 One of those really important nutrients is nitrogen. So in our atmosphere there's a really abundant supply of nitrogen About three-quarters of our atmosphere is nitrogen about a fifth of it is oxygen a little tiny bit Is carbon dioxide and then we've got some other gases that make up the rest So plants themselves can't actually access that nitrogen. So where do they get it from? So first of all when it rains which it's raining a little bit at the moment The rain will dissolve nitrogen out of the atmosphere and so some of the rain water that ends up in the soil The plants can just go woohoo And suck that straight out of the soil water and it's really easy for them to get but often that's not enough nitrogen for them So what they do is that they they form was some plants not all plants can do this But plants that we call legumes can form relationships with a bacteria called rhizobia and the rhizobia sits within the soil within the roots and forms this sort of This little environment where the plants give it sugars and energy to live and the rhizobia converts nitrogen from the air Fixes it creates a storage for that and allows the plant to access that So those plants we've got lots of different plants in our systems around in agriculture often peas Are a really important legume We've got Clovers often in pastures, but even within Australian species. There's lots of different plants that that fix Nitrogen so our acacia's are really good at fixing nitrogen Hardenburgia is a beautiful plant with purple flowers that flowers in winter And that also helps to fix nitrogen in our system And so those plants as they fix nitrogen they create these stores in the soil and as those plants die That that nitrogen gets released back into the system and is available for other plants to take that up So what happens as a plant dies? We all see dead leaves and things that drop onto the ground or within the soil as roots are Sort of sloughed off and and released into the soil other organisms will come in and start to break that down So we've all found something in the back of the fridge that's looking pretty nasty And it's a really important process not one that any of us want to be eating things at that point But that is a decomposition process. So it's these little fungi and bacteria and other organisms that help to break down Organic matter or living organisms once they die So earthworms are a really important part of that and all of these processes contribute to to helping to share and Recycle those nutrients around the system. So plants are one of the main Organisms that that takes convert solar energy and and helps to share that into our system Of course other organisms like ourselves will eat some plants, maybe not these ones They're not looking too appetizing there, but you know our cows will graze on grass convert that to meet for us You know, so we've got all of these processes where Cows called herbivores will eat other plants humans eat both plants and animals. So we're omnivores We eat both. We've got carnivores out there. They just eat meat Or other animals and of course detritivores or Decomposers that that help recycle all of those those organisms once they die and re-release them So all of these processes create this really complex interacting life system that helps to cycle nutrients and an energy around that system, but plants aren't the only ones that contribute to this This capture of energy and sharing it to the system And here we've got a plant where we've got some other mosses and lichens and things growing in the bottom of the soil And we often see out in more arid regions We get crusts biological crusts that form on the surface of the soil And when it rains and there's enough moisture and the conditions are just right they suddenly go green And that process so anywhere we see those green processes happening We've got this really important process of photosynthesis and capturing energy and and helping to build those those those Really important parts of a life cycle process So what we've talked about so far is is that solar energy How the the sun drives all of these processes? How we capture energy? How we take some really important nutrients out of the atmosphere Into plants that we release oxygen and how we get some of those nutrients through really important Collaborations or communities that form within the the soil