cal and household protein and fat. The nutritious millets largely grown in semiarid tracts under drought were mostly lost because they were neglected or bypassed.
     The chemical pesticides used to protect crops from pests had a direct bearing on human health. Though pesticides may prevent damage by pests and disease and increase pro­duction, they are poisons. Pesticide poisoning has always been associated with pesticide use. The developing coun­tries use less than one-quarter of the world's pesticides, but they suffer three-quarters of all pesticide fatalities—about 375,000 people in developing countries are poisoned and 10,000 killed by pesticides each year (Bull, 1982). These figures do not include chronic or long-term effects, such as anemia, leukemia, cancer, birth defects, sterility or sui­cide. Pesticide use has expanded more rapidly in developing countries than elsewhere. Pesticide imports quadrupled in the Philippines between 1972 and 1978. In 1979, 25% of pesticides the USA exported to developing countries were banned or unregistered in the USA itself.
     Some pesticides used were persistent organic pollutants. Despite being present in minute quantities in water and soil, they accumulate in biological systems and, ultimately, in humans, adversely affecting health and reproduction. In ad­dition, pest resistance to pesticides escalates pesticide use, which causes damage to human health, animal health and ecosystems (Nair, 2000; Joshi, 2005).

2.4.3     Effect of AKST on environmental sustainability
Agricultural production and natural resource extraction in forestry and fisheries profoundly intensified throughout ESAP over the past 50 years. Intensified food production has increased food availability but has had trade-offs on sus­tainability. Often, outside effects of modern agriculture have been masked and their sustainability has been ignored.

2.4.3.1   Effect on soil sustainability
Soil fertility has been declining: soil physical properties have been degraded and nutrients changed adversely, including less availability of major nutrients, deficiency of micronu-trients, nutrient imbalances and acidification. The degrada­tion was brought about by incorrect fertilizer use, intensive cropping, depletion of soil organic matter and a decline in soil biological activity. Depletion of primary minerals and organic matter has resulted in micronutrient deficiencies in iron, manganese, zinc, copper, boron, nickel and molybde­num. Over time, heavy crop demand intensifies the severity of the deficiency and exhausts the soil's ability to supply sufficient other micronutrients.
     Soil physical degradation has led to accelerated erosion, compaction, crust formation and excessive overland flow. India, Bangladesh, Nepal, Sri Lanka and Bhutan have 140 million ha, or 43% of the total agricultural area of the re­gion suffering from several forms of degraded soil quality (UNEP, 2005). Soil erosion is the most pervasive problem, especially in sloping and unstable agricultural land. Erosion removes the topsoil, where much of the nutrient reserve ex­ists, and consequently causes loss of nitrogen and other nu­trients. In China, about one-third of the land, 367 million ha, faces erosion problems (UNEP 2005). In India, 25% of agricultural land has degraded soil, with about 30 million

ha of fragile land under cultivation progressively degrading (Dudani and Carr-Harris, 1992).
     In intensive agricultural systems in the region, natural soil fertility has declined as a result of crop nutrient removal, nutrient leaching, chemical deficiencies and imbalances. De­pletion of plant nutrients (N, P, K, Zn and sulfur) has been the most common chemical degradation. Increasing nutrient imbalances leading to micronutrient deficiency or toxicity of trace elements have been common in continuously irrigated paddy fields.
     Soil acidification is enhanced by heavy nitrogen fertil­ization and adversely affects soil nutrient availability. Many parts of Bangladesh and northern India have acidified and salinized, with a consequent loss of nutrients (Oldeman, 1994). Also, many agricultural lands in Cambodia, Malay­sia, Thailand and Viet Nam have experienced chemical soil degradation (Oldeman,  1994). In Australia, Bangladesh, Nepal and Sri Lanka, poor soil nutrient balances were not uncommon. Test plots in IRRI revealed that rice varieties yielding 10 tonnes ha-1 in 1966 produced 7 tonnes ha-1 in the mid-1990s.
     As desertification encroaches, most prone are the arid and semiarid areas. Improper farming techniques of inten­sive farming and too many animals foraging each unit ag­gravate the situation. More than half of the 1,977 million ha of dryland in Asia are affected by desertification. Central Asia has more than 60%, South Asia more than 50% and Northeast Asia about 30%. The Gobi Desert in northern and western China expanded by 52,400 km2 over five years (UNCCD, 1998). Every year, deserts eat up 2,460 km2 more. Relentless land reclamation, deforestation and overgrazing have led to continued loss of vegetative cover and topsoil. The excessive withdrawal of water upstream in many rivers in arid and semi-arid areas cuts off flows downstream, de­stroying the riparian ecosystems that rely on the rivers. The denuded land smoothes the way for wind to blow, intensify­ing sandstorms in areas where the sand originated and in the eastern part of the country and beyond (Yang, 2004).
     Soil organisms are important for soil fertility, health and sustainability because they facilitate nutrient cycling and help improve soil structure. Continuous cropping, without considering the capacity of the soil to regenerate, usually results in decline in the amount of soil organisms. Heavy chemical inputs alter the chemical properties of the soil and cause decline in organic matter and humus, the food for microorganisms. Sound soil resource management technol­ogies for efficient and sustainable nutrient cycling such as rotating crops, green manuring and encouraging nitrogen-fixing bacteria and mycorrhizhae were not widely practiced because the dominant production systems focused on short-term productivity.
     Soil contaminated by cadmium (in fertilizer), hexavalent chromium, lead, arsenic, trichloroethylene, tetrachloroeth-ylene and dioxin increased, mostly in the northern parts of the region and parts of Australia and New Zealand (UNEP, 2005). Contaminants affecting health from agricultural land in the northwest Pacific and northeast Asia were common in the 1970s (Japan, 2000). Soil contamination from lead and arsenic was prevalent throughout South Asia and Southeast Asia. Irrigation with untreated effluent caused contamina­tion and soil acidification in many areas; in Mongolia, for