National rankings in agricultural sciences

	Country	Papers	Citations	Citations per paper
1	Scotland	1,762	19,546	11.09
2	Finland	1,794	19,779	11.03
3	The Netherlands	4,2	42,849	10.03
4	England	7,589	74,332	9.79
5	Denmark	2,733	26,576	9.72
6	Sweden	2,119	20,593	9.72
7	Norway	1,492	13,673	9.16
8	Israel	1,111	10,077	9.07
9	Belgium	2,822	24,413	8.65
10	Switzerland	2,3	20,085	8.63
11	US	40,701	340,262	8.36
12	Ireland	2,143	17,724	8.
13	France	8,639	70,796	8.19
14	Canada	7,662	59,2	7.74
15	Italy	6,719	48,434	7.21
16	Portugal	1,563	11,071	7.08
17	Spain	11,584	81,746	7.06
18	Greece	2,170	15,198	7.00
19	Australia	7,353	50,376	6.85
20	New Zealand	2,838	19,338	6.81

The data above were extracted from the Essential Science Indicators database of Thomson Reuters. This database, currently covering the period January 1999-April 2009, surveys only journal articles (original research reports and review articles) indexed by Thomson Reuters. Articles are assigned to a category based on the journals in which they were published and the Thomson Reuters journal-to-category field-definition scheme.

Both articles tabulated and citation counts to those articles are for the period indicated. Here our ranking in agricultural sciences is by citations per paper — among nations that collected 10,000 or more citations during the period — to reveal weighted impact. For articles with multiple authors from different nations, each nation receives full, not fractional, citation credit. Essential Science Indicators lists nations ranked in the top 50 per cent for a field over a given period, based on total citations. In agricultural sciences, 98 nations are listed, meaning 196 were surveyed. Thirty nations collected at least 10,000 citations in this field during the period. The top 20 are listed above, and northern European nations dominate the upper tier. For more information on Thomson Reuters Essential Science Indicators, see http://scientific.thomsonreuters.com/products/esi