“Beta, I miss those tasty bhindis that I used to relish in my childhood. Everything was so organic those days. But aaj kal, sab mein chemicals he.Un dino jaise swaad kahan raha ? ”
This is the constant lament we all hear from our grandparents. True, there was a time when farming was purely organic. However, in today’s era of booming industrialization and overpopulation, agriculture is characterized by high yields, fertilizers and pesticides. These relentless practices have backfired with visible negative implications on human and environmental health. As a result, many people believe that going back to traditional and sustainable practices such as composting is the only way to safeguard our planet for the future. Therefore, it is pertinent to know, if composting can effectively substitute fertilizers or not.
To delve deeper into this question, it is crucial for us to first understand the physiology of plants, and their nutrient requirements.
Plants meet their nutritional needs for growth by absorbing the soil nutrients, water and carbon dioxide, in addition to the required sunlight. The total essential plant nutrients include 17 different elements, which are usually obtained from the air or the soil. The nutrients required by plants are classified into two groups – Macro nutrients and Micro nutrients. Macro nutrients are the ones which are required by plants in large quantities e.g., Nitrogen, Phosphorus, Potassium, Calcium etc. while micro nutrients are those which are required by plants in smaller quantities e.g., Iron, Boron, Chlorine, Manganese etc... Usually, the soil is naturally blessed with many mineral nutrients to fulfil the basic needs of the plants, but in case of soils which are regularly used for growing plants, mineral deficiency is not uncommon. Hence, there arises a need to add nutrient rich substances such as fertilizers or compost to the soil to replenish the lost nutrients.
Are they same?
Well not at all !
Compost is the result of various decaying organic substances - food waste, garden waste and many more. It appears as an amorphous dark brown soil like substance and is rich in a mixture of natural plant nutrients as well as humus. Here are some illustrations..
According to Britannica, “Fertilizer is a natural or artificial substance containing the chemical elements that improve growth and productiveness of plants. Fertilizers enhance the natural fertility of the soil or replace the chemical elements taken from the soil by previous crops.” These are mostly soluble, readily absorbable and thus have a rapid effect on the crops. Moreover, they are nutrient specific and we can select them according to our needs. The most widely used solid inorganic fertilizers are - urea, diammonium phosphate and potassium chloride etc.
As both of them have same uses, there arises a conflict between the efficacy of fertilizer and compost. Compost promotes healthy microbe growth within soil and enhances the health of natural soil. They may have a slower release rate, but, in the long run it produces higher quality, larger yields and a more hardy soil and improves texture, porosity, and water holding capacity. Consequently attracts several soil friendly microorganism and earthworms, which further nourish the soil. Apart from that, compost is cheaper and easier to prepare than fertilizers. On the other hand, fertilizers are mostly soluble salts or solutions which are rapidly taken up by plants but it will overload the soil with nutrients. Fertilizers being inorganic and not easily degradable are detrimental to the environment. In addition, fertilizer based chemicals can leach into soil and find their ways into drinking water and food chain, causing a number of health problems in humans and animals. In the long term, it robs the soil of its pristine beauty, drastically changing its pH values and tale ends in complete degradation!
It is said that, “Compost feeds the soil but fertilizer feeds the plants.” The nutrients of fertilizer only nourish the plants but starve other rhizosphere and soil organisms by making the soil environment uninhabitable for them. Many of these soil organisms are symbionts that impact our soil.
Composting by ourselves??
Yes, let’s have a look!
Step 1: All the ingredients you need:
The materials used in compost are broadly divided into two subcategories. Green Materials consist of scraps or leftovers of fruits or vegetables , used eggshells, tea leaves or bags, coffee, plant parts, and garden wastes etc. The Brown Materials include Dry leaves, fallen twigs, old newspaper pieces, straw, cardboard, paper towels/bags etc and many more. Organic wastes such as cow dung are also a popular component used in many types of compost. Avoid using non-biodegradable materials, synthetic chemicals, ash, sickly plant materials, animal products (such as dairy, meat or bones) and oily or spicy substances, as these can irritate or repel the decomposers and disturb the composting process.
Step 2: Choosing the compost bin:
You can choose either of the open pile or the enclosed bin .But the enclosed one will retain heat and speed up the process. The size and type of container must depend on quantity of targeted substance.
Step 3: Choosing your compost location:
You should choose a location which is flat, well-drained and sunny. As composting is a slow process an undisturbed place is advisable. The chosen location is preferred with easy access for filling and emptying the contents. Ideally, your bin should be on bare soil.
Step 4: The process:
Start with a layer of coarse materials (like twigs) to allow for drainage and aeration. Cover this layer with leaves. Then make alternate layers of green (nitrogen-rich material) and brown (carbon-rich material) material. If you add a thin layer of finished compost or good garden soil between brown and green layer, it will increase the process of conversion and will make better compost. Remember to moisten each layer with a sprinkler at regular time intervals. Continue to add layers till your bin is full.
Step 5: Maintenance:
Once the bin is full make it a point to check your compost and overturn it every week so enable proper aeration and mixing. Don’t forget to mix the lower layers too. Keep adding dry material or water to maintain the correct moisture levels. The more you keep turning it; the better would be the breakdown process and odour elimination.
Step 6: Extract your compost:
Most of the active composting period vary between 14 days to six months. A perfectly mature compost must be dark brown, with a crumbly soil-like texture and a smell resembling to earth with no foul odours. All the finished compost can be removed gently from the bin, leaving the unfinished materials to continue decomposing.
Why composting?
The need of switching to composting comes with the disadvantages associated with fertilizers. The reckless use of fertilizers in the past years (starting from Green Revolution) is now manifesting itself in the side effects like water pollution, bio accumulation, long term decline in soil fertility due to reduced microbial activity and disturbance in pH level etc. Thus, composting establishes its relevance as a cheap, environment friendly, easily available and a sustainable alternative without any side effects.
Wonder how composting has an edge over fertilizers?
Firstly, it enriches the soil, helps retain moisture and suppress plant diseases and pests. It is much more affordable compared to fertilizers, thus suitable for small scale farmers. It encourages the production of beneficial bacteria and fungi that break down organic matter to create humus, a rich nutrient filled material. Moreover, reduces methane emissions from landfills and lowers carbon footprint. As a matter of fact, is a good method to ‘Reuse’ the biodegradable wastes? Its hidden benefit is that it encourages waste segregation, which is so unpopular everywhere.
Why composting not a popular option??
Firstly, fear about presence of pathogens in compost. Detection of human pathogens in compost is relatively rare but does happen. In general, survival of the pathogen is attributed to either the entire pile or pockets within the pile not reaching the sterilizing temperature. Contaminated composts, even at low amounts, have the potential to transfer pathogens to produce and eventually cause illness.
Secondly, compost contains some nutrients but often miss many minerals that are present commercial fertilizers, such as: sulphur, calcium and many more. The nutrient value of compost is low compared with that of chemical fertilizers.
The other common problems of this labour intensive process includes, space issues, bad odour and long-duration. Long-term and excess application of composts to agricultural soils can result in high accumulation salts.
The Bottom-line
Composting is much more eco friendly and healthier alternative however at present circumstances it seems difficult if composts can completely substitute fertilizers. The fertilizers have had a tremendous role in improving plant yield in short time span, therefore, their use gained momentum globally. But climaxing, composting is a small step towards waste management but a giant leap for Mama Earth.
- Article by Swati Nayak, Aishwarya, Astha Singh
Well written and very informative!!