Assessing the long-term impact of conservation agriculture on wheat-based systems in Tunisia using APSIM simulations under a climate change context

Haithem Bahri; Mohamed Annabi; Hatem Cheikh M'Hamed; Aymen Frija

doi:10.1016/j.scitotenv.2019.07.307

Assessing the long-term impact of conservation agriculture on wheat-based systems in Tunisia using APSIM simulations under a climate change context

Sci Total Environ. 2019 Nov 20:692:1223-1233. doi: 10.1016/j.scitotenv.2019.07.307. Epub 2019 Jul 21.

Authors

Haithem Bahri¹, Mohamed Annabi², Hatem Cheikh M'Hamed², Aymen Frija³

Affiliations

¹ National Research Institute for Rural Engineering, Water and Forests (INRGREF), Carthage University, Agronomy Laboratory (LR16INRAT05), Hedi Karray Street, 2049 Ariana, Tunisia. Electronic address: haithem.bahri@gmail.com.
² Institut National de la Recherche Agronomique de Tunisie (INRAT), Carthage University, Agronomy Laboratory (LR16INRAT05), Hedi Karray Street, 2049 Ariana, Tunisia.
³ International Center for Agricultural Research in the Dry Area (ICARDA), Tunis Office. Rue Hedi Karray, 2049 Ariana, Tunisia.

PMID: 31539953
DOI: 10.1016/j.scitotenv.2019.07.307

Abstract

Several circulation models are forecasting climate changes in the Mediterranean region. Accordingly, it is expected that water scarcity in the region will be higher with drastic shifts of hydrological and erosive watershed responses. In Tunisia, wheat yields have been variable over the years and are lower than the potential yields. In response, the adoption of conservation agriculture (CA), introduced into Tunisia in 1999 to help adaptation to climate change, has resulted in a substantial reduction in agricultural productivity. CA areas increased from 52 ha in 1999 to 14,000 ha in 2015. Using a modelling approach, the present paper evaluates the potential of CA to adapt wheat-based-systems to climate change in Tunisia. The Agricultural Production Systems Simulator (APSIM) model was used to predict the effect of tillage (conventional tillage [CT] vs. zero-tillage [ZT] and soil residue retention [ZT-RR]) on wheat productivity and soil fertility. Two contrasting locations in Tunisia were studied; one semi-arid (Kef) and one sub-humid (Bizerte). Results showed that the sustainable production of durum wheat under climate change conditions in Tunisia is possible through the adoption of CA practices (ZT and ZT-RR) in both sub-humid and semi-arid areas. In fact, mulching (residue retention) is more effective than CT (under semi-arid and sub-humid conditions) in enhancing wheat yield (15%), water use efficiency (18% and 13%) and soil organic carbon accumulation (0.13 t ha^-1 year^-1 and 0.18 t ha^-1 year^-1). It is also more effective for soil resilience - preventing water erosion (1.7 t ha^-1 year^-1 and 4.6 t ha^-1 year^-1 of soil loss). The present study allowed identification of 260,000 ha as priority areas for CA adoption; this represent one-third of the total cereal area in Tunisia. Appropriate evaluation of the benefits of CA on sustainable agricultural intensification would provide more arguments for effectively supporting CA adoption in Tunisia.

Keywords: APSIM model; Climate change; Soil organic carbon; Soil-water erosion; Water use efficiency; Wheat yield; Zero tillage.

MeSH terms

Agriculture / methods*
Climate Change*
Conservation of Natural Resources*
Triticum / growth & development*
Tunisia