With nearly a quarter of the world's population, China must be on its guard against any potential food security hazard.

Overuse of fertilizer is one such hazard that will likely pose a threat to the country's food security if not controlled.

Use of fertilizer has raised agricultural output by 30 to 50 percent. Most Chinese farmland is not that fertile, yet crops are planted twice a year. As a result, the land has become increasingly barren. Fertilizer has played an important role in enabling the country to maintain high yields.

But an unwanted consequence of this has been that an increasing number of villagers have developed the habit of relying on fertilizer for a good harvest. And they tend to apply large amounts of fertilizer to their crops.

Many farmers trust fertilizer to such an extent that they ignore other work that would increase the fertility of their land. They never seem to realize that they are eviscerating the sustainability of their fields.

China's output of fertilizer is the second largest in the world, but its consumption is the largest. The total amount of fertilizer the country uses annually amounts to more than 54 million tons and that of nitrogenous fertilizer is 33 million tons. The use of fertilizer per hectare of farmland was 341 kilograms in 2009, higher than most countries.

Statistics from the Ministry of Agriculture (MOA) show that the fertility of 40 percent of the country's arable land has been degraded to a large degree, and overuse of fertilizer has contaminated 10 million hectares or 7 percent of the total area of arable land.

Worryingly, compared with the early 1990s, the organic matter contained in the country's arable land has decreased by 35 percentage points.

At a meeting convened by MOA in July, a plan was made to promote the use of fertilizer in a reasonable manner. From 2011 to 2015, the five years of the 12th Five-Year Plan, soil in 60 percent of arable land will be tested to see how much and what kind of fertilizer should be used. Over the five years, the effective utility rate of fertilizer is expected to increase by 3 percentage points from the present 40 percent on average.

The MOA will also try to increase the use of manure by 10 percentage points during the five years and the crop stalks to be used as fertilizer will increase by 10 percentage points. All these will hopefully increase the fertility of arable land, promote agricultural ecology and make agricultural products safer.

However, these are far from enough, a mechanism must be established to encourage rural villagers to use more manure rather than fertilizer. They should also be made aware of the fact that it is in their interest to maintain the fertility of their arable land by applying fertilizer in a scientific manner.

(China Daily 08/17/2011 page8)