We breathe in oxygen that plants have generated. We’re dependent on the plant world for our very survival. Plants also need oxygen to survive. How do we make sure there’s enough oxygen for non-plants and plants for optimum health?
Oxygen Keeps the Carbon Cycle Circular
We start by making sure all parts of the carbon cycle are functioning efficiently. The carbon cycle is circular. It starts with photosynthesis, then plant respiration, and ends back at photosynthesis. Within this cycle, plants use oxygen in processes that create isomers, water, carbon dioxide, secondary metabolites, and the oxygen we breathe.
Isomers influence the structure and function of many molecules and determine the health of your crop. They affect cell elongation, germination, and seed set and create more secondary metabolites. When a plant is healthy, flavonoids and terpenoids (secondary metabolites) protect it from pests and diseases.
Oxygen is the catalyst for converting the glucose created by photosynthesis into an energy form usable by plants. That energy is known as ATP (adenosine triphosphate) and is the result of photosynthesis with the addition of a phosphate molecule. All living beings use ATP as energy.
Oxygen is expelled from plants as a by-product of photosynthesis, along with water. Plants supply the oxygen we breathe and they create rain (given the right conditions).
You may not want a chemistry lesson, so the short story is that without the right amount of oxygen, photosynthesis isn’t very effective. Your crops will be stunted and your yield low.
How Circular Is the Carbon Cycle?
Carbon and oxygen go hand-in-hand in creating healthy plants. It’s interesting to see the formulas for photosynthesis and plant respiration side by side. Photosynthesis is the breathing in of plants, respiration is the breathing out.
Photosynthesis: 6CO2 + 12H2O + sunlight → C6H12O6 (glucose) + 6O2 +6H2O
Cellular Respiration: C6H12O6 (glucose) + 6O2 → 6CO2 + 6H2O + ATP (energy)
Sunlight in the presence of oxygen and carbon creates glucose, oxygen, and water vapor in plants.
Plants get rid of the waste products of photosynthesis through respiration. Those waste products are water and excess oxygen. The plant creates energy in the form of ATP.
Plants also respire CO2, but the net result is that carbon and oxygen are stable and there’s more oxygen for non-plants (like us) to breathe.
How Does This Impact Your Crops?
The biological, chemical, and physical structures of your plants and the soil are interconnected. When there is any kind of stress on plants—drought, nutrient deficiency, or waterlogging—the processes of photosynthesis and respiration are less efficient.
High temperatures and drought affect how your plants breathe through their stomata (small openings on the undersides of leaves). Plants want to retain water in these stressful situations, so the stomata are open for much shorter periods of time. That means there can be a build-up of oxygen in the form of reactive oxygen species that are toxic to plants and can cause a great deal of damage.
The physical characteristics of your soil determine how much oxygen is available to roots for uptake and growth. Photosynthesis isn’t the only way plants obtain oxygen. The soil structure, whether compacted, clay, or sandy, is a determinant in optimum crop growth. Those soil characteristics affect the oxygen available to plant roots.
When you drive farm equipment over your fields, you’re creating compaction. If you also have clay soil, this can be a serious problem. When plant roots don’t get enough oxygen, they take in less water and nutrients. The lack of oxygen impacts how much of the sugar created through photosynthesis plants can use. Lack of oxygen affects a plant’s efficiency, growth rate, and yield.
Sandy soil has large soil particles, and there’s plenty of space for oxygen. But plants need a balanced environment, and multiple factors go into optimum plant health. Water is a common limiting factor in sandy soil. Adding organic matter in the form of cover crops and manures can begin to alleviate issues associated with both clay and sandy soils. Cover crops used with a no-till system can decrease compaction for stronger root systems.
Plant respiration occurs both from leaves and roots. Stomata on the undersides of leaves open and close to allow oxygen to enter and carbon dioxide to exit. Yes, plants need oxygen to fuel metabolic processes, but they also need carbon dioxide.
Root hairs increase the area for exchange of all gasses, including oxygen, to the soil. But this can only happen if the soil has enough air spaces to absorb the oxygen. An optimum oxygen supply to the root zone increases root development so plants can absorb more water and nutrients. Your crops will perform poorly if the soil is compacted without pore space for oxygen molecules.
Improve Soil Structure and the Oxygen Potential of Your Crops
The use of intensive tilling and synthetic fertilizers has had a detrimental impact on soil health. It has led to compaction, salinization, and loss of soil biota that create pockets for root development. Oxygen is in short supply in many cultivated fields. Tilling increases the oxygen content of a field in the short term but at the expense of long-term soil health.
When the soil is out of balance, whether from too little or too much of a nutrient, plants cannot achieve optimum potential. Most plant problems are caused by environmental stress, sometimes from extreme weather and sometimes from agricultural practices.
Are you ready to improve the balance, and oxygen flow, to your crops for a better ROI? Contact our team at STBiologicals.com and we can show you how to tweak your ag practices this fall for a more profitable 2025. We’re here to help you succeed. When soil speaks, we listen.
