Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/26/2006
Publication Date: 5/1/2006
Citation: Contreras-Govea, F.E., Albrecht, K.A., Muck, R.E. 2006. Spring yield and silage characteristics of kura clover, winter wheat, and in mixtures. Agronomy Journal. 98:781-787. Interpretive Summary: Kura clover is a high quality forage for dairy cattle, but it can be difficult to harvest because the plants grow along the ground, rather than standing erect. Because kura clover is such a hardy forage, its growth can be temporarily suppressed with herbicides allowing other crops to be grown within a field of kura clover. One potentially interesting crop to grow with kura clover is winter wheat, sown in the fall and harvested in late spring for silage. The wheat should allow the clover to be harvested more easily. We grew winter wheat separately as well as in a stand of kura clover, measuring the yields and seeing how the individual crops and the mixtures would ferment in laboratory-scale silos. The mixture yielded as much kura clover as kura clover grown by itself, but the amount of wheat in the mixture was about half that of wheat grown by itself. The mixtures as well as the individual crops fermented well in the mini-silos. Overall, the mixture of kura clover and wheat, wheat yielded somewhat less than a field of just winter wheat, but the mixture was a much higher quality feed than either winter wheat or kura clover for dairy cattle. This mixture looks like a practical way for dairy farmers to boost the yield of high quality forage within a kura clover system.
Technical Abstract: Kura clover grown in monoculture is difficult to harvest mechanically because of its decumbent growth habit, and legumes in general have poor ensiling characteristics. This study was conducted to assess kura clover-winter wheat forage yield, evaluate kura clover silage characteristics and determine if mixing with winter wheat improves its usefulness as a silage crop. 'Cardinal' winter wheat was sown in monoculture and into an 'Endura' kura clover sward in autumn, and harvested at boot and milk stages the following spring. Sole kura clover was harvested at the same time as winter wheat. In addition, two mixtures of kura clover with winter wheat were created at each harvest by blending desired proportions from crops grown in monoculture. The mixture of kura clover with winter wheat yielded 7.4 Mg/ha while sole kura clover yielded 3.4 Mg/ha and sole winter wheat 9.05 Mg/ha. However, kura clover yield in the binary mixture (3.1 Mg/ha) was similar to sole kura clover. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations were 49% and 28%, respectively, lower in kura clover than winter wheat and intermediate in mixtures. Fermented mixtures had similar pH to sole winter wheat (pH 3.9 vs. 3.8) and lower than sole kura clover (pH 4.1). The proportion of total nitrogen recovered as non-protein nitrogen in silage was 9% lower in kura clover and in mixtures than in winter wheat. Water-soluble carbohydrate (WSC) concentrations of wilted forage were higher in the mixture than sole kura clover (157 vs. 105 g/kg DM), and the mixtures had lower WSC than sole winter wheat (198 g/kg DM). Lactate concentration was 13% higher in silage from mixtures than sole kura clover. Spring yields of kura clover-winter wheat mixtures are greater than sole kura clover and mixture silage characteristics are better than sole kura clover.