Today's webinar coordinator and moderator is David Lamm. David is the leader of the National Soil Health and Sustainability team, located here at the East National Technology Support Center in Greensboro. And with that, David, I'm going to turn the webinar overto you so you can introduce the topic and our presenter. Thank you very much, Holli, and I want to send out a big welcome to everybody. And I want to apologize for my voice. I'm battling a cold, if you can believethat in the middle of summer. And it's decided to settle in my voice box there,so if I sound a little raspy, it'sjust because that's just the way it is. I'm really excited about today's webinar. It's the last one in the soil series. This'll be the 10th one. And I think we saved the best one till last. I've had an opportunity to hear Klaus speak as part of the SoilRenaissance Forum that was held earlier in the summer,about mid-July. He participated along with Dr. Honeycuttand a few other folks, and he'll explain moreabout that, what that is. Klaus is a farmer from Penn Yan, New York,and he farms with the lake, the organic grains,and he's just a wealth of knowledge. And I want to give you folks a head up-- this presentation isa lot of pictures, so don't miss out. There's not gonna be a lot of written language in this one. You're gonna have to listen and take notes,because this gentleman has a lot to offer when he's talkingabout organic farming and building soil. And pay attention, because this is a rare opportunity. And also, I give Klaus a big thank you, to start off with. He had a group from Cornell out to his farm this morning,he's on the webinar with us this afternoon. I don't know when he finds time to farm the 1400acre he has there in New York. He must have it figured out. So we got Klaus. I appreciate your time, and I turn it over to you. I wish I had it figured out some days. Talking about soil health, a lot like human health,we don't think about it except in the absence of it. And really defining it can be a problem for us. But I think the NRCS definition of soil health is a good one. We had a meeting where we discussed soil healthand tried to define it for several hours,and went around in circles and then came backto the NRCS one, which I think reallyattests to how well thought out it was. Right now, I'm almost afraid to quote itbecause I'll get it wrong, but ithas to do with the ability of soilsto function, to do what we want them to do. And I would go a little further on this definition of soilhealth and say that it is creatingan environment in our fields, in our soil, thatis suitable for the crop that we're trying to grow there. And just for an example on this, if wewere to grow-- I'm kind of muddying the waters,but if we were to want to grow a tree fruit crop,I would think that some of our parameters and some our thingsthat we're looking for in the soil to be healthymight be different than what they are in a row crop. But be that as it may, a lot of the functions in soil healthare going to be the same-- the ability to absorb waterrapidly; the ability to hold water sothat when there are periods of excessive we can store it,and then when there are periods when we're not getting water,that we can bring it back; the abilityof the soil to resist diseases. Those are all key pieces of soil health. When I became interested in it, itwas right about when Cornell was starting their work. And we were noticing that yields of especially vegetable cropswere dropping. And nobody could quite understand why. We had better fertilizers, we had better pesticides. But for some reason there was something pulling backthe yields where they just weren't performingas well as they had before. And a group was called together. And I really want to give Cornell credit. It wasn't just a pathologist or justsomebody who studied weeds. They brought together what's known as a program workteam, which represented almost all disciplines thathave to do with agriculture, so that wewere looking at the soil from many aspects. And it's interesting-- back when modern agricultural researchstarted, [INAUDIBLE] did his work on mineralsfrom the soil going into plants. And he came up with the theory of the barrel with the shorteststave limiting what the yield is. But it's really a lot more complicated than that. And when we do a soil test, we'vegotten very good at doing chemical soil tests. But we may not be identifying whatis our yield limiting factor. And yield is probably the simple one. If we're really looking at health,there are other factors. So I'm going to take you on a thought process. I want everyone to think about whathappens when you abandon a field, something that'sbeen in row crops intensively farmed. What happens the first year?And I would hazard that in most parts of the country,if it's been something that was in corn or soybeans,that the first year when we abandon it,it is covered with broad leaf weeds,things like lambsquarter, ragweed,redroot pigweed, probably some velvetleaf. The interesting thing about these weeds, somethinglike a pigweed or an amaranth can produce closeto a million seeds. And when we come into the second yearafter a field that's been let go,we actually have many orders of magnitude more seeds layingon top of the same species that were there the year before. But in the second year after being abandoned,almost none of this grows. There's a different group of species. What has happened here, is the environment in that soilhas changed. And this takes me back around to a more refined definitionof soil health. And that is, a healthy soil is providing an environmentthat the species that we're growing is best suited in. That way the species we're growing ideallyshould be biologically better adapted for the environmentthat we provided it than any of the other species. Now if we make the connection back to human health,if we're in an environment, a person, wherewe have the right nutrition, we have the right temperature,we have what we need, we would expect to be healthy. And if we come into an environmentwhere maybe it's too cold, too wet, we're not adequately fed,we would expect to get sick. I really think the analogy works very well here with soil. When we first started farming organically,here in Penn Yan, one of the big advantagesthat I found in organic farming, wasthere were markets for almost anything we wanted to grow. I had farmed conventionally for 20 years,and sad to say, quite often, my profitwas entirely in the subsidy moneythat I was getting, where I would plan a crop of cornknowing that it's not likely to be profitable. Prices were low, inputs were fairly high,but we were getting enough subsidyto make up the difference. I also knew that if my corn followed, say,clover or alfalfa or some other legume crop,that it would take less inputs to produce a good yield,and that I would almost always make more money. And this created a tension for me,because the rotation crops didn't have a good market. Once we went to organic farming, wefound that we had markets for almost anythingthat we could grow. And that made it a lot easier to create a healthy rotation,especially things-- the obvious thingswould be like northern corn rootworm, corn borer--some of our weeds became easier to handle because of the waywe rotated. Also, we could grow our nitrogen and notneed the off-farm inputs. But that wasn't really what we were thinkingwhen we made our switch, that was justsomething we discovered. When we first made the change transition to organic,it was entirely economically motivated. We weren't making a good living on our farm,at least we didn't think we were making as much as we wanted to. We had kids coming along, and we wantedto be able to send them to collegeand maintain a good standard of living. One day we saw an ad in the paper that was offering us,at that time, the astronomical price of $6 a bushelfor wheat, which was roughly double the conventional price. And I went to our local experts, and they assured methat organic farming was something that probablywas appropriate for a small backyard plot or a marketgardener. But it was totally impractical and undoable on the scalethat we were talking about it. And I guess that was all the encouragementI needed to at least try it. But we did all the calculations of how much yield we could loseand how we were going to come out of thisif the experiment failed. We definitely laid our plans for,what if we make a big mistake here?But what we also did was went to Cornell and studythe Mann Library. And when we went there, we were looking for two major things. We were looking for what machinery or other thingswe could substitute for the herbicides we'd been using,and how we were going to be able to provide somethingto substitute for the fertilizer we'd been using. And I know now that those were exactly the wrong questions. You can farm organically that way,but it's really farming conventionallywith organic inputs and to sell them is very satisfactory. It's not a successful way to farm,it doesn't produce good yields, and it certainlydoesn't produce good profits. But what I found that was unexpected,when I was doing my search in the library,was a professor he's kind of the guru of weeds in Germany. He's credited with being one of the first peopleto do experiments with herbicides. And in his writings, there was a conceptthat kind of turn my thinking upside down. I'll share a quote with everyone. What he wrote was that every crop should followits most suitable predecessor, so that the vigor of the cropalone will check the growth in weeds. Now that was a bit of a surprise to me,but it kind of made sense. Another thing that he wrote was that cultural practicesform the basis of all weed control,while the various other means shouldbe seen as auxiliary only. Now these were interesting statements,coming from the guy who was pioneering using herbicides. And they raised more questions in my mindthan they did answers. But in finding the answers, I learned some thingsthat made a lot of sense to me whenI thought about them out in the field. One is a concept back to when we talked about abandoningthe field, and you have the first year all broadleaves,or annual type weeds that make a lot of seed,and the second year, almost none of those weeds,but a different group. And if you waited a third year, wewould start going into more perennials, goldenrod,some of these abandoned cropland weeds. And then if we waited a little longer,we'd start seeing brambles and woody plants,and then the beginnings of trees,and we would have a succession of species. What Dr. [INAUDIBLE] was writing aboutwas essentially creating an environment in our fieldthat give us a natural succession thatwas providing the right environment for the cropthat we were going to grow. And the concept really made sense to mefrom a yield standpoint, too, because if the environmentin the field makes our crop be the favorite species,it would have advantages over everything else. If you go back to our analogy to human health,if we're in an environment that's not favorable to us,we get sick. Well, if the crop's in an environment that'snot favorable to it, it gets quite diseased,you start seeing insects, you definitelyare going to have more weeds because the crop's notas vigorous or as competitive. And it really does help hold with that analogy. In addition to these things there's,back to what a crop needs-- and I'mgoing to skip here to match the slide.
At Cornell University, after we'dbeen farming organically for some time andhad very good results-- and I'm fast forwarding here. We were pleasantly surprised with how quickly we learnedhow to make the system work for us. And we started with a rotation that Iwas somewhat familiar with already. And that would be a winter small grainthat was frost seeded to a legume, which,in our case, the most successful legume was medium red clover. The next spring that would be turned underto grow a crop of corn. That corn would be followed by either soybeans, or dry beans,or some other-- or spring small grain, somethingthat had a lower nitrogen requirement. And that spring small grain or soybeanswould be followed by a winter small grain, which would thenagain be underseeded to clover, and come back to corn. Now that's an oversimplified version of the rotation,because there's all kinds of branches and optionsthat we could add to that. But our search for, what do we doabout replacing the fertility-- we had to find manure. Dairy manure will not meet the needs of a heavy corn cropunless we're putting on some really high rates. And if we're having to import the manure because wehad no animals on our farm, the freightwould become pretty burdensome. So we settled on poultry manure. And we did our first couple of years just kind of by guess. And I wanted to know how much we should be using. I wanted to do some research, or see some research, thatwould tell us what is the optimum amount to use. And to do that I wrote a research proposaland submitted it to an organic funder who promptly turned itdown. They didn't like it. I had a friend at Cornell who said, can I use this?And he turned it into another organization, actuallya conventional organization. And they funded it for five timeswhat I had originally asked for. And we set up a randomized block wherewe used GPS to map out a 20 acre field. And we did a random block of many different ratesusing poultry litter. And we did use our basic rotation. So the nitrogen for the corn part of the systemwould be also supplemented by nitrogen from the legume. And we used, for our one x-ray, actually whata conventional consultant would have recommendedfor a field with that soil test. And we decided to do zero, half of that. And then we doubled it. And I think we went as high as six-- well four timesor whatever. It was a high multiple above whatwould have been used under a normal conventional system. We ran this for five years and analyzed through the rotationcycle where we got the best yield. We had used a yield monitor on a combine. But we didn't just look at yield. We also had our weed ecologist from Cornell, Chuck Mohler,would come out and analyze the weed growth. We did soil health analysis from Niel, who's our extensionspecialist-- came out and studied what impactsor differences we might have seen in the soil. We tried to look at it from a multi-disciplinary approach,everything that we could learn from this. And what we learned was quite interesting. From an NP&K standpoint, or at least for a P&K standpoint,we showed that the conventional yield responsecurves were the same as the organic ones,that when we put on poultry litter,we could find our top yield at just about the same place whereif we were using other sources of that phosphorusand potash-- which was a really important thing to learn,because it told us we could rely on someof these pieces of research that had been pretty well doneand established from the beginning. We did learn something surprising. And that was that we were almost never short of nitrogen. We though nitrogen was going to be a big challenge. But what the research we did in that field-- and then later,Cornell University did a systems trialwhere there was a conversion between a regular,on a good upstate New York soil type,from conventional farming into organic. They followed essentially what were standard practiceson a large number of successful organic farms. And that research backed up the same finding,that nitrogen was almost never a yield limiting factor. Even if we only had a poor cover crop of medium red clover,we were growing more than ample nitrogento make maximum yield in our crop. And I think that's really significant,and it should be pointing out, not just for organic farmers,but for other farmers, that wherewe're relying on imported manure for nitrogen,we are probably causing ourselves some problems. In this trial on our farm, we saw that yieldof weeds never tapped out, even at six timesthe rate where we had the top yield of corn. We were still getting an increase in the weed pressure. And the way we're measuring the weed pressurewas going out and weighing the weed biomass. And I think that was pretty significant. We've also found the time of yearwhen we put the manure on had an impact on weed pressure,where if we put the manure on an actively growing covercrop the season before, it not only was betterfor the environment, but it also give usa lot less weed pressure than the crop. And from that, I wish more farmers had paid attentionto that, because there are so many farmers who are applyingmanure hugely in excess of where they'regetting maximum benefit from it. This is based on research that is pretty well documentedand was done under the discipline of universitytrials. Klaus, can I ask you-- I need to clarify this. So you're saying that where you put the manureon at a time and a half to the acre, you maxed out your yield. But when in excess, all you did was raise more weeds?Is that basically what you were saying?That's exactly right. And I'm glad you brought that up to strengthen that point,because I really-- we were surprised. And we thought we could push the fertility and push our yields,but all we did was push the yields of the weeds. And it was not just the number of weeds that sprouted. And incidentally, these weeds were not in the manure. This manure was carefully heated to make surethat we weren't importing weeds. But it had a biological effect. It increased the germination of weed seeds in the soiland also increased their growth. The time of year makes sense, when we think about it now,where it was going onto an actively growing cover crop. Whatever it was in the manure thatwas stimulating the weeds was being taken up by the covercrop and then returned slowly the next year to the crop,where, when we put it on the spring,it was there to feed the weeds right off the bat. So I think that's a really significant finding. This might look like an odd picturethat I just brought up for a soil health discussion. But it brings a point in what we're plowing down. And I think for a lot of us, we think soil test,and we think and NP&K and trace elements. But how often do we really think about what'sin that green matter that's being returned to the soil?And I did these calculations basedon actual tests that were done on our farm. And this crop that's being plowed herewas roughly three tons of dry matter. We were turning in 240 pounds of N, 30 pounds of P205,and 120 pounds of K2O. Now that was not showing in the soil test. That was cycling through the cover crop. And I believe we are not even scratching the surfacewith cover crops, what they can do for us in termsof being a nutrient sink. And this is in the fall and through the winter, when we'vegot rain and leaching conditions,these crops are actively growing and picking up those minerals. They're adding carbon to the minerals. And what I think is underestimated, or underappreciated, is that these cover crops alsoprovide food for our microbes. You think about this three tons in the spring,there were an additional four ton the fallbefore that were turned under after a small grain crop. And I still remember the guy who was running that tractorsaying, what are we going to do this mess?We can't get rid of this cover crop. It's nothing but a problem, because we're notgoing to be able to handle it with our machinery. When spring came the ground was virtually bare. And if you look closely, you can see earthworm castingsall over the place. This stuff was earthworm pasture. And we had, even with plowing, whichI know the plow is supposed to destroy organic matterand it's supposed to destroy earthworms,but we had at least two orders of magnitudemore earthworms than I've ever seen on the farm before. And because of the amount of food we were putting down. I like to upset both conventional and organicfarmers with some of the talks I do, where I ask,how many of you think the chemicalsthat we're using are killing the earthworms?And of course, all the organic farmerssay, yeah that's what's doing it, that's what's doing it. And then I ask, well how many of youthink it's the tillage that's killing all the earthworms?Another group of farmers will be yelling,yeah it's the tillage that's killing earthworms. And I say, you're both wrong. It's starvation. Now how well are your cattle goingto grow if they lived on a diet of old dead crop residue?Now there's no protein there, there'svery little protein, there's very little energy,there isn't much in the way of minerals. How could we claim to be producing increasesin earthworm populations if we're starving them to death?This is regardless of what kind of tillage we're doing,regardless of what kind of chemicals we're doing,if we want to have a lot of life in the soil,we have to feed it. And I think that's a really important factorall the way through. I've had the picture of the plow here for another reason. The plow has been blamed for a lot of damage,and it's been responsible for a lot of damage to soil. I wish the resolution was a little better here,but you notice we're plowing quite shallow. And there's a little bit of green sticking up. When I was in high school, I had a really great teacherwho used to say he used to be botheredas we got bigger and bigger tractors. And the boys in the coffee shop loved to talk about how cleanthey were plowing and how deep they were plowingand how nice it looked when they were done. Think about where does the fence post trot off?Generally in the top four inches. Why would we want to turn all of our organic matter down10 inches deep and, what's worse even,flip it and create a layer so that it's all buried that deep?It's in a zone that's anaerobic, it'sin a zone where there's relatively little activity. It's also being placed down so farthat it's not doing us any good. When we plow it back up a year later,that would tell me that it's not gonethrough an aerobic breakdown. Much more likely, in those anaerobic conditions,we get biology that makes methane, makesCO2, makes ethylene. The products of this organic matter,if it's turned down deep, are not things that are desirable. And I really think the damage that the plow hasdone to the soil has really increased tremendouslysince we've gotten big horsepower tractorsand plows that are able to grow really deep. If you go down to Lancaster and seewhere the Amish are plowing, I didn'tsee very many furrows there that were more than fouror five inches deep. And the organic material is kind of mixed into that zonewhen they turn, and that's the way everybody did it for years. But in recent years I see a progression,and I'd like to call this the coffee shop progression, whereeverybody is showing off how much black smoke they can blow,and how deep they can plow, and how cleanly they can flip it. And then the next thing, you see the plow parked and they'reusing a chisel plow because their yields went downor because their soil has been damaged. And I think it's because we're making very poor use. First of all, we're not putting enough organic matter down. We're not using cover crops on anywhere near enough farms. But even when we do, we're putting theminto the soil in a way that they're notgiving us a lot of benefit. That's my little soapbox. Klaus, can I ask a couple-- I had a couple questionscome in here. They were wondering about-- you know,you're talking about that nutrient content. When is that going to come availableas far as the crop growth of say, your fallout with cornor the proceeding, or the next?That's a really good question. The rule of thumb with the nitrogen is that half of it'llcome available during the crop year. But that's only part of the answer. Of course, that'd be 120 pounds of N. But there's also the nitrogen the root nodules leftin the ground, and there's the nitrogen from the fall before. And Cornell has done some really interesting studieson our farm, studying nitrogen fixation. And we're finding legumes are like people. They're basically lazy and only work as hard as they have to. So in these systems where there's a lot of nitrogen,the legumes really are fixing less,and we're actually recycling some of the same Nover and over. And that's been done by tagging with a nitrogen isotopeand actually following it through the cycle. But what we're finding is that, upto the level where we got optimum yield,we seem to be in good shape. And the bigger problem is, if we can'ttime the mineralization of that nitrogen correctly--it's a little bit like the cavalry came thereafter the Indians got done-- if the nitrogen becomes availablelate, the crop needs it upfront. And then the nitrogen is made availableafter the crop needed it, all it'sgoing to do is make weeds grow. So that is one of the reasons that organic farmers relyon tillage more, is because, whether we realize it or not,is timing the mineralization of that organic material. I don't know if I answered that question completely. No, I think that's good. And I had another question. Do you think you would achieve these kind of nutrient cyclingbenefits if you would just not plowthat under-- let that come across or rolledit, or something like that, just knocked it down?The question is, could we do this without plowing?Yes, we definitely could get the nutrient balance. But I'm not sure-- depending on whereyou are in the country-- like in the north,it's quite cool in the spring-- it would come slower. So while we would have the same amount of nitrogen,there are some environments where leaving it on topwould make it mineralize more slowlyand come at a later point than where we really wanted it. And I think that's why, especiallyin the northern areas, no till quite oftenis accompanied by some extra nitrogen. But it's a, it depends answer. Actually all of this nitrogen would cycle,it just may not cycle exactly when we want it to. And that's a place where maybe weneed to be looking at the species. The nitrogen in clover is tied upwith a fair amount of carbon. We did some experiments where we used Austrian winterpeas, which had a huge amount of nitrogen. And I know the Rodale Institute has done some research wherethey used hairy vetch and rolled it. And they found that, by delaying the corn planting datesslightly and then rolling these legumes thatbreak down a little faster, they wereable to time the mineralization with the needs of the cropand have no yield drop. So again, this is a really important question,because it has to do with not just quantity but alsothe timing of when it comes available. Any other questions in this area?Well no, I think you kind of summarized those good. But the key is timing, I think is what I'm hearing from you. Yes. And that kind of makes sense, Simon,when we learn to use the sidedress nitrogen. The reason we're sidedressing is that we'retiming its application with the needs of the crop,and we're also trying to avoid losses. We're trying to avoid having leaching or tie-upsthat we sometimes get on cool ground, which protects waterquality but protects our wallets, too,so that we're not buying extra justfor what's going to be lost. One more quick question, and I'll let you continue. How long-- you talked about this successional moving from where you were to where you are now,and then you jumped into this manure thing. How long do you think it took you before you started to reap some of the benefits of this increased soil health?The nutrient cycling is basically what you've been talking about. Yeah, this is a really good question. It depended on crop order we used. We found that if we were trying to move into corn,we lost money for-- it took about five or six years before things worked if we started with corn as our first crop, after getting off the synthetic fertilizers. When our first crop of soybeans--we would actually have a full crop the first year with soybeans. They're very efficient feeders. Then we would have a yield depression in the second year when we followed them with a grain. And then after we had the clover plowed down,we would be-- the system wouldn't be up to speed,but it was up to speed enough to growa crop of a heavy nitrogen-using crop with no yield depression. So in that system it took us about three years. But if we started with the wrong cropit could take five or six years and there would be a lot of red ink between when you startedand when you finally got it running. So again, this has to do with order of plants order of crops. And it has to do with using our headsand using the information that's available to us. And a lot of farmers, especially when we first started,lost a lot of money trying to growa heavy nitrogen-using crop like corn before their land wasready for it. And that creates an environment that's really notgood for corn, and it makes for some pretty sick corn. So this picture probably looks familiar to a lot of people. If we could pan over to the left,there would be a whole row of silos. This was the field that always got the manure. It was our neighbor's field. He keeps telling me, I wish you'd quit using that pictureand use one of your own fields. But what's growing in this field is lambsquarter, pigweed,and velvetleaf. And in this particular case, they were about six feet tall. The corn and soybeans were four feet tall. And this was a case of making an environment wherethese weeds were better adapted. Even though the soybeans were doing great,the weeds were doing better. And the reason I mention the silos is there'ssomething about these weeds that kind of gives ussome hints as to what's happening underground. These are non mycorrhizal weeds. And we're tying back to the soil test work. We saw an increase in weeds when weused more manure than where our optimum yields cameon the crop. We're way past that point in this field. And incidentally, this field had been cultivated fairly well,too. These are just the weeds that were in the row. What's interesting about these weedsis that non mycorrhizal plants reallythrive where phosphorus levels are high. In fact, very high phosphorus inhibits mycorrhizae. Most of our crops have mycorrhizal root systems. And what mycorrhizae are, is a fungusthat's in the soil that actually helps the plant excess water,but more importantly, phosphorus. It becomes, in effect, extension of the plant root system. And it goes out and explores a lot more of the soilthan the crop root itself would. And, in the process, feeds the crop,these minerals that are hard to find. Now the crop, on the other hand, is producing a lot more energythan what we see, what we harvest. And some studies-- I've seen up to 50% of some plants' energyproduction from photosynthesis is given offin the form of root exudates, which are very high sugar, highin minerals, high in protein-- very high quality foodthat the plants are giving off, and feeding thingslike the mycorrhizae and probably millionsof other species that grow around the plants' roots. If we look at what's going on here,the crop is actually farming microbes around its roots. There's a symbiosis going on here. While it's below ground, then we don't see it. We see the effects of it above ground. And this is one of the drivers of soil health,is what kind of an ecosystem do we have underground?So back to this picture-- the cropis not getting its normal advantage here. In fact, I've seen some research thathinted that these mycorrhizal fungi, in returnfor the sugars they get from the plants,not only help the plant get phosphorus,but they also inhibit the growth of other plantsthat are non mycorrhizal ones, like the lambsquarterand the pigweed. But when we've applied so much manure and over fertilizedto the point where the soil is hostile to the mycorrhizae,it gives these non mycorrhizal plantsa large biological advantage over our crop. And at that point, we can hide thatby using an herbicide to kill the plants that are betteradapted and allow our crop to survive. Or, in the case of an organic farmer like I was,stand there and wonder, how are we going to survive this,and how are we going to control these plants?I don't know about the rest of you,I'm sure we've all seen Palmer amaranth that kind of tall. Velvetleaf used to be the bane of my farm. When we converted organic at first,velvetleaf, by midsummer, would be so bigthat you could hardly pull out of the ground. In fact, you had to be pretty ruggedand the ground had to be a little dampto pull out a velvetleaf by the roots,and they were commonly 12 feet tall. I noticed something after we change our farming system. We started cover cropping every chancewe had as part of our organic system. We added more diversity. We were growing small grains and notselling it, not removing the strawbut leaving it out there as a soil amendment. After about five years of this, the velvetleafstarted showing some yellow. And I think-- the picture on the left,you can see on the foreground that velvetleaf,those leaves aren't-- while the plant's doing fine--those leaves aren't quite 100%. The picture on the right was takenin a field that had been where the old barnyard was. And the first two years I farmed it organicallywithout herbicides, I just mowed it down. The velvetleaf had taken over. But over time-- and this is using the cover cropsand using a more diverse rotation--the velvetleaf didn't get as tall anymore. And then we started noticing midsummerthe leaves turned yellow, like the oneson the left but more profound. And then after a while they would turn blackand they'd fall off. In the picture on the right, that velvetleafis just a hair over four feet tall. And it died before the summer was over. It made no viable seeds. All the leaves came off. And we found-- we actually asked one of our friendsat Cornell to tell us what was going on. And he found velvetleaf and thracnosewas the actual cause of death. It's very closely related tomato and thracnose. This particular race has no effect on tomatoes,but it will kill velvetleaf, Hollihocks, and mallows,I guess none of which I feel a whole lot of sympathy for. So I thought this was great. This ought to be the answer to our organic--we can grind this stuff up and spray the spores on the field. And in my research, I found that there had been at least oneor two attempts at producing a spray made of this. The problem is, if you put it on a place,you wouldn't have repeat sales, because if the disease tookhold the next year, it would still be thereand it would still kill the crop.
The bigger problem was-- and thiswas what was pointed out by our friendfrom Cornell who identified the disease-- was that he wantedto know why it was killing our velvetleaf. And on other farms where the velvetleaf seemedto be doing better, the velvetleafwould show signs of the disease and grow out of it,kind of like in the picture on the left,where yeah, it's got some sick leaves,but plant overall is still doing fine. And I think he was asking the right questions. He said, why does your velvetleaf die from it?This goes back to the idea of the environment. The environment in the field, when we first converted,made velvetleaf the best adapted species, or at least oneof the best adapted species. As the soil changed, the rotation was different,the inputs were different. The environment in that soil was changing in some profound ways. We couldn't always see it, but we could see the effect. There wasn't just one disease in this velvetleaf. What we found out later was that the early yellowing was causedby a virus called Abutilon yellows,which was vectored by whiteflies. We had an interesting field day on our farmabout 15 years ago, where the purpose was to show peoplecultivation equipment and how to use it. But everybody was clustered around these velvetleaf plants. This was in a severe drought, it was about 100 degrees outside. And they were covered with whiteflies,and yet the crop didn't have a bug on them. And I think this showed us that, because the plant wasunhealthy, the insects were moving in and attackingthe unhealthy plant. And in the process of sucking juice out of those plants,they were vectoring in the virus, the Abutilon yellows. And all those factors together left that plant so compromisedthat when the thracnose came, it killed it. You could bend over and pull these four foot velvetleafplants out of the ground. They didn't really have that big of roots. And the plant in the foreground is a lambsquarter. That's another none mycorrhizal plant. And it, too, in that environment,wasn't doing so well. Somehow over several years, the environment in that soilchanged back to favoring mycorrhizal plantsover the non mycorrhizal plants. And I think that carries an important lesson for us,that every plant that grows in the soil changes that soil. And those changes make the soil the best environmentfor something else, back to our succession of species. Every plant seems to have niches that it wants to fill. I'd be really curious to understandthe biological triggers that make the plant know. Why don't spring plants sprout in the fall?Why don't fall biennials sprout in the spring?At least, most of them don't. There seem to be biological cues in these plantsthat either tell them to sprout now, conditions are rightand you can grow, or maybe you better wait for a better chanceto grow coming down the road. If we could understand those signalsit would make farming a lot easier for us. The reason I use this picture is the field on the leftwas just drilled organic soybeans. They were double cropped, but there was virtually no weedsthere. And we had a couple of years when it got really late--and your heaviest weed pressure tends to be the end of May. Generally by early June you have a little less emergence. When you get to late June, you reallyhave greatly reduced emergence of those early spring weeds. And a crop like soybeans actuallygets a competitive advantage then, just by the time of year. I learned something really interesting by growingthese soybeans. When you plant them late like that,it's too late to be coming back in and planting a wintergrain on time. While the soybeans are still ripe, relatively early, rightaccording to what their group is,you lose just enough time in these northern climatesthat it's really too late to be planning wheat. And we did an experiment there. We threw on no till spelt, wheat triticale,drove through the field-- one time I hired an airplane. And we found there's a window-- I call it yellowleaf. About the time you see the first yellowleaf, you can do it. When we tried doing it earlier thanthat, it actually was killed, it was smothered. I think there was too much shade, too much competition. But what I saw happening was that if we hit that window justright, the winter grain would take off and geta really good start. If I waited too long after that, yeah the winter grainwould start, but it just didn't seemto get the same kind of a take off. My guess of what's happening is that we'vehad a succession there where there was a living rootsystem from the soybeans. Again, take this as a guess, but I think it's pretty educatedguess. And then when we no tilled by broadcasting the wintergrain into this system, where there was a living rhizosphere,and all these functions were actively going out in the soil,they were providing the services to the plant roots of the graincrop that tillage would have providedif we had waited longer. The good news is, by the time we combined those soybeans,we already had a four inch tall well established crop of grainin them. And it's also a whole lot cheaperto just throw that seed on top of the groundthan to work the ground up and use conventional tillageto establish a grain crop in the fall. And I'm going to digress here a little bit. Two more thoughts on tillage. I think the reason-- farmers aren't stupid. The reason the plow has so much widespread use,especially before they built the plows bigger and deeperand started doing the wrong thing with them,was that it worked, that it did result in higher yields. And I think it was the timing of the nitrogen,but also it helped destroy organic matter. Now when you burn organic matter,you're making fertility available to the next crop. And farmers observed that when you do this,it cycled the nutrients faster and your next crop grew better. The problem came when they did it too muchand they were extracting more every yearthan they were putting back. Remember, a lot of these systems didn'thave cover crops in them, and a lot of themdidn't have a lot of animals. So this continual plowing was like constantly drawing moneyout of the bank without putting as much as the interestback in, and you ended up depleting the organic matter. I think we could go the opposite extreme,and I've seen that in New York. I've been asked to consultant on some fields thathave been in hay for 50 years. They'd just been hayed, nobody had put any fertilizer on them,they just got mowed. And year after year, these fields got weaker. Some of the organic matters in those fields were 5% to 8%. And farmers were asking, well I'vegot so much organic matter, how comenothing wants to grow here?Well it's because we had pulled our phosphorus and potassiumand our nitrogen down so far that the microbes were evenstarving to the death in this ground. We had robbed it. That organic matter was very much like if youhad a millionaire starving to death because he wouldn'ttake any money out of the bank and use it. I think when we're-- we need to talk about managing organicmatter. I think a good goal is to always puta little more back than what we burn up,or a little more back than what we're using. But there is nothing wrong with using organic matter. We want to have a healthy, active soil life. And if we're going to have soil life, it has to be fed,it has to eat something. And that something is organic material. The problem comes is when we're consuming more than whatwe're using. I also think there's quite a lot of researchavailable, especially older research, that indicatesusing synthetic nitrogen can create a very similar situationto what overusing tillage can cause,that it results in a continuing decline in organic matter. And I remember talking with Dr. Rakowski about someof the long term no till trials. And these were trials, I'm pretty sure,without cover crops, where they were disappointednot to see organic matter go up. Actually, it went down. It went down slower than where tillage was used,but it still went down. And I remember him mentioning that hewas going back to the data from the moral plots, whichhad, early on, indicated that the use of synthetic nitrogenwithout enough organic material to feedthat microbial bloom that comes when you put onwas depleting organic matter. So it's just some observations that I'vegot, some speculation. But I really like these-- sorry. Well no, I was going to ask a couple questionswhen you were done there. And I know you got some other things. Real quick-- related to that, do youthink the timing-- you know, because wedid go from plowing in the spring to plowing in the fall. And as far as nutrient cycling and all that-- comment on that. Oh, that's important, yes. Thank you for bringing that up. Well fall plowing, talk about drawing--you know, whenever we do tillage,it's like drawing money out of the bank. But if we're doing it in the falland the crop won't be planted till next spring,we've had time for that nitrogen to lay there, mineralize,and be leached away, where it doesn't do us any good at all,it's just damaging the water. So when the plow is used at the wrong time of year--and I understand some soils are high in clayand they need to be fall plowed, quote unquote,because of the structure, the physical nature of them,we're getting a big loss in organic matterwith no offsetting benefit. And I think that's a major expense. I think we need to look at any kind of tillage as an expense. It's an expense in terms of the fuel that we're using,but it's an expense, and if it's a withdrawalfrom the organic matter bank account that'sin our soil-- which, it's OK to make a withdrawal if you'reinvesting it in something that gives you more back--but if we're just withdrawing it and not gettinga return from it, it's destroying our capital. I don't know if I digressed too far there. No, no, it's good. OK I'm going to talk about one other experiencewe had regarding soil health. This was one where soil health testing paid offfor us in a big way. It more than doubled our yields. We were growing edible dry beans. When we first converted to organic,it was almost like printing your own money. We had better yields than the conventional farmersand we were getting a sky high price for them. This was before the Chinese were dumping theirs on the market. And they grew great. The second time we've grown-- and all the old farmers said,you need to grow them about once every seven years or five yearsat the soonest. So we waited our minimum amount of timeand go back and plant them again. The next time they didn't grow quite as good. Figured, well maybe we did something wrong this year,or maybe it was the weather. By the third time around some of these fields,we had heavy root rot, we had very poor production,we had no resilience when the weather turned bad. They just fell apart when we had too much rain. And we just didn't know what was going on. Professor George Abawi at Cornellwas studying this problem. And these roots were just covered with nematodes. A lot of damage, lot of abrasion,and then Pythium, Rhizoctonia, Fusarium would move inand literally would destroy the root systems. George did what I consider really brilliant researchin the greenhouse. He would take a variety of phaseolus vulgaris, dry beans,that was known to be very susceptible. And he would take a sample from dozens and dozens of fieldsand plant those samples out in the greenhouse, wherehe controlled the conditions, and put these susceptiblebeans in them and grow them out. And he would grow them to a pointwhere-- I don't know how many leaves they had,but it was relatively early. And he would wash the soil off and do a root reading. And he could predict-- the first thinghe used this for, he could predictvery accurately whether it was a good bet to plant phaseoluswhich, at that time, edible dry beans were a big crop in NewYork, and so were snap beans. They're both the same species. And he had a very good handle on whether your field waslikely to be profitable, if that's what you grew,and whether you're going to have root rot, and how much. And he scored it on one to five. But then he did something that I consider a stroke of genius. He started asking, what would happenif we had a different crop preceding the bean crop?What effect would that have on our disease level in the soil?And he tried all kinds of different crops. I saw the research once. He must have tested 50 or 60 different crops. And what you would do is get a root rot reading,and then-- plant the crop on the soiland then get a root rot reading. And he found some species that you planted in between,even though it wasn't the beans, made the root rotreading worse. Some species were neutral, some give you a small improvement,and some gave a huge improvement. There were two species in there in particularthat gave huge improvements in root rot scores. They actually, in what we know now,they were destroying the nematodesand the root rots both. Yellow mustard was one-- I know Michigan State's donea lot of work on yellow mustard--where just a 60 day crop, or 45-- dependingon the time of year, 45 to 60 days. Short term cover crop of yellow mustard--when that was turned into the soil it would-- there'san enzyme in yellow mustard, there's a compound in itcalled glucosinolate, which is, when you put mustardon your hot dog, that's what makes it sharp. But there's an enzyme in this same leaf,and this is the story that Dr. Honeycutt talked aboutat the Soil Renaissance press conference. That enzyme makes the glucosinolate turninto isothiocyanate, which is a gas. By turning in a crop of yellow mustard,we were fumigating our fields. It's actually a biofumigation. Another crop you can do that with is sorghum. And a lot of farmers who are onion farmersand were really suffering from nematode problems near us thatwere on muck learned that they could actuallyafford to give up one year of cropping,plant a crop of sorghum and turn it in just for that fumigationeffect, because of how it would clean up the nematode problemand the onions would grow so much better afterward. But in our case, yellow mustard was indicated. There was one other cover crop that really improvedroot health ratings, and that was buckwheat. But in our case, George recommendedwe try to find a way to grow yellow mustard before plantingdry beans. And the window that we tried was after a crop of field corn. Now in our area, we have to use every bit of seasonwe have to get the corn right. And if we have good corn, it's really hardto get anything to grow in it that amounts to anything,because it's so competitive. But there's a period when we're not using the land very well,and that's from about early Marchuntil we plant the dry beans, whichcan be as much as three months. And yellow mustard is very frost tolerant,and there are varieties that are-- the culinary varietiesthat have no hard seed. That means they don't lay there and become weeds in the sensethat most weeds have some seeds that come right away,and some that lay there until the conditions are right,and some of those are called hard seed. Well yellow mustard has been bredto not have the hard seeds. And we started broadcasting about eight poundsper acre of yellow mustard seed in March into our corn stocks. And the first thing we found was that the yellow mustard reallylikes a little more nitrogen. That is one place where it would payto put on some chicken manure or some dairy manure,because the brassicas are heavy feeders. And that time of year, when it's cool,there's not a lot of fertility. So that's a point aside. But George also said, when you're spreading this,now, leave some strips in fields or leave half a field,because I want to see what effect you're having. So we started growing these yellow mustard cover crops,which incidentally now, we try to cover every field of cornwith yellow mustard before the next crop. And he found that if you had a root rot, whatever the root rotrating was, it improved by one. So on a scale of one to five, where five is all deadand one is zero disease, if you read two and grewa crop of yellow mustard, it would move you to one,or if you were at four, it would move you to a three. Now that's a substantial improvement in root health,just for growing a crop that we've no tilled in. And I love cross-seeding or spinning crops on. It's cheapest form of no till thereis, because you don't have to buy expensive equipment. But that was a major change for us. We started seeing our root health improve. Then we decided to try to add buckwheat, whichhad a completely different mode of action. You know, the yellow mustard we understand,and so sorghum would be the same way. But these are crops that produce the glucosinolateand turns into isothiocyanate and it fumigates the soilwhich, incidentally, when Michigan State studied it--while it's a fumigant, it's seemed to be selective. It seemed to do a lot more damage to the pathogensthan it did to the beneficials, which is-- we don't know why,but it's a lot better job of selectingto kill what you don't want and not kill everything. But the buckwheat, we found, has an organismthat grows around its root system that produces cutinase. Cutinase is an enzyme that breaks downthe cell wall of fungi. And buckwheat was equally devastating to the root rotorganisms that were in the soil. So we brought buckwheat in after a winter grain harvest. So for instance, after malting barley,if we had season enough, we'd grow dry beans. Malting barley also improved-- or barley, as a crop,as long as it wasn't underseeded to the legume,would improve the root rot ratings. But if it was too dry to grow dry beans,we would plant buckwheat. So our farm, then, we had in a typical rotation cycle,we have a couple of mustard and a crop of buckwheatbefore we came back to dry beans. And we not only brought our yields of dry beansback up to what they had been before we startedhaving the root rot problems, we actually went beyond there. That's one of those years you brag about for probablyhalf your life before you have another one like. In 2008 we had some dry beans that yielded wellabove 4,000 pounds per acre. But we've never had anywhere near the root rotissues or the disease problem since we changed our rotationto manage that disease. And it just shows us how having more biodiversity on a farmcan make quite a difference. Before I go on to this next piece,were there any questions on this?Well yeah, Karl just got a few more here,and then we'll kind have to wrap this up in a few minutes. There's a question related to-- coming backto the clovers that came in, did younotice a difference between varietieswithin the red clover, as far as-- Imean, 240 pounds of nitrogen is an awful lot of nitrogen as onebeing a more of a [INAUDIBLE] producer than others?We found that any clover that was-- like our medium reds,they'll make two or three cuttings. They all seem to be pretty equal. I think it's more important to have medium red clover,or to have a clover that's well adapted to where you arethan to worry about one variety or another. I really think we've badly underestimated the nitrogenfixation ability of our legumes. I know I had the old textbook thatsaid red clover could make up to 50 pounds of N thatcould be credited to the crop. And I kind of believed that for a while,and then I started doing my homework. If I grow clover, hey, even if it's not a great yield,I'm taking-- six pounds of proteincontains one pound of N. And I've seldomseen clover that didn't make more like 300 or 400 poundsthat we could remove in the hay. And I've seen alfalfa produce 500 or 600 pounds of Njust in the form of what's being removed in the hay. I think some of these textbooks were written by people--that these things get repeated over and over in,the way I put once, until some idiot puts itin a textbook without checking. And then it becomes fact. Sometimes you need to ask questionsabout some of the things that get repeated. Yeah. And you mentioned a couple times this soil health testing. What is it you're doing?OK, this soil health testing is an evolving process. And right now any test which NRCS is running--and that's more of a way to imitate what a root would findin a way that more direct our synthetic fertilizeramendments. But the Cornell soil health testsare looking for other yield limiting factors. And quite often, we've done are such a great jobwith fertilizer and chemical soil testing,that that's seldom the yield limiting factor anymore. So one of the soil health tests that wehave had good results with is one I just described. They call it the disease suppressiveness test,which is done in a lab just by George Abawi. Another one is the water holding capacity test. There is another test that is done,and this is all part of this kind of a battery of tests,just like you test for NP&K, boron, sulfurs, ink, you testfor all these different factors. Aggregate stability-- this is a testwhere you take a chunk of soil and you just wash it,and you're measuring how much of the soil will break upand how much will stay in stable aggregates. This is a really good indicator for soil structure. It's a good indicator for water holding capacity,even though we're measuring it directly. And then there are tests that measure the resistance, howhard the soil is, the resistance of roots. Now, the penetrometer out in the field is OK,but it has a major weakness, because thatchanges with moisture. So in a lab, they're taking this soiland bringing it to a known level of hydrationand then doing penetrometer readings, both for the surfaceand in the deeper layers. These are all measures of soil healththat directly tie back to your productivity. And they are ways of identifying what is your limiting factor,not just for yield, but also for plant health. And once you've identified what those limiting factorsare and measured it, then you canstart working on improving it. Interesting thing is, almost every soil health measureis improved by using cover crops,but some cover crops are better than others,just like I described in the disease suppressance. OK Karl, we're going to have to about wrap this up. I got two more questions. And those folks are in the Cornell test,if you just Google Cornell soil health test,they've got an excellent manual online. You can download and you can read justexactly what Klaus was talking about,and it does a good job of explaining what they areand what to look for. And you can also-- it has instructionsif you want to try and get some of your samples tested. And you had mentioned earlier, your quote,I think that's the thing that's-- [INAUDIBLE] preparewith this has stuck with me, is every crop should follow itsmost suitable predecessor. Who was that made that quote?Because I got people here wanting to Google this guyand find that out. Well his name was Bernard Rademacher,R-A-D-E-M-A-C-H-E-R. And probably his best paper wastranslated into English-- this was written in German,but it was translated into English in a journal calledHerbage, H-E-R-B-A-G-E. And I think it might have been 1940or '41, the paper itself was written '39. And I remember for years, the old Kraft and Rainer agronomybook, which shows how old am. But it had all these charts that had German varieties on them. They had been lifted from Rademacher's paperin the weed section, in the American agronomybook that was used in the '50s and '60s. And I finally found the original sourceby looking through the bibliography. But eOrganic has this paper translatedinto English mounted on it. The only problem I've had with eOrganicis it's not a very user friendly site,but you should be able to get the entire paper at eOrganic. OK. Well with that, Karl, I'm going to have to cut you off,because we've run a little bit past time. And again, I appreciate your wealthof knowledge and your energy. I don't know if you've got any closing comments. I might let you go. I know you were going to make a couple comments thereabout the ragweeds and the chickory,but-- go ahead, do that, then we'll have to sign off. Each one of these plants is a specialist. Every plant that grows in the soilfits a certain environment. And it can actually-- along with the soil health tests--understanding which conditions these weeds are favored byis a soil test itself and can be usedby a manager who's really sharp. This is the idea of seeing what you're looking at. When you look at these weeds, maybe weshould see something telling us that I'm herebecause the soil is such and such. It's kind of a parting thought, that maybe wecould be learning an awful lot from nature, justfrom that concept. Incidentally, this is a picture of a field of buckwheat. It's kind of pretty but it's smells like a cat boxwhen they're blooming. Well it sounds like we need to have you back, sir,for another hour discussion on that topic, Klaus. And with that, I'm going to have to cut it got it off. And again, I appreciate your input and your willingnessto participate and encourage everybodyto continue listening. We do have another organic and soil health webinar in October. I don't know exactly the date. That would be you folks out there on our mailing list,make sure you watch that, or listen and look for that. I believe it's going to be Dr. Kristine Nichols, who has juststarted at the Rodale Institute. We'll be talking a little more about the connectionbetween organic farming practicesand improving soil health at that time. And with that, I'm going to say thank you for participating,and look forward to visiting with you in the future. Thanks for having me. Incidentally, that corn in the background is.
Thank you for visit my webside see you later.
0 Komentar untuk "Managing for Soil Health on an Organic Farm - A Farmer's Perspective"