The database, launched on Thursday, includes 1,006 deals covering 70.2m hectares (173m acres) - or roughly half the size of western Europe. Data on further deals will be added on an ongoing basis.

Some highlights from the database:

• Eastern Africa has the largest number of recent investments, with 310 deals.
• Indonesia is the country with the largest area of land acquired by investors ? 9.5m hectares. The Democratic Republic of the Congo comes second, with almost 8.1million hectares.
• The Indian government, Chinese telecommunications firm ZTE International and Indonesian company Indah Kiat Pulp & Paper are the top three investors, having acquired more than 10m hectares around the world between them.
• The vast majority of the deals are for agricultural projects (690 deals covering 50.2million  hectares). Forestry is the next largest sector (94 deals covering 12.7million hectares).
• Of the agricultural deals, fewer than 30% are for food crops alone. Almost 20% are for non-food crops such as biofuels and livestock feed.

The Land Matrix database [ http://www.landportal.info/landmatrix ] is now the most comprehensive public source for information on international land deals - but it is not perfect. Some countries, for example, may be over-represented in the data simply because they are more transparent and routinely publish contract information. In other cases, the data may be skewed towards investors or countries that have featured in more media reports.

This makes it difficult to draw too many conclusions from the data. For example, there appears to be a sharp decline in deals since 2009 - but although this could correspond to a drop in investments, it could also be driven by a fall in media interest or an increasing reluctance to disclose information about deals.

Researchers warn that smaller deals are often harder to track and may be under-represented in the database. Data for deals struck after 2010 is still being collected, cross-checked and verified.

Researchers hope that releasing the data and inviting the public to crowdsource new information will help address some of these issues. The site [ http://www.landportal.info/landmatrix ] lets users "report a land deal" or submit further details on deals already recorded. This information will be independently verified by researchers before being included in the database.

DATA: download the full spreadsheet [ https://docs.google.com/spreadsheet/ccc?key=0ApF51UgS889tdE1EblRCdUh2bUE0ZjRHM09XSlZtYmc ]