American Society of Agronomy (ASA) http://www.agronomy.org/
The ASA is one of the most important scientific societies for providing educational materials, scholarly and trade publications, and networking opportunities in agronomy. The site offers an RSS feed of articles of interest from a variety of sources that would be difficult to check individually. Despite its name, the Society does have strong international interests and works with many affiliates around the globe. Because of the highly intertwined relationships, ASA is closely connected with the Crop Science Society of America (CSSA) and the Soil Science Society of America (SSSA). There is even a shared site, http://www.asa-cssa-sssa.org that mirrors the construction of the ASA site and links to each of the individual sites as appropriate. There is also the ability to search across all publications produced by the three organizations, although full text is available only to individual or institutional members.
Crop Science Society of America (CSA) http://www.crops.org/
CSA's website features a similar RSS feed of articles. It includes articles of general interest to agronomy and articles specific to crop science.
Soil Science Society of America (SSSA) http://www.soils.org/
SSSA's site also has an RSS feed of recent articles making headlines. Additionally, this site links to other soil sites and soil science projects around the country.
ASA/CSSA/SSSA Blog http://www.asa-cssa-sssa.blogspot.com/
This blog serves all three organizations and covers issues that have interest across the board. Topics for discussion often cover science policy and legislation before the House and Senate.
Agronomic Science Foundation (ASF) http://www.a-s-f.org/
The ASF is also affiliated closely with ASA/CSSA/SSA. It is an organization that provides funding to further research in the areas of agronomy, soils, and crop sciences. Funding largely comes from individual and corporate donations.
Agronomy Society of New Zealand http://nzsap.rsnz.org/
Although focused largely on New Zealand agronomy, this site does list a substantial number of links detailing the industrial and research aspects of New Zealand and Australian agronomy.
Australian Society of Agronomy http://www.regional.org.au/au/asa/
The highlights for this site include the full text for their conference proceedings back to 1992 and full text news articles on a variety of agronomy topics.
Canadian Society of Agronomy http://www.agronomycanada.com/
This site, fully available in either English or French, features past newsletters, information on awards, and has an extensive job seeker/recruiter area.
Crop Science Society of Japan (CSSJ) http://wwwsoc.nii.ac.jp/cssj/index-e.html
CSSJ was founded in 1927 and has provided an organization to disseminate information on crop sciences and agriculture nationally and internationally. Most notably, they publish two open access journals, Plant Production Science and the Japanese Journal of Crop Science.
European Society for Agronomy (ESA) http://www.esagr.org/structure/
ESA promotes agronomy within Europe. However, much of the site is limited to members. One area that is freely available is a searchable database of articles. These articles were submitted by ESA members as being significant in the field of agronomy.
International Union of Soil Sciences http://www.colostate.edu/programs/IUSS/
This site has a very extensive list of divisions in soil science which acts as a good introduction to the outline of soil science studies.