Traditional agriculture contains low-carbon smart rice fields | tradition | wisdom

Traditional Chinese agriculture is a model of "harmony between man and nature" and "the way of nature", providing wisdom and solutions for the development of modern ecological low-carbon agriculture, and providing important inspiration for the sustainable development of world agriculture

China's important agricultural cultural heritage sites are like shining pearls scattered on the vast land of China, witnessing the continuous growth of China's excellent traditional agricultural culture. In these heritage sites, the seemingly ordinary ancient and traditional cultivation methods contain the green and low-carbon Chinese wisdom everywhere.

Agricultural cultural heritage sites are a living gene pool of climate resilient animal and plant resources. The National Crop Germplasm Bank of the Chinese Academy of Agricultural Sciences, located in Beijing, has a capacity of 1.5 million copies and currently has over 540000 long-term preserved crop germplasm resources. Among these precious germplasm, there are rice varieties such as "Xiaozhan Rice" collected from Tianjin, "Xiaofeng" from Dehong, Yunnan, and "Golden Seedling" and "Honggu" Xiaomi from Aohan, Inner Mongolia. Through tens of thousands of years of evolution, domestication, and thousands of years of traditional farming cultivation, these farm varieties not only have strong climate resilience, but also are tolerant to barrenness, disease, and pests. Although the yield is not as high as modern high-yield varieties, the quality is excellent and the flavor is unique. It can reduce the use of about 30% of fertilizers and pesticides, and reduce greenhouse gas emissions by more than 20%. These rare agricultural varieties are still nurturing local people and revitalizing industries, providing excellent genes for modern adaptation to climate change and innovation of green and low-carbon emission varieties.

The traditional rice cultivation system that is tailored to local conditions is beneficial for reducing methane emissions. Methane is the second largest greenhouse gas after carbon dioxide. Rice paddies are one of the main sources of methane emissions, but their emissions are much lower than those of nearby natural wetlands or swamps. The ancestors of China adapted to local conditions by opening mountains and terraces, building embankments and embankments, digging and stacking mud. They built a rich and diverse rice field system and rice cultivation system on the banks of steep mountains and rivers and lakes. Rice fields such as terraced fields in Chongyi, Jiangxi and stacked fields in Xinghua, Jiangsu, as well as ecological rice cultivation systems in Guangnan, Yunnan and Long'an, Guangxi, still preserve the intact traditional Chinese rice cultivation culture. Due to the strong aeration tissue of rice plants, they can transport oxygen from the air to the anoxic paddy soil. This can not only reduce the activity of soil methane producing bacteria and reduce methane production, but also promote the activity of methane oxidizing bacteria, consuming 80% of methane oxidation in the soil. Therefore, the methane emissions from rice paddies are only about 30% of those from natural wetlands. In addition, traditional rice cultivation places great emphasis on collecting river mud, pond mud, ditch silt, etc., and directly or through composting, applies them to rice fields as fertilizer. This not only reduces the amount of fertilizer applied to rice, thereby reducing greenhouse gas emissions from rice paddies, but also reduces organic matter accumulation in natural wetland depressions, leaving methane producing bacteria with insufficient "food" and significantly reducing methane emissions in natural wetlands or depressions. In addition, in the traditional rice farming system where rice, fish, and duck coexist, fish and duck activities can significantly increase the oxygen content of rice paddy water and soil, thereby inhibiting methane production and promoting methane oxidation, reducing emissions by more than 15% compared to flooded rice fields.

In the book "Qi Min Yao Shu" nearly 1500 years ago, China had the technique of rotating grains and beans to cultivate the land, which was known as "changing grain and fields every year". The traditional dry farming system that combines land use and land cultivation can promote carbon sequestration and emission reduction in farmland. The concept of "constantly improving soil fertility" is an important traditional agricultural ideology in China. The ancestors achieved continuous improvement of soil fertility through measures such as planting green manure and other nutrient crops, applying organic fertilizers, and intercropping rotation. In agricultural cultural heritage sites such as Qitai dry farming system in Xinjiang, Fumeng dry farming system in Liaoning, and Wenyangtian farming system in Daiyue, Shandong, as well as in the Yellow River, Huaihai River, and Northeast China, the crop rotation and intercropping planting systems that are being vigorously promoted, all adhere to the traditional Chinese agricultural concept of "constantly improving soil fertility" and the combination of land use and land cultivation. According to the Food and Agriculture Organization of the United Nations, the annual nitrogen fixation of leguminous crops worldwide reaches 130 million tons. In addition, traditional dry farming such as crop rotation and intercropping can promote the formation of soil macroaggregates, protect soil organic matter, improve the stability of soil organic carbon, and enhance the carbon sequestration capacity and carbon storage capacity of farmland soil.

The traditional planting and breeding system of agroforestry helps rural energy conservation and emission reduction. The Chinese ancestors not only obtained food and other agricultural products from farmland, but also obtained more agricultural products needed for daily life from mountains, rivers, forests, fields, lakes, grasses, and sands through methods such as agroforestry and crop breeding. There still exists an energy-saving and emission reducing planting model that replaces fossil energy with natural biomass energy in agricultural and cultural heritage sites such as the Zhagana Agriculture, Forestry and Animal Husbandry Complex in Diebu, Gansu, the Alukerqin Grassland Nomadic System in Inner Mongolia, the ancient mulberry tree group in Xiajin, Shandong, the Yellow River ancient channel, and the Shaanxi Ancient Zaoyuan, the sericulture system in Tongxiang, Zhejiang, and the tea culture system in Fuliang, Jiangxi. Animal manure has become a household fuel for herdsmen, and the pruned branches of fruit trees can be used as fuel for daily cooking and winter heating for villagers, and even processed into biomass compressed fuel. In Gaolan Ancient Pear Garden, Gansu, pruning each acre of pear trees can generate 1.5 tons of branch biomass fuel per year, which is equivalent to saving 0.75 tons of standard coal. In Tongxiang, Zhejiang and Xiajin, Shandong, each mu of mulberry tree can produce about 1 ton of branches per year, which can be used as biomass fuel, equivalent to saving 0.5 tons of standard coal. These biomass come from carbon dioxide fixed by photosynthesis in agricultural and forestry systems, which is burned and then emitted into the atmosphere. It is a process that takes from nature and returns it to nature, without increasing greenhouse gas emissions, and can offset the carbon dioxide emissions from fossil energy consumption.

The world today is facing challenges such as global warming, declining biodiversity, and ecological degradation. It is urgent to find solutions based on nature and build a new system of climate resilient agriculture and food that is naturally improving. Traditional Chinese agriculture is a model of "harmony between man and nature" and "following the law of nature", providing wisdom and solutions for the development of modern ecological low-carbon agriculture and important inspiration for the sustainable development of world agriculture.