Birdsfoot Trefoil Management. II. Yield, Quality, and Stand Evaluation

AbstractManagement recommendations for birdsfoot trefoil (Lotus corniculatus L.) are based mainly on research conducted in the northern USA. The relevance of this work to more southern‐adapted birdsfoot trefoil cultivars needs to be examined. These studies were conducted to determine the effect of stubble height and harvest interval on herbage yield and quality of northern‐ and southern‐selected birdsfoot trefoil cultivars when grown in the southern USA. Two field experiments were established on a Cecil sandy loam (clayey, kaolinitic, thermic Typic Hapludult) soil near Athens, GA. ‘Fergus’ and GA 1 birdsfoot trefoil entries were harvested every 21, 28, and 42 d to stubble heights of 5 and 10 cm. The birdsfoot trefoil entries ‘AU Dewey’, ‘Dawn’, Fergus, Ga 1, and ‘Norcen’ were harvested to 3, 5, and 10 cm every 21 d. Entries AU Dewey, GA 1, and Fergus were most productive, but herbage yields of all entries increased with length of time between harvests. Harvesting every 21 d at a 3‐cm stubble height generally reduced yields. After 2 yr, stands of AU Dewey, GA 1, Dawn, and Norcen were reduced 59, 45, 24, and 15%, respectively, while Fergus was unaffected. The AU Dewey and GA 1 entries should be allowed either a higher stubble or regrowth periods longer than 21 d because of erect growth habit. In vitro dry matter digestibility of all entries remained high (> 700 g kg−1) throughout the season and was not affected by harvest treatment. Results of these studies indicate that birdsfoot trefoil cultivars respond differently to harvest management.