Susty Living Series: The Gains of Rice Straw

A few weeks ago I stumbled on a video about a Thai entrepreneur who had figured out a great way to turn rice straw into recyclable and bio-degradable plates. And boy was I wow-ed (if that is a real word)! For those who do not know, rice straw is the vegetative part of the rice plant that is left behind after the rice grain has been harvested. For some farmers, this by-product of rice production is viewed as waste which should be burnt on the field but for others, especially those who operate mixed farming systems with livestock; it is a major source of forage/feed additive for the livestock and ever nourishing nutrients for the soil, when ploughed under.

Rice straw on the field

The short video clip summarises the innovative process from cutting up the straw to boiling for several hours to a couple of other processes and voila! A beautiful and very sustainable version of the "paper plate" or "take away" or "take out plate" is born.  This got me thinking like hold up, hold up, HOLD UP! Nigeria, my home country, produces rice, right? Yes! In fact, Nigeria is the largest producer of rice in Africa and the 14th largest producer in the world following the rice giants of China and India. The natural environment of the country is so rich that rice is cultivated in every ecological zone of Nigeria. I mean every single one; from Kebbi to Ebonyi to Ogun and Benue states, to name a few. This means that there are tonnes and tonnes of purposeful straw that is not bring used to full potential. Keep in mind that based on weight, rice plants produce an equal amount of rough rice to rice straw i.e. about 50% each.

This gave me an idea and I did some research into other ways which the "waste" from rice production can be converted sustainably and I was not disappointed.

Picture 1: Paddy straw mushroom. Picture 2: Oyster mushroom

Picture 1: Plates made from rice straw. Picture 2: Straw to biochar

In Housing - Starting from here in Nigeria, I found a 2016 article in a local paper detailing a proposed project of 10,000 housing units made with rice straw and ABS technology in Gwagwalada area of the Federal Capital Territory. The project was backed by the Federal Mortgage Bank in collaboration with a property development company and a European Export bank. The choice of Assembly Building Block (ABS) technology was because it is patented and licensed for the construction of all kinds of buildings adapted to a region and the choice of rice straw was for its durability - it can last 20-50 years with minimal maintenance and also creates additional wealth for the farmers.

As Food - Did you know mushrooms that can be gotten from rice straw? Volvariella volvacea or paddy straw mushroom is not only the easiest mushroom to cultivate with an incubation period of 14 days; it also requires very little investment cost. With as low as 10kg of dry straw, one can harvest 0.kg of mushroom. One can also cultivate the nutritious oyster mushroom AKA Pleurotus on poor-quality straw.

In Fuel - Taking a more technical route, many researchers have documented the immense potential which rice straw possesses as a source of alternative, renewable bio-energy. Certain thermal and biochemical processes are applied to convert the straw to ethanol, hydrogen and methane which can replace fuels for combustion, heat and electricity generation.

As Soil improvement - Rice straw can be used to produce a carbon-rich material known as Biochar which helps repair the soil by improving productivity, carbon storage and the filtration of water percolating through the soil. Biochar is a charcoal-like substance which is gotten from the burning of rice straw and other biomass elements in a process called pyrolysis, which minimises oxygen levels, reduces contamination and stores carbon safely. Not only is the heat and energy from pyrolysis a source of clean energy, but biochar is also a stable form of carbon that doesn't easily get lost in the atmosphere.

The opportunities possible with rice straw are numerous with varying economic and environmental benefits. The major challenge encountered appears to be the supply chain for straw. Collecting rice straw involves picking up the rice straw materials, compacting them into bales and transporting them for processing or storage, and these require a lot of resources and energy, which makes the end products very pricey and inaccessible for mass usage. Various scientists and green organizations are working tirelessly to develop new technologies to increase the collection and utilization of rice, transforming it from the "waste" material it is so widely known as to a source of the "wealth" for regions and the environment.