Agriculture in the Malaysian Region

Chapter 3. Land Use and Environment

Land Use and Environment 23 23 chapter 3 Land Use and environment The perception of environmental limitations to agriculture has varied from time to time and from cultural group to cultural group. Thus, the shifting cultivator prefers well-drained land where the felled trees will readily dry out and give a good burn and regions where clear running water is available. The peasant rice-grower avoids the difficult soils and drainage problems of the coastal mangrove fringe and freshwater swamps, preferring the recent alluvial soils which are not deeply flooded. The estate-owner or tree-crop small-holder seeks rolling uplands, especially those of granitic or basic volcanic origin (though the latter are rare), not only because these provide satisfactory soils, but also because much of the alluvial lowland is already occupied, by rice especially. This situation did not occur everywhere , though; in Selangor, for example, tree-crops were to be found on Selangor series soils, one of the best alluvial lowland soils in the country, simply because they had been very little developed for rice when agricultural settlement began. Significant areas of coconuts and rubber existed in Lower Perak for much the same reason — rice was less economic than tree-crops (see Hill 1977). By contrast, the lowlands of Kedah and Perlis were already largely developed for rice when the phase of tree-crop expansion began at the end of the nineteenth century. This is not to suggest that the physical environment does not set limits to certain crops at particular times and in particular places, but only that these limitations are relative rather than absolute. They are relative to the basic facts of free-enterprise economics, since the countries of the region have always been essentially capitalist, though governments have played a major role, especially in ameliorating environmental limitations by irrigation and drainage — the particular preserve of a whole government department in Malaysia. Temperature is nowhere an absolute barrier to plant growth, though it is generally held that the yields of rubber and oil palm are sufficiently 24 Agriculture in the Malaysian Region depressed at altitudes above about 300 m to make it unprofitable to grow them. At the same time, land above this level (and sometimes below it) is often steep and broken, so that terracing or planting in pits becomes expensive while the reduced mobility of the workers also makes harvesting costly. The reduction of temperature with altitude favours the growing of temperate vegetables in areas above about 1,200 m which have ready access to urban markets. Market-gardening on soils of granitic or similar origin at Cameron Highlands (Peninsular Malaysia) and at Kundasang on the Gunung Kinabalu massif in Sabah are examples. These slopes, which may exceed 35°, are cultivated in tiny, sometimes terraced plots. Water supply is the most important climatic limitation, affecting annual crops much more seriously than perennial tree-crops. The shallowrooting crops of shifting cultivators are most at risk, since run-off in jungle clearings is very rapid, at least in the early stages of growth. The result is a high degree of yield variability from harvest to harvest. In plains areas, rain is traditionally trapped on rice-fields by means of low mud bunds. Although yields are less variable than on hill-slopes, they are nevertheless less stable than on lands where water can be supplied on demand, usually by artificially flooding the whole controlled-irrigation area. Nevertheless , even artificial irrigation is not wholly free from the effects of variable rainfall, since in most schemes water storage capacity is limited and in some cases non-existent. The whole question of the relationship of rice yields to variations in rainfall has been studied little, perhaps because of the general difficulty of isolating this factor from others in an uncontrolled , field situation. In respect of rubber, however, Wycherley (1963) has suggested that though it has yet to be conclusively shown that long periods of drought reduces the yield of latex, yields are nevertheless reduced in the third and fourth months of the year as a result of “wintering”. Although Hevea is evergreen, mature trees usually defoliate regularly once a year following a dry spell, which in Peninsular Malaysia normally occurs early in the year. Refoliation follows and during this period yields may fall to between 30 and 80 per cent of normal in any one area depending upon the particular clone being grown. As a result, tapping may become uneconomic. Other things being equal, it would seem that wintering and subsequent...