Crop Diversification in the Asia-Pacific region - United Nations in ...

other hand, the size of an average holding is smallest in the Region, and the land to man ratiohas declined rapidly over the years. The per capita agricultural land available in the Asia-Pacific Region in 1961 was 0.35 ha, which declined to 0.27 in 1988 and further reduced to0.25 ha in 1997. A further decline in land availability is inevitable due to urban developmentand industrialization in many of those countries, leading to unprofitable units for cropproduction.Crop production can be increased by increasing the extents of agricultural land,which as evident from the above becomes an impossible task. The other alternative is tobring additional land under cultivation by expanding into marginal lands in differentcountries, but these have been almost exhausted and even with heavy investment may remainmarginal. Hence, of the available options, increase in intensity of cultivation and in yieldsper unit area are the only available options to meet future food needs to feed an everincreasing population.Technologies continue to be developed in various countries that will have an impacton future crop production. Most of these technologies are directed towards increase in yielddue to less land availability. In the future, therefore, increases in food production to enhancefood and nutrition security have to be achieved through intensive cultivation and high yieldand to a minor extent through increase in land areas. Over 75 percent of the high yieldincreases will arise from improvement of the yield of crops, with the balance from expansionof land area and cropping intensities.In the future the potential for yield improvement will be through technologicalinnovations. The potential yield increases are likely to be greater in the developing countriesthan in the developed countries. It could be argued that the yields in the developed countrieshave reached optimum levels due to the full exploitation of the available technologies, a"technology fatigue", whereas the yields in the developing countries are always lower thanthe potential yield under experimental conditions. The yield gaps, which exist in most cropsand the actual volumes at varying levels in different countries, point to the need fortechnologies which are less expensive. Estimates indicate that the yields, obtained in the lessdeveloped countries are about half to one third of those of the developed countries and evenwithin the Region wide variations are observed. Therefore, there is much scope to increasethe yield of crops.There is a school of thought that the majority of small-scale farmers could be liftedout of poverty without the use of modern technologies such as improved seed, fertilizer andcrop protection chemicals. They believe that soil fertility could be increased by organicmanures, farmer bred and maintained indigenous varieties, biological or mechanical controlof pests, diseases and weeds and human power to carry out farm operations. Although thelow input sustainable agriculture (LISA) is getting popular in some industrialized countriesits direct transfer to developing countries will have some resistance. With the presentchanges in the labour market and global trade, it cannot be applied and may not be relevantto the Asia-Pacific Region.3. CONCEPT OF CROP DIVERSIFICATIONCrop diversification can be a useful means to increase crop output under differentsituations. Crop diversification can be approached in two ways. The main form and the157