Modeling the constraints to productivity of subsistence dryland farming

Authors: Jaradat, Abdullah

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/13/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Production practices of subsistence farming in the Old World may have contributed to the depletion of natural resources and the gradual decline of agroecosystem services. Annualized yields of traditional and alternative crop rotations derived from field experiments and from archived records for countries in the Fertile Crescent were used in a simulation and statistical modeling study. The objectives were to identify constraints to sustainable crop production of subsistence farmers and predict yield gaps due to projected climate changes. Spatial (longitude and latitude coordinates of 28 locations in the Fertile Crescent) and temporal variation (the years 2010, 2050 and 2100, respectively corresponding to RCP2.6, RCP4.5, and RCP8.5 Representative Concentration Pathways) in soils, maximum temperatures, rainfall amounts and monthly distribution, accounted for major differences in projected annualized crop rotation yields. Consequently, the growing season will be shortened, thus widening current yield gaps between actual and potential crop rotation yields and forcing significant changes in the farming systems and the choice of crops that can be grown by subsistence farmers. With 50% probability, subsistence farmers may be able to achieve as large as 67.0% (under RCP4.5) or as small as 34.0% (under RCP8.5) of their water-limited crop yields. However, whether these yield gaps can be closed agronomically, ecologically, and sustainably, remains an open question. The impact of simulated climate change on subsistence farming was widespread over the Fertile Crescent, it is expected to be more pronounced in the central and northern parts of the Levant, a region most impacted by the Mediterranean climate.