We’re coming across numerous efforts on replacing plastic products with those created out of agri-waste. This represents a huge opportunity wrt plastic substitution with compostable/more bio-degradable alternatives. Of course, there’s questions around lifecycle energy costs, transport footprint (with centralised production and even export!) and wrt the value accrual at the point where the raw material exists.
But we really are faced with a bigger dilemma : In a country where soil carbon levels have fallen dramatically, plastic mulch sheets are being used at a crazy scale, is it ok to even think - at this point - in terms of “agri-waste” for organic material that the soil could and should benefit from? Is it not nutrient and water extraction at a massive scale which then needs replenishment using fertilizers and other additives (chemical or otherwise) which have their own footprints and costs?
What’s the right way to look at this? (And God, what a messed up web of cross dependencies we’ve created!)
One of the ways agri-waste can be tackled and soil organic carbon & fertility can be increased at the same time is converting agri-waste to biochar and then using it as a fertilizer.
Biochar is a type of charcoal that is produced by burning organic materials, such as wood chips or agricultural waste, at high temperatures in the absence of oxygen. The resulting material is a stable form of carbon that can be used to improve soil health and reduce greenhouse gas emissions. Biochar has been shown to increase soil organic carbon, which in turn can improve soil fertility, water retention, and nutrient cycling.
By converting waste materials such as crop residues, manure, and forestry byproducts into biochar, farmers can create a valuable product that can be used to improve soil health and reduce the amount of organic material that is sent to landfills or burned in open fields. This not only reduces the amount of greenhouse gases that are released into the atmosphere, but also provides a source of revenue for farmers.
One key challenge for Biochar production is that the current solutions are based on centralized large scale production units hence there are transit costs (and emissions) that are involved. But, it has been gaining a lot of traction lately and hopefully, we’ll see a good solution in some years.
Mash Makes is an Indian company working in this space. I had spoken with them some months ago and they seem to be doing great work. @sameershisodia Check them out!
The addition of biochar to farming practices can require a variety of changes at the farmer/farming level, depending on the specific goals and context of the application. Some common changes that may be necessary include:
Adjusting soil pH: Biochar is typically alkaline, which means that it can raise the pH of the soil it is added to. However, most of Indian soils are acidic so this is an added benefit of using bio-char.
Changing nutrient management: Biochar can absorb and hold onto nutrients, which can affect the availability of these nutrients to crops. The nutrients are released slowly over time and hence the plants receive a sustained dose of nutrients. The farmers may need to alter nutrient management practices and hence don’t need to constantly use fertilisers as fertiliser leeching is reduced.
Altering irrigation practices: Biochar can affect the water-holding capacity of soil, so farmers may need to adjust their irrigation practices to ensure that crops receive adequate water. Watering too much in one go can cause water logging issues for example. But since biochar holds water into the soil, the soil
Modifying planting methods: Biochar can alter soil structure and improve soil fertility, so farmers may need to modify their planting methods to take advantage of these changes. For example, they may need to plant crops in different locations or at different depths.
Changing equipment and application methods: The addition of biochar may require changes to farming equipment and application methods. For example, farmers may need to modify their tillage practices to incorporate biochar into the soil, or they may need to purchase new equipment that can apply biochar evenly.
However, these changes are easily implementable and in fact reduce the work-load of the farners. The main constraint with bio-char adoption is making bio-char cost effective and scalable.
