Posted July 1997
See also: Environment Specials
"Sustainable development is the management and conservation of the natural resources base, and the orientation of technological and institutional change in such a manner as to ensure the attainment and continued satisfaction of human needs for present and future generations. Such sustainable development in the agriculture, forestry and fisheries sectors conserves land, water, plant and animal genetic resources, is environmentally non-degrading, technically appropriate, economically viable and socially acceptable." (FAO, 1988)The challenge this poses for China is to design agricultural commodity and environmental policies that achieve food security goals while enhancing both natural resources and human welfare. An understanding of the context in which current practices and policies have emerged will facilitate the identification of impediments to and opportunities for sustainable agriculture.
We begin by looking at China's population and the pressure this places on its two key agricultural resource endowments, land and water, in order to provide an overview of the physical context of current production activities. This is followed with a discussion of the economic and social context of agricultural production and rural activities including issues of income distribution, gender and rural energy use. These factors have a major influence on the choices facing China's rural economy. Finally, we examine how agricultural policy influences resource and degradation.
The emphasis of Chinese leaders on maintaining food self-sufficiency exerts additional pressure on the limited natural resource base and constrains the evolution of development in rural areas.
While development policies have successfully increased food production and industrial output over the past 15 years it is apparent that this has been achieved at a significant environmental cost. The majority of these costs have been treated as externalities (i.e. the negative impacts were "absorbed" in the form of deterioration of the human environment instead of being internalized at the source of the production). Depletion and pollution of water resources, land degradation, soil erosion, loss of biodiversity, desertification and deforestation are now sufficiently widespread that they constrain further economic growth in the agricultural sector.
The remarkable success China has had over the past half century in feeding its population will be made more difficult in the decades to come by three major trends.
|Land resources||World average (ha.)||China average (ha.)|
|Corrected value based on revised estimated arable land area of 139 m. ha.|
China's available land resource is not only limited in quantity
but also in quality. The best arable land (i.e. no significant constraints
as regards soil type, fertility, slope or climate) accounts for only 40
per cent of the total, 34 per cent has limited constraints, 23 per cent
has significant constraints (China's Cultivated Land, 1995). About 3 per
cent of arable land is not suitable for production.
|Country||Cropland ha.||Nitrogen kg||NPK kg||Grain Production (kg)|
As can be seen in tables 2 and 3, Chinese farmers use their land intensively, and are relying more on fossil fuels for farming than ever before. The use of agricultural machinery, electricity and irrigation have grown rapidly since 1979. Fertilizer use has grown at more than 15 per cent per year and the ratio of organic to inorganic fertilizer has declined by nearly half between 1980 and 1990.
Although the rate of conversion of land into and out of agriculture is not an ideal basis for analysis - there is a need to assess what kinds of land are being developed for farming and whether sustainable farming systems can be, and are being, introduced.
If present trends continue, the arable land area will decrease by 6.7 - 7.5 m. ha. by the turn of the century and the average arable land per caput will be reduced to 0.1 ha, just 60 per cent of that available in the 1950s. Significantly, the greatest loss of crop land is taking place in the eastern coastal areas where the cultivated land per capita is already less than 0.07 ha.
China's grassland resource amounts to 330 m. ha., of which about 11 m. ha. has been subject to improvement. Nearly one-third of this grassland is considered overgrazed, with desertification already affecting 67 - 87 m. ha. and increasing at a rate of 1.33 m. ha./year. The total desertified area has more than doubled in size since the 1950s.
Hills and mountains cover 65-70 per cent of China's territory. Although national guidelines prescribe that annual cropping should not take place on slopes with gradient in excess of 30 per cent, soil erosion is increasing and about 1.5 m. km2 (17 per cent of the total area) are now affected. The areas of particular concern are along the Yangtze River, where the rate of erosion has doubled since the 1950s, and Sichuan Province where 44 per cent of the land is affected and about 2 m. ha. are losing an average of 110 tonnes of soil per hectare per year. Nationally, soil erosion now affects 30 per cent more land than in the 1940s.
About 33 per cent of land with slopes greater than 8 degrees is used for growing crops. More than 7 per cent of cultivated land has slopes that are greater than 25 degrees. Nutrient loss from cultivation on sloping land is severe, amounting to 47 tons (in active ingredient, or 112 tons in product weight) of chemical fertilizer and more than 13 tons of organic fertilizer per square kilometer per year.
Policy incentives to produce food and raise rural incomes has not only expanded land use for agricultural crops, but it has also reduced agrobiodiversity due to specialization. The high-yielding varieties (HYVs) of the major green revolution crops, wheat, rice and maize, have a narrow genetic base. In 1990, the use of HYVs covered more than 80 per cent of the area under cultivation whereas 25 years ago almost no HYVs were in use. Many native races of rice and other food crops have been lost, together with potentially valuable qualities and characteristics, especially those resistant to different pests and diseases.
Achievements in productivity gains have mainly taken place in the resource-rich regions of China. The marginal upland regions, about 70 per cent of the national territory, were neglected as were crops such as small-grains and tubers. For example, from 1975 to 1995, the yield per unit area of sorghum, millet and potatoes increased only by 3 per cent, 2 per cent and 1 per cent annually respectively.
Central planning offices often compelled research and extension services in the resource-poor provinces and autonomous regions to concentrate on green revolution crops. Most scientific research papers from these regions concentrate on rice, wheat and maize.
On marginal lands the suitability and production stability of traditional crops are much better suited to farmers who must carefully manage their production risk than are the green revolution crops. For example, during periods of drought when wheat fails in the arid mountain areas of north-western China, the potato can reap at least 60 per cent of its normal yield. For this reason it is called the 'life-saving grain' (in China potato is classified as a grain crop) by the local farmers.
Although much of China's domestic animal diversity is still intact, it is now coming under pressure. As human diets in China have changed to demand more meat, pig and poultry production have increased - growing at more than 10 per cent per year for the last decade. This has created pressure to replace lesser known breeds with specialized, high production varieties thus, threatening breeds that possess biologically unique characteristics.
|Year||Grain yield, (t/ha sown)||MCI||Irrigated land (%)||Agric. machine power kw/ha||Fertilizer (inorganic) kg/ha||Inorganic to Total|
|1992 and 93 from Rural state book Mach power: 1,000 watts/ha. inorganic : kg/ha. fertilizer/ha.|
At present about 80 per cent of the total national water consumption is for irrigation. This has caused the depletion of water resources, especially the non-renewable deep ground water in the north of China, as well as pollution from pesticides and fertilizers, salinization.
Since then, the total forest cover has actually increased due to afforestation of about 5 m. ha. annually. But the afforested areas mostly comprise plantations of cedar in the south and poplar in the north which cannot substitute for the loss of natural forest bio-diversity.
Deforestation in species-rich areas such as Hainan, Xishuangbana and Southeast Tibet is believed to have caused the extinction of 500-800 plant species since 1957 and endangered a further 3,000-5,000 plants and more than 300 animals. The ecosystems now under the most immediate threat are grasslands and wetlands. China's wetlands are among the most important wildlife habitats in the world but are considered wastelands by the local population and the Government which use them as economic development zones.
If present trends continue, during the next decades China will lose many natural ecosystems that lie outside its nature reserves - including most of their coastal wetlands. The development of a national Agenda 21 for forestry in China is an important first step in the direction toward more strategic management of China's forests. However, a national policy on biodiversity conservation and on wetlands management with clear lines of authority are needed if China is to protect these resources.
There are significant seasonal variations in rainfall among the different areas of China as well as from year to year. The ratio of the maximum to the minimum annual runoff on a yearly basis is 2-3:1 for the Yangtze and Zhujiang rivers in the South, 4:1 for the Yellow river and 15-20:1 for the Huaihe and Haihe rivers in the North.
Agriculture consumes about 50,000 m. m3 annually (including crop farming, livestock raising, drinking water and other uses in rural areas), accounting for 81 per cent of the total water use. Irrigated land accounts for 48 per cent of the total cultivated area and consumes over 95 per cent of the agricultural water use.
The prime farm land of northern China (including Beijing, Tianjin, Hebei, Shanxi, parts of Henan, Shandong and Liaoning) is experiencing a severe water shortage. Over 70 per cent of the total resources have been exploited and there is little remaining potential for expansion. The water tables of some aquifers in the North China Plain are declining at 1 meter per annum.
The intensive farming techniques used on irrigated lands enable them to account for two-thirds of the total grain production. Although the extent of irrigation has not grown in recent years, the demand for water arising from intensified industrial and human needs is increasing at about 8 per cent per annum.
An example is the Huanghe, Huaihe and Haihe River Plain (3H), which is considered to have the greatest potential for agricultural development due to its vast area of arable land and relatively low yields. This area covers about 10 per cent of China's territory but has less than 2 per cent of the water resources. The gap between water supply and demand is equivalent to about three-quarters of the annual rainfall.
In Changzhou District, Hebei Province, more than half of the current grain production depends upon irrigation which can provide less than half of the total volume of irrigation water that is required. So almost one-third of the current grain production in this district cannot be sustained with irrigation. The production is dependent upon withdrawal of groundwater which is falling by more than 1 meter per year. Each meter drop in the groundwater level will double the pumping cost over the next 10 years.
Mis-use of water resources (i.e. over-application and/or poor drainage) is responsible for nearly 10 per cent of the total desertified area in the north of China. New irrigation in the northern arid region, with higher evapo-transpiration has caused soil salinization and mobilization of fixed dunes along the middle and lower reaches of continental rivers such as Talimu and Manasi.
The combined effects of increased water demand by households, industry and irrigation is depleting several aquifers and causing subsidence of large areas around Beijing and Tianjin where about 50 per cent of the cultivated land depends on irrigation. About 70 per cent of total grain output and 80 per cent of fruits and vegetable production takes place on irrigated land.
Many large irrigation schemes constructed in the 1950s and 1960s were hastily designed, constructed to low standards, and built with poor quality materials and equipment. Many were not completed or still lack distribution and drainage networks at the tertiary and farm level. Now most systems require major upgrading, rehabilitation, and completion. Such projects present opportunities for high return investments but must be accompanied by adequate environmental management.
Almost 7 m. ha. of irrigated farmland has been affected by salinization and alkalinization as a result of indiscriminate irrigation without adequate drainage, or application of insufficient water to flush salts through the soil and into the drainage system. Of the total area, about 2.7 m. ha. are in the basins of Hai, Huai and Yellow Rivers where nearly 15 per cent of the cultivated area is affected. Some of this land can no longer be farmed, whereas mild to moderate salt levels on the remainder have reduced the yields of rice, corn, soybeans and wheat by up to 25 per cent and even cotton, which is salt-tolerant, by 10 per cent.
Untreated wastewater, mostly urban sewage, is used to irrigate about 1.4 m. ha. Acids and heavy metals in this water impair the soil chemistry and in some areas an impervious subsoil hardpan is formed. Studies in Tianjin by the Agricultural Environment Protection Institute over an eight-year period showed 8.4 per cent of wastewater-irrigated farmland produced crops that exceeded safe standards for contaminants.
The efficiency of water use in China is low. The effective utilization index (EUI) which is the ratio of water technically required for a crop divided by the amount actually used, is less than 50 per cent nation wide. This compares to 60-70 per cent in the United States and more than 90 per cent in Israel .
Current studies project that the use of biomass, which made up more than 70 per cent of the rural energy supply in 1979 will decline to less than 40 per cent by the year 2000. Meanwhile, the use of coal will increase from less than 20 per cent to nearly 50 per cent.
Technologies based on renewable sources of energy such as solar water heaters, solar photovoltaic cells, wind mills, ethanol from biomass, and biogas from organic residues have an expanding market among rural users in part because of overall shortage of energy and due to their increasingly competitive costs. Apart from biogas, they still make up a relatively small share of the total energy consumed in the rural sector.
Climate change is an important issue for China. Current models indicate that a doubling of CO2 could reduce agriculture production by 10-12 per cent in the developing countries. The main source of greenhouse gas emissions is the energy sector, due to the predominance of coal-based power plants.
Most of the rural industries in China (e.g. brick making factories) do not use any emission controls on their flues and frequently operate using highly polluting fuels and technologies. This has led to considerable acid precipitation. In Szechuan and Guizhou provinces, widespread damage to coniferous forests has occured. In addition, there are significant emissions of sulfur dioxide, nitrous oxides and carbon monoxide that reduce plant productivity and affect human health to the extent that farmers are less able to engage in economic activities during periods of the year.
In other regions the application rates range from less than 200 kg/ha. in the north-east, north and north-west regions to 550 kg/ha. in Zhejian, over 800 kg/ha. in Guangdong and Fujian, and 775 kg/ha. in the suburbs of Shanghai.
These extremely high rates suggest that significant portions of the nutrient are not being taken up by the plant in the form of increased production but are either being washed into water courses and/or retained (unused) within the plant material. This implies that farmers are incurring significant additional costs in the form of the excessive fertilizer application, the labour to apply it and the environmental damage arising from water pollution.
This increased use is estimated to be responsible for about half of the 162 mt increase in grain production between 1978 and 1995, as well as much of the increase in production of cash and high-value crops.
Nitrogen fertiliser is the most widely and intensively used and also causes the most environmental problems. Thirty per cent of fertilizer applied in China now is ammonium bicarbonate, a volatile form of nitrogen, in which much of the nitrogen escapes into the atmosphere before it becomes available to the plant.
The ratio of organic fertilizers to total fertilizers used has declined from 60 per cent in 1980 to 46 per cent in 1995.
The use of green manure has declined rather sharply since the 1970s because of the perceived high opportunity cost of "non-productive" land use. Area sowed to green manure declined from 7.5 m. ha. in 1980 to 4.4 m. ha. in 1991. Continuous cultivation of the same crops (viz. rice, wheat, maize) combined with overuse of mineral fertilizers have resulted in significant reductions in soil organic matter content and nutrient status. Almost 11 per cent of the cultivated soils have limited organic content; nearly 60 per cent of the cultivated land is deficient in phosphate; 30 per cent is deficient in potash; and 14 per cent is deficient in both phosphate and potash. The proportion of soils with good inherent fertility has decreased from nearly 33 per cent to just 20 per cent.
The domestic production of mineral fertilizers requires substantial industrial energy supply and is accompanied by high levels of pollution. The proposed doubling of fertilizer production would make the mineral fertilizer industry the second largest consumer of coal in China.
Between 1952-90, pesticide use increased by more than 110 times. During 1980, the peak year, more than 537,000 tons of pesticides were used. Although this has declined, there remains evidence of widespread harm to the environment and human health. Unfortunately there is very little systematic monitoring of these pollutants.
In order to deal with pest resistance and low quality of pesticides, sprays are usually over used, resulting in the loss of beneficial insects and poisoning of humans as well as livestock and poultry. Rough estimates are that about 100,000 people are accidentally poisoned annually in China, of which 10 per cent are fatal. At present, 28 species of pests and 1 bacterium species are reported to have developed pesticide resistance.
The adoption of farming systems based on high-yield varieties, irrigation, chemical fertilizers and large-scale mono-cropping has reduced agro-ecosystem diversity and rendered crops more vulnerable to pest damage. Whilst this problem can be contained by the judicious use of pesticides as part of an integrated pest management (IPM) or integrated crop management (ICM) system, inappropriate use of pesticides can exacerbate the problem by creating pesticide resistance in the target pest populations. During the past ten years, the cotton crop has experienced continuous application of high doses of (-cypermethrin, with the result that there has been rapidly increasing resistance in cotton bollworm populations. In 1992, there was a 40 per cent decrease in cotton production in North China due, in part, to this pest.
Environmental conservation departments in China have estimated that mis-use of pesticides in China has led to about 9,520 m. yuan in costs per year in the form of lost labour, contaminated food, and land and water pollution.
However, continuous use of plastic film has negative environmental effects. Studies show that about 2.5 kg. of plastic per mu remain in the soil on the average when the land has been covered for more than 3 years. If the remaining plastic pieces weighed 3.0 kg per mu, the vegetable yield would decrease by 2 per cent to 10 per cent compared with the farm land without plastic coverage.