 If we expect to be healthy as people, we really need to eat healthy food and that's really the whole point for me growing a garden is to be able to grow healthy food and you can't grow healthy food without healthy soil that can support those plants as they grow and produce whatever it is that we want to grow to eat. So we'll get started here with a little definition. Years ago we used to refer to soil health as soil quality. Now the term soil health is pretty much the standard but it's the continued capacity of the soil to function as a vital living system that sustains plant animal and human health. So if you think about your own health that's your capacity to function and if you go to the doctor the doctor checks you over and determines how well are you functioning and if you're not functioning very well how can your function be restored how can your health be restored so that you can do everything that you're supposed to do or that you would like to do and really move forward and accomplish what you want to accomplish. So that's what we're going to be talking about this evening is how does the soil function and how do we restore and maintain the soil's ability to function so it can produce the healthy food that we want to grow there. Now I typically do presentations that are a little bit more interactive but I still included a few things in here where I ask a question and then we examine the answer. So the first question is what functions do you expect your soil to perform and for most people no one's really ever asked them that question before. They've never really thought about what what do I expect my soil to do how do I expect it to perform and the answer is really pretty simple we expect it to grow crops and so if we dig into that a little deeper we realize that what crops need to grow is soil that will infiltrate water the water will be able to move into the soil when it rains or when we irrigate and that soil will be able to supply the nutrients that those plants need and then we look at well how does the soil perform these functions how does it do that and really the answer to that is it's a it's a biological system the soil is a biological system if you don't remember anything else about what we talked about soil health this evening it's that soil is a biological system and it's all about the glue makers and when I say the glue makers I'm referring to the organisms the microorganisms for the most part that live in the soil that create all the sticky substances that hold soil aggregates together and so aggregates the term aggregate is a soil science term it's a $20 word for lumps and clumps of soil so the the aggregates are not held together just by clay or just by silt they're held together by biological glues and bacteria make sticky substances to help things stick to them that they then use for food and they start to create the first small micro aggregates where they actually stick sand silt and clay together to form these very small aggregates fungi in the soil have sticky substances on their exterior that they use to seal themselves so they don't lose the moisture they don't lose the things that they're transporting back to the plants and they create even larger aggregates and these aggregates are habitat for the soil they're the place where all these organisms can live and they store a lot of the nutrients and water that the plants will ultimately access so these microbes need to be well fed if they're going to make good glues to hold the soil together so we need to make the soil into good habitat for them so that they can make those good glues so when we look at aggregates we refer to that as soil structure just like you would the foundation of your house that's part of the structure of the house these aggregates are the structure of your soil and these aggregates develop and maintain themselves best under the least amount of disturbance so if we look at minimizing disturbance we can maintain these aggregates and build these aggregates so tillage can only destroy soil aggregates it cannot build them it can only break them into smaller pieces so tillage really results in poorer habitat for the soil food web so the first bomb that I'll drop on you this evening is that tillage is bad for the soil and if I were going to design an implement that would destroy soil structure the fastest it would be a rototiller so and I guess I could look at the little tab down here to see how many people left the left the meeting here after I said that but you really need to learn how to do less disturbance to your soil if you're going to build aggregates and really make it into good habitat for what lives in the soil so let's take a little bit closer look at what lives in the soil yeah we sometimes refer to it as a soil food web because it can be pretty complicated there's a lot of different organisms that live in the soil but I like this diagram that comes from the soil biology primer because it shows us the whole picture of what is supposed to be going on in soil we have the sun we have green plants we have the roots of those plants in the soil and then we have the smallest soil organisms the bacteria and the fungi and then we have the predators that feed on them and so on up through the the soil food web but what I really wanted to emphasize here was that it's the green plants that really provide the bridge the link between the power of the sun which we get for free and moving that energy from the sun into the soil so a green plant as a fill does photosynthesis the products of photosynthesis are oxygen and carbohydrates sugars and the plants will then take somewhere in the neighborhood of a third to a half of those carbohydrates that it produces and put them into the soil to feed these soil organisms these soil organisms in turn create stable aggregates that help water infiltrate for the plants and feed the plants in return so this is a cycle this is a mutual arrangement here that's supposed to be powered by the sun okay so what the soil food web does it immobilizes which means captures or holds on to and releases cycles plant nutrients creates these stable soil aggregates that allow water to move into the soil and provide habitat for all these organisms and allow root movement etc and if you stop and think about it 90% of the agronomically important things that help plants grow soil functions are performed by soil organisms so if we look a little closer it arises here if you want to dig up some actively growing plants you'll see this soil stuck to their roots and that's where all this activity is where these sugars are coming out of the roots and feeding these organisms it's a zone of really concentrated biological activity so managing for soil health we're going to think about managing for soil health what is the most limiting element in the soil and most people would answer nitrogen I always put nitrogen fertilizer on must be nitrogen but really it's carbon and carbon is the glue and the energy and the life of the soil 78% of the earth's atmosphere is nitrogen so that's not a problem there's organisms that will capture nitrogen and some of your plants phosphorus potassium calcium magnesium etc are all abundant in soil mineralogy and there's organisms that can access those primarily fungi in cooperation with bacteria so I guess that's a second bomb that I'll drop on you is you really don't need fertilizer if your soil is functioning if your soil is not functioning then you definitely do need fertilizer because your plants aren't going to be able to access it from their biologic partners in the soil so as we increase the organic matter the black part of your soil they can vastly increase the water holding capacity and really help that soil provide water not only to the plants but to the organisms in the soil and if you really stop and examine what happens to any fertilizer nitrogen that you put in your garden only about a third of that at best actually ends up in the plant the rest of it ends up somewhere else in the soil food web or it gets lost so of that total soil organic matter about 10% is alive is the living part and that's the part that makes nutrients available regardless of the source so managing for soil biology and soil health these are really the four keys that you need to think about need to minimize disturbance of the soil need to maximize the diversity of the plants rotation or cover crops so that we have lots of different food sources for those organisms in the soil keep living roots in the soil as much of the time as possible so that that food supply from the sun energy from the sun going into the soil is functioning it as much of the time as possible and keeping the soil covered with plants and plant residues you should very rarely ever see your soil it should be covered with plants with plant residues so if you think about those four items those four principles they're really focusing on creating the most favorable habitat possible for the soil food web so quickly to kind of hit on each one of these a little bit soil disturbance the primary disturbance is going to be physical disturbance from tillage we can also disturb what lives in the soil with pesticides or fertilizer or other amendments that we're adding to the soil and then we can have biological disturbance which would be a lack of plant diversity or a lack of food or cover to help the biology that lives in the soil need to maximize plant diversity so we need to grow pool season things warm season broadleaf grasses lots of different types of plants and make sure that we grow them in some kind of a sequence so we're not growing the same things in the same place every year okay you don't want to grow your tomatoes in the same spot every year your corn in the same spot every year move around switch around where you plant those things from year to year and then we can also use cover crops and a diverse mixture of species is usually the best so living roots how much of the times yourself have living roots you can you know that's a good question to ask yourself and how could i improve on that could i leave my plants out in my soil and let them stand out there in green and growing instead of pulling them out early in the fall grow lots of different things even if there's things that you don't eat they can still be beneficial to pollinators or other organisms in your garden so cover crops perennials winter annuals biannuals lots of different things that we can think about growing in our gardens to add that diversity and keeping the soil covered we need to have that armor to protect the soil aggregates from raindrop impact from ultraviolet radiation from drying out from all those things that make it less hospitable to the organisms that live in the soil there's a lot of arthropods insects that live in the soil that cycle nutrients in that residue that's near the surface and that's an important part of the food web that we often don't think about we need to conserve moisture and moderate the temperature in the soil as we go through the summer and make sure we keep that soil hospitable so the soil food web keeps working all the time we don't want it to stop so the benefits of managing for soil health ndsu gives a 50 pound nitrogen credit per year per acre if you're not tilling the soil fungi increase phosphorus some water supply to plants we have improved soil aggregation so we get water moving roots moving everything that lives in the soil fed and happy with a place to live and we have fewer weeds and diseases as we increase the diversity and the capacity of the soil to do what it's supposed to do so how would we know if your soil health is improving we can look at so aggregate stability water infiltration organic matter increase crop response reduced input costs and we can even do some really fancy analysis and look at soil biology if we if we wanted to so how to begin a no-till garden it might seem kind of obvious but the first thing is don't till the soil smother or spray to kill the existing vegetation so you have a soil that's ready for you to plant what you want to grow into it and then plant that those things with minimal soil disturbance just by scratching a little line in the soil with the shovel but not tilling the whole soil you don't need to till all of the soil just to plant a little tiny slot of seeds let your crops grow pull the weeds rather than hoe them so you don't disturb the soil and plant more weeds and mulch to suppress the weeds whether you use grass clippings or hay or straw whatever the case is to mulch to smother those weeds and then plant more than one crop if you have the opportunity and the growing season to be able to do that so just looking around my whole yard there's ways that you can manage for soil health in your garden for your perennials like grapes raspberries strawberries apples hops even along mow it high and let it lie you don't need to fertilize it you don't need to water it so much just mow the grass high so the plants stay healthy and it feeds the earthworms in the soil okay so to kind of wrap this up as we go we have fewer weeds we need less herbicide for weed control we have increased soil biology we need less or no fertilizer we have increased earthworms and increased water infiltration you know we have less work and more fun