Living Land

[

] 166

Returning agricultural productivity to former

tin mining land in Peninsular Malaysia

Dato Dr Sharif Haron, Dr Mohamad Roff Mohd Noor, Dr Wan Abdullah Wan Yusoff and Rohani Md. Yon,

Malaysian Agricultural Research and Development Institute

or more than a century, tin ore was one of the main

pillars of Malaysia’s economy which was based on

primary commodities. The prominence of tin in the

economy lasted until the world tin industry collapsed in

the mid 1980s. Following this event, the country’s tin

industry greatly reduced its activities. With the collapse

of the tin mining industry large tracts of land, which have

been used for depositing tin tailings, are left vacant. ‘Tin

tailings’ refers to the materials other than the tin miner-

als coming out of the mining process that were deposited

on the mined or unmined land adjacent to the mining

sites. Three types of tin tailings are usually found in the

tin mines: gravel (>2 mm), sand (coarse sand, 2.0-0.2

mm and fine sand, 0.2-0.02 mm), and slime (silt, 0.02-

0.002 mm and clay, <0.002 mm).

It is estimated that the total area of ex-mining land in the

whole of Malaysia is about 127,550 hectares. About 60 per

cent of the ex-mining land has been rehabilitated or reused

for other puprposes. Present uses of the ex-mining land

include housing and settlement areas, industrial estates,

agriculture, aquaculture and animal husbandry, tourism

and recreation facilities and public institutions and facilities.

Presently, about 50,000 hectares of ex-mining land

remain unused. These areas are found quite near the urban

areas. Most of these areas are tin tailings which have been

deposited with sand, therefore they are known as sand tail-

ings. Like other marginal soils, sand tailing is a problem

soil because of its poor physical and chemical properties

making it unsuitable for crop growth. The sand tailing

contains coarse sand grains with less than 5 per cent clay

content. The sandy texture of sand tailing leads to excessive

internal drainage and low water holding properties. Sand

tailing also has a high surface temperature.

Sand tailing has a pH of about 5 or less and is characterized

by a very low level of bases, phosphorus and nitrogen. Organic

Margenta groundnut planted on sand tailings, producing a yield of 300 g/clump

Images: MARDI

iving

and