Let Organic Agriculture Become a Zero Carbon Partner
At the end of the COP 27 Climate Change Conference, climate change has become an urgent issue in the world. “Carbon” has attracted the most attention. Soil and plant are especially important players in this "carbon cycle." Photosynthesis in plants captures carbon dioxide from the atmosphere, “carbon emission” forms organic soil; when broken down by micro-organism in the soil, and excrete carbon back into the atmosphere as a gas , it can become the source of greenhouse gas emission and can be like a potential stock. Yet, amongst the many agricultural production, because organic and friendly farming does not use chemical fertilizer, it can reduce more carbon emission than many chemical fertilizer manufacturing processes.
Tze Xing Organic Agricultural Foundation (TOAF) has pushed for organic/friendly farming for over 25 years. Since joining the UN Framework Convention on Climate Change in 2021, TOAF pushed hard for renewable soil in the “Four Thousandth Initiative” ; and at the same time wished to explore if Is organic farming is helpful in carbon emission? In Taiwan’s current organic farming practices, what are the breakthrough in carbon emission, if any ?
How much carbon content in the world’s soil would enable it to achieve a net zero effect? Currently, carbon contained in the world’s soil is about 150 billion tons, which is almost double the atmospheric carbon dioxide. At the 2015 COP21 Paris Climate Summit, France started the “Four Thousandth Initiative” and estimated that if the carbon content of the top soil increase by 4 parts per thousand annually, it can balance the global release of atmospheric CO2. Therefore, it called for strong promotion of environmentally friendly agricultural practice to maintain and improve the soil quality. In practice, 4% of the goal requires adapting to local conditions, and is not an absolute standard figure; but it highlight through soil management, the importance of increasing soil organic carbon content. (SOC)
In the practice of organic farming, is recycled/renewable soil beneficial in capturing carbon? Using meta-analysis data from the 74 research studies by a multi-national research team compared organic and non-organic farming system (pairwise comparison) to determine the difference between SOC.
The conclusion: compared with non-organic farming management, the soil organic carbon (SOC) in organic farming showed a significant difference in the high value.
But there are conditions for organic farming to capture carbon. In its white paper, "Regenerative Agriculture and the Soil Carbon Solution” the Rodale Institute, the global pioneer organic farming in the US, used various farming system data from all over the world and pointed out that through regenerative agriculture farming management, it can store more than 100% of the current annual carbon dioxide emission, maximize carbon sink and reduce emission! Besides not using pesticides, chemical fertilizer, it encourages the building of a system for healthy soil - at least to include covered crops, residue cover, composting, crop rotation, and less ploughing, etc. If organic agriculture cooperates with no tillage and crop coverage, after two years, the SOC will increase 9%, after six years, it will increase 21%!
In terms of institutional environment, in the related sub laws of the Taiwan organic agriculture promotion law, there are "the production environment should implement good soil management, grow covered crops, avoid soil exposure, and adopt appropriate crop rotation, intercropping or timely fallow”, etc. which benefit SOC method. Although these are in principle only and is not a mandatory standard for organic verification, we can see when Taiwan promoted organic farm product verification ten years ago, the institutional environment conducive to the operation of carbon sink had long been paved.
“Organic” Effort in "Carbon Sink”
In practice, past effort of applying “no pesticide, chemical fertilizer” as its main objective in organic farming may not benefit agricultural carbon sink.
Here are some areas where Taiwan’s organic farming can further strive to improve:
(1) Minimized Ploughing Frequency
In Taiwan, ploughing is a very common practice, (the benefit of ploughing: ploughing can bring the deep layer of nutrients to the surface and enable the crops to grow better) But at the same time, it is can easily lead to the erosion of carbon- rich topsoil, and weaken the growth of Mycorrhizal bacteria, destroy soil pellets, and cause the original stable soil carbon to be released into the atmosphere which further destroy the existing stored soil carbon. Therefore, there is an urgency to avoid tilling or minimize the ploughing technique in farming.
(2) Use Suitable Organic Fertilizer
The purpose for using organic fertilizer is to provide timely nutrients to crops, with fast results mainly through high nitrogen fertilizer composition. This type of organic fertilizer often uses soy bean meal as the main ingredient. Although it yields quick effect, it is not beneficial to carbon sink. It may even speed up soil acidification and enable microorganisms to quickly decompose the organic matter present in the soil, speed up the release of renewable carbon. To promote carbon sink in soil, the use of such fertilizers should be reduced.
(3) Change the Management of Green Manure Crops
Although farmers may grow plant-based green fertilizer during leisure time to provide nutrients for the next crop, but most of them are turned into the soil before the flowering season. Currently, the composition of green fertilizer is mostly fiber and semi-fiber, less lignin ingredients, and has limited benefit to renewable soil carbon. On the other hand, the Rodale organization promotes "covering crops”, is different from the green manure crop in that the covered crops prevails on the topsoil when they are more mature, increasing the carbon in the soil, and reducing soil erosion. If soybean meal is used to cover the crop, it can also immobilize nitrogen and add more benefit to the soil.
Practice the Carbon Sink Farming Method and Work Together to Move Towards Net Zero
If Taiwan’s organic agriculture practice is to truly benefit renewable carbon, there are many areas in the production method which need to be adjusted. Perhaps many people may regard soil in tropical or subtropical regions such as Taiwan and other regions, organic soil matter decomposes quickly, which is not conducive to renewable carbon due to its high temperature and heavy rain. But a French research team carried out a global scale analysis based on various agricultural experiment data in the tropics, discovered that carbon sink rate is not greatly affected by the climate! The key to affecting carbon sink lies in the way of agricultural operations，and the amount of soil carbon input. Therefore, reducing ploughing, crop rotation, applying organic matters are still worth striving for. It seems that we should not underestimate those of us in low latitudes.
TOAF has been a long-term promoter of organic farming, and we feel more duty-bound to do this. TOAF has promoted the green conservation badge for over ten years, specially organized the first "Green Conservation Footprint Award” acknowledging model farmers. In addition to production, and the two awards in ecology, the "Carbon Exchange Special Award" has been specially added to encourage farmers who increase organic matter content through grass cultivation, covering crops and reducing ploughs on the land.
According to the UN statistic, one-third of the world’s soil has degraded. "Nourishing the soil" is not an overnight work. It requires step by step with footprints moving forward. In the future, we must refer to documented references to find the appropriate renewable carbon farming method suitable to local farming and gradually accumulate empirical observation and experience on the ground to form technical guidance and operation guidelines. We look forward to exploring and working hard with scientists and farmers!