听力原文：Good morning and welcome to our inaugural lecture on Agricultural Economics. Toda

听力原文： Good morning and welcome to our inaugural lecture on Agricultural Economics. Today's topic is the world's production and trade of rice.

As you are all well aware rice is the staple ingredient in the diet of much of the world's population. Its importance as a food cereal in the human diet cannot be underestimated. In fact, it's a close second to wheat—about 560 million metric tons of rice is grown each year compared with about 600 million metric tons of wheat. Coarse grains, such as corn, sorghum, barley, oats, rye, and millet mostly go into animal feed which, by the way, is seen by many as a wasteful and inefficient use of fertile land because around 4 kilos of grain is needed to produce about half a kilo of beef. Some 900 million metric tons of coarse grains are grown annually worldwide and a further 300 million metric tons of grain is produced for the oil in its seeds...Now, I'll return to the subject of rice production...

What do we know about rice production？ Well, firstly, rice produces more food energy per hectare than any other cereal grain and almost as much protein per hectare as wheat. Secondly, the production of rice has more than doubled in the last 40 years. How has this increase in production come about？ Mainly as a result of improved field yields—the actual land area planted in rice has only risen by about 30 %. As you know, rice is primarily grown in flooded fields and therefore cultivation area is restricted by the sort of soil and the availability of water.

Although rice can be grown on dry land—it is essentially after all a type of grass—the yields and quality in this case are much lower and other grasses and weeds can easily overtake the rice. As yet there are no herbicides that can selectively kill other grass types without killing the rice. Much of the world's rice is still grown and cultivated by hand because for mechanized farming the land must be able to be drained and hold heavy equipment.

Of the total rice production, it's no surprise to learn that the greatest proportion by far is grown and consumed in Asia. You will see from the chart that the leading producers of rice are China at around 39% followed by India with a quarter of the total, Indonesia produces almost one tenth and other countries, like Bangladesh, Vietnam, Thailand, Japan and Brazil, grow another 25—almost 26—percent of the total.

As I said before, most rice is consumed in the countries where it is grown. That means that very little rice is actually traded and for this reason the market price is very volatile.

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