Tackling climate risk to sustainably intensify smallholder maize farming systems in southern Africa

Abstract

Sustainable intensification (SI) of low input farming systems is promoted as a strategy to improve smallholder farmer food security in southern Africa. Using the Limpopo province South Africa as a case study (four villages across a climate gradient), we combined survey data (140 households) and quantitative agronomic observations to understand climate-induced limitations for SI of maize-based smallholder systems. Insights were used to benchmark the agroecosystem model APSIM, which was setup to ex ante evaluate technology packages (TPs) over 21-seasons (1998-2019): TP1 Status quo (no input, broadcast sowing), TP2 Fertiliser (micro dosing), TP3 Planting density (recommended), TP4 Weeding (all removed), TP5 Irrigation, TP6 Planting date (early, recommended), and TP6 All combined (TPs 1 to 5). An additional TP7 (Forecasting) investigated varying planting density and fertiliser in line with weather forecasts. Input intensity levels were low and villages expressed similar challenges to climate risk adaptation, with strategies mostly limited to adjusted planting dates and densities, with less than 2% of farmers having access to water for irrigation. Simulations showed that combining all management interventions would be expected to lead to the highest mean maize grain yields (3200 kg ha-1 across villages) and the lowest harvest failure risk compared to individual interventions. Likewise, simulations suggested that irrigation alone would not result in yield gains and simple agronomic adjustments in line with weather forecasts indicated that farmers could expect to turn rainfall variability into an opportunity well worth taking advantage of. Our study emphasises the need for a cropping systems approach that addresses multiple crop stresses simultaneously.

Crop production in Türkiye: trends and driving variables

“…The wheat harvest failure reached almost 0.5 M ha in an extremely dry growing season in 2007-2008 (figure 6). Such a negative relation also confirms that the lack of water availability particularly during anthesis and grain filling phases (terminal drought) would result in harvest failure at large scales (Nelson et al 2022).…”

Assessment of the relations between crop yield variability and the onset and intensity of the West African Monsoon

“…The interactions of genotype by environment and management (G x E x M) are simulated on a daily time step (Mandrini et al, 2022). APSIM model has been developed (Keating et al, 2003) and widely tested in subhumid semi-arid environments of Africa to simulate the performance of various cereal and legume crops under different farming systems (Whitbread et al, 2010;Akinseye et al 2017;Hoffmann et al, 2020;Nelson et al, 2022).…”