Plants_nutrients

We have spent a lot of time talking about plant water uptake with vascular tissue root pressure, transpiration, and we have spent a lot of time talking about different plant tissues and cells and organs for a minute I want us to focus purely on plant nutrients plants have 17 essential an organic nutrients for elements that they need to grow and go through reproduction there are nine what we call macronutrients these are not the macro because they are large these are macro because they need a lot of them in the plant's. I know this is counterintuitive to some of you but we need to think about macro in this case as being a large amount and not a large molecule so the first four on this list carbon hydrogen and oxygen and nitrogen probably do not surprise you in the least C - H - O - N are the big nutrients that any living organism needs on this planet number five and six sulfur and phosphorus round out the top six and give us 98% of a plant's dry weight. What does this mean? if I take a plant and dry it evaporating all the water from it -- the remaining weight of the plant those top six elements will make up 98% of that plants weight. That's an amazing number given what is going on inside a plant at any one time potassium calcium and magnesium also critical for number of plant functions including growth and reproduction but those top six are really the key that you should focus on there also eight micronutrients again micro not meaning that these are small molecules or small elements but instead meaning that plants actually need very little of them chlorine and iron and so on zinc copper nickel these are all things that if you would look at your multi vitamin bottle these have a small percentage in all of our multivitamins but again like for us in our plants they are going to act as what we call cofactors they are going to work with enzymes to make the plant function more effectively what we don't wanna have happen is those to buildup in large concentrations large concentrations of micronutrients would actually be toxic to you or to the plants or to any living organism but out of this list what we wanna think about is what are critical for both our macro nutrients that we mentioned a minute ago and these micronutrients as far as their use in the plants when we look at plants in agriculture we spent a lot of time thinking about what's the correct dosage of fertilizer to add to these plants and we'll talk about this more later on we talk farming and look at global climate and its effect on farming and vice versa but on the figure in the screen at the top you see a very nice healthy green leaf but then there are three what we called deficient nutrient leaves or nutrient plants here. The second one being nitrogen and phosphorus and potassium and the bottom notice the different colorations. So phosphorus deficiency actually results in, that purplish of color on the leaves the nitrogen deficiency and potassium deficiency actually demonstrate themselves in a similar color pattern but notice where it's located nitrogen deficiency tends to be towards the center of the leaf potassium deficiency towards the outside and so if you were keeping plants at home either inside or in your garden and you notice these sorts of patterns developing on your leaves you could actually apply a correct fertilizer to deal with this and help your plant to do much better and be much more successful so the nitrogen and phosphorus potassium or what we call NPK fertilizers. Remember potassium is K. That is a very common fertilizer combination for plants almost every plant on our planet is nitrogen or phosphorus deficient and most of them are both meaning that you may have leaves the look nice and green and healthy like the ones at the top but if you added a little bit of nitrogen and phosphorus that plant would do better so we've start a look at alternatives to just straight fertilizers on our fields and what many folks have started using rather than the inorganic chemical fertilizers is compost so compost is derived from decaying plant material and a mixture of bacteria and so what we're looking for here is returning a decomposed organic matter back to the plants to help support their growth now in this kind of scenario we are actually looking for a very balanced ratio of nitrogen phosphorus and potassium and other nutrients that the plants require. Composting has become a very common practice today and seeing more and more of it associated particularly with organic farming measures