Alternate wetting and drying (AWD) in rice: a map of the research field
Data: OpenAlex, retrieved 2026-10-04. One search defines the field: works whose title, abstract or
OpenAlex keywords mention alternate wetting and drying, AWD or intermittent irrigation together with rice or paddy.
The query, what was checked and what looked wrong are in field.md. An independent re-count of
every number is in checks.md. The data behind each figure is in data/.
Each API link below is a search and costs 10 OpenAlex credits to open (the free daily allowance without a key
is 1,000).
1. Works per year
OpenAlex finds 2,945 works on alternate wetting and drying in rice, 2,494 of them from 2000 to 2025. The field was small until the late 2000s (16 works in 2000, 65 in 2010). It has grown almost every year since, to 325 in 2025. The 2025 jump, and the dip in 2022 (175, after 218), may partly reflect how many repository, dataset and preprint records OpenAlex holds for recent years, not only research activity.
2. The institutions that publish most
The International Rice Research Institute leads (138 works). Next come Chinese universities and academies (Yangzhou, Chinese Academy of Sciences, Shenyang, Wuhan, Hohai, Huazhong) and institutions in Bangladesh, India, Pakistan and Japan, where AWD is promoted to save water and cut methane. UC Davis is the only US institution in the list. Places 14–16 are tied at 33 works, so the list has 16 entries. A work counts for every institution among its authors.
Query: ("alternate wetting and drying" OR "alternating wetting and drying" OR "intermittent irrigation" OR AWD) AND (rice OR paddy) (OpenAlex works,
search.title_abstract_keywords)
Institutions: International Rice Research Institute,
Yangzhou University,
Chinese Academy of Sciences,
Bangladesh Agricultural University,
Tamil Nadu Agricultural University,
Bangladesh Rice Research Institute,
Shenyang Agricultural University,
Wuhan University,
Hohai University,
Huazhong Agricultural University,
Ministry of Agriculture and Rural Affairs,
University of Agriculture Faisalabad,
University of California, Davis,
National Agriculture and Food Research Organization,
Japan International Research Center for Agricultural Sciences,
Chinese Academy of Agricultural SciencesData: OpenAlex, retrieved 2026-10-04.
API call: https://api.openalex.org/works?search.title_abstract_keywords=%28%22alternate+wetting+and+drying%22+OR+%22alternating+wetting+and+drying%22+OR+%22intermittent+irrigation%22+OR+AWD%29+AND+%28rice+OR+paddy%29&group_by=authorships.institutions.id
3. The journals that publish most
Agricultural Water Management carries the most (109 works), then Field Crops Research and Paddy and Water Environment. These are agronomy and water-management journals, with environmental journals (Science of the Total Environment, Agriculture Ecosystems & Environment, Journal of Environmental Management) where the greenhouse-gas work appears. Places 10–11 are tied at 20. Only sources OpenAlex types as journals are counted.
Query: ("alternate wetting and drying" OR "alternating wetting and drying" OR "intermittent irrigation" OR AWD) AND (rice OR paddy) (OpenAlex works,
search.title_abstract_keywords) with filter
primary_location.source.type:journalJournals: Agricultural Water Management,
Field Crops Research,
Paddy and Water Environment,
Agronomy,
The Science of The Total Environment,
Agriculture Ecosystems & Environment,
International Journal of Current Microbiology and Applied Sciences,
Journal of Environmental Management,
Plant and Soil,
Soil Science & Plant Nutrition,
Irrigation and DrainageData: OpenAlex, retrieved 2026-10-04.
API call: https://api.openalex.org/works?search.title_abstract_keywords=%28%22alternate+wetting+and+drying%22+OR+%22alternating+wetting+and+drying%22+OR+%22intermittent+irrigation%22+OR+AWD%29+AND+%28rice+OR+paddy%29&filter=primary_location.source.type%3Ajournal&group_by=primary_location.source.id
4. Arkansas: who writes with whom
44 works (1.5% of the field) have an author at an Arkansas institution: the University of Arkansas (Fayetteville and the UA System / Division of Agriculture), Arkansas State University, or a USDA-ARS unit in Arkansas. Most come from one connected group of authors at the University of Arkansas and the USDA Delta Water Management Research Unit, with partners at UC Davis. This group works on AWD, methane and water use, around Michele Reba and Benjamin Runkle (their 9 works together are the strongest link). A second group at the Dale Bumpers National Rice Research Center (Anna McClung, Jai Singh Rohila) works on rice varieties, grain quality, and arsenic and other trace elements in grain under AWD. The works run from 2013 to 2026 (all years, not only 2000–2025); a few are only loosely about AWD, e.g. a rice QTL paper and an economics paper on sea-level rise. There are 501 co-author pairs among 126 authors, 65 of them with an Arkansas affiliation. Some people have more than one OpenAlex author ID and appear twice. Authorships without an author ID are left out (see field.md).
Query: ("alternate wetting and drying" OR "alternating wetting and drying" OR "intermittent irrigation" OR AWD) AND (rice OR paddy) (OpenAlex works,
search.title_abstract_keywords) with filter
authorships.institutions.id =
University of Arkansas at Fayetteville,
University of Arkansas System,
Arkansas Agricultural Experiment Station,
Arkansas State University,
Arkansas State University System,
Arkansas Biosciences Institute,
Dale Bumpers National Rice Research Center,
Delta Water Management Research Unit,
Dale Bumpers Small Farms Research Center,
Harry K. Dupree Stuttgart National Aquaculture Research Center,
Arkansas Children's Nutrition CenterData: OpenAlex, retrieved 2026-10-04.
API call: https://api.openalex.org/works?search.title_abstract_keywords=%28%22alternate+wetting+and+drying%22+OR+%22alternating+wetting+and+drying%22+OR+%22intermittent+irrigation%22+OR+AWD%29+AND+%28rice+OR+paddy%29&filter=authorships.institutions.id%3AI78715868%7CI2799691083%7CI2799886051%7CI125956826%7CI3211005485%7CI4210152116%7CI4210093500%7CI4210117108%7CI4210110627%7CI4210132170%7CI4210146069&per_page=100&cursor=%2A&select=id%2Cdoi%2Cdisplay_name%2Cpublication_year%2Ctype%2Cprimary_location%2Cauthorships
OpenAlex data is CC0. Scripts that make every file: work/scripts/; call log with costs:
work/calls.csv.