Composting and Vermicomposting From Organic Wastes

The sustainable methods of composting and vermicomposting from organic wastes are being introduced internationally by recycling organic wastes, transforming kitchen scraps, yard trimmings, food wastes, leaves, and other biodegradable materials to obtain organic fertilizers, nutrient-rich compost and worm castings that enhance soil fertility and improve biodiversity.

Introduction to Composting

Soil is a primary source of nutrients required for plants for growth. There are 17 nutrients found in soil of which three main essential nutrients required in larger proportion are Nitrogen (N), Phosphorus (P) and Potassium (K). These are called macro-nutrients. Others include Calcium, Magnesium, Sulfur, Zinc, Iron, Manganese, Copper, Boron, Molybdenum and Chlorine.

The sustainable practices of decomposition of organic wastes for composting and vermicomposting is helping to transform kitchen scraps and yard debris into nutrient-rich soil amendments.

These are somehow less essential, not required in larger proportions but still help boost the crop production. These are called micro-nutrients.

What are Soil Nutrients

Nutrients are preserved in the soil in various ways, for instance, decomposed animal and animal wastes and plant material, the atmosphere, bacteria activity and fertilizer and water. These processes provide nutrients to plants in a water soluble form that seeds and plant roots can absorb which help their growth.

Soil Macronutrients: Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium Mg, Sulphur (S)

Soil Micronutrients: Iron (Fe), Manganese (Mn), Copper (Cu), Zinc (Zn), Boron (B), Molybdenum (Mo)

Non-Essential Nutrients: Cobalt (Co), Strontium (Sr), Vanadium (V), Silicon (Si), Nickel (Ni)

Scientifically, the Micronutrients, also referred to as ‘trace elements,’ are absorbed by plants in small amounts but they’re still essential to their healthy growth. Micronutrients are therefore as important as macronutrients. Iron, for instance, helps catalyse chlorophyll formation.

Boron is crucial to photosynthetic processes, while Manganese, Molybdenum and Copper are vital for enzyme activity. So the growth and productivity are both dependent on many factors like quality of the seed, soil quality, water, climate and the infrastructure itself. Over the years, the Soil Sciences has emerged as an important academic subject at advanced agricultural studies in colleges and universities.

Besides the conventional ways for soil analysis, there are remote soil sensing technologies and machine learning (ML) tools like Soil Cloud being used in United States, to accurately extrapolate data points between the field samples which create accurate, high resolution data maps.

They paint a vibrant picture of soil attributes and provide actionable data maps for an integrated view of the soil. These technologies help obtain soil structure, moisture levels, soil compaction factors and nutrient profile.

What is Composting

There are many ways to enrich the soils having deficient or insufficient components to boost its performance for better growth and healthy yields. There are chemical fertilizers which are natural or artificial substance containing the chemical elements that improve growth and productiveness of plants.

Similarly there are composts which execute the same activity but are comparatively safer for soil, plants, human and the climate.

Composting is a controlled, aerobic (oxygen-required) natural way of recycling process through natural decomposition that converts organic materials like food waste and plant leaves into a nutrient-rich, biologically-stable soil enhancement or mulch. This end product of this process is compost.

Microorganisms feed on the materials added to the compost pile during the composting process. They use carbon and nitrogen to grow and reproduce, water to digest materials, and oxygen to breathe resulting in nutrient rich material as an organic fertilizer.

It is one of the most appropriate way to reduce our trash, address climate change, and build healthy soil. By turning our food scraps and yard trim into compost, we transform our waste streams into a beneficial, value-added soil amendment and use it to protect the environment and create healthy communities.

Can We do Composting at Home?

There are both ways to prepare composting materials. We can do it at home and it can be prepared commercially. People in USA and in many other countries are using these procedures at their homes.

It is a resourceful way to recycle the food scraps and yard trim we generate at home all the year and can manage our waste more sustainably.

We can reduce the volume of materials that might otherwise be disposed of in landfills or trash, for instance, leaves, grass clippings, yard trim, and food scraps and prevent powerful greenhouse gases being emitted into the atmosphere.

Composting involves minimal effort, equipment, expense, and expertise and can be a fun.
We save money by producing a free, high-quality soil amendment which reduces our use of fertilizer and pesticides.

We can use compost to build healthier soil, prevent soil erosion, conserve water, and improve plant growth in our garden and yard.

The crop yields from such soils are healthier and safer for humans.

What is Community Composting?

Interestingly, if anybody doesn’t have a space for composting, participating in a local municipal or community can also be considered for composting program which may collect the food scraps or offer a designated location where we can drop them off and do this work.

In United States community composting sites are locally available and often dispersed throughout a town, city, or neighborhood.

They may be located at schools, farms, community gardens, parks and other public lands, at community organizations, and in rural to urban areas. Community composting can be scaled and designed to fit the needs and resources of a community.

Though sites may be small as compared to municipal or commercial composting facilities, community composting can scale up to handle more materials by adding or expanding the size of existing sites.

This, in future, will be an important tool for climate change and providing a host of unique benefits for environment, economy and community.

How is Composting Done

Organic materials, such as wasted food (mainly vegetables and fruit), dry leaves, and untreated wood chips are collected and piled up in preferably fabricated box or otherwise in any open place where the temperature remains between 80 to 140 degrees Fahrenheit to execute the decomposition process.

The process time may vary in different conditions. Lower temperatures normally slower the decomposition process. These organic materials are known as feedstock in the composting process.

Composting requires a specific carbon-to-nitrogen ratio of the materials added, as well as adequate oxygen and moisture, so that the microorganisms in the system can thrive as they digest and break down the organic materials. The structure of the compost pile also contributes to the success of the composting process as factors like waste size and pile density affect oxygen and moisture levels.

As materials decompose, the temperature of the pile rises and then falls. The natural decomposition process results in a dark, crumbly, earthy-smelling material called compost.

Additionally, particles of sufficient size of waste wood can also be used as compost bulking agents to provide structural support and maintain air spaces within the composting matrix to maintain its quality.

How Much time Composting Takes?

A to 6-8 weeks of a standard decomposition environment would yield a good compost material. Similarly from a 100kg of fresh organic material we can get 15 to 25kg of compost. The amount of compost required for land depends upon the actual requirement of the user.

Generally, for top dressing or amending soil, about 2 to 5 centimeters of compost is applied for home gardens. Many crop yield studies in US and some European countries have found higher crop yields in plots with added compost as compared to plots without added compost.

Composting at Larger Scale

Commercial and industrial composting is executed at large-scale composting facilities which can handle a high volume of organic materials. These facilities normally provide compost materials to the residential, commercial, and institutional sectors.

Commercial composting diverts significant quantities of organic materials from disposal facilities which collect feedstocks from regional geographic areas which helps in safe disposal of food wastes.

Understanding Vermicomposting

Like Composting, Vermicomposting is a kind of composting in which certain species of earthworms are used to enhance the process of organic waste conversion and yield a better end-product.

This is a mesophilic process utilizing microorganisms and earthworms. Earthworms are fed with the organic waste materials essentially called feedstock which passes it through their digestive system and gives out in a granular form (cocoons) which is known as vermicompost.

Vermicompost are earthworm excretions called castings, which can improve biological, chemical, and physical properties of the soil. The chemical secretions in the earthworm’s digestive tract help break down soil and organic matter, so the castings contain more nutrients that are immediately available to plants.

Additionally the worms are also an organic food for the household and commercial poultry.

Which Materials Can be Used for Vermicompost 

A wide range of organic residues, such as straw, husk, leaves, stalks, weeds, livestock wastes, poultry litter, dairy wastes, Food waste (feedstock), organic fraction of Municipal Solid waste, bagasse, digestate from biogas plants etc. can be converted into vermicompost.

Role of Earthworms in Vermicomposting

Each earthworm weighs about 0.5 to 0.6 gram and eats waste equivalent to its body weight and produces cast equivalent to about 50 percent of the waste it consumes in a day. The moisture content should range between 32 and 66 percent and the pH is around 7. The level of nutrients in compost depends upon the source of the raw material and the species of earthworm.

There are approximately 3600 types of earthworms. Red earthworm species, like Eisenia foetida, are most efficient in making compost because they tolerate temperatures ranging from 0 to 40°C but practices show more regeneration capacity at 25 to 30°C and 40–45 percent moisture level in the pile.

These worms can be piled up in bins having adequate drainage and ventilation facility, raised beds, windrows and surface of the grass. Some worms however live below the surface also.

Using Compost Worms for Poultry

Red Worms which are mainly composting worms are quite good feed for poultry and chicken containing protein and other essential vitamins and minerals. For chickens, this nutrient-rich organic feed helps promote health and rapid growth.

Additionally, earthworms are often readily available in the ground also, so they are a convenient options for chickens and their offspring to have their feed from an open natural source. Normally, a mature chicken can eat 60-80 worms per day which would be quite expensive and may cost around 25 to 30$ per week.

However, chickens need variety in their diet so earthworms should be given to chicken in moderate quantity as a balanced diet alongside other organic feed like ground insects, corn, herbs, greens, grains, soybean etc and insoluble grit as supporting substance to ensure a balanced feed that provides them with the nutrients they need to stay healthy and growing.

Similarly the organic meat and eggs obtained from such poultry are considered safer for human health having higher fat, vitamin and protein content as compared to those which are fed with chemical, antibiotic or hormone based feed. In US there are now organic food stores and online sources selling organic chicken products with the label “Organic”.

However the authenticity of such stores may be checked prior to purchase from such stores. There are also government guidelines and laws to study which regulate and labels food as certified organic foods.

Benefits of Composting 

The sustainability of organic wastes is as important as the other recyclable materials. The extra ordinary use of chemical fertilizers in recent past is leaving adverse effects primarily on the ground water, crops, environment, plant health and is damaging useful herbs and microorganism.

Secondly the chemical fertilizers contain some secondary ingredients which may cause disturbances to health.

The long duration use of Chemical fertilizer reduces the microbial activity and imbalance of the pH of the soil. The composts and vermicomposts are advanced and organic substances widely being used in homes as well as commercially to obtain healthier and safer plant yields.

Similarly, worms used in vermicomposting are safer and healthier diet for poultry for producing organic meat and eggs. The organic poultry and poultry products thus have a healthier impact on human health as compared to artificially grown foods.