Table of Contents
- What is Humus?
- 13 Reasons Why Humus is Vital for Soil
- 1. It is an Important Nutrient Source
- 2. Improves Water Holding Ability
- 3. Causes Soil Aggregation
- 4. Improves Soil Structure
- 5. Prevents Soil Erosion
- 6. Prevents Leaching
- 7. Have a Buffering Effect
- 8. Increases the Oxidation of Complex Organic Substances
- 9. Improves Sub-Par Soils
- 10. Increases Soil Richness and Acts as Nutrition for Microorganisms
- 11. Increases Cation Exchange Capacity (CEC)
- 12. Humus Increases Soil Temperature
- 13. Maintains the Nutrient Cycling Process
- Best Practices for Increasing Humus in Soil
The basis of any food system is the presence of healthy soil. Healthy soil is one which comprises decomposed organic matter or compounds that go through the course of decay to create humus. Additionally, such soil yields healthy crops that in turn afford nutrition for the health and comfort of users. Crops acquire their nutrients from organic matter and minerals both.
What is Humus?
The organic matter is basically what is known as humus – healthy soil component comprising of animal and plant remains that decompose to sustain the plants or increase soil fertility. The presence of humus is essential for soil health. Soil Quality depends upon appropriate availability of humus and this is greatly helped by provision of adequate organic matter levels in soil.
P.S: I suggest you read up on Organic Regenerative Agriculture as well!
Humus is therefore considered the backbone of crop production because it has a key role in their development. Most soils used for agriculture have almost 2% to 10% of organic matter. Still, even in such a tiny portion, they are still extremely essential. This means the soil is alive and has a distinctive bionetwork.
A healthy soil, thus, has organisms that transform decomposing matter, minerals, and dead matter into nutrients for plants. The extent of biological activity or disintegration rests on the amount and variety of organic matter. Humus is the final form of compost.
Furthermore, soil fertility depends upon interplay of chemical activities and interactions of nutrients amid the water, soil, and the broken down organic matter. As such, this not only outlines the purpose of humus in the soil but similarly its profits.
Here are some of the amazing advantages of humus to enhance soil fertility.
13 Reasons Why Humus is Vital for Soil
1. It is an Important Nutrient Source
Organic matter has nutrients that are let out after the decomposition by soil organisms. Data shows that each percent of soil’s organic matter in the top 6 inches of soil releases about 10-20 pounds of nitrogen, 1 to 2 pounds of phosphorus, and 0.4 to 0.8 pounds of sulfur per acre per year.
These elements released by the broken down organic matter assist in the vegetative evolution of a plant, anthocyanin production, amino acid formation, chlorophyll production, amongst other significant roles that create a healthy plant. Humus also supports the soil microbes like algae, protozoa, fungi, bacteria, among added species such as insects and earthworms that make a living component (soil ecosystem) which help in the breakdown of nutrients.
The organisms disintegrate the organic material in the soil by consuming and mixing them with the soil minerals for the plants that are then later ingested by primary users and up the food chain by humans. In effect, humus provides a reservoir for the plant nutrients available in the soil for balanced plant growth.
2. Improves Water Holding Ability
For the soil to be healthy, it must be sufficiently wet. It must have a decent water retention capacity too, catering to diverse crop requirements.
Organic matter offers the soil the capacity to hold on to water. It works like a sponge and it has the ability to hold water, around 90% of its own mass. Water being retained by the organic matter is readily accessible to the crops when required.
3. Causes Soil Aggregation
Soil aggregation occurs by the clumping together of soil particles. Organic matter has the ability of making the soil particles clump together because of its adhesive characteristics to create soil aggregates. Soil aggregation improves soil structure which is a feature of healthy soil as well.
4. Improves Soil Structure
Soil structure is the accumulation of soil particles in differing arrangements. A good soil structure is important for healthy plant growth as well as soil stability. One of the most noteworthy aspects influencing soil structure is the existence, or lack thereof, of humus.
Soils with high fraction of humus have greater aggregate stability fostering good soil structure. Soils with low ratio of disintegrated organic matter have substandard structure and cannot provide optimal crop production apart from rendering the soil susceptible to erosion.
5. Prevents Soil Erosion
According to the field data statistics used by Universal Loss of Soil Equation (ULSE), a rise in the soil organic matter from 1% to 3% lessens erosion by almost 20% to 33% due to increased stable soil aggregate formation caused by organic matter.
Humus promotes water permeation which in turn aids in prevention of surface runoff. What is more, soil with a large quantity of humus has a steady soil aggregate which makes it difficult for the particles to be swept by causes of soil erosion such as water and wind.
6. Prevents Leaching
Healthy soil is made of minerals and nutrients required by the plant. But, because of untoward weather trends among other elements, these nutrients and minerals can be leached to deeper points where the plant roots might not extend, making them unobtainable for plant use.
However, with the existence of decomposed organic matter, leaching is preventable.
The process of humification includes activity by microbes which discharge sticky and gum-like mucilage. This mucilage is central in the creation of the tilth or crumby structure of the soil. It joins the soil particles together and increases the ventilation of different soils.
Similarly, it gives rise to chelation – a process whereby surplus nutrients are attached to the broken down organic particles of the humus and as a result, inhibit them from being leached.
7. Have a Buffering Effect
Different harvests develop different pH levels in soils. In this respect, good and healthy soil is one which can offer the ideal pH value for particular plant growth, which is only possible when there is ample humus in the soil.
Furthermore, soil bacteria prosper finest in the most beneficial soil pH. Humus has a safeguarding influence on the soil and stops extreme basicity or extreme acidity.
Research has moreover proven that soils with a larger quantity of humus are capable of adjusting the level of pH value which lets plants to grow under ideal conditions as variations in the pH value lead to stunted crop harvests.
8. Increases the Oxidation of Complex Organic Substances
The decaying process of organic matter has a direct influence on the oxidation procedure of complex organic compounds like the lignin-like humus. These compounds are fragmented into simple sugars, aliphatic compounds, amino sugars, and phenolic acid.
These compounds are additionally decomposed into microbial humus or biomass that are then turned into humic assemblages after restructuring and additional oxidation.
The humus contains fulvic and humic acids, which are essential to linking minerals and metal hydroxides in the clay.
9. Improves Sub-Par Soils
Humus has the capability to transform the property of any soil. Sandy soil, for example, has reduced water retention capacity, high drainage, and fewer soil nutrients and microbes.
Clay soil, on the other hand, has greater aggregates that have decent water retention but then there is deficient aeration along with reduced rate of water infiltration and drainage. Soil with large proportion of clay is a dense compacted soil where many plants cannot grow properly.
Placing humus on sandy soil will improve its water holding ability, raise nutrient concentration, and decrease leaching. Adding more amount of humus in clay soil can support increased aeration, lessen water holding capability, and escalate nutrient content.
Humus would also decrease the weight of clay soils by means of the separation of clay particles and permit air circulation along with easier water drainage. Thus presence of humus improves the soil texture.
Additionally, the lessening of clay soil mass can be achieved by mixing it with sandy soil. Actually, clay soil with a small quantity of humus is practically solid because of its compact nature and if dry, it turns out to be problematic to work with. Moreover, the humus would also enhance other soil aspects, like the pH factor.
10. Increases Soil Richness and Acts as Nutrition for Microorganisms
Fertile soil is one which holds all the essential nutrients in appropriate quantity for optimum growth of plants. Such soil has a decent structure, consistency, prime levels of pH value and temperature, and all the required microorganisms. A soil that is fertile is considered as fit for plant growth but it’s only labeled productive if it has humus.
The beneficial effects of soil organic matter and humus on plants stem from the interaction between microbes and organic matter. Humus affects positively the survival and efficiency of the microorganisms. Even cellular metabolism during respiration, photosynthesis, and nitrogen fixation is affected by humus.
Thus, humus has the main role on pH control, drainage, soil structure, amongst other significant soil characteristics.
11. Increases Cation Exchange Capacity (CEC)
The comparative capacity of soils to collect one specific group of nutrients, the cations, is denoted as cation exchange capacity or CEC. The colloidal aspect of humus supports it to raise the soil’s cation exchange capacity.
The exchange makes the soil able of packing nutrients through a process known as chelation. Throughout rainy periods, the cations can certainly leached by rainwater runoff but with the addition of humic substances, they are kept in place.
12. Humus Increases Soil Temperature
One more vital feature of healthy soil is its capability to sustain ideal temperatures. The black or brown color of soil humus being of a darker hue helps with the retention of warm temperatures. Microbes, too, function better in warm soil and this means that the adding of humus would assist in delivering them with the warmth needed to flourish.
Beneficial activity of any soil microorganism is directly dependent on provision of optimum environment including appropriate soil temperature range.
13. Maintains the Nutrient Cycling Process
The decomposition of soil organic matter into humus by the microbes using it as nourishment through humification and mineralization offer nutrient for plant development. Dead organisms and waste product and are broken down also, providing nutrients for plant progress.
After these plants are full-grown, they are eaten by the animals and their residual matter decays to create further nutrients for other plants. Thus benefits to the plant growth are directly proportional to the soil organic matter level.
The soil organic carbon is a component of soil organic matter . Crop residue contributes to the maintenance of soil organic carbon stores, a key component of soil fertility .
This process is incessant whereby plants take in nutrients to develop, they are consumed by animals, animals then leave waste while some expire, and they lastly decompose to create nutrients.
Even manure has to be turned into humus before it can be used as a organic fertilizer. This cycle is the foundation of healthy soil that can help with crop growth and the continued existence of all animal species.
Best Practices for Increasing Humus in Soil
You may very well wonder that keeping the above benefits in view, how can we ensure adequate presence of humus in soil. One way is to ensure presence of nitrogen in soil to encourage microbial activity.
An important fact is that humus has carbon/nitrogen ratio of about 12 to 1 and both are essential to create humus. Actually soil carbon is usually abundant in land where grass pasture is planted as well as that with crop residue .
The presence of nitrogen can be ensured by planting legume crop which provides for nitrogen fixation. In this way legume crop be used as cover crop as well as green manure when it is ploughed back into the soil.
Nitrogen can also be added as organic soil amendment through animal based manure. An astute grower would go for crop rotation to manage availability of soil organic matter to foster development of Humus
To conclude, placing humus in the soil will boost soil fertility and improve the growing of saplings and other flora while also reducing the requirement for watering to a minimum and provide support in making plants more robust against disease.