Traditional/Indigenous Technologies for Combating Desertification

 

Traditional knowledge and practices have their own importance as they have stood the test of time and have proved to be efficacious to the local people. Some of these traditional practices in the fields of agriculture - crop production, mixed farming, water harvesting, conservation of forage, combined production system, biodiversity conservation, forestry, and domestic energy, to mention a few. These are briefly described below.

Traditional/Indigenous Technologies in Agriculture Crop production
The tank system is traditionally the backbone of agriculture production in semi-arid region. Tanks collect rainwater and are constructed either by bunding or by excavating the ground. It is estimated that 4 to 10 ha of catchment is required to fill one ha of tank bed. In the Thar Desert, traditional systems of land and water use met environmental challenges in various ways.

 

The limited crop-growing season led early inhabitants to rely on animal husbandry and farming of hardy millets in the summer season. However, one group of indigenous cultivators (Paliwals) devised arainwater-harvesting technique fully capable of growing winter season crops. As early as the 15th century, the Paliwal cultivators followed a unique practice of water harvesting and moisture conservation in suitable deep-soil plots.

 

These plots as also surrounding catchment area were developed with care and managed to make the system a self-contained unit for winter cultivation. Under conditions of intense evaporation, the moisture threshold and soil fertility was maintained. The total energy input, rainwater, sand-silt-clay accumulation, and the cultivator’s own activities were interwoven into a complete production system of winter crops. There was a progressive increase of yields every year as more and more fresh silt, clay and humus accumulated and widened the vertical and horizontal dimension of such plots.

 

The ratio of farmland and catchment area was regulated to be 1:11 so that the critical supply of moisture was maintained. This is known as the Khadin system of cultivation. In this system, the nearby uplands and rocky grounds are also used as catchment for collecting rainwater. There are still as many as 500 big and small khadins covering a total area of about 12,140 ha. Another indigenous system known as Achar and Pine suited to low lying areas of Bihar was developed.

 

In Tamil Nadu, the practice of nangai-mel-pangai (dry crops on wetlands) was common. If the monsoon seemed not to be promising at the planting time, farmers would plant high quality dry crops, usually ragi or cholam (varieties of millet), under tank irrigation. If the season looked good, they would plant paddy.

In Central India, a very old cultivation system based on water harvesting and runoff farming in the Narmada valley locally known as haveli still exists. This system is location specific, like other indigenous runoff farming systems of the country. It is practiced in areas with black cotton soil. Fields are embanked (average height of embankment being 1 m) on four sides. Rainwater remains in the field until the beginning of October. A few days before sowing rabi (winter) crops, the excess water is drained off. Water is let out very gradually. The cultivators know from long experience which field ought to be drained first. The water from one field enters into another, and then another till it joins the natural drainage or lake. There is a mutual understanding amongst the farmers as to when to release the water.

Bhil tribals developed another system called patt. The principle of this system is simple and comprises bunding (embankment) of a stream at a point to provide astatic head of 30-60 cm, sufficient to divert water into the irrigation channel. The gradient of the channel is less than the gradient of the streambed and climbs to a height varying 3-25 m. This system allows double cropping.

 

Mixed farming
The bulk of natural resource base of the arid region is most suited to pasture based livestock farming. The traditional wisdom of the dryland farmer clearly manifest in the evolution of system of mixed farming – including crop and animal husbandry – which matched the potential and limitations of the natural resource base. The misuse of land, namely ploughing the lands best suited to natural grasses was rectified by the practice of crop and long fallows (bush fallow) rotation.

 

Traditional Water Harvesting Systems
India has a rich history of use of traditional systems of water harvesting in almost all the States. Conservation of both surface and groundwater has been an integral part of India for many centuries. Archaeological records are available of their use by ancient civilizations in India. In fact, ponds and tanks represent an important community resource for drinking water in rural India even today. The main attributes to their success are the sound scientific knowledge and methods on which they have been built.

 

The types of water harvesting are different depending on the physio-topography and rainfall pattern of the region and the extent of rainfall. However, many of these traditional practices were abandoned during and after the colonial rule. India also has high levels of ground water, which have supplemented the surface waters especially during lean season as well as in regions which are rainfed. The types of systems and water harvesting practices in the different parts of India have been explained in a lucid manner in the Fourth Citizens’ Report “The Dying Wisdom” of the Centre for Science and Environment, New Delhi. The storage of even the scanty rainfall, through simple as well as extensive types of traditional water harvesting of surface and ground water have been the important sources of water in arid regions such as Rajasthan and Gujarat.

 

These include surface water systems such as the lakes, talabs, nadis, canals and groundwater systems such as wells, Kunds or Kundis, baoris, and johads. These practices have often saved the drought-affected regions from problems of water famine. The serious problems of water shortages in many parts of the country, particularly during this year’s drought, are being largely attributed to the discontinued use of traditional water harvesting practices. The programmes of the Government such as the DDP, DPAP and the integrated watershed projects have an element for harvesting the traditional water system and involvement of the local communities in the maintenance.

 

Success Stories of Use of Traditional Water Harvesting Systems
In the sandier tracts of the Thar Desert, the villagers have evolved an ingenious system of rain water harvesting known as Kunds/ tankas, the local name given to a covered under ground tank was developed primarily for tackling problem of drinking water. These are either owned by communities or privately. Village ponds (nadis), Kundis and tankas in Rajasthan and virdis in Gujarat were common for meeting the drinking water needs of the inhabitants. In Southern India tanks and their catchments had religious importance and were not polluted.

 

Traditional Water Harvesting Systems A. Types of Surface Water Systems Nadis: Nadis are village ponds used for storing water from an adjoining natural catchment during the rainy season. A nadi is essentially a natural surface depression. Some have stone walls built for extra storage and for water retention. Most villages in Rajasthan have their own nadi and the site of nadi is selected by the villagers based on the available natural catchment and its water yield potential. Water availability from a nadi would range from two months to a year after the rains. The location of a nadi had a strong bearing on its storage capacity due to the related catchment and runoff characteristics. Nadis were heavily relied on for human and livestock needs. A survey done by the Centre for Science and Environment found that the drought affected districts of Nagaur, Baramer, and Jaisalmer were found to have 1436, 592, and 1822 nadis respectively. They meet 37% of the water needs. The Jodhpur town has about 25 nadis in and around it. However, the water is not very suitable for human consumption but are important source of water for livestock and for irrigation and for recharge of wells. Talabs: Talabs are ponds and are water reservoirs situated in valleys and natural depressions. Tanks: In other districts of Rajasthan, tanks stored water during the monsoon, for drinking purpose . Tanks are in situ structures with massive masonry walls on four sides and floor. They are either square or rectangular and have an enormous water holding capacity. Tanks were provided with an efficient system of canals to bring rainwater from the catchment areas in the outskirts of the town or city. Lakes: Very deep depressions of talabs form lakes. The Padmasar and Ranisar lakes in Rajasthan are good examples of lakes, which even today are important sources of drinking water. Overflow from talabs and lakes, especially during the monsoons, help in the recharge of wells and baoris. Earlier these could support a large township round the year and a major part of the year. But with increasing destruction of the catchment area, and poor state of canals, these lakes are not getting adequate water. Khadin: Khadins consist of earthen embankments to capture and conserve the surface runoffs in agricultural fields. The local people grow natural vegetation upstream Khadins, which binds the earth and checks wind erosion. Canals: Canal systems consist of numerous water courses, channels and aqueducts to carry rainwater to the city’s various tanks, nadis and talabs. Johads: Johads are water collection barriers and are essentially embankments to arrest rainwater during the monsoon. The Johad bed is subsequently used to cultivate crops. B Groundwater Systems Kunds or Kundis (circular pits with dome like covering) have long been used as storage reservoirs in the water scarce districts of Barmer, Nagaur, Bikaner, Chru districts in Rajasthan . Wells: Wells are deep underground pits lined by cemented masonry . This is the most common system of harvesting of groundwater. Baoris: Baoris are community step wells. Shallower than wells, they have the capacity to hold water to almost its full capacity as the system lets very little evaporation. The baoris in Jodhpur district have been an important source of drinking water.

Conservation of Forage Resources
The pastoralist (nomadic cattle re