This is the VOA Special English Agriculture Report.
Population growth and economic changes put pressure on farmers tomake their fields more productive. As a result, the use of mineralfertilizer is expected to continue to increase.
There are many different kinds of fertilizers. Many have beenused since the very beginning of agriculture. Farms that raiseanimals have a ready-to-use fertilizer that comes from their dailyoperations. Organic fertilizer usually comes from animal waste,plant material or wastewater. But these are not all.
Some crops fertilize the soil by themselves. Beans releasenitrogen. Crops like alfalfa can be left to break down. But, thesemethods supply limited amounts of soil nutrients.
Farmers, trade groups and policy organizations generallyrecognize that manufactured fertilizers are necessary. They say itis simply not possible to create enough food without them.
Mineral fertilizers are not organic. The kind used most arenitrogen-based. Nitrogen from the air is mixed with hydrogen fromnatural gas. This process produces ammonia gas. Other nutrientelements are then added to the ammonia. Today, the biggest producerof nitrogen fertilizer by far is China. It produces more thantwenty-one million tons a year.
Another group of fertilizers is made from phosphorus. Crushingthe mineral apatite produces this nutrient. Morocco, the UnitedStates and China are major producers of phosphorus.
Potassium, or potash, provides a third important crop nutrient.Once, it was made by burning wood. But it is also present in mineralforms that can be mined.
These substances are the basic products of the fertilizerindustry.
Mineral fertilizer may permit agriculture in places with fairlypoor soil. It can also stop soil from becoming infertile.
Fertilizer does not provide all the answers to productiveagriculture, however. Experts say soil biology and biotechnologymust also be studied. And they say farmers must considerenvironmental concerns and possible health dangers. Too muchfertilizer can pollute groundwater and damage lakes, rivers andwetlands.
But, fertilizer does increase crop productivity. Next week, wewill talk more about the issues and the demands of the future.
This VOA Special English Agriculture Report was written by MarioRitter.