Importance of Healthy Soil
Food Web

importance of Healthy Soil

  1. rainwater on plant and soil
Healthy soils are essential for healthy plant growth, human nutrition, ecosystem services such as water filtration and supporting a landscape that is more resilient to the impacts of drought, flood or fire. They help regulate the Earth’s climate and stores more carbon than all of the world’s forests combined. Healthy soils are fundamental to our survival.

However, many of our land management practices have caused significant damage to our landscape, resulting in widespread degradation and depletion of soil health. To many people, soil is just ‘dirt’, something that is used for growing plants in the back garden, or that farmers use for producing crops. But there is far more to soil than this.

Without soil, life as we know it simply would not be able to exist.

Facts about soil

Soil is the basis for plant growth It contributes to the maintenance of both the natural and planted landscape. It supports forests, wetlands, jungles, prairies and grasslands that spawn the planet's amazing vegetative biodiversity.

Soil supports animal biodiversity, above and below ground It's essential to the lives of wildlife, domesticated livestock and a fathomless number of micro/macroorganisms.

Soil is a living system A single gram of healthy soil contains millions of organisms including earthworms, nematodes, mites, insects, fungi, bacteria and actinomycetes.

Soil is a frontier for exploration Only about 1 percent of soil micro-organisms have been identified.

Soils process recycled nutrients Macro and micronutrients such as nitrogen, phosphorus, potassium even carbon, so that living things can use them over and over again.

Soil stores water Soil is important in providing an adequate water supply and maintaining its quality. Soil and the vegetation it supports catch and distribute rainwater and play a key role in the water cycle and supply. A one  percent  increase in organic matter in the top six inches of soil would hold approximately 27,000 gallons of additional water per acre.

Soil stores vast quantities of carbon Soil organic matter is one of our major pools of carbon, capable of acting as either a source or sink. More carbon resides in soil than in the atmosphere and all plant life combined.

Soil mismanagement has contributed to climate change The world’s soils have lost between 50-70% of their original carbon stock, much of which has been released into the atmosphere as carbon dioxide

Soil is in trouble The Food and Agriculture Organization of the United Nations (FAO) estimated that 33% of soil is moderately to highly degraded through erosion, salinization, compaction, acidification, chemical pollution and nutrient depletion, hampering soils’ function and affecting food production

Soil that is not covered with vegetative matter is vulnerable Soil is being swept and washed away 10 to 40 times faster than it is being replenished

We can rebuild carbon stocks in the soil A considerable part of the depleted soil organic carbon (SOC) pool can be restored through conversion of marginal lands into restorative land uses, adoption of conservation tillage with cover crops and crop residue mulch, nutrient cycling including the use of compost and manure, and other systems of sustainable management of soil and water resources

Soil Basics

‘Soil’ has several different meanings depending on the context.  Generally, soil is defined as "the unconsolidated mineral or organic material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants." Soil is the “skin of the earth” and is capable of supporting life on earth. The farmer and gardener may think of the soil in terms of the top few inches  (called topsoil) –based on the depth of a plow, spade or garden fork. Many tend to ignore what’s underneath in this deeper material (subsoil) which is important for plant growth, support and the storage and transfer of nutrients and water. Even more are unaware of the biology of soil -that soil is ALIVE.

Properties of soil

Soils are complex mixtures of minerals, water, air, organic matter as well as countless organisms which call soil home.

Sand, silt, and clay make up the mineral particles of soil.
Sand is the largest particle, silt are medium sized and the smallest particles are clay. Most soils are a combination of all three. The relative percentages of sand, silt, and clay are what give soil its texture. A clay loam texture soil, for example, has nearly equal parts of sand, slit, and clay.

Sand – 2.0 to 0.05 mm
Silt – 0.05 to 0.002 mm
Clay – less than 0.002 mm

Soil structure is the way soil particles aggregate together into what are called ‘peds’.  Peds come in a variety of shapes depending on soil texture and environment. Management practices that reduce soil cover, disrupt continuous pore space, compact soil, or reduce soil organic matter, negatively impact soil structure.

Soil organic matter helps develop stable soil aggregates. Soil microorganisms that are fed with organic matter secrete a gooey protein called glomalin, an effective short-term cementing agent or glue for large aggregates. Organic glues are produced by fungi and bacteria as they decompose plant residues.

The term soil tilth refers to the soil’s general suitability to support plant growth, or more specifically to support root growth. Soil tilth is a function of soil texture, structure, fertility, and the interplay with organic content and the living soil organisms that help make-up the soil ecosystem.
  1. soil structure
  1. soil profile
Dig down deep into any soil, and you’ll see that it is made of layers, or horizons.

O (humus or organic) -Mostly organic matter such as decomposing leaves. The O horizon is thin in some soils, thick in others, and not present at all in others.
A (topsoil) -Mostly minerals from parent material with organic matter incorporated. A good material for plants and other organisms to live.
E (eluviated) -Leached of clay, minerals, and organic matter, leaving a concentration of sand and silt particles of quartz or other resistant materials –missing in some soils but often found in older soils and forest soils.
B (subsoil) -Rich in minerals that leached (moved down) from the A or E horizons and accumulated here.
C (parent material) -The deposit at Earth’s surface from which the soil developed.
R (bedrock) -A mass of rock such as granite, basalt, quartzite, limestone or sandstone that forms the parent material for some soils – if the bedrock is close enough to the surface to weather. This is not soil and is located under the C horizon.

Soil Ecosystem

Soils are rich ecosystems, composed of both living and non-living matter with a multitude of interaction between them. There are literally thousands of interactions going on between the soil and the surrounding environment.  Without these interactions, such as leaf litter produced every autumn which feed soil life, the cycles of nutrients and of life are interrupted.

Soils play an important role in all of our natural ecological cycles—carbon, nitrogen, oxygen, water and nutrient. They also provide benefits through their contribution in a number of additional processes, called ecosystem services. These services range from waste decomposition to acting as a water filtration system to degrading environmental contaminants.
  1. soil interactions
Soil is a natural protector of seeds and plants. Within a soil ecosystem seeds can disperse and germinate. The soil provides a physical support system for plants, while both retaining and delivering nutrients to them. This, in turn, provides humans and other animals with a source of food as well as resources for potential medicinal or other goods. In addition, soil can both hold and release water, thereby providing for plant growth, flood control, and water filtration and purification services.

The diversity and abundance of life that exists within the soil is greater than in any other ecosystem. A handful of soil can contain bil­lions of different organisms that play a critical role in soil quality to support plant growth. Although we understand the vital services that these organisms provide by breaking down organic debris (plants, animals, and other organic materials) and recy­cling nutrients, scientists have only begun to study the rich and unique diversity that is a part of the soil ecosystem.

Soil Food Web

Soil is not an inert growing medium, but rather is teaming with bacteria, algae, microscopic insects, earthworms, beetles, ants, mites, fungi and other microbes that are the foundation of an elegant symbiotic ecosystem. Millions of species and billions of organisms make up a complex and diverse mix of microscopic and macroscopic life that represents the greatest concentration of biomass anywhere on the planet. This is the soil food web.

The creatures living in the soil are critical to soil health. They affect soil structure and therefore soil erosion and water availability. They can protect crops from pests and diseases. They are central to decomposition and nutrient cycling and therefore affect plant growth and amounts of pollutants in the environment.

  1. soil food web
The soil food web is the community of organisms living all or part of their lives in the soil. A food web diagram shows a series of conversions (represented by arrows) of energy and nutrients as one organism eats another. All food webs are fueled by the primary producers:  the plants, lichens, moss, photosynthetic bacteria, and algae that use the sun’s energy to fix carbon dioxide from the atmosphere. Most other soil organisms get energy and carbon by consuming the organic compounds found in plants, other organisms, and waste by-products.
Soil microorganism functions
  • Make nutrients available for plant uptake (in the soil or from the atmosphere)
  • Build and maintain soil structure therefore soil erosion and water availability (eg. forming aggregates)
  • Protect plants from foliar and root diseases
  • Build water-holding capacity in the soil (eg. improving organic matter accumulation)

Soil Microorganisms

Feed on organic matter, store and cycle nitrogen, and decompose pesticides. Help keep nutrients in the root zone and out of surface/ground water. Enhance soil structure, improving flow of water and reducing erosion.

FUNGI Up to 3,000 species of fungi are in the soil. Some feed on dead organic matter like crop residues that are more difficult to break down–others are parasites that attack other microbes. Some fan out from the root to get more nutrients and hold more water for the plant, delivering nutrients to the plant in exchange for carbon. They bind soil particles into aggregates (glomulin) and improve organic matter accumulation.

PROTOZOA Feed on bacteria, fungi, and algae. When they eat bacteria, their main food source, they unlock nitrogen that’s released into the soil environment slowly. They convert organic nitrogen to inorganic nitrogen that’s available to plants. Increase decomposition rates and soil aggregation by stimulating bacterial activity.

NEMATODES These microscopic worms are an important part of the nitrogen cycle. Most are non-pathogenic and don’t cause disease. They eat other organisms in the soil & provide a food source for other soil organisms that influence soil structure.

Arthropods Decompose and shred organic matter as an important part of the nitrogen cycle. Improve soil structure through burrowing and the creation of fecal pellets.

EARTHWORMS Expel partially decomposed organic matter, produce nutrient-rich casts, and make lubricated tunnels that aid soil structure and water movement in the soil.
Many effects of soil organisms are a result of the interactions among organisms, rather than the actions of individual species. This implies that managing a healthy food web is not primarily a matter of inoculating with key species, but of creating the right environmental conditions to support a diverse community of species. We can aid in their health and function by providing them the best food possible... organic material.

BacteriaL and Fungal Soils
Bacterial soils have a high ratio of nitrogen-rich organic material. In pastures and agricultural crop land, due to primarily consisting of green material tend toward the bacterial side as opposed to fungal -think 'green manures' and livestock making manure. Bacterially dominated soils are the type of soil that herbaceous — soft-stemmed plants, like most of our vegetables — prefer.

Fungal soils are associated with healthy, well-established forest systems, which tend to have a lot of woody material within the top layers and laying on the ground. As trees drop branches and limbs, certain fungi break them down, taking nutrients from the soil and feeding it to tree roots. In turn, the roots supply the fungi with sugars produced from photosynthesis, and this creates a symbiotic relationship between the two. As old trees die, fungi feed them to living trees, and the cycle goes round and round. It’s the right idea for fruit trees and food forests.
  1. inky cap mushroom
Tips for Creating Bacterial and/or Fungal Soils
To create bacterial soils, which is what we want for annual vegetable crops, we simply need to replicate what happens in nature. We can help this process along by burying or creating composts with kitchen scraps and grass clippings (GREEN matieral) along with BROWN, carbon-rich matter like cardboard boxes, paper, and leaves. Vermicomposting (using worms to speed the process) produces even more bacteria-rich soil. Compost can be applied to the soil as a solid, or it can be used to create compost teas and extracts.

For fungal dominated soils, the right choice for growing trees, we need to add a lot of woody organic material. This can be mulching with wood chips or bark applied to the soil surface, as it would be in the forest. Most importantly, though, fungi don’t like to be disturbed. Tilling the soil destroys the intricate network of mycelium (stands of hyphae that are fungi's body whereas the mushroom is it's fruit) that makes the whole system function, both by breaking the strands and by exposing the light-sensitive growth to the sun.

Sheet Mulch

soil improvement, weed removal, and long-term mulching
in one Method!

What is Sheet Mulching?
Sheet mulching is a layered mulch system that nurtures the soil and replaces existing lawns or other vegetation, eliminating the need to remove unwanted plant material. The layers suppress weed growth and break down naturally – creating a vibrant ecosystem that gives you healthier soil and plants. You start with a biodegradable weed barrier like cardboard, and from there build a thick, layered substrate with compost, alfalfa and mulch. As the materials break down, worms and other soil microorganisms move in, softening the soil below, and creating a healthy, aerated bed where once there may have been compacted, dead dirt.
  1. layers of sheet mulch
The Layers
There are many ways to go about sheet mulching with many differing opions on what works best. We utilize a couple of different layering systems depending on the desired goal of the area.
Lawn Removal:  The image shown here is the simplest and most effective layering system for the lawns we remove using sheet mulch. It consists of apply cardboard over the exisitng vegetation ensuring that it overlaps by at least 10". Make sure to water the cardboard completely as this will help hold it down if there's a breeze and also stimulates decomposition when the other layers are added. Next add a 1" layer of alfalfa which promots the growth of benifical protoza which are huge producer of plant ready nitrogen. Then add 2" of straw and finally 4" or so of arbor chip mulch.
Garden Bed Creation: Kitchen scraps and/or fresh compost such as livestock manure is a good first layer over the area for a new garden as this activates decomposition which is the driving force of sheet mulching -ensuring the existing vegetation does not grow back is key!  Next, lay down the cardboard overlapping the pieces by 10” or more and water it thoroughly. Next liberally apply humus rich compost across the entire area to innoculate beneficial soil microorganisms to the new garden.   If needed you can also use your native soil mixed with compost. After the compost is spread apply a few inches of alfalfa to promote microorganism growth. Then apply several inches of the final mulch of your choice -straw for annual gardens and arbor chips or bark for perennial beds.
Some Important Details
  • If you're going with a perennial bed then the woodier the mulch the better (perennials prefer fungally dominant soil) so any trees/shrubs in your yard can be pruned and shredded for mulch. If it's an annual bed then straw mulch works well (never hay, it is filled with seed).
  • If you need to get tree mulch from off-site you can try to track down local tree trimmers and see if they’ll drop some at your house -but the tree seed factor would need to be evaluated (Privet tree is great mulch but can be filled with seeds that germinate readily and will rapidly overgrow your garden).
  • Planting small plants and seeds: just uncover the area for the plant, down to the cardboard, and make an X in the cardboard to let the roots penetrate easier, place the plant in and back-fill. For seeds just dig them into the compost to the depth they prefer, cover back up and water everything in well.
  • Planting trees and large shrubs: plant them BEFORE sheet mulching. It's not difficult to sheet mulch around larger plants just ensure the cardboard is never too close to the trunk or base of the plant, keep it at least 4" away.
  • Sheet mulching in the Fall or Winter is the best time for free moisture which helps decomposition. We’ve done sheet mulch projects where the cardboard is gone in just 6 months with adequate moisture vs. 2 years in very dry areas of the yard.
  • Always remove the tape and/or staples from the cardboard before using it. It’s quite bothersome to garden with bits of tape surfacing all the time and no fun for those of us who like garden with bare hands to get a staple cut.

Some our Sheet Mulch Projects over the years

Find more details at's website 'Lawn to Garden'

Mulch-on Site

Mulch-On-Site (MOS) techniques are our company Best Management Practice for green waste reduction and building healthy soil.  Green waste is any organic (carbon based) material removed from a landscape or garden such as grass clippings, flower and shrub debris, leaves, and larger tree trimmings.

Our MOS method is a specialized technique of cutting, chipping and shredding virtually all healthy organic material trimmed out of the landscape during routine management or custom service visits.  After mechanically breaking down the organic material into smaller pieces we then neatly place the fresh mulch back into the landscape for further decomposition by soil organisms.  This process is usually done by hand pruners on the spot but we will use a Chipper-Shredder to get the materials small enough to Mulch-On-Site.
  1. mulch on site -chipper/shredder
Why Mulch-on-Site?
The leaves, plant debris and bark from dead-heading and pruning, some weeds and all naturally fallen debris are reused/ recycled into the soil of the landscape.  Incorporating these materials into the landscape, by directly applying this layer of food, Mulching-On-Site facilitates what takes place in a natural ecosystem.  MOS allows naturally occurring nutrients (Nitrogen (N), Phosphorus (P) and Potassium (K) as well as micro-nutrients to flow into your landscape through this consistent addition of organic materials. The organic materials feed soil microorganisms which in turn feed your plants so the need to fertilize or amend the soil is decreased substantially while populations of soil micro-organisms necessary for abundant plant life flourish.

The noxious organic materials (i.e. diseased, pest or chemical ridden plants, invasive weeds and seeds as well as some notorious disease spreaders) are hauled off-site to the local composting facilities.  Noxious material can be hot composted  but it does need to be monitored more accurately than composting healthy organic materials (monitor the heat and activity to ensure pathogens and weed seeds are killed). 

Mulch-On-Site methods further reduce energy inflows and outflows of the landscape by diminishing the need for movement of organic materials on or off-site.  By regularly utilizing the MOS technique within our urban landscapes pollution, fossil fuels, agency resources, forest degradation  -to mention only a few-  are vastly minimized.

Benefits to Mulching-On-Site
  • A resource efficient method (reduced, reused & recycled green waste, fossil fuels and financial resources)
  • Pollution is reduced (creates natural biofilter to purify rainwater as it percolates through soil for groundwater recharging each season)
  • Decreases negative off-site impacts (little 'waste' goes to local facilities, forest product conservation -i.e. conifer mulch)
  • Creates stability over time (reduced maintenance time and cost in mature landscapes)
  • Helps to restore injured soils (increased soil biodiversity replenishes sterile soils over time)
  • Keeps healthy sites healthy (decreased need for fertilizers by small but constant N-P-K additions)
  • Minimizes inflows and outflows (reduced need for movement of organic materials on or off-site)

  1. mulch on site diagram
  1. forest garden
  2. lawn to landscape conversion
  3. lawn to landscape conversion
  4. lawn to landscape
  5. rainwater mulch basin
  6. deer grass
  7. lawn to landscape conversion
  8. rainwater harvesting system