In Mali the partners will focus on irrigation and disease-resistant crops
A US government aid agency has formed an alliance with a group headed by former UN chief Kofi Annan to try to boost African agriculture.
Mr Annan has called for a "green revolution" to solve the food crisis.
The new partnership aims to invest in Africa's inadequate infrastructure, as well as developing new seeds and fertilisers.
Mr Annan says that 40% of African crops are lost after being harvested - a problem which new roads could ease.
The alliance between the US Millennium Challenge Corporation (MCC) and the Alliance for a Green Revolution in Africa (Agra) focuses on small-scale farmers.
Akin Adesina, Agra's vice-president, said the partnership would focus on boosting production in three "breadbasket areas".
These were the Sahel region where millet and sorghum crops dominate; humid zones where root and tuber foods do well and the east and south of the continent where maize is the dominate crop.
"We believe that we can have a green revolution that allows farmers and households in the Sahel to be able to feed themselves while also allowing those who are eating maize, yams and cassava to be able to feed themselves," he told the BBC's Network Africa programme.
Mr Annan said there had been 30 years of silent hunger in Africa, where farmers exported food in the late 1960s but now only produced a quarter of the world average per acre.
"Collaborations such as ours are essential to putting in place long-term solutions to the food crisis," Mr Annan said after signing the deal.
"Today, the efforts of our farmers are thwarted by a lack of access to good seed, fertilisers, and financing.
"Some 95% of African agriculture is dependent on rain-fall; and farmers lose an average of 40% of their crops after harvest," he said.
"We need better technologies for efficient use of water; improved market infrastructure; and paved roads so farmers can get their harvest to market."
MCC head John Danilovich said that the deal was an "important day for African farmers".
"It combines the investments that MCC has made in many sub-Saharan African countries in agriculture and public infrastructure such as roads and irrigation to complement Agra's investments in providing the rural poor with seeds and fertilisers," he told the BBC.
The initial focus of the partnership will be on:
- Ghana, where a great and improved varieties of seeds will be made available to farmers
- Madagascar, where extremely poor rice yields will be the focus
- Mali, where the focus will be on irrigation and disease-resistant crops.
To date Agra has already invested $330m and MCC $1.7bn in African agricultural development.