Long-term agricultural research at Rothamsted

In the mid-nineteenth century John Bennet Lawes and Joseph Henry Gilbert established a series of field experiments at Rothamsted (Hertfordshire, in south-east UK) to examine the benefits of mineral fertilizers and organic manures on the production of several important agricultural crops. Seven of these “Classical” field experiments continue today. The Broadbalk Wheat, Hoosfield Spring Barley and Park Grass Continuous Hay experiments are perhaps the most widely known of these long-term experiments (LTEs). The experiments quickly demonstrated the importance of fertilizers and manures as a source of mineral nutrients, especially nitrogen (N) and phosphorus (P), for plant growth and development. Subsequent findings highlighted the need for good weed and disease control, the value of crop rotation, liming and the use of modern short-strawed cereal varieties. Yield trends for wheat and barley on Broadbalk and Hoosfield respectively have followed the national averages, clearly demonstrating the capacity for arable soils in temperate NW Europe to sustain good levels of crop production for well over a century provided exported nutrients are replaced, soil pH is kept around neutral, soil structure is maintained, and pests, weeds and diseases are adequately controlled. In addition, the experiments generate information of value to agroecologists, farmers and other land users on the management of semi-natural systems to maintain and enhance biodiversity. They are an invaluable resource for monitoring the impact of agricultural management and environmental change, especially climate change, on the crop-soil system and other semi-natural habitats. Provided the experiments, sample archive and associated data are well-managed and used together with new analytical techniques and ideas they will continue to provide a resource for agricultural research as relevant today as when the experiments started 175 years ago.