Effect of Cutting Height on Alfalfa Yield and Quality

Introduction

Variation in cutting height affects forage yield and quality. Less stem tissue is harvested with a higher cutting height resulting in higher protein and total digestible nutrient (TDN) content. Higher cutting heights may also result in less wear on equipment. In 1988, a study was initiated at SIDC to determine the effect of cutting height on yield and quality of alfalfa.

Materials and Methods

Five varieties of differing winter hardiness (Algonquin, Anchor, Beaver, Pioneer 526, and Roamer) were established at SIDC in 1988. The evaluation of 5 cm and 10 cm cutting heights were done on a small plot basis in 1989. Two cuts were taken June 21 and August 8, respectively.

Results

Recommendation

• Use a short cutting height to maximize forage yield
• Slightly increased TDN and protein can be gained by using a higher cutting height

All varieties responded similarly to the cutting height treatments. Although the results were not statistically significant, the 10 cm cutting height produced an 11% reduction in yield on the first cut and a 4% reduction on the second cut as compared to the 5 cm cutting height. Protein and TDN were increased slightly at the 10 cm cutting height (Table 1).