Speaker 1: The idea of soil quality has been around for a long time, tillage operations began years ago to help fight off weeds and help crops grow without competition. Now, with the development of chemical products to do those things for you, Oklahoma State university researches like Jason [Morn 00:20] believe no-till is the way to go when it comes to improving soil quality.
Jason: The concept of soil quality is that the soil functions not simply to grow crops, but the soil also provides functions for water purification, water flow regulation and general environmental quality. Because if we have eroded soils and we have water quality issues, if we have wind erosion, we have air quality issues.
No-till will actually … because of the accumulation of soil structure improvements, soil structure, you’ll get rapid infiltration out here whereas in a tilled field, it will crust over and then you get run off. Of course anywhere, that will cause flooding and then just a general reduction in the function of the soil.
Speaker 1: To show us just how much of an effect no-till can have on your soil, Jason drilled out a core in a no-till field.
Jason: What we have at the surface which is critically important, is we have a lot of nice structure that’s developed with the root growth and we have a root channels and things like that, that will be developed in this no-till ground. You see how it breaks off in nice large, regularly shaped crumbles like cookie crumbs?
Speaker 1: Yeah.
Jason: That’s what we call nice surface soil structure.
Speaker 1: We found that nice soil structure when all the way down to the bottom of the core. Next, we went out to the field to check out what kind of residue you can expect to see in a no-till operation.
Jason: This is a really nice example of a no-till field with very good accumulation of crop residue. Residue is by far a very … one of the most critical components of no-till soil quality because it’s protecting that soil surface from the impacts of rainfall. A lot of people think that the flow of water down the slope is actually the erosive force, but it’s actually the impact of that raindrop, hitting the soil surface that is the most powerful part of that rainstorm. You get the surface residue, you look at it, can you see bare ground here?
Speaker 1: No.
Jason: That’s the beauty of no-till. It’s protecting the soil from erosion, it’s protecting the soil from crusting.
Speaker 1: You have quite a bit of layer here before you even … [inaudible 03:03] this one.
Jason: Yeah. You have a lot of layer and one thing to notice is we’ve got weak straw here. We’ve got soybean residue here and then we’ve got even cornstalks coming out. This corn would’ve been grown in the summer of ’08, that’s how long that’s been here and that’s really nice. What this residue also does in addition to protecting the soil surface, is it provides essentially food for biological activity in burrowing insects, worms and things of that nature, that are also importantly with respect to improving soil quality.
Speaker 1: We want to get a closer look, so we dug a hole to check out the surface soil.
Jason: Again, you can see all the darkness. You can actually, if you look real close, you can see warm cast right there at the very surface. I don’t know if your camera can pick that up, but this is a lot easier to look at the surface of the soil when you dig it up. If you dig it like there’s a wormhole, water’s going to be able to move from the surface just like very rapidly down that wormhole to get to the subsoil and moisten that subsoil. Again, you’re just seeing that beautiful cookie crumb …
Speaker 1: It’s just breaking apart like that?
Jason: Just beautiful soil.
Speaker 1: How long before we actually see the soil look like this? People who are doing no-till for the first time, this isn’t going to look like this right away, correct?
Jason: No.
Speaker 1: How long is that process?
Jason: You start to see some of these features come on in maybe three years or so.
Speaker 1: Okay.
Jason: The first year, in fact … We should really go to a cultivated piece of land, so you could see what a surface crust look like. That’s the first thing you want to get rid off and it’s a very easy thing to get rid off.
Speaker 1: That’s not you can get rid off right away or you have too …?
Jason: Well, through maintenance of crop residue. If you got crop residue on your field, then you’re not going to have surface crusting. Anywhere there’s no residue, yes it’s going to crust but if you got a nice good blanket of residue, then that crusting is going to be [mountain 05:18].
Speaker 1: To get a better idea of just what Jason was talking about, we went to visit a cultivated field. You’re going to show us the difference between this field and what it’s like to be in the no-till field?
Jason: Yeah. Of course, the very obvious observation is there’s no residue here because we’ve turned that in, that’s the function … One of the functions of cultivation is turn that residue in.
Speaker 1: Yeah. You can see a lot of bare ground here.
Jason: Get it decomposed. Yeah, you’ll see a lot of bare ground and what you’ll see is that surface crusting I’m talking about. In fact, it’s probably easier if I can … just to get a shovel full. You could see how that surface breaks apart. This loose, moist soil underneath and then you’ve got this crust at the surface, that’s it. You’re going to to impede water movement because what happens again is the raindrop hits the soil, the soil particles move around and fill in all the pores in the surface and that initiates run off.
Speaker 1: This doesn’t break apart like the other one?
Jason: No. Quite the same.
Speaker 1: Quite the same? Yeah.
Jason: What you’ll see is a lot of just single, very small aggregates. Of course, it tends to be little drier so that’s part of it, but a lot if it is there’s just not any structure, it’s what we call this massive structure is the tillage and cultivation, it breaks down all those aggregates and essentially decomposes them.
It will function directly after cultivation, that’s one of the reasons why we cultivate is to loosen the soil to allow the plants to grow. That cultivation then, allows for erosion both wind and water erosion. It also allows for that surface crusting to occur which is going to impede water infiltration, increasing run off and increasing erosion. Also, limiting the amount of water [while 07:23] getting them in the soil for crop production because we are in a water limiting environment, so we want as much water in the soil as possible.
In cultivation through its [inputs 07:36] on the surface, actually can limit over the long term, the amount of water [while 07:42] getting into the ground.
Speaker 1: All right. Thank you so much for bringing us out here today.