RDCs invest around $540 million a year, comprising $325 million from rural industry, via producer levies, and $215 million from the Australian Government.

The evaluation, from the Council of Rural Research and Development Corporations' Chairs (CRRDCC), looked at a sample of 32 randomly selected projects from a pool of 600 and found a minimum average return of $11 was achieved for each dollar invested in 2007 dollars.

"This report shows the Government's rural R&D model is exceeding expectations and delivering benefits not only to the primary industries sector, but also producing other very positive social and environmental benefits way beyond the scope of the original investment," said Enzo Allara, chair of the CRRDCC.

The evaluation also found that just 36 highly successful projects returned $10.5 billion in quantified benefits, made up of $5.5b in direct benefits to the rural sector and $5b in spillover benefits to the wider community.

The $5.5b in direct benefits from these 36 projects - just 6pc of the total project pool - more than pays for the RDCs' entire $4.5b investment in the program's 600 projects over the past 10 years.

The report, Measuring economic, environmental and social returns from Rural Research and Development Corporations’ investment, provides the first year of results from an ongoing evaluation of RDC-managed investments.

"While there are significant environmental and social benefits, because of the difficulty in measuring these effects, these benefits are often undervalued," Mr Allara said.

"However, over the course of this evaluation process, we were able to quantify a number of public benefits including an investment in food safety research led by Meat & Livestock Australia which resulted in $503 million in social and related-industry benefits."

* A copy of the full report is available at the Rural RDC website.