Exploring the plant and soil mechanisms by which crop rotations benefit farming systems

Crop rotation, which involves growing a sequence of different plant species on the same land (Karlen et al. 1994), has been a valued farm practice for thousands of years. According to Parker (1920), crop rotation evolved primarily from experiential learning. This technique was developed by early farmers to improve soil productivity, as they had experienced low yields due to continuous cropping with a single species. However, monoculture, cultivating the same crop year after year on the same land, has re-emerged in many parts of the world, driven by the goals of food security and economic benefit. Increased use of inorganic fertilizer in the monoculture system has masked land degradation trends and avoided crop yield loss but there have been impacts on sustainability of farming systems.