ENERGY AND AGRICULTURE
The world demand for food is expanding more rapidly than ever before in history
By Dr. S.M. Alam
Nuclear Institute of Agriculture,
Jan 22 - 28, 2001
The world is lightened to an extent of 38.3 % by burning of coal, wood and vegetation, 19 % through hydro (water), 17.5 % through nuclear energy, 14.9 % by gas, 9.9 % by oil and 0.4 % by others (wind, landfill gas and solar) means. The energy generated through such means is used to run industries, use in household affairs and agricultural productivity. Similarly, per capita consumption of electricity in different human requirements and in different countries of the world are as (kilo watt hours): USA (11,753), Japan (6,176), Singapore (4,889), Malaysia (1,146), Iran (724), Thailand (636), China (448), Pakistan (340) and India (292). There are nearly 2.5 billion people in the world without access to electricity, so there is an urgent need for a strategy, of renewable energy source usage for the benefit of mankind.
Energy use in food production has been increasing faster than many other sectors of the world economy. The major question is how to stop uncontrolled human population growth. Man must solve the ultimate problem of increasing population numbers. We must find genuine ways to increase food production on the world's limited arable land resources through the efficient use of fossil energy. Suggestions have been made that the world's potential arable land might be doubled with irrigation and the significant alterations of parts of the ecosystem. Only about 12% of the world's cultivated land is now irrigated. Unfortunately, irrigation and other environmental manipulations require enormous amounts of energy. For example, a litre of water weighs 1 kg and about 12.2 million litres (12,200 metric tons) of water are needed to produce 5000 kg of corn/ha in the subtropics. To produce the high protein calorie diet consumed by the average American, about 160 million hectares are utilized for crop production in the U. S.
The world demand for food is expanding more rapidly than ever before in history. Increase in population and changes in its spatial distribution have aggravated the food situation during the last 35 years. Besides population growth, rising affluence, agricultural inefficiency and misguided political expediency have contributed to the further aggravation of the problems. Rising affluence is rapidly emerging as a major new claimant on the global food resources. Currently, the agricultural resources necessary to support one inhabitant of a more affluent country can support on an average five citizens of developing countries such as Bangladesh, Uganda or Colombia and many more. Shortages and higher prices for fuels have resulted in increasing prices and shortages of crop production inputs such as fertilizers and pesticides. Recently, fertilizer prices increased from 3-2 fold in various parts of the world. Pesticide prices increased from 2-5 fold and again in some areas none was available. Shortages of these and other agricultural inputs that depend on fossil fuel for their production have had a significant impact upon agricultural production in all parts of the world. The present years are crucial for mankind. Population numbers are currently over 6 billion and 16 billion by the year 2135. Food shortages in the world already exist, at least half of the world's population is suffering from protein calorie malnutrition. The standard of livings can generally be achieved by way of sustained economic growth over a number of years. Growth development of agriculture and industry requires energy.
The per capita consumption of energy in Pakistan is very low in the world. In any development plan of our country the growing demand of energy assumes great importance. For development of economical growth, the major effect in the next decade world have to be through an increase in the production of coal and a search for new reserves of oil. Our oil reserves are limited. Our dependence on imported oil is on the rise every year. We have several large reserves of coal, but our coal has high ash content. Coal used for power generation in the country has ash content of about 48 %.
In the production of food for mankind, relatively a few crops are utilized. The estimate is that of fifteen crops provide nearly 90% of the world's food for man. These crops include rice, wheat, maize, sorghum, millet, rye, barley, cassava, sweet potato, potato, coconut, banana, common bean, soybean and peanut. These fifteen crops also occupy about 3/4 of the total field land of the world. With the current and future shortage of energy resources, alternatives techniques will be required to make more effective use of energy resources in agricultural production as well as its other utilization for human benefit. Some of the practical alternatives which might be employed in crop production may be as: Labour: (Labour is the source that is in abundant supply and becomes more abundant in less developed countries as the world population continues to increase. Therefore, every effort should be made to make crop production labour intensive within the viable economic constraints. To increase the labour inputs requires careful consideration of both the economic and social aspects of the problem.
Fertilizers account for almost half of the energy used in agriculture. The single largest input in the US and also in many other countries are fertilizer (N. P and K). Compared with phosphorus and potassium, the use of nitrogen requires the largest quantity of energy in crop production. Thus as energy supplies decrease other potential fertilizer sources such as livestock, manure, some agricultural wastes and other organic wastes can be utilized.
Thus, when fertilizer is applied to during one year by either 3 cows, 22 hogs, or 207 chickens. Besides, adding nutrients to the soil, manure adds organic matter, which increases an average hectare of corn at a rate of 125 kg nitrogen, 35 kg phosphorus and 67 kg of potassium; the same and of nitrogen is available from manure produced the number of beneficial bacteria and fungi in soil, makes ploughing easier, improves the water holding and percolation capacity of soil, reduces soil erosion, and improves the ratio of carbon to nitrogen in the soil. These same advantages, results from the use of crop and other organic wastes. Tractor is an important input in the agricultural work. Although, it reduces the work of at least 13 labourers, but its work in the field minimize the time consuming factor required for preparation of a field. But, tractor needs energy which is generated by the application of gasoline or diesel. About 9.4 litres of gasoline are used for tractor application per hectare. Pesticides/insecticides are also important input in the control of insect/pest swarm in the agricultural fields. Their application to the crop is only possible through the use of energy in form of petrol. Thus energy has great link in the operational work for the improvement of soil fertility.
Conclusion: To maintain the supply of energy to keep the food system going, hopefully new energy sources will be developed. The energy used in crop production can be divided into two categories: (i) energy used to increase yields (fertilizers, hybrid seeds, etc); (ii) energy used to reduce inputs (machinery, gasoline, etc). Food production in the less developed countries will have to depend primarily upon energy inputs to increase yields and less upon heavy machinery. A surplus of labour already exists in many parts of the world.
The problem of population control must be reemphasized. The human population cannot continue to increase without a continual decline in living conditions and worse misery than the majority of the world population faces today. The world urgently needs population control in each and every nation. Our efforts in agriculture are forward increasing food supplies and "buying time" to implement population controls.