Enhancing soils anywhere enhances life everywhere

This was the theme of last year’s World Day to Combat Desertification which is observed every year on 17 June. The World Day to Combat Desertification has been observed since 1995 to promote public awareness relating to combat desertification, land degradation and the effects of drought. The year 2006 was observed as International year of desert and desertification.  Desertification is one of the world’s most alarming processes of environmental degradation. This issue is often undermined by a common perception, that it is a natural problem of advancing deserts in some faraway places. If desert invokes images of sand in your mind then expand your imagination as there are polar and cold winter deserts as well. The arid tracts lying in the rain-shadow of the main Himalayan range are commonly referred to as cold deserts. They include the trans Himalayan areas lying across the towering main Himalayan mountain wall and the inner dry valleys within this range, both of which fall in the rain shadow of the soaring mountains, thereby remaining largely unaffected by the monsoon system that brings rain to other parts of India. Ladakh is a cold desert.  In fact, broadly speaking, desertification is about land degradation: the loss of the land’s biological productivity, caused by human-induced factors and climate change. Land degradation is defined as lowering and loss of soil functions.  It affect one third of the earth. Desertification results chiefly from man-made activities and influenced by climatic variations. It is principally caused by overgrazing, over-drafting of groundwater and diversion of water from rivers for human consumption and industrial use. Soil fertility has declined due to overuse of chemical fertilizers. Land degradation is becoming more and more serious worldwide in recent years, and poses a threat to agricultural production and terrestrial ecosystem. Land degradation includes loss of top soil, physical changes like damage of soil structure (compaction), chemical changes like salinization, sodification, acidification, deposition of heavy metals and an overall declination of fertility and productivity of soil. It is estimated that nearly 2 billion hectare of soil resources in the world have been degraded which includes approximately 22 % of the total cropland, pasture, forest, and woodland. Severe erosion of the fertile top soil through wind and water action is aggravated by intensive mining, deforestation, improper land management as well as injudicious tillage practices in agricultural fields. Besides that a sizeable amount of loss of top soil has been has been attributed to brick making and pottery. Brick making is robbing top fertile soil (30 cm depth) at the rate of thousand square kilo meter per year.  It is important to note that it takes centuries to replenish 3 cm of top soil.

Land degradation is also caused by water logging and excessive salinity. The most serious threat to the land is posed by deforestation. Heavy rainfall during monsoon damages the soil too. Steep slopes encourage rapid run-off leading to soil erosion, especially on the southern slopes of the Himalayas. In fact, major portion of the Himalayas are prone to landslides and erosion. Urban encroachment on agricultural land is another burning problem.

A major impact of desertification is reduced biodiversity and diminished productive capacity, for example, by transition from land dominated by shrublands to non-native grasslands. Soil is the hot-spot of biodiversity.  Beneath feet they construct a wonderful world. Each community of this ‘under world’ is working honestly for correcting the soil condition and making soil live so that above ground plant growth is ensured and thus biodiversity is maintained. Thus, belowground diversity influences the nature and makeup of above ground diversity. The year 2010 was the International Year dedicated to Biodiversity. Desertification, land degradation and drought dramatically affect the biodiversity resident in the soil.  Healthy soils produce life, and yet soil health depends a lot on how individuals use their land. What we do to our soils determines the quality and quantity of the food we eat and how our ecosystems serve us. Our increasing ecological interdependence also means enhancing soils anywhere enhances life everywhere.

Land, the marvelous product of nature, without which no life would survive, is now at stake worldwide. The time has come to sustain it for our sustenance.