Soil is everything! Huadong black soil raised rice and red soil to grow tea. Chen Zunxian studied it for 42 years and selected the "county soil" of Taiwan.

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People often say that they love the land, but do you really know what the soil of your hometown is? Chen Zunxian says that most Chinese people do not know the soil under their feet, nor do they know the uniqueness of the native land, but big countries in the world, such as the United States, regard soil as an important strategic resource, and each state represents "state soil." some state governments even legislate to protect state soil.

Chen Zunxian, a senior soil survey and soil pollution expert and distinguished professor of the Department of Agronomy and Chemistry at National Taiwan University, who retired in 2017, is currently vice president of the Taiwan Institute of Water Resources and Agriculture, based on decades of soil survey data in the country. representative soil series are selected for each county and city.

Chen Zun-hsien, who has been a "native" all his life, says that there are many advantages in understanding "county land." not only will it be very helpful to farmers to grow crops, but local governments should also know about county land and have a better grasp of local future development and planning. (for soil information, please see the end of the article.)

Chen Zunxian, a soil expert, found out for the whole Taiwan that the children of Tainan farmers who grew up on saline soil represented by each county (Photography / Lin Yijun) were admitted as soil experts in the agrochemical department.

Chen Zunxian starts with the soil of his hometown. Born in 1952 in Xuejia Town, Tainan County, he is a standard peasant. He recalled that in the 1960s, Xuejia near Beimen District was mostly saline soil and a variety of sweet potatoes, because of poverty, food and sweet potatoes could only be served with lard, not meat. Later, after the saline soil was improved, onions, garlic and general crops could be grown.

He still remembers that at that time, the soil in Xinying Town, Tainan County, was too sticky to loosen. He had seen cattle ploughing the fields with difficulty. At last, they all knelt down, and the soil was still difficult to loosen. "it's called looking at Tiantian, which is all used to grow sugar cane."

Later, Chen Zun-hsien was admitted to the agrochemical department of National Taiwan University. At that time, the score of the agrochemical department was comparable to that of the current medical department, and his classmates were Hao Longbin. After continuing his doctoral program at the Institute of Agricultural Chemistry, he went into the field of soil investigation. "my teachers all told me that soil investigation was unpopular, but there was no need to worry about people taking jobs." When Chen Zunxian stepped in, he found that the soil survey was not only unpopular, but also extremely lonely. "after graduation, the research wanted to talk to experts, but as a result, there were fewer than 10 domestic scholars."

This lonely road to research is by no means easy. Chen Zunxian has traveled all over Taiwan and dug up the whole Taiwan. Taking the investigation of the background value of heavy metals in the soil as an example, he and the research team of three other universities have dug up 9000 samples of the mainland in the past ten years. For each sample rice, 40 ears of rice were collected from the same field, evenly mixed, and then reduced according to the quartet to obtain a representative sample. Finally, the report on the content of heavy metals in soil and rice in Taiwan was compiled, and every word was the result of painstaking investigation.

Tai-Kang profile of Taikang soil Series in Tainan (courtesy of Chen Zunxian) soil is not only an essential element for crops, but also an important strategic intelligence.

In 1988, the United States came to Taiwan to hold the "International Conference on the Application of Agricultural Land Survey and Classification in the Asia-Pacific region." this was also the first time that he was shocked by the importance of soil knowledge, and what shocked him even more was that compared with Asians, countries around the world are more interested in Asian soil. "it was only later that I knew why, because the soil resource database is important strategic intelligence, especially the Japanese and Americans."

He explained that once a country has a full grasp of soil survey information, it is possible to calculate the types, production and maximum feeding population of crops suitable for growing in the country. For large countries, whether from the perspective of long-term strategy or trade production, soil database and application information are extremely important information. For people, soil has multi-functional agro-ecological service value, such as crop production, purification of water resources, decomposition of poison self-purification, support of living environment and so on.

American legislation requires the protection of continental soil and the development of planting strategies according to the soil system.

With regard to the degree to which countries attach importance to soil, Chen Zunxian explained that the information provided by the soil Information Center of the European Union can even become a basis for national development policy programs and indicators; while the United States is the first country to emphasize the importance of soil survey and classification technology and the establishment of GIS databases, the Natural Resources Conservation Agency of the United States Department of Agriculture began to require states to legislate to protect representative states in 1980. "the state soil is the representative soil of each state, and the differences in grain supply, crop characteristics and climate characteristics (soil moisture and soil temperature) produced by each state are related to the state soil."

Chen Zunxian explained that the general soil organic matter content is 1%, which requires about 40 kg of nitrogen fertilizer per hectare, while the black soil along the Mississippi River in the United States contains 8% organic matter, which is 8 times that of the general soil. Crops can be harvested without fertilization in the soil. As a result, the land along the Mississippi River in the United States has become the largest and most important producer of soybeans and wheat in the world.

Globally, the black soil belt, which stretches more than 2000 kilometers long and 500km wide from the south of Russia to Eastern Europe, as well as the black soil belt of Heilongjiang Province in northeast China, are the most important agricultural areas in the country.

Three elements of county soil: land occupation, uniqueness and crop production

For the agricultural and forestry United States, the importance of protecting state land is tantamount to ensuring future agricultural productivity and economic development. Chen Zunxian believes that the concept of state soil is also applicable in Taiwan, where there are many small farmers. The prefectures, counties and municipal governments know the characteristics and distribution of the representative soils in their counties and cities, and they will be more conceptual and forward-looking in the overall industrial planning of crop cultivation and management. Farmers in villages and towns know the soil characteristics of their farmland, and they also know how to manage crop nutrients and soil moisture.

In 1988, Taiwan had completed the soil survey data of agricultural land and some hillside land in various counties and cities, but there was no concept of county soil. Chen Zun-hsien believes that in order to become the representative soil or soil system of a county, several conditions must be examined: the soil system should occupy at least more than 1000 hectares of soil in the county and city, whether it is a typical soil in the county and city, its importance to local crop production, and its uniqueness in Taiwan. Then it was reviewed and evaluated by other experts, and finally in 1993, the list was compiled, and each county and city had 1 to 4 representative soil series.

By spreading out the distribution map of the representative soil series of any county and city, we can see the distribution profile of the representative soil series marked by different colors in the county and city. Chen Zun-hsien explains that these counties are selected on the basis of local major crop-producing areas and their uniqueness. "632 soil series have been established in Taiwan's agricultural land, and 430 have been established in hillside soil. If a small number of representative counties are selected, it can cover a large area of productivity in each county and city."