Cover crops can provide multiple agroecosystem services to crops produced in conservation agriculture systems. South African grain producers in the Mediterranean climate region are reluctant to integrate cover crops in rainfed systems since cover crops replace cash crops leading to nancial losses. Using cover crops as fodder can help cover input costs, while providing a range of advantageous services to the cropping system. The aim of this study was to investigate how cover crop mixtures and the utilisation of cover crops affect soil quality, the quality and quantity of the mulch as well as wheat (Triticum aestivum L.) produced in the subsequent year. Methods A two-year study was conducted in the Western Cape Province of South Africa. In Year 1, diverse legume and cerealbased cover crop mixtures were partially grazed, cut and material removed for haymaking, or left unutilised as a mulch. In Year 2, spring wheat (Triticum aestivum L.) was planted to investigate the effects of cover crop mixtures and utilisation method on subsequent spring wheat yield. Results Cover crops used as hay or for grazing did not affect (P < 0.05) grain yield of wheat that followed in rotation. Legumebased cover crop mixtures increased (P < 0.05) wheat grain protein content regardless of utilisation method. Soil quality and nitrogen content improved (P < 0.05) when cover crops were grazed. Conclusions Cover cropping can be used by South African grain producers as an important agronomic tactic to improve system productivity and support sustainable intensi cation of rainfed cropping systems.

The pressures from population growth, changing diets and climate change are driving the need to transform global food production to ensure efficiency, improved reliability and more sustainable production methods. The arable land for crop production and permanent pastures in South Africa account for 10 to 12 percent of the total land surface. South Africa is classified as semi-arid, with the average rainfall below the world average. Dryland agriculture thus has to identify and promote management systems with high water-use efficiency; this is crucial in a country with a debilitating water deficit. Climate change is expected to exacerbate climate variability in South Africa and thus exert even more pressure on rain-fed dryland production. Conservation Agriculture is a holistic set of principles aimed as a guide to sustainable, reliable and climate smart farming practices. Although initially set as a guide for grain farmers the principles are also applicable, through adaptation of the three basic principles, to other agricultural commodities. The three principal system have been extensively promoted with successful adoption and adaptation in many countries. This paper aims to highlight the research results and challenges of rain-fed Conservation Agriculture in South Africa.

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