Field of Science

The Great Leap Forward and soil erosion

"dal letame nascono i fiori,
dai diamanti non nasce niente"
"from dirt flowers are born,
from diamonds nothing comes"
"Via del Campo" by Fabrizio de André (Italian poet-musician)

In Geology soils are defined as the uppermost layer or substratum of earth, it supports most of the plant life and is therefore also essential for all heterotrophic life. Soils are the results of complex interactions between the biosphere-atmosphere-lithosphere and hydrosphere over long periods of time - oversimplifying the remains of the weathering of rocks enriched by organic debris.
Soil degradation and erosion was and still is one of the major threats to soil quality and function. Erosion is a natural process; however human influence and mismanagement can significantly increase the velocity and extent of this process. Unprotected soil can be rapidly eroded by wind or washed away by running water - logging, overexploitation, monocultures can damage, even destroy the plant cover protecting the soil. Irrigation and processing can condense the soil or modify its chemistry. The collapse of many civilisations in the past was triggered by the erosion and degradation of soil, followed by decrease in the agricultural production and widespread famine and death. Even in the 20th century humans - mainly politicians - made such errors leading to terrible consequences for the entire population.
The areas of China covered with Loess are characterized by very fertile soils. For millennia such soils were cultivated by farmers. However, this yellowish, fine-grained, carbonate-rich aeolian sediment is very vulnerable to erosion by wind and water.
Near the small village of Westeregeln (Thuringia, Germany) past quarrying activity has exposed Mesozoic gypsum and limestone formations, covered by Pleistocene sediments. The uppermost part of the stratigraphy is represented by a postglacial soil developed on Loess - a sediment deposited during the last glacial period. Note the secondary infillings of the burrows of animals and the different colors of the horizons of the soil.

The rise of the communistic party under the leadership of Mao Zedong in China after 1966 had a profound impact on society and the environment - it caused one of the greatest humanitarian catastrophes in modern times and effects are still visible in modern China. Inspired by the apparent success of the U.d.S.S.R. under Stalin the Chinese party intended to transform in only few years the rural agriculture economy into a socialistic power - The Great Leap Forward - (as envisaged in the propaganda poster at the top of this post, displaying the production of grains skyrocketing) - following a strange mix of science, personal opinions and pseudoscientific claims, like these formulated by Trofim Denissowitsch Lyssenko, one of the leading agriculture scientists of Stalin's regime.

A preliminary 5-year plan was adopted in the years 1953 to 1957, consisting of a complex pattern of logging and reforestation - in only few months estimated 10% of China's forests were transformed into farmland. To increase the production of iron simple backyard furnaces were constructed, the increased demand for fire-wood led to an even faster deforestation and subsequent soil erosion. Heavy equipment, as used on the cultivated fields in the Russian plains, lead to tillage erosion on the slopes and in the soft soils of the Loess Plateau.

In the years 1957/1958 a second, even more ambitious plan for the next 12-years was adopted - with even more catastrophic effects.

Farmers should plant 12 to 15 million plants per hectare instead of the previous 1.5 million, Mao thought that plants would grow better in a large collective - as results of this overexploitation and the concurrence for light and nourishments most plants in fact died. Plant species ill-suited to the local soils and climate were planted on large areas - especially maize (Zea mays mays). The dense root system of this grass species tends to seal off the soil, water can no longer infiltrate and the upper part of the soils get cloaked by mud particles, limiting the diffusion of oxygen into the soil and finally heavily damaging the growing plants.
The construction of dams and canals modified the catchments of rivers and the hydrology of entire regions; this lead to widespread erosion of the fertile soil and reservoirs became clogged with sediments and could no longer provide water.

The resulting decrease in agricultural production lead to a terrible period of starvation in the years 1958 to 1961, estimated 40 to 30 million people died in this period. Extremist Mao Zedong and many of the leadership of the communistic party ignored, however, the facts and affirmed instead that the famine was the result of saboteurs or opposing political forces - a fiercely which-hunt to find a scapegoat was initiated. Only in 1962, the reformations were taken back and the situation improved.
Despite the disastrous results other communistic countries, like Cambodia, Ethiopia and North Korea, adopted questionable agricultural methods during the 20th century, with similar results.

Soil degradation and erosion are still major problems in modern China., Nineteen percent of the area of the country is still affected, but also in many other industrialized countries of the world soil has become a valuable resource on the global market. China and India are buying or renting large areas in underdeveloped countries.
This solution is however problematic, considering that the food production in many of the involved countries is not capable to sustain even their own population.

China´s today politics is an example of a conflict of interests similar to all developed countries. It invests in reforestation, conservation areas and environmental protection. However, at the same time, industry and the increasing population demands for further land use and resources.

BORK, H.-R. (2006): Landschaften der Erde unter dem Einfluss des Menschen. Wissenschaftliche Buchgesellschaft, Darmstadt: 207

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