Prof. H.P.M. Gunasena stated that most of the countries in the Asia-Pacific Region depend on agriculture for their economic development. Hence, their agricultural sectors focus on food production, gainful employment, foreign exchange earnings, capital accumulation and labour replacement.
Many of these countries are moving towards industrialization due to their open economic policies resulting in a gradual shift in the population from agriculture to the industrial sectors. The agricultural population in the developing countries of the Region has declined from 66 to 62 percent and in the developed countries from 7.6 to 7 percent from 1988-1997. This shift has two major repercussions on crop diversification in the Region. These are the high cost and non-availability of labour in the cultivation seasons. As cost of labour is escalating, there is a need to develop less labour intensive crop production technologies.
Although crop production can be increased by expanding the cultivable area, this option appears to be marginal, even with heavy investment. It is also noted that the land to man ratio is declining rapidly in the Region and presently stands at 0.25 hectares. In the future, increased food production has to be achieved through increasing yield per unit area and by crop intensification. It is estimated that 75 percent of the production increases will arise from the improvement of yield of crops, and the balance from increases in land area and cropping intensities. Therefore, the development of appropriate crop production technologies will be essential.
Crop diversification is a useful means to increase crop output under different conditions. It should be approached in two ways. The commonly understood mechanism is the addition of more crops to the existing cropping systems, which is the broadening of the base of the system. This method of horizontal diversification has special significance under small-holder production systems and has been responsible for production increases due to high cropping intensities. The system of multiple cropping has been able to increase food production potential to over 30 t/ha with an increase of the cropping intensity by about 400-500 percent. The other type is vertical crop diversification which reflects the extent and stage of industrialization of the crops. It has to be noted that crop diversification takes into account economic returns from different crops, and is different to the concept of multiple cropping. Both types of diversification will be essential to improve crop yields and income generation at local, regional and national levels.
The major constraint in the Region is low productivity coupled with high population pressure and negligible area of land available for expansion of cultivation. Therefore, under such circumstances, the available option is intensification of crop diversification using more modern technologies. These will include balanced crop nutrition, agricultural mechanization, irrigation, use of improved seed and other planting materials, and use of new technologies such as protected cultivation and organic farming. In crop diversification aiming towards sustainable production systems, far greater emphasis should be given to farmer participation in adopting and implementing new technologies. Often crop diversification efforts have failed due to ignorance of farmer involvement and external and internal factors that effect the system. New technology development will enhance crop diversification. The development and utilization of technologies should be supported at national levels through appropriate policies, capacity building and effective implementation mechanisms.
