Understanding Our Soil: The Nitrogen Cycle, Fixers, and Fertilizer

part1, peas beans and clover are among the 18 000 species in the pea family. most species in this, family including these three are known as nitrogen fixers they increase. the level of nitrogen in the soil, which plants need to produce proteins so they. can grow and chlorophyll so they can photosynthesize one way, to use this in the. garden is to interplant nitrogen fixer with other plants that need a lot, of nitrogen. or you could plant a nitrogen-fixing cover crop like clover for fertile soil next year. okay, this can be useful but doesn't nitrogen fertilizer do the same thing but more. conveniently why bother with, this nitrogen fixation thing understanding this requires us to understand how. nitrogen fixation works which in turn requires, us to know the broader nitrogen cycle so. let's start with the big picture nitrogen makes up 78, of the earth's atmosphere by. volume but most of this nitrogen takes the form of two nitrogen atoms, strongly bonded. together which isn't very reactive and is useless to plants for it to become plant. available, we need the help of bacteria various species of bacteria eat atmospheric nitrogen and. poop out ammonium this, gets eaten by other kinds of bacteria which poop out nitrite. which gets eaten again by other kind, of bacteria. which poops out nitrate all of. these forms of nitrogen are available for plants especially nitrate, which is the easiest for. plants to use plants can take this up directly if it is near, their roots. but they most often rely on strands of fungi that attach to their roots and. bring, nutrients to them in exchange for the sugars and carbohydrates the plant roots exude. dead plant material is, also rich in nitrogen and gets brought down with the help. of worms whose poop is a delicacy, among nitrifying bacteria some of the ways nitrogen. exits the soil is when the crop is harvested when, water carries it away or. when it becomes gaseous and returns to the atmosphere or if the soil, lacks oxygen. different anaerobic bacteria grow which convert nitrates back into atmospheric nitrogen notice that these things. only, happen with loose nitrogen from the soil and not with nitrogen embedded in organisms and fertilizer adds pure. nitrogen, without the organisms so when it rains huge amounts of it runoff and pollute. the water loose nitrogen, molecules are also much more prone to volatilization releasing huge amounts. of nitrous oxide a potent greenhouse gas, into the atmosphere but that's not all such. quantities of pure nitrogen irritate earthworms which end up dying, or leaving it disrupts the. helpful fungus on plant roots and changes the soil ph making it inhospitable, to bacteria. in short it kills the soil when the nitrogen all gets used up or washes. away, the organisms aren't there to help the plants get more but now you have. to add more fertilizer, which worsens the problem and these organisms did much more than. just supply nitrogen the root fungi also, brought up important minerals for the plants and. microorganisms to use when, the plant dies the bacteria disperse into the soil resulting in. an abundance of bacterial allies for future, plants nitrogen needs you know how earlier i. said that water can carry soil nitrogen away this nitrogen, ends up in rivers which. can disrupt the ecosystem by enabling algae to dominate but remember this only, happens to. the organisms that live on the surface of the water and not the organisms in the water that live in the ground or in the air and the organisms are not there to do anything about it but, they do have the ability to do something about it and they do that by creating a web of organisms freely sharing the nitrogen. nitrogen cycle depends heavily on life in the, the soil without them. the plants would be quite sad but, you may have noticed if the fixation process. is done by bacteria where donitrogen fixation plants fit into, this believe it or not. nitrogen-fixesing plants don't fix nitrogen rather they create habitat for the bacteria that, do the. roots of this clover plant have little nodules that house huge amounts, of nitrogen -fixing bacteria. the, ammonium that these bacteria create slowly releases into the. soil for neighboring plants and when, these bacteria die, the nitrogen they create is released back into the air. and the nitrogen that the bacteria create is then released back to the soil. so. we know that the, nitrogen cycle is dependent on life. soil nutrients it's no wonder that the nitrogen cycle. is declining you can see that the soil nutrients. have no the life that life or life or. life or you can look around you and you can. see that this. is contributing to climate change.