Which sowing strategy for durum wheat in Algeria to adapt to climate change?

Given the projected climate change, farmers in North African countries usually experiment adaptation strategies based on early sowing, use of early varieties and fertilization. However, information on the effectiveness of early sowing as a strategy for adaptation to climate change on durum wheat crop is very limited. This article aims to help managers advising more effective sowing practices. Two sowing strategies are studied: a dynamic date (depending on the onset of useful rainfall), and a prescribed (fixed) date. A crop model, with two types of input (crop and climate), is used to simulate, at the daily time step, phenology, water balance, and durum wheat yields. The future behaviour of durum wheat is simulated using climate projections provided by the ARPEGE-Climate model of Meteo-France under the medium A1B SRES scenario for the distant future (2071-2100). In the case of a fixed sowing date, global warming shortens the growing cycle by 31 days during the vegetative phase, water balance is negative, accumulation of dry matter is reduced and the actual yield decreases by 36%. With a dynamic sowing date, an extension of the reproductive phase accompanies the shortening of the vegetative phase and the crop cycle is shortened by only 15 days. Total dry matter is reduced, but the water balance, favoured by early sowing, is positive. Consequently, the yield in the possible future climate is kept at the same level as in the current situation. Our results suggest a sowing strategy based on a dynamic date; they provide managers with tools for facing the challenges of climate change impacts on durum wheat cropping.