Bill Gates speaks at the Economic Club of Washington, D.C., on March 8 , 2011. (Jeffrey MacMillan/FOR THE WASHINGTON POST)

After years that have seen riots over rice shortages in Asia and record low world reserves of staple crops such as wheat, software-billionaire-turned-philanthropist Bill Gates argues that there is a simple solution.

Grow more food.

In a new push for the Gates Foundation, the Microsoft chairman is focusing on basic research on crops such as cassava that hold little interest for the world’s agriculture multinationals but which are important for family farmers in some developing nations.

With productivity gains leveling off for major crops, such as soybeans and corn, Gates — in an annual review of the foundation’s work — said that boosting the productivity of small farms may be key to a new “green revolution.”

“The speed and productivity increases should rival that period,” he said in a recent interview, referring to the decades since the 1960s when the development of high-yielding hybrid crops, better pest and land management, and other advances led to plentiful supplies and falling prices of food staples.

That era may be at an end, some food analysts said. Rising demand, slowing technological advances and limits on the availability of arable land may usher in an era of higher and more volatile prices, they said.

The effect has been episodic. After rising to record levels in 2010, for example, food prices have moderated and are expected by the World Bank to fall this year.

But the result can still be devastating to poor countries. This has led banks, government aid agencies and nongovernmental organizations to focus on finding ways to make poorer nations more self-sufficient in food production and less dependent on the ups and downs of world grain markets and weather patterns.

Unlike the time-consuming methods once needed to create hybrid crops, Gates said, DNA sequencing should accelerate scientists’ ability to, for example, identify the genes that make cassava resistant to viruses.

Gates and others have urged the world’s major economic powers to commit more money to the type of basic research needed to fund the breakthrough science that would expand production of crops such as cassava, sorghum and millet — second-tier plants that farmers in Africa in particular turn to when other, typically imported food becomes too expensive.

The world recession and ongoing financial crisis in Europe, however, have crimped funding for food security programs. Pledges from a conference of major economic powers in Gleneagles, Scotland, in 2005 have yet to be fulfilled; only about half of the billion dollars promised to the Global Agriculture and Food Security Program has been paid, with U.S. donations still falling short despite a $135 million contribution in the most recent federal budget.

The basic research promoted by Gates is just one of the challenges. The World Bank has set up programs to develop financial management tools that encourage small farmers to plant, while others have focused on the development of markets, roads and other infrastructure that can help them sell their products.

In the developed world, “the interest remains but everybody has their budget constraints,” said Kimberly Elliott, a senior fellow at the Center for Global Development.” A lot of the attention now is on just holding the line.”