Hey folks,
we know our trees use corbon dioxide during the photosynthesis process to produce sugars by the help of the sun. Oxygen is the waste product of this operation. This is where the most of our oxygen comes from and what makes life on earth possible.
But what happens under the soil? Isn´t there growth, isn´t there life? Sure, but there is no light, photosynthesis isn´t possible. How does this work?
The simple answer is breathing. Like other microbiotic specims and fungus, too, the tip of the roots activily take-up oxygen and burn it in the presents of water and carbohydrates into energy and carbon dioxide, which is released into the environment again.
The majority of this ‘earth-breathing’ comes from bacteria and fungus and only an smaller portion is related to root growth.
So keep your soil well drained and the surface clean from weeds and other blocking stuff and let your trees have a deep breath again.
The prerequisite for the water absorption of the root is that the salt concentration in the root cells is higher than in the soil water. The nutrient salts must thus migrate into a range of high salt concentration during recording. Since this is not possible, the ions must be taken in energy consumption against a concentration gradient in the root hair cells. Because the cell membrane is impenetrable to the ions, they are transported by special carriers and thus reach the cell interior. The energy for these processes is generated by the root respiration. This is also the reason why the plants often show nutrient deficiency symptoms when waterlogged. This helps soil loosening, as it promotes gas exchange and thus leads to increased root respiration and increased nutrient salt intake. The root should also be supplied with sufficient reserves.
To a limited extent, the plant can exclude nutrient salt ions from the uptake. This is because for certain ions certain carriers are present, which are based on the electric charge and the ion diameter. The potassium and ammonium ions have the same charge and approximately the same diameter. For this reason, they compete for the same carrier. If there is an oversupply on one of the two ions, the other is absorbed in smaller quantities. This phenomenon can lead to a lack of nutrients and is called antagonism. This phenomenon also occurs, for example, in soils or substrates rich in lime. There, the calcium ions accumulate at the root due to their large concentration in the soil solution and inhibit the uptake of other ions, such as magnesium and potassium ions.
Degen/Schrader(2002)
Unless you do bald cypress bonsai. Want a good base? Drown your tree. Weird and wonderful things happen to hormones and root tissues when the oxygen runs out. Since I’m fighting mosquitoes with a film of insecticidal oil, the oxygen runs out sooner!
And throw away advice from anyone who tells you that knees are for gas exchange. Bah! They’re not snorkels. They store starch.
is the general rule which is true for all plants and
the species specifics
I’m not the species expert so I couldn’t make any comments to bald cypress.
In general there are at least two ways for our trees to gain the energy for their metabolic activities. We all knows photosynthesis, but this way is not feasible to generate the activity for e.g. protein or fat synhesis. Photosynthesis drives the production of sugars which will be polymerized to starches.This process generates oxygen and takes place in the chloroplasts of the cells. The sugars are the universal substance to gernerate energy at any location of the plant. At the roots no photosynthesis takes place. Here comes the energy rich sugars into place. In e.g. the mitochondrians the sugars will be oxydized in the presents of oxygen and the releast energy is used (in the form of ATP) to drive all other metbolic processes as dicribed e.g. above. In fact the oxygen balance of the tree is positive but for any two oxygen molecules the plant generates one is required to drive the dicribed process. In addition to that the microbes in the soil use oxygen, too because the couldn’t use photosynthesis. If they didn’t get oxygen the will do fermentation.
Theses are the reasons for a call to a well aereated soil.
Interesting points! Cheers bonsai brethren. Few points made lead me to believe there may be some misunderstanding that I’d like to clarify. Although you guys might be aware, stuff gets lost in translation. One point was ‘microbes switch to fermentation’. As far as I know, microbes don’t switch gears. You have aerobic and anaerobic microbes. Totally different critters.Waterlogged means aerobic guys die or go elsewhere. Population shrinks or disappears. Anaerobes go crazy , populations rise. Typically, anaerobic microbes are the guys responsible for bacterial or fungal disease. Increasing soil oxygen boosts aerobic microbe populations and they outcompete bad guys minimizing your plants exposure to infection. Second point I thought was a bit off, if I understood correctly, please forgive otherwise, was no green life in soil. No photosynthesis, how is there oxygen? Microbes respire, causing the existence of oxygen underground without green plants. Oxygen in soil is there by way of pore space. Micro pores macro pores, atmospheric oxygen finds its way as long as there is pore spaces. Critters and roots in soil use this oxygen they don’t create it. Available oxygen is a limiting factor for root growth. You have pore space you have oxygen you have roots. No plants on the trail, cause foot traffic compacts soil. No pores no oxygen no roots no plants. Aquatic and bog and water loving plants have special adaptations that allow them to get by with roots under water. Somewhere in Pacific Northwest researchers found roots half mile down in tunnels, this is possible because of soil with good Pore space. In contrast, build new house, big machines compacting wet soil, can’t even get grass to grow, trees shrubs won’t survive, water won’t percolate, mud everywhere. Oxygen for your plant roots is about maintaining pore space outdoors or in a bonsai pot. Good pore space means beneficial microbe populations outcompete bad disease causing microbes=healthy plant roots =healthy plants.
Oh and one more. Certain plants, like conifers rely heavily on microbes because they have deficiencies in ability to take up certain nutrients, like phosphorus for example. Nitrogen moves easily thru soil, phosphorus does not. It could be sitting right next to a root and root can’t get at it! Enter mycorrhizae, let’s make a deal root. I’ll get you all the phosphorus you want if you give me some sugar(exudate). Deal is made, microbe get sugar plant root gets phosphorus!
