South Africa currently faces a wheat (Triticum aestivum L.) crisis as production has declined significantly over the past few years. The objective of this study was to explore opportunities for improving yields in intensive irrigated wheat production systems of South Africa through analyses of yield gaps, soil fertility constraints and conservation agriculture practices. The study was conducted in the major irrigation wheat production areas across four geographical regions: KwaZulu-Natal, eastern Highveld, warmer northern and cooler central. Actual yield (Ya) based on long-term yield data ranged from 5.99±0.15 t/ha to 8.32±0.10 t/ha across different geographical regions. The yield potential (Yp) ranged from 7.57 t/ha to 11.45 t/ha. Yield gaps (Yp–Ya) were in the range of 1.58–3.13 t/ha. Yields could be increased by 26–38% through closing yield gaps. On 88.37% and 13.89% of the fields in the KwaZulu-Natal and warmer northern regions, respectively, there was strong evidence of the practise of conservation agriculture, but none in the other regions. On 42.31% of irrigated wheat fields, soil organic carbon was below 1% at a soil depth of 0–20 cm. Fields in which conservation tillage was practised had double the soil organic carbon of conventionally tilled fields (2.15±0.10% versus 1.02±0.05%), but greater acidity and phosphorus deficiency problems. Sustainable approaches for addressing phosphorus deficiency and acidity under conservation tillage practices need to be sought, especially in the KwaZulu-Natal region.

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South Africa currently faces a wheat production crisis, suggesting that current policies, research and development projects may not be well aligned to farmer priorities. Through exploratory research, which included field inspections and farmer and researcher interviews, we identified the major constraints to irrigation wheat yield and explored opportunities for improving the yield and farmer profits. The dominant constraint to yield was identified as the low market price for grain, which makes farmers reluctant to invest in inputs for increasing wheat yield. Poor cultivar choice, cereal-based monocropping, the high cost of irrigation, inadequate irrigation water, low crop stands, soil acidity, no-till practices and red-billed quelea (Quelea quelea) birds are negatively impacting yields. Most importantly, we highlight a misalignment between current research efforts and farmer priorities. Recommendations for corrective measures necessary to improve yield and farmer profits are provided. This new knowledge will be useful to policymakers and researchers for better orienting investments in research and development projects aimed at addressing the current wheat production crisis in the country.

South Africa currently faces a wheat production crisis, suggesting that current policies, research and development projects may not be well aligned to farmer priorities. Through exploratory research, which included field inspections and farmer and researcher interviews, we identified the major constraints to irrigation wheat yield and explored opportunities for improving the yield and farmer profits. The dominant constraint to yield was identified as the low market price for grain, which makes farmers reluctant to invest in inputs for increasing wheat yield. Poor cultivar choice, cereal-based monocropping, the high cost of irrigation, inadequate irrigation water, low crop stands, soil acidity, no-till practices and red-billed quelea (Quelea quelea) birds are negatively impacting yields. Most importantly, we highlight a misalignment between current research efforts and farmer priorities. Recommendations for corrective measures necessary to improve yield and farmer profits are provided. This new knowledge will be useful to policymakers and researchers for better orienting investments in research and development projects aimed at addressing the current wheat production crisis in the country. Significance: We highlight a misalignment between current research efforts and farmer priorities in the wheat sector, and provide new knowledge for better orienting investments in research and development projects aimed at addressing the current wheat production crisis.

Wheat (Triticum aestivum L.) houses a wide range of nutritional components such as iron (Fe), zinc (Zn), vitamins and phenolic acids, which are important for plant metabolism and human health. The bioavailability of these nutritional components is low due to their interaction with other components and low quantity in the endosperm. Biofortiication is a more sustainable approach that could improve the bioavailability of essential nutritional components. Substantial progress has been made to improve nutritional quality through the application of conventional, technological and transgenic approaches. This has led to the discovery, cloning and introgression of the Gpc-B1 gene; the invention of online databases with minimally characterized biosynthetic, metabolic pathways and biological processes of wheat-related species; the establishment of genetic variation in grain Fe and Zn content and the biofortiication of wheat with Zn by the HarvestPlus organization. Nonetheless, the biofortiication of wheat with micronutrients and phenolic acids is still a challenge due to incomplete understanding of the wheat genome, biosynthesis and translocation of selected nutritional components into diferent wheat grain compartments. There is a need to integrate selected omics technologies to obtain a holistic overview and manipulate key biological processes involved in the remobilization and biosynthesis of nutritional components into desired wheat grain compartments.

The effects of conservation strategies on soil organic carbon (SOC) and phosphorus (P) dynamics in dryland wheat under semi-arid temperate conditions are not well understood. This study quantified the effects of tillage and straw management on SOC concentrations and stocks and P fractions after 40 years of dryland wheat under a semi-arid temperate climate. The treatments were straw management (burned and not burned) combined with tillage methods (conventional tillage (CT), stubble mulch (SM), and no-tillage (NT)). Fertilizer nitrogen (N) and P were applied annually at 60 and 12.5 kg ha−1, respectively. The soils were sampled from 0–50, 50–200, 200–400, 400–600, 600–800, and 800–1000 mm depths, and analyzed using standard methods. The concentration of SOC was not affected by tillage and straw management, except in 200–400 mm where it was higher where the straw was burned rather than retained. The total C stock (0–1000 mm) was higher under NT with straw burning, CT with no burning, and SM, than NT with straw retention and CT with burning. In the topsoil, NT had significantly (p < 0.05) higher Bray 1 P, NaOH II Pi, and residual P than SM and CT, while burning straw increased Bray 1 P and NaHCO3 Pi concentrations. The findings imply that while the SOC concentration is not significantly affected by tillage, but is increased by burning in the subsoil only, the total C stock is improved by NT with burned straw, CT with straw retention, and SM, while the labile P fractions are increased by NT with burned straw, relative to CT with burned straw, in the semi-arid dryland wheat region.

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