Helianthus tuberosus as an alternative forage crop for cool maritime regions: A preliminary study of the yield and nutritional quality of shoot tissues from perennial stands

This paper presents the results of a preliminary investigation of the potential of the Jerusalem artichoke (Helianthus tuberosus) as a perennial forage crop for cool wet areas of northern Europe. The experimental work included a 3-year study of crop growth and development, and a two-season evaluation of the nutritional value of the shoot tissues for livestock. Under low-input management, crop stands produced yields which are comparable with the potential yield of cereals or grassland in the UK. However, the ability of the crop to take up mineral nutrients from non-fertiliser sources indicates that the success of perennial cropping would depend upon fertiliser application. The crops were free of obvious pests and diseases. Observations over two seasons indicate that the crop can be harvested during August (after tuber initiation) without incurring serious yield penalties in subsequent seasons. Digestibility studies showed that the shoot tissues had a nutritional value to the ruminant which was similar to that of good-quality grass hay, but that the protein level was lower. Ensilage of the shoot material with molasses yielded a well-preserved lactic silage, and intakes of silage dry matter were higher than would have been predicted for grass silages of similar composition. It was concluded that these findings justify further evaluation of the species as an alternative crop for cool wet areas.