 How are you doing? Awesome, awesome. So, my name is Amir. I'm an associate professor of soil management and integrated cropping systems at Southern Illinois University. And today I'm going to talk about cover crops, especially cover crops in corn production systems because that's a lot more challenging than having cover crops before soybean. And then I cannot walk you through what we've been doing with cover crops and how did we end up doing precision planting of cover crops? Before I start, there are a lot of graduate, undergraduate students involved that are listed here in blue color and that so many people are involved in the projects that are being funded. And so I want to acknowledge all of them and then also indicate that we're very lucky to work with Illinois Farm Bureau, Lauren Laird-Kings and basically they've been very helpful and supportive of us. We get funding from Illinois NREC, North Central State, we are part of precision sustainable agriculture which is the U.S. NIFA funded project and also Illinois Department of Agriculture. So I'd like to start with basically cover crops and why we do cover crops and what kind of benefits we can get from them. We did a survey and there are a lot of surveys out there that can ask why do we do cover crops and what is our main reason to do cover cropping? And a lot of times the response are always targeting at reducing basically erosion. And that's great because that means that the growers are really understanding that how invaluable their top soil is and that reducing erosion means that we're keeping that soil intact in our system to function for us the best. We have Illinois nutrient loss reduction strategy, so we are in Illinois and their target is to reduce nutrient losses by 2025, nitrogen and phosphorus. And basically a lot of my research is targeted at nutrient cycling and then with the hope of reducing basically nutrient losses and then capturing that nutrients and basically finding ways that do not reduce yield while doing that. So I think if we want to advocate something we have to kind of understand that it's much easier for the growers to accept it if they see they're not at least getting a yield penalty for implementing a practice that could be also environmentally beneficial. Along the way as you do this basically cover crop implementation depending on the basically crop biomass or residue you will start like adding some benefits like organic matter to the system. Adding organic matter to the system especially like when we target weed suppression when we have higher organic basically material input or plant biomass inputs. We are basically adding more materials to the soil that would build some organic matter. Building some organic matter synergistically provides many other benefits including increasing infiltration and above all like the resiliency to weather extremes that we are seeing. So basically high organic matter soils usually they have higher buffering capacity meaning their resistance to change and that is very important in all these like erratic rainfall we get all of a sudden 4 inch 5 inches of rain in a day and that's pretty important. One thing that is missing here is increasing yield. Sometimes cover crops can actually help us with increasing yield. For example you can have scenarios of losing nitrogen and having something like a legume that add nitrogen to the system can supplement what was lost and make sure that you don't lose yield. So this is the reason that why we do cover cropping but to get the best of them we need to implement them well. So I work with John Pike and he always tell me that cover crops go into your system so you have to manage them as a system and then how you can manage them best to give you the benefits that we are looking for. These are the list of like 5 hours cover crop management including right species and then like a lot of times our options are cereals, legumes and brassicas and then sometimes we mix them to see the benefits we are looking for. We have right seeding date, right seeding rate, right planting methods so the planting methods could be what we came up with is this precision planting but in reality it's like the normal planting meaning either you go and drill or now we basically spread the seeds. You can use drones now, nowadays, so many other ways that you can plant it but like to really get the seed soil contact the best like drilling probably give you the best stand and then that precision planting is basically based on a drilling method that is modified and now I'm going to talk about like all of those and what we are doing and what we are finding and then we have like termination time and that termination time can vary from like really small basically plants being terminated early all the way to like for example a right getting to a heading a stage and then being like lignified and then basically try to get the best for example with suppression that's your target for and then like there are like tools like basically I think there is one mid-west basically cover crop tool that gives you options to go and choose at what time what species is the right and what seeding rate you can choose among these basically cover crop management scenarios one thing that is really known and it's really easy to target is that seeding date and I'm not going to talk about it because it's really obvious you go on time and plant the cover crops they're going to give you a good benefit you go late you get you will get poor stand establishments in some cases you won't get any benefit you just waste your money and that becomes a very typical like brassicas for example they usually in our environment winter kill so if you plant them late and then they have a very short growing period and they're going to die and so they're going to be small they don't do any of the benefits you're looking for if you plant them early they're pretty amazing like they can grow well they're huge they can help you with your soul compaction capture nutrients and all of it so I think seeding date is something that we know and that's something that like it's going to be less research on because of all the things we know how we manage cover crops and also nutrient management whether it's nitrogen fertilizer or manure or whatever nitrogen source that we have will impact the components of nitrogen cycle and especially what I'm really interested in this loop of mineralization meaning they're basically organic and become basically available and or the other way immobilization meaning available and become immobilized and not accessible but to the plant and then all this process of nitrification that then goes to leaching of nitrate that is like one of the targets that we hope to avoid or denitrification which will become like a greenhouse gas it's a pathway for nitrous oxide emission as a greenhouse gas we can look at it another way is this is a Stanford equation for nitrogen management or nitrogen fertilizer recommendation and this is a short version of it so you have n in the crop minus n that is in the soil divided by fertilizer efficiency and then Doc Begiel came and kind of like expanded that soil and aspects of it which is really a lot of things we do with cover crops will influence these soil and and to some extent like also fertilizer efficiency was the nitrogen management but so those soil and like you can see that they're like you know organic and organic and involved and then if you have like a cover crop there will be like crop residue that like become available very quickly or stays there for a while to become available and then some like if it's you're adding a legume to the system that fixes nitrogen will add to the system one thing they did not talk about is that sometimes that could change in another direction for example if you have a really high residue rye that immobilize and that means instead of like removing that from your crop need that actually might end up adding some end to the system you need to add more end to the system to compensate for what is being unavailable this is an example of a serial rye so that they basically yellow or orange lines is how the corn is growing and taking up nitrogen and then the green is how the cover crop in this case serial rye is decomposing and releasing end to the system and then so here you can see that like this is an example of a Maryland coming from this cover crop and calculator so China if you go to that calculator give some information from your cover crop the biomass of it and some like composition it could kind of simulate what's what you're going to get from it and then so in this case we have like 5,000 pounds of dry matter biomass carbon traction is 40 that means it's more than what we want in terms of like C2N ratio to have mineralization up and rather than immobilization of it to some extent so that the number is magic number is 25 and then here it shows that it has 65 pounds and break that means the end in the plan was 1.3 percent so you have your biomass times 1.3 percent you'll end up with that 65 pounds of nitrogen break and then it is literally telling you that within six weeks after basically terminating that cover crop you only got 30 pounds of it available to the corn and then so the point is the synchrony of that dry with the corn is not great the end amount of end also being released is not is not as good as you want to now I want to show you another example which is clover this is crimson clover and you have kind of the same scenarios corn growth is the same and here you have 4,000 pounds per year that means that clover was really planted on time you get such a biomass from a crimson clover it's great and then your C2N ratio is 13 that's a lot lower than 25 that means you expect that clover to quickly decompose and release end to the system and then you have basically 120 pounds of end break here in that plant biomass that means you probably had 3 percent nitrogen that's what you expect your your legumes they usually have more end percent in them if you get a biomass that usually adds up to a lot more end in the plant and then so here you can see like 85 pounds of that has been released by within that 6 weeks that could be great or not great depending on how you manage your nitrogen if you go and front load end for example early in the season and then you have 85 pounds on top of it you're really exceeding what the crop can remove that early and that could potentially lead to some leaching losses if you account for that and think about can I use that and synchronize that with my fertilization practice maybe use side-dress end later when at like v6 of corn estate or even v8 corn estate and then get that benefit of legume releasing end and then side-dressing end when the corn really needs it I think you'll get a better response in terms of production of the corn and decreasing nutrient losses that you might see in this scenario so one of the questions we have is that okay so you have these legume cereals and brassicas each of them give you something each of them they have their challenges and so you have to choose sometimes so I talked to a lot of the growers they would rather for example have a legume before corn because they are worried about yield penalty that a cereal rye for example give them and that's not desirable to them on the other hand legumes are harder to establish like you have to be on time to really establish a good legume at the same time they will give you benefits of nitrogen so that's what they love about and then if you don't manage that legume well your basically chances of end leaching is a lot higher and that's like against what we hope to do in Illinois getting the yields but like reducing those losses and then one thing is that can be done is to really account for that end and adjust for the end to that not having excess end balances what I mean by end balance is like how much your corn is removing versus how much end is being added to the system so difference will give you a balance and a lot of times excess end balances means you had more applied than what the crop removed and that could potentially be lost to the environment with the cereals they're easy you can even be late and still get a decent establishment with winter cereals especially like rye it grows literally everywhere and then also we have to be careful so if you have a rye in the system you push it for a little bit of a later termination that might lead to your approach change in terms of how you manage nitrogen within the system because that could immobilize and you could then manipulate timing of your fertilization or amount of fertilization to kind of account for that change so what we are seeing with the research we're doing with some folks at SIU is that like a lot of times we have legumes like we have soybeans and then we have a legume on top of it to go before corn right it's a corn-soybean rotation we are seeing increased leaching with legumes after soybean and that is not what we hope to see any time we had rye or wheat or a tritical something like that that captures that residual and from soybean we are seeing reduction in leaching but that becomes a challenge of if you have that cereal before corn how can we manage this to make sure we do get those environmental benefits but not have yield penalty for the growers so adopt it and in brassicas if you don't really get it on time probably we shouldn't bother much because we've done and we've got like very small plans that I think didn't do much to us but if you get it on time that's awesome that's a good source to try and here comes the mixture so sometimes you will get benefits you would basically manipulate the potentially negative effect of a rye by including a legume in the mixture one thing that becomes tricky is how do we find the combination right because getting that seeding grade right these two compete right one usually cereals are out competing the legumes especially with scrims and clover how do we manipulate that seeding rate to get a combination that gives us the right C to N ratio and gives us basically the biomass we are looking for with N to synchronize with our crop production so within that we are a part of a 15 location basically a study this is funded by USDNFA basically what they are going to look at is look at how these cover crops meaning cereal rye, a legume in some locations that's veg cherry veg and in some locations like ores is crimson clover before corn and they want to know if the mixture of the two would benefit the corn in that rotation and how would that compare to a no cover crop so we basically look at and then they have a bunch of nitrogen rate trials to basically see what is the response to nitrogen having those cover crops in this so they start from a fall for example the first year was fall 2020 it goes all the way to May, the spring and then plant the corn goes all the way to the fall and that will give you one cycle from one fall to the next fall this is an example of cover crop biomass across all those locations that we had data for the one in the red is ores and you can see that so the rye is the yellow and green is legume or clover for ores and then this is weeds and you can see like as you have the rye in the system even in the mixture which we cut the rye biomass to half meaning we went from 60 pounds sitting rate to 30 pounds sitting rate but the clover was 25 and we cut it to just 20 still rye dominated that scenario so your whole biomass is mostly from rye than from clover and it's in some places it's way worse even here's an example, here's an example, here's an example some, the ones that they had veg in it it competes a lot better with rye than crimson clover this is the response of like basically corn to nitrogen so you can see the rye and you can see like two things happen one, the yields decreased to some extent not much but a little bit also it needed less nitrogen as a result so you got some yield cut but also less nitrogen requirements there when we did the mixture that kind of went away so that's one benefit of like incorporating that legume in the mixture probably eliminated some potentially animobilization that could happen by rye in that scenario and then legumes and fallows were like kind of operating the same probably because we didn't get a lot of legumes to really push for that excess benefit that we are hoping for and I'll show you they do benefit you when you're unlimited that benefit goes away once you apply enough N so it masks the N benefits from the legume once you have enough N by fallowizer this is an example of like Illinois per se of those three sides and I want you to look at the Wisconsin you see literally no response no response, no response very little response and a little bit more response and that's also an example of N kind of N being a little bit tied up by rye and then kind of being eliminated by having the mixture and then this is typical of Wisconsin because of so much probably manure being applied in the history of manure in the system that the response to N was in a good year that probably had a lot of manureization was not seen so one thing that I really like is to understand whether seeding rate that we are using 60 pounds all the way to like 90 pounds too much or too little and how can we help growers to capture what they're looking for in the sense that reducing their production costs incorporating cover crops in the system so in this case this is winter rye we chose 4 rates of 175, 50 and 30 pounds per year and then we look at the biomass of rye within that system and one thing you can see that the first one that 100 is higher statistically than the 30 pounds per year they are all the same statistically this is kind of higher numerically but this is definitely not but if the goal is with suppression you want to go for a higher side if the goal is nutrient capture and cycling not really because take a look at here this is nitrogen in the plant remember in the beginning I told you when you do basically calculating nitrogen in the plant is your biomass times n percent that will give you this much n in the cover crop as you're increasing the seeding rate probably you're capturing a little bit more biomass your n in the plant is reduced your plants are becoming more lignified that means they're also becoming harder to decompose when you put that together with nitrogen uptake they are all the same so if the goal was to having more biomass for with suppression higher n was better but if the goal was capturing n the lower side is better because lower seed cost for the growers getting the same benefit easier to plant into because it's a little bit less sparsely, light penetrates better so a little bit warmer it gives you all those benefits too we also check if we try that with a hybrid rye which is a bit more palatable easy to decompose a little bit aggressive rye would that be different than a normal rye it wasn't to be honest it gives you a little bit higher yield but not necessarily higher basically benefit that you would hope to do that with having a hybrid rye versus a local rye so then these are like high and low rates high means 90 pounds per acre and low means 60 pounds per acre so 60 was fine and then didn't matter which one you choose this is another one we looked at termination data of wheat crop so you can see here clearly we had a fallow ones that were terminated early ones that we left to be terminated at planting we call it planting green and then ones that we actually went ahead and removed the residue so we kind of like cut it and bail it out interestingly every time we did that residue removal we ended up with corn stand reduction that was significant and we think what happened is that corn starts bleeding basically allopathic exudates that will impact the population of corn and basically influence the basically corn production overall that is significant enough that with no matter how much end we put on we couldn't capture the yield penalty to match those three other treatments this is the end basically in the growing seasons of corn you can see that by having late terminated cover crops in this case wheat you can see like the end in this system is lower in several basically occasions but also you can see that having that cover crop especially that late terminated cover crop that is shown by green color versus the red color which is your basically fallow treatment every time the fallow treatment soil moisture is operating at the lowest level meaning if you had a dry soil condition that late terminated cover crop that caused a mat on the soil surface helped you and compensated for some of that end that was immobilized so when we did actually manage that nitrogen by 2x2x2 starifralization and split that end 100 pounds in the beginning 100 pounds at cider's time we matched the yield which was very positive in that sense so one of the things that we were worried about was that yield penalty by cereal cover crops this is basically what we mean by precision planting so think about the corn row they are 30 inches apart when you plant cover crops they are 7.5 inches apart most of the time that's 19 centimeters when we say precision planting we are literally skipping that dry on the corn row meaning we only have those 3 in the middle and nothing on the corn row that reduces that interaction between the cover crop and the corn giving that corn a chance to basically not interfere with the roots especially or the residues of the cover crop and then be able to perform better and then you can manipulate it in different ways and I'll show you some this is a project that we are working on with Eleanor and Rick actually Shalmer also just came to see if we do precision planting meaning that we do that, skip that corn row and you can see here so there's nothing there where the corn row goes would that first of all provide the same benefit of solid planting of rye meaning every 7.5 inches and it does like every single side year we had it either matched the biomass or increased the biomass because of like basically reducing the rates a little bit but basically putting it all together in this section that kind of pushed the plants a little bit fight for being a little bit taller and they were taller a little bit every time we got the same basically biomass and then every time we matched the corn yield in that system only two times we did not so only two times when we had a fallow which is in that white bars we lost yield because we couldn't do 2x2 inferrization we didn't have the capacity in that side to do it this is another example here I just compared these basically having a clover that is a skip row versus not having it this is a mixture of those you can see here is a mixture of multiple of these under all the rows versus having three on the corn rows and then having clover sorry clover on the corn rows and having rye in the middle and it still didn't matter so you are getting the same benefits and the same biomass by implementing yield and that's I think that's awesome that's going to help us a lot selling the idea of you can do cover crop being not losing the cover crop biomass benefits at the same time helping corn to basically cope better with having rye in the system to capture that nitrate for us and you can see like here also here you have like skip rows and then that's the mixture scenario here I just wanted to remember I told you like clover or clover skip row will benefit you benefit the corn when n is limited here is an example at the lower nitrogen rates always always we are talking about 15 29 23 yield increase by having clover versus no cover crop in the system when the n was limited that's n coming from clover but once you go and give enough n to the corn by fertilizer that benefits gone it might show up in your grey nitrogen content because plant doesn't understand it takes up n but it uses in some of that and for yield gain the rest of it will not give you more yield otherwise we would always get a linear response to nitrogen this is another one this is a basically north central serre partnership plant and then it's a bit complicated but the goal wise if we do annual rye grass with serre rye in mixture and then only in the middle rows and then having legumes on the side or nothing on the side or old radishes on the corn row would we get the same basically cover crop benefits and we need so whether these are the wedge ones so V stands for wedge or basically all means all radishes and then you can see that the biomass is almost the same the difference in this case was when you have clover with rye you lost basically clover in competition with rye so rye dominates your clover when you had wedge that's the biomass of rye in the system it's not the same so wedge really competed well with rye and that means you have more in your scenario plus basically lower siton ratio that hopefully will benefit your next crop well it didn't to some extent only in this case which wasn't statistically did and I think maybe we lost in that scenario or having that combination of oats and radishes on the corn row plus wedge in the system benefited somehow that resulted in that some basically yield increase in that case in that side here and two, three more slides and then I'm done this is the benefit of doing cover crop on basically carbon soil carbon basically looking at the manganese oxidizable carbon at the top soil and then going all the way to like 90 centimeter depth or 1 foot deep and then looking at also carbon stocks after six years of cover cropping and by having cover crops whether it's a skip row or not a skip row using carbon stocks in the system compared to a no cover crop scenario so even within six years starts showing benefits a lot of those benefits are way more easy to capture at the top soil than the sub soil this is another one we look at the aggregate size distribution that's usually we use that for wind erosion we don't see any benefits there but when we look at aggregate stability we are seeing cover crop winds showing an improvement in aggregate stability that means they're resistant to rainfall events and they can hold their particles together so overall I think basically legion cover crops could increase your yield especially if you get rainfall events or use that wood really or adjusting the nitrogen forization to give them opportunity to show their value to us and winter cover crops definitely capture soil then but we have to understand they might cause any mobility issues we have to have strategies of end management to make them work for farmers and definitely implementing data skip row or precision planting help with that then I think what we've seen all these side years like capturing what is the right nitrogen rate is very difficult so I think we should really move towards a little bit of precision nitrogen management and then there are tools that we can capture and understand and predict and in the cover crops event with the models that I just showed you then how much of that would be available to adjust or undergo management practices and then overall I think winter rise seeding rates more than 40 if the goal is not just with suppression it's just waste of money we can really adjust the rates to capture whatever we want to get and then be basically more economically viable for farmers with that I'd like to thank you for paying attention to me maybe over time but I'm happy to answer any questions you have