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close this bookBiodiversity in the Western Ghats: An Information Kit (IIRR, 1994, 224 p.)
close this folder5. Agriculture
View the document5.1 Rice diversity and conservation in the Konkan
View the document5.2 Conservation of traditional vegetables in the backyard
View the document5.3 Genetic diversity in mango and cashew
View the document5.4 Floriculture and arboriculture
View the document5.5 Enriched biodiversity by plant introductions
View the document5.6 Impact of introduced plants
View the document5.7 Effects of pesticides on biodiversity
View the document5.8 Khazan (saline) lands

5.8 Khazan (saline) lands

The tidal estuaries of Goa stretch some 30 km inland. Either side of the estuaries lie "khazans": saline floodplains that lie below sea level at high tide. Over centuries, Goans have reclaimed these lands with an intricate system of dykes (bunds) and sluice gates. These barriers prevent salt water from entering the fields.

Eight of the 11 talukas (subdistricts) in Goa have a total of 17,500 ha under khazans. At least 2000 ha (12% of the total) are under dense mangrove vegetation. The mangroves help protect the outer side of the mud and laterite bunds that enclose the khazan. The total length of these bunds is about 2000 km.

Cultivation of the khazan lands dates back at least 3000 years. After 400 A.D., royal charters granted them to high-caste Hindu (Brahmin) settlers. Age-old co-operative, self-governing institutions known as gaunkaris or communidades reclaimed the khazan lands, engineered the intricate system of bunds and sluices, and maintained the khazan infrastructure. In 1975, this complex task was transferred to government-supervised "tenants associations". These are comprised of farmers who benefit from a particular protective bund. There are 138 such associations in Goa with a total of 20,000 farmer members.


Before reclamation


After reclamation

Biodiversity

As a result of careful management of the khazans, the estuarine biodiversity has been largely retained and enriched despite population pressure in these areas. The khazans have a wide range of indigenous and introduced plant species, many tolerant to salinity.

Mussels, clams, oysters, crabs and prawns arc harvested seasonally and appear in village markets. The fish and shellfish sustain a large population of indigenous and migratory birds and the "mugger", or marsh crocodile.


Khazan and estuarine areas of Goa

Biodiversity of khazan and estuarine lands

Plants: Endemic and introduced
Mangroves: 15 species
Rice: 17 salt-tolerant varieties are cultivated
Grasses and weeds: 20 species
Fish and shellfish: 10 varieties of edible bivalves, 6 of mussels, and clams, oysters, crabs and prawns
Birds: Many resident and migratory birds
Crocodiles, other reptiles
Mammals
Insects and other invertebrates not fully studied
Microflora: Salt-tolerant species of bacteria, fungi, algae and other microorganisms. 150 species of fungi so far known. Many potentially useful microorganisms have been found. Some can degrade oil, other petroleum products and pesticides. Others accumulate heavy metals such as iron and manganese.

Rice

Conditions in the khazan pose special problems for agriculture. The khazan soils are poorly drained and acidic (pH 4.8-5.3), relatively high in organic carbon and iron, and low in calcium.

Numerous types of wild rice have evolved to suit the saline conditions of the khazan. Over centuries, farmers have cultivated rice, selecting and replanting the best strains. In this way, new salt-tolerant varieties have developed, containing genes of enormous value to plant breeders. But these traditional varieties are gradually being replaced by modern, high-yielding varieties. The older varieties and their germplasm are disappearing.

Salt-tolerant rice varieties used in khazan farming

Asgo

Babri

Belo

Chagar

Corguto

Damgo

Dodig

Giresal

Kendal

Kochri

Kusalgo

Patni

Rungo

Shirdi

Sotti

Valai

Xitto



Khazan land agro-ecosystem

Cost of a sluice-gate

There are about 600 sluice-gates in khazan areas of Goal Every year the wooden structure needs replacement. This structure is made from beams of local matti timber. Planks of mango or ghoting are used for shutters and horizontal beams. Each structure needs 100 cubic feet of wood and costs Rs 35,000.

Economic value of the khazan

Besides agriculture, the khazan ecosystem supports 200 ha of traditional salt manufacture, 2000 ha of coconuts and intensive fisheries.

It employs 40,000 farmers, 15,000 horticulturists and toddy-tappers (known locally as renderos), 10,000 fisherfolk and 10,000 others. These activities generate about Rs 150 to 250 million a year. It is estimated that more intensive sustainable use of the khazan land ecosystem could directly and indirectly generate a total of 115,000 jobs.

Impact of "development"

Development activities have had significant impacts on the ecology and economy of the khazan and estuarine areas.

Unfortunately the pace of degradation of the khazan ecology has increased in recent years. This is due to short-sighted planning, public apathy, industrialization and urbanization. The economic lives of the poor will continue to be affected, unless something is done to conserve or restore this complex and valuable ecosystem and its biological resources.

Employment types

1. Estuarine and tidal areas

· Fishing
· Shellfish collection
· Shell extraction for lime-making
· Boat transport

2. Embankments

· Building, supervision, repair, maintainance

3. Farming

· Cultivation of salt-tolerant rice during monsoon
· Pisciculture on co-operative scale after monsoon
· Intentional flooding every 3 years to kill weeds and pests

4. Plantation crops

· Mainly coconut. Also cashew, banana, mango, papayas, onions, chillies
· Seasonal crops
· Vegetables, tubers
· Salt production

The declining salt industry of Goa

From 1891 to 1991, the number of salt-producing villages in khazan areas of Goa dwindled from 36 to 13. The number of working salt pans fell from 268 to 119, and crude salt production declined from 40,000 t to just 18,000 t per year.

Activity

Ecological impact

Economic impact

Deforestation in river catchment

Increased sediment load, lower biodiversity

Shellfish industry declines

Uncontrolled urban growth

Overload on life-supporting systems

Housing, transport, sewage disposal problems

Pollution (effluents, solid waste, sewage)

Bioaccumulation of toxic residues, eutrophication, loss of aesthetic value

Rivers choked, aquatic life dies, lower fish catches, salt industry harmed

Barge traffic

Erosion of protective embankments

Rice and coconut crops decline; added maintenance cost

Mining

Increased heavy metal load

Agriculture, shellfish and salt industries harmed

Reclamation of low-lying land

Land-water equilibrium disturbed, other areas flooded

Flood damage, loss of pre-existing employment

Road and railway construction

Drainage pattern affected, erosion

Agriculture affected

Uncontrolled pisciculture

Increased soil salinity

Damage to rice, coconut and salt production; groundwater contaminated

Sand, shell and mud extraction

Erosion on bunds, destruction of subsoil fauna

Food chain damaged; soil conservation agents stressed

Slums and scrapyards on bunds

Vegetation cleared, land and water polluted

Local administration stressed

Unique agro-ecosystem

The khazan lands are a unique agro-ecosystem that has proven its sustainability through centuries of use. Although they are the result of conversion of natural estuarine ecosystems, they do not seriously alter either its physical or living components. Instead, the khazans work with existing natural features. Unlike many modern forms of agriculture, the range of agricultural species and varieties adds to the diversity of the estuaries.

Prepared by Nandkumar Kamat

Information kit produced by
WWF-India, Goa division and the
International Institute of Rural
Reconstruction.