ALMOST 10 per cent of Australia's prime farmland is foreign owned, a new report claims.

Foreign ownership levels were found to be the fifth highest in the world.

A study by leading international environmental scientists found 4.64 million hectares of prime, high rainfall or irrigated agricultural land in Australia was now in foreign hands.

The study was conducted last year by a leading European technical university, the Politecnico di Milan in Italy and the University of Virginia in the US.

It found there was a "dramatic increase" in trans-national land and water deals, occurring at "alarming rates".

Farm leaders and commentators say the report's findings are further evidence Australia urgently needs its own register of land ownership.

"A register would be a much better way to get this debate on a rational footing, without having to rely on overseas research," Australian Farm Institute executive director Mick Keogh said yesterday.

Victorian Farmers Federation vice-president David Johinke said farm lobby groups were "pressing hard" for all political parties to make a commitment to a land register before the federal election.

"At the moment we are operating in the dark and have to rely on reports like this to give us some sort of idea what is going on," Mr Johinke said.

According to the report, Australia accounts for almost 10 per cent of "relatively inexpensive" highly productive farmland with access to water, globally, that has been "land grabbed" by foreign countries and corporations.

The Democratic Republic of Congo has had the highest amount of land acquired by such entities with eight million hectares, followed by Indonesia (7.1 million ha), the Philippines (5.1 million ha) and Sudan, (4.69 million ha).

The report estimates 9.78 per cent of Australia's highly productive cultivated land was now foreign-owned.

Land grabbing, "the transfer of the right to own or use the land from local communities to foreign investors through large-scale land acquisitions", is described as a "new form of colonialism", which has intensified rapidly in the past four years.

The main countries doing the buying are the UK, which has acquired 9.3 per cent of all land purchases; the US has bought 7.8 per cent and China has 7.2 per cent.

Australia is also buying, but this only accounted for 0.006 per cent of the total global land grabbed.

Looking at water resources, the US has bought the most water in foreign countries, followed by the United Arab Emirates and India.

The trend has been driven by rising food demand, biofuel production and rising oil prices, it found.

Mr Johinke said farmers were "starting to work on their election priorities" and a foreign investment register was high among them.

"We are expecting any government which is coming in will have a register so agriculture can move forward," he said.

"We need to be able to identify key areas of national priority as far as our agriculture is concerned."

Mr Keogh said land registers were well established in New Zealand, the US, Canada and most other developed countries of the world.

"This will need co-operation of states and there is a fair chance they will see this as a sensible initiative."