The United Nation Food and Agriculture Organization said that farmers need to produce 70 percent more food to feed an expected 9 billion world population in 2050.

According to the UN body, this amounts to one billion tons more wheat, rice and other cereals and 200 million more tons of beef and other livestock.

In its report "State of the World's Land and Water Resources for Food and Agriculture", the FAO said that a major "sustainable intensification" of agricultural productivity is needed on existing farmlands to meet the world's future food needs.

According to this first ever UN global assessment of the earth's land resources, 25% of all land is highly degraded. The UN findings also noted that although most of the available land is already being farmed, the methods used actually lead to soil erosion and wasting of water, thus decreasing productivity.

The report said around eight percent of the land is moderately degraded, while 36 percent is stable or slightly degraded and 10 percent is ranked as "improving." The rest of the Earth's surface is either bare or covered by inland water bodies.

According to the UN report, water around the world is becoming more scarce and salinated, while groundwater is becoming more polluted by agricultural runoff and other toxins.

To meet the growing food demand, the UN agency called for new farming practices like integrated irrigation and fish-farm systems as well as overall investment in agricultural development.

The UN said the amounts needed until 2050 would be $1 trillion in irrigation water management alone for developing countries, with another $160 billion for soil conservation and flood control.