:03:22:28 - 00:03:46:10 Todd Gleason The university has done a lot of work. Different subject area, same problem, relatively speaking. Instead of soil movement we're talking about nutrient movement. This time, the university has done a lot of work looking at nitrogen applications. What do we know about splitting, for instance, nitrogen application in the spring and the fall and how well that works? 00:03:46:13 - 00:04:05:06 Doug Gooker Well, we know, we know for a fact that if we put nitrogen on the fall, with there being no growing crop on fallow ground, which is very typical that we run and usually do have a risk of loss. 00:04:05:09 - 00:04:43:13 Doug Gooker Even with a nitrification inhibitor, we will still have some loss. We won't have near the loss as if we don't use a nitrification inhibitor. But we still have a loss. And so we understand with farming that getting all the nitrogen on in the spring or during side dress may not just be physically possible for farmers, I mean just physically possible, but the idea of only putting on 50%, it greatly reduces the amount of nitrogen that is susceptible to being lost through leaching. 00:04:43:16 - 00:04:50:27 Todd Gleason Other potential issues that farmers might face if they decide to do a split application, or to do side dress? 00:04:50:27 - 00:05:11:24 Doug Gooker Timing. Have, having, having side dressed in the past. It never rains until it's time to side dress. And so, it you have to have a plan B and so if it's too wet to side dress, how are you going to do it? 00:05:11:27 - 00:05:35:01 Doug Gooker The other thing is, is that are there ways that you can side dress that are quicker than maybe pulling an anhydrous tank down through the field, can you use 28 and use rolling colter applicator where you can roll at 8 or 9 miles an hour and cover and you have a 24 row applicator, so you're covering you. 00:05:35:01 - 00:05:48:27 Doug Gooker If you're going to side dress, you're going to have to be geared up and equipped to do it or have a plan B, such as a custom applicator that can come in with high clearance equipment to get that in on. 00:05:49:04 - 00:05:57:16 Todd Gleason Finally, do you have really any advice for producers who are looking to switch either to no till, or spring applied N? 00:05:57:19 - 00:05:58:19 Doug Gooker Okay. 00:05:58:21 - 00:06:35:00 Doug Gooker For no till, no till having been a no tiller and starting a lot over 30 years ago, back in the dark ages. The biggest thing is, is that no till actually works extremely well with cover crops. Because when we go to no till, our soils are used to this constant turning in conventional agriculture. So we have a very high bacteria count, but we have very few of the, the fungi and other organisms that really break down residue. 00:06:35:00 - 00:07:00:24 Doug Gooker Well. And so if in the first few years of no till, we can end up with a residue mat at the heavy residue mat, where if we use cover crops, this rapidly brings in these organisms that help decompose. And we don't have those traditional issues in no till. The other thing is, is that no till now we consider strip till to be no till. 00:07:00:26 - 00:07:23:25 Doug Gooker And quite honestly, if you're going to do no till, do strip till because you're still tilling one third of the ground when you put that strip in. You're just not tilling the other two thirds. And you don't really needed to till that anyway. So you can strip till that one third where you're going to plant the seed, you're going to make a nice raised bed to plant it in. 00:07:23:25 - 00:07:42:23 Doug Gooker So next spring the row middles may be wet, but that nice raised bed you created last fall is going to be nice and warm and ready for you to plant in. And besides, you can then put your phosphorus down deep in the fall, which is even better way to keep it from moving. 00:07:42:26 - 00:07:53:12 Todd Gleason Jennifer, Doug talked about several things as it relates to nutrient loss, using nitrogen inhibitor in the fall, maybe split application or even side dressing. 00:07:53:12 - 00:07:57:08 Todd Gleason What do the statistics and science. Tell us about these? 00:07:57:11 - 00:08:13:20 Jennifer Woodyard Yeah. So I talked a little bit about the phosphorus practices. And then there's also the nitrogen side of course. So as you're going into harvest and thinking about what you're going to do after harvest, if you're going to apply nitrogen in the fall, you should really consider putting on a nitrification inhibitor. 00:08:13:22 - 00:08:37:15 Jennifer Woodyard So in the nutrient reduction strategy, they talk about if we were to use nitrification inhibitors on all tile drained corn acres, we could see a 10% reduction in nitrate N loss per acre. And then thinking about, doing a split application. So if you did 40% N in the fall, 10% pre plant and 50% side dress, we could see a 15 to 20% reduction in nitrate N loss per acre. 00:08:37:18 - 00:08:48:16 Jennifer Woodyard And on a similar note, if we switched to only spraying applications of N on tile drained corn acres, we could still see that 15 to 20% loss reduction in nitrate N per acre. 00:08:48:19 - 00:08:53:23 Todd Gleason One final note: anything a producer just should not do this fall? 00:08:53:24 - 00:08:58:14 Jennifer Woodyard Yeah. So if you're going to till this fall, you really don't need to till soybean stubble. 00:08:58:16 - 00:09:16:06 Jennifer Woodyard There's not a lot of residue there. So when you go in until it, you're just really removing that and kind of exposing the soil to erosion this winter. And then it's really important to at least keep residue cover on sloping soils, especially because we can see a lot of water erosion and wind erosion occur there during the winter as well. 00:09:16:09 - 00:09:33:02 Jennifer Woodyard And then if you want to apply, anhydrous in the fall, really you need to wait until soil, temperature is at 50 degrees, which is normally about November 1st. And then consider applying a nitrification inhibitor with that so that we can slow that conversion of ammonium to nitrate. 00:09:33:04 - 00:09:38:03 Todd Gleason Thank you Jennifer. Jennifer Woodyard and Doug Gooker are both with the University of Illinois Extension. 00:09:38:09 - 00:09:44:11 Todd Gleason They join us on this fifth episode of the Nutrient Loss Reduction podcast. I'm Todd Gleason.