irrigate是什么意思？

The biggest challenge here is irrigation, which consumes 70% of the world's fresh water.

Millions of irrigation wells in many countries are now pumping water out of underground sources faster than rainfall can refill them.

Millions of irrigation wells have significantly lowered water tables in almost every state.

As water tables have fallen and irrigation wells have gone dry, China's wheat crop, the world's largest, has declined by 8% since it peaked at 123 million tons in 1997.

When this water is used for agricultural irrigation, farmers risk absorbing disease-causing bacteria, as do consumers who eat the produce raw and unwashed.

Most of these operations draw irrigation water from local rivers or lakes.

Irrigation is the primary agricultural use of human waste in the developing world.

In poor, dry regions, untreated wastewater is the only viable irrigation source to keep farmers in business.

Facing water shortages and escalating fertilizer costs, farmers in developing countries are using raw sewage ( ' , 下 水道污水) to irrigate and fertilize nearly 49 million acres of cropland, according to a new report—and it may not be a bad thing.

Better irrigation can dramatically improve crop yield and about 40% of the world's food supply is currently derived from irrigated land.

Facing water shortages and escalating fertilizer costs, farmers in developing countries are using raw sewage to irrigate and fertilize nearly 49 million acres of cropland, according to a new report—and it may not be a bad thing.