On-farm irrigated wheat yield in the Yaqui Valley in north-west Mexico from 1960 to 2019

(prepared R.A.(Tony) Fischer 14 August 2021) This dataset contains three data files that were obtained and/or constructed an analysis of 60 years’ yield progress with irrigated wheat yield in northwest Mexico: 1. Wheat harvested area and average yield each harvest year for the irrigated Cajeme District of Sonora State, Mexico, from 1960 to 2019 (file name = 1. Annual wheat average yield and harvest area 1960 to 2019, Yaqui Valley (Cajeme District) 2. Monthly average Tmax, Tmin, precipitation total and frost days from November 1959 to April 2019 (only for November to April each year, which corresponds to the irrigated wheat season) for a location at or near the centrally-located CIANO (now CENEB) agricultural research station of the Yaqui Valley. Monthly mean solar radiation (Rs) was added from November 1967 (unavailable beforehand) (file name = 2. Mean monthly wheat weather 1960 to 2019 Yaqui Valley). 3. Daily solar radiation (Rs), Tmax and Tmin from November 1967 to April 2019 (again only for November to April each year) (file name = 3. Daily wheat weather 1967 to 2019 Yaqui Valley). Locating and acknowledging the exact original sources of these data is not easy, but is explained at the beginning of each file and within the files if the source varies. The wheat area and yield data is publicly available soon after harvest, having been collated by Cajeme District grain receival authority in Cd Obregon, who also regularly provide updated multiyear records of the finalized annual numbers. This District comprises the bulk of the irrigated Yaqui Valley and has been synonymous with the Yaqui Valley for outsiders. The weather data comes from the International Maize and Wheat Improvement Center (CIMMYT) headquarters, which has operated a weather station at CIANO/CEBEB experiment station, located centrally in the Yaqui Valley since 1968. However, for most numbers before 1968 the State Hydraulic Resources (CONAGUA in Cd Obregon), using data held by CIMMYT was used, and a few numbers after 2000 were obtained from the Hydraulic Resources in Cd Obregon and the Sonora State meteorological service (REMAS in Hermosillo). A large part of the daily Tmax and Tmin data (1968 to 1999), although originally from CIMMYT, was collated by Professor L.A. (Tony) Hunt of Guelph University, Canada, as was the daily and (monthly) Rs data from 1968 to 1983. From 1984 the NASA web site has continuous daily Rs data closely matching the Hunt numbers, so this source was used thereafter, while Hunt and Fisiologia data (adjusted to match NASA data) was used from 1968 to 1983. Tmax and Tmin data are also available on the NASA site but did not match CIMMYT data well and was never used. So the weather data has several sources, which increases the risk of error. Only the very strong relationship right across the 60 year period between totally independent variables yield and Tmin reassures us that the weather data is sound. A follow-up study (and associated database) will disaggregate the causes of the spectacular progress recorded.