Humans Nutrition

It is significant to note in the decadc of the seventies that more than 80% of the increase in production of cereals in the Asian countries has occurred through the increase in productivity. It is equally significant to note that any further increases in production would also have to come largely by increasing productivity,because there is a restricted scope of increasing area under food crops. More than 80% of the arable land is already inder cultivation and the remaining 20% or so is mainly marginal land Therefore, further expansion of net cultivated land will not only be costly, but also ecologically unsound.

While the countries in this region recorded the highest rate of growth(2.5%) in cereal yield in the world during 1971 to 1981 , the actual yield levels of cereal crops are considerably lower than those in developed regions. Average yield of cereals in the Asian region was about 2100 kg/ha against about 3500 kg/ha in Europe and North America during the triennium ending 1981 . Considering the major cereals, rice is the foremost crop of most of the Asian countries. In some of the countries, rice paddy accounta for more than 90% of the country’s grain production. Yields of rice paddy vary widely from country to country. The details are given in Table3.It can be seen that four  out of the 18 rice producting countries, namely China, Korea (DPR) ,Korea(Rep.) and Japan recorded yields of more than 4 tons/ha. There were seven countries whose rice paddy yields ranged between 2 and 3 tons/ha,except Indonesia with an average yield of 3.3 tons/ha. The remaining seven countries produced less than even two tons/ha. The yields of the coarse grains in Asia were still lower and variable,being only about 1500 kg/ha against 2545 kg/ha in the rest of the world. Wheat yields shown in Table4 progressed at a higher rate of about 3.6% per annum but that, too, is considered moderate. The country performances varied considerably. While Japan and Korea recorded 3000 kg/ha, the major wheat producing countries of the region from about 1600 to 2000 kg/ha. From the analysis of yields it is revealed that there is a great scope of increasing the adsolute yield of the major cereals in the region.

The modern cereal production technology is centered around the HYV’s for which adequate quantily of quality seeds, fertilizer and irrigation are the major inputs. As regards fertilizers,despite the impressive 11% annual rate of growth of fertilizers during the 1970s, the average rate of the fertilizer application of about 60 kg/NPK/ha in most of the Asian countries, is far below the recommended doses and the average level of application in some of the countries in the region. The fertilizer doses in some of the countries of the region are even less than 20 kg/NPK/ha. It is further disturbing that the rate of increase in fertilizer use in the Asian countries during the past3 to 4 years has declined.This trend must not only be checked but aslo reversed. Indigenous production and efficient distribution of fertilizers including subsidy and price incentive should be stepped up. Measures must be develop and widely adopted to increase the efficiency of fertilizer use.
Irrigation should receive high priority in national planning. Effective water management will economize the water use and maximize and stabilize production. Water harvesting devices under rainfed counditiona technologies suitable to congenial and stressed crop growing conditions, including rain-dependent agriculture should be developed and widely adapted.

There is an ample scope for increasing cropping intensity particularty in the tropical and sub-tropical Asia. Presenty, cropping intensity in the Asian Region is less than 120 percent. With the increasing availability of fertilizers and water and appropriate crops, especially legumes and their varieties (short-duration photo insensitive), cropping intensity must be increased.