The effect of crop rotation on agricultural sustainability in the North-Western Free State, South Africa

Abstract

Crop rotation has potential to maintain and improve agricultural sustainability. The effects of crop rotation are known to be site-specific which led to this study’s objective of determining the effect of three different maize rotational systems in the North-Western Free State. This semi-arid region with its sandy soils is dominated by maize production. A field trial with maize in rotational systems with soybean and cover crops was established. Three aspects of sustainability were monitored: Soil health, total digestible nutrition and yield. Soil and maize kernel samples underwent soil health and nutritional testing respectively while yield data was collected. All data were analysed using descriptive and inferential statistics. Rotational systems and seasonal variation played a role in all aspects of sustainable agriculture investigated. Seasonal variation was seen in the wetter second season, with soil health and yield negatively affected. Although there was an association between maize soil health and yield, a rotational effect excluding soil health was observed, with the maize in rotation with cover crop and soybean performing better despite unhealthier soils. In addition, soybean production improved up to 40% over time in rotational systems. Overall, rotational systems focusing on maize production in the area were viable and contribute to agricultural sustainability and food security.