 Everybody, to the much addition of our NDSU Extension high tunnel webinar series, now this is one of those talks that everybody has been asking for, identifying and managing high soil salts in high tunnels. So we had sent out a survey to our stakeholders and overwhelmingly this was one of those issues that everybody seems to face. Now I'm very privileged to introduce Terence Nenek. Now he is a retired extension professor from the University of Minnesota and he's credited with pioneering the use of high tunnels in our region and he literally wrote the book on it. He authored the Minnesota high tunnel production manual for commercial growers and he has just been a general friend to the industry so we appreciate interacting with Terry and learning from him. I did ask him earlier this week whether he was more, whether he was busier than ever in retirement and he did say yes. He in fact is the president of the Minnesota fruit and vegetable growers association so he was responsible for helping organize that fantastic conference they put on every year and he certainly, he certainly lectures all around the country. So we're very appreciative of your time and thank you very much Terry. Thank you very much Esther. I hope everybody can hear me here. We have people on from long distances. Before I get started here I just want to credit my colleague Carl Rosen. Carl and I have worked together for many, many, many years on high tunnels and fertilization and high tunnel salts and we've all seen a lot and it's you know when we first started in the high tunnels we figured well you know we were coming up with a system that was pretty well foolproof. We didn't really have any problems. We were never going to have any problems but since we really got going in the early 90s, mid 90s strong we found out that that basically isn't the, isn't the case here. So I just want to talk a little bit about what I am going to talk about today what we're going to look at here. We're going to start out with what are salts and then we'll take another look at why salts accumulate in high tunnels. Why do they do that and maybe not so much in some of our fields and I know we have people on from all over the Midwest and there's some areas that have a lot more serious problem especially with outside production than we do right where I'm at but a lot of the growers I work with do have problems with salts in high tunnels. So what effects of salts on plant growth? What do salts look like? A lot of different symptoms out there. So how do we actually measure these problems? We want to look at plant tolerance to salts which ones can tolerate it a little bit better here and then we're going to spend quite a bit of time on managing high tunnels for high salts in high tunnels. So that's kind of what I really want to cover today here in the next hour or so. So here's a picture of some salts. I don't think we any of us have a case that bad under right there but you know it doesn't take a case that bad to cause a lot a lot of problems. So let's look at some soluble ions in solution. That's what they basically are. We have cat ions maybe those of you remember chemistry a little bit remember that they're positively charged and ions are negatively charged and it doesn't make a lot of difference as far as salts in the name of the game here they're they're both salts and both can negatively affect growth in excess amounts. Now salts actually occur all around us of course life can't really exist without salts but just to give you an idea here it occurs in all natural water even rainfall. We look at salt water and it will vary quite a bit in salt water from from one geographical area to another round the world but on an average is 4.7 ounce per gallon of salt in salt water. Now that's a lot of salt but if you look at fresh salt water or I'm sorry if you look at fresh water we're only looking at about two hundreds of an ounce per gallon of salt. So there's very very little in fresh water now that will vary around the country. So I highly suggest that you know some of you may be looking at FISMA and some of these other federal programs but that's Farm Safety Modernization Act but the truth is you know it doesn't hurt to test your water just to make sure that you're not in a freaky situation especially for pulling off surface water. Now what are some of the common salts that we have? Calcium CO2 pardon me CA calcium magnesium potassium. Potassium is our nightmare in high tunnel production I'm going to talk quite a bit about that. Sodium sulfate chloride bicarbonate carbonate and nitrate and some are you know more serious than others because of our use and maybe just basically how they flow or they infiltrate up in the soil so that's kind of what we're looking at today as far as you know what are the salts. Now you know we have what we call natural salt accumulation and basically we're looking at desert climates and there's a lot of people who wonder you know what do we mean by a desert climate. Well in agriculture we kind of look at less than 20 inches of rainfall per year which means that a lot of North Dakota and Western states are basically a desert climate from a legal definition but not as we look at you know deserts as we think about vacationing in the desert or something like that. So if soils that have limited drainage or leaching there's a lot of different reasons why they may have a limited drainage but whatever it is we got to look at is the rainfall or added water in many cases that actually leaps the salts out of there. Now when water evaporates we have an upward salt movement and you know we can always talk about poor quality irrigation water and if you are irrigating I mean you do have this problem especially in eastern Minnesota you may want to really look if have a test on irrigation water. So most soils and waters in Minnesota have very very low salt and I say most but we do have some problems in western Minnesota in localized areas but as a rule in our agriculture fields we really don't but as you move west a little bit and the rainfall goes down pH could go up and we can have some problems so again you know testing is kind of the way. So let's look at why salts actually accumulate in in high tunnels. Well think about it here high tunnels are similar to a desert climate they may or may not get 20 ounces of water a year or 20 inches of water a year but in reality they are shed it from rainfall and they are covered so no rainfall or snow. The only water input is usually through irrigation so we have to you know really think about how much we irrigate it and we can flood a lot of our salts out of there. Now and so we have to manage to provide enough water for crop growth but the you know we look at evaporation and transportation equals you know water input. So basically we're supplying this through irrigation now a lot of people they really technically run their irrigation very very close we use different tensiometers whether they're electronic or some of the old-fashioned type and don't really apply any extra water. Well that water is put on some of the salts may be definitely absorbed by the plan for plant growth but we don't have any infiltration of water taking this out and I agree it's a it's a tough call sometimes because we don't want to evaporate or move all the salts down in the soil because a lot of them are very you know important for plant growth but salts accumulate due to carry over a fertilizer different soil amendments a mineralization of organic products and we we know um those of us that have studied soils quite a bit know that the plants will not utilize a hundred percent of what you put on in one year so we are getting a little bit of carry over every year from plants not utilizing it either through just basically being tied up into soil or often maybe over fertilization on one comment I hear a lot from growers is these high tunnels are very very profitable especially maybe tomatoes and some of these other crops and I'm going to over fertilize because it's cheap to put on an extra 20 or 30 dollars or whatever of fertilizer you know in these high tunnels of course depending on the size of your high tunnel but the truth is it can be detrimental because the plants are going to use it and somehow it's just going to accumulate um evaporation wick salts upward we usually don't have that much in trouble in high tunnels most growers are using some type of a plastic so that you know helps there and um in natural systems rainfall will lead to salts to lower depths so what we're really saying here is rainfall or some type of irrigation whether it's drip or going in there and flooding really helps now we're going to see in a couple other slides here that that's not the holy solution that there is but let's take a look at effects of salt on plant growth um what does it do while salts or salinity reduces water uptake we can see a good example here of the top plants i think they're peppers on the right where they actually look like they're suffering from drought and um actually they're not if you can look really close next to the plant you can see that the drip tape was working but the salts basically stopped the um water uptake at least as much as they knew they need so on salt lowers the um soil water potential that plants can can take up or that they have and so basically it's harder for roots to take up water so now these ions or salts as we call them can accumulate to toxic levels and pretty serious on that we'll take another look at that here shortly here but what are some of the things that um we we do i'm stunning leaf burn wilting curling and this picture on the bottom here of tomatoes is one i see over and over and over again in high tunnels people will call up and say jeez the edges of my plant are are burning or or something of that nature and you can see the browning again you know on the outside now what i see what really happens is people will go in there and fertilize extremely heavy and trying to get gross they'll mix the they'll mix it into the top three to five inches and they're actually causing a temporary if i could use that word high salts in some of their soils in the tunnels so you know you basically want to make sure that fertilizer is mixed right and a lot of people are are moving to fertilization we'll talk about that here in a minute here but you know that that's the thing that we have to do think about is prorating our our fertilization throughout the season sometimes in high tunnels and you know it varies with species cultivar and grow stage germinating seeds they're the most acceptable a lot of use are probably in the agronomic business or outside gardening and all the literature will tell you keep the fertilizer especially potash and nitrogen at least two inches away from the seed well there's reasons for that there's reasons why companies john deere and in case i h have built machines that in their planting system with their discs and everything else that basically keep all that fertilizer you know away from the seed and it doesn't take a lot of fertilizer especially nitrogen and potash to definitely inhibit or destroy germinating seeds okay so what are we looking at here again as we look at the plants here especially on the upper two again we can kind of see the damage moving on to the outside of the plants you know and we basically mentioned earlier that water uptake is often restricted and of course the outside of the leaves here are basically the ones that are going to get the water the last so they're going to basically start burning also another factor is the cells that are being formed here to increase the growth of the leaves or the plants you know are basically probably the easiest way to plant it are extremely tender in the high salts just like seed it can um it can burn them and destroy them now here we're moving on to um the other type of plants here um cucumbers and peppers you can just kind of see how cucumbers are extremely you know we'll look at this here shortly here what plants you know but i guess the take home message here is when you see outside damage um you can be pretty sure that um you've either got cells now some people fully your feed then we're going to talk a little bit about fully your feeding but we usually don't get too much damage from fully your feeding unless you just really really excess it because of the nutrient mixture in most not all but most fully your feed them compounds so how are we going to measure these soluble salts you looked and you seen some damage or maybe you know you you know are just basically concerned do i have any well but you can usually test them through a regular soil test if you ask i see some of the companies like agbis and um in dairyland and them basically will automatically include that in a lot of their tests depending on what you pay for it's not a terribly expensive test but anyway so you collect the samples from the top six inches of the soil we know that in high tunnels we've kind of at least in minnesota looked at about a nine inch test because of the um small root structure of a lot of these plants in some of our high tunnels but anyway um six inches will give you a lot more or a lot better reading the nine inch because it won't delete it if you take a six inch and a nine inch or six inch in a foot and you've got salts down that deep um you know you could have some serious problems so salts are measured with the conductivity meter um the electrical conductivity is is measured in milli ohms per centimeter and um we won't get into the mass there but just kind of remember that it is numbers we're going to talk a little bit about that so we submit to a soil testing lab and we and you want to request if you think you got these exaggerated paste soluble soil salts test now some of the labs most especially minnesota eastern north dakota will screen soiled with the one-to-ones soil water test if the um milli ohms are under one per centimeter then a saturated um paste test will actually be run so in a way you'd really don't need to ask for it but if you think you may have salts it's always good to put on a soil test i i think i have salts you know we want a very accurate test on that so how do we interpret it you're going to get a number back on your soil test how a million ohms that basically tell you the amount of salt and it's really interesting how they do test this um technically you can almost test it at home but cost you some dollars but anyway the numbers you want to be a um alert of is from two to eight and with two you basically have no problems two or less now that'll be for some of the sensitive plants that we're going to look at from three to four some plants will be affected and if you get up there to five to seven many plants are going to be affected and if you got a eight or higher you're looking at extremely salt tolerance plants um i think of asparagus when we were growing up or i was growing up my my parents grow grew about 35 acres of asparagus and dad still had the idea when the weed problem got bad you put a lot of salt down the row and it did take care of the weeds i'll say that and it didn't seem to bother asparagus but you know when that asparagus got tore up you had some problems so i'm trying to plant something else or one of the things we always did is is try to put another um some crop between the row come low growing crop and of course they wouldn't survive at all so just kind of remember these numbers um we do have some some data we're going to show you at the end and some publications where you can get a hold of this but basically for many um high tunnel crops we're looking at two or less um aptly no more than four okay so let's take a look quick at at what crops um are tolerant now we actually took this from our um nutrient management for commercial vegetable crops fruit and vegetable crops manual and this is online if you just type it in um it has all the recommendations not only for salt which is only a page or two but all the different vegetable crops as far as um np and k liming um sulfur applications about anything you should probably need to know on fruit and vegetable crops and of course there's no no charge on that you can download it or just look at whatever page you want whenever you want it okay i think we're back in business okay let's look at um soluble salt and what crops are we really kind of looking at here um we're looking at um blueberries which we grow some in high tunnels not a lot carrots green beans onions radishes raspberries and especially strawberries um extremely extremely touchy they need to be under two preferably under one um so you need to think about that i've seen many instances where people would try to put strawberries in the tunnels and the leaves are turning and i've seen it to the point that the strawberries actually just about die they can barely survive so that's some important and then we move up to scale a little bit and um we look at three to four um apples cabbage celery grapes lettuce um i'll make a comment on lettuce now we're getting all kinds of new varieties out there um lettuce for restaurants and coming out of high tunnels getting very very popular and some of them are a little touchy at three even so you just want to um you know do that and you can always put a test it and one of the tests that i often use or tell growers to use is get some green bean seeds you can do one of two things you can either um scoop up soil at a depth of six inches in other words you're taking the whole core up from zero to six inches put it in a pot put your green beans in there and you'll some drastic browning if um if the um number is high otherwise you can just plant some in in the greenhouse between some other crops and the green bean will show it before most of the crops um again um peppers potatoes and sweet corn um we start going up to scale now you get you get up into five to seven you've got some potential problems here i'm luckily um you'll see tomatoes are in this group okay um and cucumbers are in that group which um i'll probably the two most um grown um crops in high tunnels at least in our area i know we're getting out to more and more crops all the time but um so anyway you know when if you've got tomatoes and cucumbers problems you're going to have to take some some drastic measures and you're also going to have to figure out why i got there i mean why in the world are am i having problems i'm getting it up to five or seven and then i looked on the real high end um you know asparagus um swiss chard i don't know how much swiss chard is grown but i don't think too much but anyway they will really take it and i have you know people who you know found out they couldn't go strawberries that had to go back to some of these crops i mean um and it's really interesting the um some coal crops like broccoli will take it very high but cabbage and some of the other crops or coal crops won't so just kind of keep that in mind um you know like i say you can always get this chart um either online or just review this um um webinar that we're doing now these are some of the high tunnels on our farm we have seven of them and i test them every year for salt now you can look on the um and have some of the other fertility too but you can look at the at the high tunnels and high tunnel one was built in the mid 90s and it's been in tomatoes or peppers most every year um this is one of our experimental tunnels and we can see that the number is still under one um we only have one tunnel um high tunnel five that is up to 1.47 and i'm still trying to um to figure out why if some of the help excuse me possibly over fertilize that one or something like that but you can see even after um pushing 20 years in some of these high tunnels with proper management you can keep this um salt down now if you're in an area that's starting with high salts um before you build a high tunnel then that's another situation that you're going to have to look at um for some type of um correction so how do we manage these salts or these soluble salt problems um again um have your soil and water test it and the reason i say your soil because you know we recommend that high tunnel producers um do a soil test every year and you can start to see it climb i mean some growers that you know i work with you know it started in at um one and next year went up to 1.5 and then 1.75 and two and eventually ended up at around five or six so um you know if you test every year you can kind of see if you got a problem with it climbing um you know you're going to have to if they're high you're going to have you know some remedies um again um locate your high tunnel on the soil that drains well we teach that in some of the basic classes um youth crops in rotation that are our salt tolerance um some of the coal crops um you know some of the cover crops but like i say tomatoes are probably tomatoes and cucumbers are probably one of two of the i should say two of the um crops that are grown mostly in high tunnels and when you've got problem with them you know it's getting pretty pretty high i did mention plastic mulch before um it does reduce evaporation and reduces salt accumulation on the soil surface um with that said i've been on growers farm where they actually taken the plastic off and you can actually see the salt on top so um you know probably a case of over fertilization with the wrong products avoid over application of nutrients um boy you know try to do it by soil test recommendations some of the lab we're working with with um you know we realize that you're going to be taking a lot more crop off we're going to show you some slides on that crop off in in high tunnels versus um field production um again i will say in our neck of the woods um high tunnel salts are mostly due to overcap application of fertilizer but not always and just because you're organic does not mean you don't have any problems um we'll talk about that here shortly too um compost is a big thing here um manure compost salt levels in a michigan survey you can see we're really a high minimum was was two um average um 5.7 would put you on the edge of almost growing tomatoes and of course the maximum was 23 now we feed a lot of animal salt um i should say we see we feed all animal salt at at some level some manures are a little bit more touchy than others i think of beef manure because of you know the high salts that they accumulate um and or i shouldn't say accumulate but um consume and basically the excuse me the small amount of grain in that that they eat so basically you know when i talk about beef manure here i'm talking more about the cow calf type of manure rather than the you know the feedlot you know type of manure um um we haven't had any trouble with horse manure and a lot of our research but um you have to remember when you compost something in manure is very very common you really want to compost it but it does concentrate things you know you start out with a great big pile and by the time the composting process is over it's really condensed it's really went down so themselves have really you know um concentrated themselves so just something to think about i am not telling you to not to use compost and manure because it's going to be hard to to get really good yields without it i'm not saying it's impossible a lot of people say well i'm going to get around this by using plant compost well that is one aspect of things but on the other hand um the manure the compost from manure you know is usually a lot more valuable as far as the amount of nutrients that you can really get out of them now one thing that they used to say a lot of years ago is you know get this stuff composted fast we're going to add some nitrogen to it we're you know maybe um we're going to try and build up you know some potash so with the nitrogen you're actually adding salt so just remember um that because you know when we put this compost manure in a high tunnel we're doing at a high level i mean you only put it an inch or two deep sometimes a little bit more but you start looking at that at tons per acre and multiply that out you're putting it in there pretty heavy and so i'm just kind of keep that in mind Darien we do have a question in the chat box for Vicki can the pH levels in your soil indicate salt concentrations here to a certain point yes um usually the higher pH soils will definitely have a tenancy to have more salts um basically because the flip side of that is basically because the sands um have more water go through them a lot easier and sand won't hold on to the ions as much as the as the heavier soils if your pH is is really high and by high i'm talking you know seven and a half to nine i'd have i'd be concerned if it's you know seven even seven five i wouldn't worry too much about it um if it's outside production you know so i hope that helps a little bit um oh another question from randy what type of compost plant or animal was surveyed in michigan that was that was planned i'm sorry that was animal okay and like i say that's where you're probably going to have your your problem like doubt if you're going to have any problems with plant compost unless you would put a lot of them your reon or something like that to try and compost it in a hurry um so if you are using high salt compost um analyze for nutrients as well as salts um we actually did quite a bit of um manures at um crookston and we really didn't see a lot but again it it can happen um again to answer your question compost with high salts are usually manure based unless they're really fertilized heavy in a plant um base compost to make it compost a little bit better um and you know you you're definitely going to want to probably use um some manure um base fertilizer especially if you're organic but um you know just don't get too carried away with it now if you want to be technical we say you know apply you know based on nutrient content usually nitrogen if manure compost has 10 pounds available per ton apply 10 to 15 pounds an acre which is only 688 pounds per square foot now if you look at our nutrient management guide it does give you the pounds per ton of compost and regular manure um of different animal species and that can um definitely make a difference but if you really look at a tunnel okay if you look at a tunnel that's um 20 by 100 that's 2000 square feet so that means you're going to be putting somewhere in the neighborhood of um what 17 hunchy 6 7 1400 um or a little bit less the newer in that whole tunnel all that is a lot as compared to what I've seen you know growers use so again I would run a test on it I mean I think they're kind of pushing this a little bit more than we need to but um you know it is something to really need to be aware of um plant-based compost low salt can be applied at higher rates but again you know you almost got to double it to get the same amount of nutrients and again it would depend on you know what what plants you're looking at versus what manure you're looking at but I haven't ever seen any trouble with um with plant-based compost the biggest problem I've seen with plant-based compost to be honest with you is herbicide concentration and I know this seminar isn't on that but I've seen um um people go out and intentionally either take hay or something and compost it or worse yet from the city compost and um the lawn owners they often apply a lot of um 2 4d or or some related chemical on there you compost it it's really concentrated so that's where I've seen most of the problems with um plant-based compost is is basically in the area of herbicide damage and that's a tough one because sometimes all you can really do is dig to four out of your high tunnel out to a the six inches to a foot and replace it so let's look at where the problems is inorganic fertilizers um you know we have we want to use lower salt fertilizers now we have here most of these products are one that we use in what we call commercial fertilizers but where's the where's the problem here well I look at ammonium nitrate coming down here at 105 well you can't even buy ammonium nitrate in minnesota anymore basically because of the problem with it blowing up so um you know that's really not too too available but so you look at some of these they're they're in the in the 60 range as a rule but you get down to potassium chloride which is 0060 which is basically a big component of vegetable crops um you know you're looking at 116 so you can see using straight potassium chloride or even mixed like going down and buying some um 1919 19 from the local um fertilizer company i'm sure they're using potassium chloride because of the of the cost in in their fertilizer mixes well a couple of things here you can see that is is pushing almost double push pushing almost triple the one that down here that says potassium sulfate which is another form of um of potash so basically um potash is going to be your number one problem as a rule now nitrogen is um can be um but we found out that potash is our is our real problem now here it is potash is the real problem that we have at least with commercial um agronomic potash the real problem is potassium chloride has a salt index of 116 which is about the highest it's often the most demanding nutrient now back in 2008 2009 2010 2011 we did studies on this was actually a crookston but we did studies with what's the fertilizer use of different crops um we basically worked with tomatoes and cucumbers we wanted to see you know um what the soil tests were before the season what the soil tests were after the season and you know which ones were the were the problem ones well when i teach this session here it usually goes on about an hour so i just pulled a slider two out they show you what the deal was and i think this was we were running about 40 to 50 pounds of plant of covert tomatoes that year well we can see before the season and this is at a six inch depth and we actually did test down to um 24 but we won't probably have time for that today but you can basically see the potash level when we started with 1349 now that's just really off the chart um but we can also see after harvest we were down to 173 so basically the plants basically used all them all that potassium to basically produce that crop now that's a pile of potassium of course you start getting up there towards the 50 pound per plant i'm that's kind of you know a little higher than most growers get but they're getting this with a research project you can also see the nitrogen which is basically um went up at 263 you know basically used well over 200 i don't know why this phosphorus numbers stayed the same that's a mystery but phosphorus is usually not a problem because of the little salts so what are we looking at here we look at tomato fertilizer used for 40 pound plant of product and you can see um you know what the fruit uses what the vine uses in total so basically what we're required to produce this crop is um that's about 100 ton per acre outside 600 pounds of nitrogen only 80 pound of phosphorus but again 940 pounds of um of potassium or 1128 pounds of k20 as most of us buy it on the open market but we can see where that runs into a problem um so how what do you got to do if you're just using straight commercial fertilizer that could be high in salts well in a 26 by 96 high tunnel and you can do the math you know there's 43,500 square feet in an acre um you know we're looking at um a little over 20th of an acre here so what do we got to put in that tunnel to produce that 40 pound plant now i'm not saying everybody goes out and fertilize this because you're probably not getting 40 pounds if you're getting 20 to 30 you're probably doing pretty good but here again you're going to have to put 64.29 pound of k20 or equivalent in a in that soil mix you know only 10 and a half pounds of um i think we use 1846 or 1152 i can't remember and you know almost 30 not quite 35 pounds of actual nitrogen so it does take a lot of fertilizer and that's part of our other problem i want to talk about nutrient uptake um you know two things basically i want to remember first well it's got to be there and that's the problem we know we can't produce top-notch high quality high profitable crops without fertilizer being available to the plant and two it's got to be in a water solution now i'm not going to spend a lot of time on on these scales here but um we carl and i worked on this here and basically you know um this is here the the pound per acre of um of tomatoes and how much weekly and and potash you basically need we didn't do the phosphorus on this slide because but you can see as the um the daily as the plant gets up into here in the 71 91 days 92 to 112 where you're depending on the variety of course where you're producing a tremendous amount of tomatoes you're harvesting every day you can see what the uptake basically is um we also um broke this down here this is just for your information here um as per 100 square feet in four foot rows um so basically you know most of our growers have tunnels anywhere from 50 to you know several hundred feet so you can kind of easy figure this out here the only problem here the question is what do you basically use now several years ago i had the opportunity to work with a major company on premixed fertilizers now for that chart that we had a long time ago in this presentation we talked about you know different fertilizers um which ones have low salt intra you know um low salt um content that whole ball of wax well the whole thing is if you're going to follow that and do that it takes a lot of work you may have several different types of products you're using um so so the companies are saying Jesus high tunnel deal is going to be really big i think i can um profit on this so you know what can i do well so we went to a lot of premixed fertilizers that probably going to solve some of your high tunnel um salt problem that you have them first of all um you got to buy the right stuff we're going to talk about that i'll tell you it's not going to be the cheapest um we usually look at great greenhouse grade things because greenhouses um we're dealing with seed germination we're dealing with very young plants and these products will contain very low salts at least on you know the salt scale okay so we're looking at you know what i call premixed high tunnel fertilizers um there's a there's a company here and there's several others now i'm not going to get into a lot of different ones called plant marvel and that's the one that i basically work with and we came up with several low salt fertilizers that are um of different nutrients that you can either apply at different times or just use a basic 2020 i'm depending on what your soil tests are that are extremely low in salt and they're mixed and they also contain all the micro nutrients and again i throw this here um back of the bag always you know read the directions on that type of thing that doesn't mean you can be careless it doesn't mean you're never going to have any salt problem but we can actually go ahead and drastically reduce them so um what what are we doing here what what um products are in these here um we look at urea ammonium but we also have to have a little bit of calcium nitrate in there potassium nitrate is going to be the big carrier for for potassium um we have soluble sources of organic fertilizers fishy motions i'm just making sure you're going to get one that's going to go through the drip tape here and i'm looking at a at a fertilizer um i'm one of the national teachers for the farm safety modernization act and we're spending a lot of time on on different fertilizers and how they basically not only affect growth but you know what's the um situation with um with um organic problems you know as far as um human safety is concerned a lot of this is going to come out but make sure that fishy motion has basically been treated and it's not raw as all they can say at this time so basically um you know if you will look a most recommendation for n in potassium or n and k are basically um in pounds um per acre um where i say we broke them down into ounces per linear feet so on some of these bags they do give you a a real good thing but using them product as a rule of thumb you're not going to have to worry a lot about salts okay um these are some of the mixtures that are available from different companies if you want to get technical about it um you know um we look at transplants from day one to seven we have a high-foss fertilizer then we want to grow it out from you know a week to about 30 days a low-foss fertilizer then at first flower again we're looking at um you know high pot high higher potash their plants are really putting on big amount of growth and um and high phosphorus because we really want to make them seem bloom and that type of thing then once we really start um getting producing um that type of thing we're looking at um a common fertilizer that's um higher in potash a nitrogen low in phosphorus here in the same with um growing to the end of the season so you can kind of manage things with this um but it's still going to take a lot of nutrients here and a lot of people will just go in with a with a straight triple 20 um that's put together right and um they can get by with that um but you know definitely watch your soil test what if the plant growth is poor but the soluble salts are getting high um we do have some options but there's not a lot um we look at you know leach the salts out one thing you can do is remove the covering and let rain leach nutrients out you can also go in there with a sprinkler um post harvest irrigation with drip um one thing that we do is we really run the drip heavy for a week um on and off sometimes two weeks at the end of the season and just kind of flood things it I think that's one of the reasons why some of our soil tests aren't as high as I would like um but it takes a lot of water to do this now look on the bottom of this slide we're looking at the amount of water can be substantial to be effective so um in six inches um to leach out 50 percent of the salts in the top foot um six inches of water 12 inches to lease out 80 percent and 24 inches to leach out 90 percent of the salts now for each inch of water that you're putting inside that high tunnel if you're using a sprinkler whatever situation is is 623 gallons per thousand square feet so it is a thing like you can just run a water hose in there for five minutes and you think your problems are solved it's going to take a lot of water um now this is one of the reasons why people with um high tunnel problems and salt have basically run the rows on the same run the plants on the same rows every year I know you can talk about um these these problems and other things but they can take the drip tape and then get a lot of water on there so basically it does take a lot of water you know to lease these out but again I mean what we're really looking at is um you know in the first six inches of soil here that we really want to take care of so um so apply it early see the application of good quality water fill the root zone and leave cells from the upper six to 12 inches this is why we highly recommend um running the irrigation um heavy the minute they're transplanted or basically before depending on you know how soon you're getting into your high tunnels um use shorter irrigation intervals keep soil moisture levels higher between irrigation it be loose to salt now you know a lot of you who use tensiometers say well you know I'm not going to kick my tensiometer on till it's 40 or something like that well the soil's getting dry at 40 50 but if you've got salt problems you're probably going to want to think about kicking it on about 20 and keep them soil moisture is high between irrigation and salty loose now I've had one grower that I work with so basically what we ended up doing during the growing season um after we saw that problem is kicking on his drip tape for about 45 minutes to an hour every single day in the plant pulled right out of it but they were relatively young they showed it right away again you can use sprinkler irrigation um takes a lot of water um we have to realize that leaching will also um lease nutrients so you know don't over apply here um again what are the the causes um lack of rainfall high amounts of fertilizer um I didn't really get into a lot on um on um fertilization but this is the one reason why we try to fertilize at least on a weekly basis and there's very inexpensive ways you can do that without going to a several hundred dollar system but um you know so you want to fertilize what you think the plant is going to need if you don't do it all at one time at least you're going to get some some plant uptake we do a lot with um soil or pardon me with leaf analysis but on the other hand um you know that isn't going to give you a pure reading either so again a monitor with a simple soil test um the bottom line is if you've got high salts you're going to have to use um irrigation or some type of ways to apply water in excess of the crop needs and we kind of recommend that you do it with a plan after you build the high tunnel kind of start it don't let them build up in the first place do your soil test every year and just kind of monitor them um you can remove the the cover in the fall I mean the one thing that we do is you know you have to replace this plastic every so often so we try to take it off in the fall when we're going to put it back on in the spring um and the thing with salts too is the continual application of water that takes them down and isn't putting an inch on and then letting the soil dry out put another inch on it's it's the continual wetness and the continual saturation of water in the soil that really takes out these salts and again a monitor the salts don't over irrigate if they're too high um on your list here there's some other um publications that have worked with salts um my colleagues um in Pennsylvania um all over have done a really good job here um so um take a look at some of these if you um have some time um there's quite a few on here that um that I put on so um any questions anybody has I see we got about five minutes or so left welcome to turn on your microphones so Scott if you could enable people's microphones or if you do not have a microphone you know please type your question in the chat box not seeing any questions in the chat box this is your chance don't be shy if you think of some questions here down the road or as you're ready to fertilize your tunnels or if you do have a problem feel free to drop me an email because you'll hear North Dakota with with the abundant snowfall we've had at least in eastern North Dakota is that we can certainly haul you know shovel some snow into the high tunnels too um and have that melt so that's that's another possibility too so is there anybody here that has had or has seen problems with the salt in your high tunnels for questions here okay well we hope everybody had the opportunity to learn a little bit today and uh as tunnels become more and more popular um we probably will run into these so now's a good time to um educate yourself and kind of do some prevention every year yes organization act trainings across minnesota are you doing about four of those no i'm sorry i couldn't hear you ester uh no are you running some food safety modernization act training in your state yes we are we've done um three already and we have one um next week yet i think and that we're going to finish it up and then um toward fall we want one in um the Fargo moorhead area and and um i think we'll we'll have one you know maybe push in Alexandria we haven't decided the location but we got to start doing a little bit more with the western and northern parts of the state and in fact this is a major issue for us here in north dakota too um so you're having produce safety alliance rower training and that is being um being conducted by connie landis fisk at cornell university in cooperation with julie garden robinson from nbsu and holly mobby from dakota college so this is a really important issue for us and we do have the training on april fifth from eight a m to five p.m in jamestown and it's only twenty five dollars which covers the cost of meals um but an extremely important training for us now if you are interested in registering for this training you could google nbsu field to fork and um that's right on the website and i'll also send out a reminder to everybody via our listserv if you're not on our listserv you know send me an email and i will put you on the list but this is so very important with all the new federal regulations regarding produce safety um and it's just good practice to know what the good agricultural practices are right and i will add to that after that um there is a basically a twenty five thousand dollar threshold that you sell under that but we actually have been having a lot of smaller growers um attendees that want to keep their produce safe um if you have produce that's contaminated with bacteria or something it doesn't make any difference what size you are so um you know all the growers should think about attending yes it really is insurance for everybody to know what the regulations are and how you can be in compliance and and how you can be a good producer and then are you also covering um the basics of manure safety and and and you know when that can be applied yes definitely matter of fact i'm the one that actually teaches the session on what we call soil amendments you get into a lot of manure safety which is a big thing with um compost how to compost um you know some of the dangers of raw manure the program is not that hard because there's only certain crops that are covered um under the law i mean if you're looking at them sweet corn or asparagus some of these crops that are not frequently consumed fresh are usually not covered but that don't mean you can't have any problem with them that's exactly right i'm not seeing any questions here but thank you so much terry this was just really beneficial um i know this is a huge issue across north dakota with both our high ph and our high soil salts that we have and combining that with our fertilizer salts it makes for for quite an issue in both north dakota and south dakota and western minnesota but thank you for sharing your knowledge with us and um we hope to we hope to sponsor you again for further webinars in the future we always enjoy having you okay well thank you very much and good luck to everybody that's on here all right thank you everybody and if anybody wants to be on our list serve but isn't you know send me an email or you can certainly type your email in the chat box here thank you everybody and have a good week and stay warm and dry