Intercropping Kura Clover with Winter Cereals to Increase Spring Forage Production.

Kura clover (Trifolium ambiguum M. Bieb.) has lower yield and much greater nutritive value than alfalfa (Medicago sativa L.). There is potential to increase yield while maintaining reasonably high nutritive value by intercropping Kura clover with winter cereals. The objective of this research was to compare forage yield and nutritive value of cereal-legume mixtures, with cereals or Kura clover grown in monoculture, and harvested at two different maturity stages in spring. Winter rye (Secale cereale L.), winter wheat (Triticum aestivum L.), and winter triticale (×Triticosecale rimpaui Wittm.) were sown in autumn in monoculture and mixture with Kura clover over 4 years. Average yields were 4.7, 4.1, and 2.6 Mg ha^-1 monoculture cereals, mixtures with Kura clover, and Kura clover harvested when cereals were in the boot stage. Because of rapid stem elongation of winter cereals and Kura clover, milk stage yields were almost 100% greater. Clover proportion in mixtures decreased from 52% in boot to 38% in milk stage. Forage mixtures and monocultures harvested at boot stage were higher quality than at milk stage. Winter rye had greater forage quality at boot stage and lower at milk stage among the cereal crops, and winter wheat and triticale were similar at both stages. The quality of mixtures and monoculture Kura clover was always greater than that of monoculture grasses. Mixtures had on average 28% greater crude protein, slightly greater in vitro true digestibility (>4%) and neutral detergent fiber digestibility (>3%), and 14% lower neutral detergent fiber than grass monocultures. Therefore, winter cereal crops can be successfully managed with Kura clover for forage production in the Upper Midwest by maximizing forage quality with boot stage harvests or achieving higher yields by harvesting at the milk stage.