Impact of novel harvest strategies and improved cultivars on alfalfa yield and nutritive value in a Mediterranean environment

Abstract

Background

The development of alfalfa cultivars with improved digestibility may minimize the yield-quality tradeoff, enabling higher quality with late-harvested forage and possibly higher yields.

Methods

An irrigated experiment conducted over 4 years compared 28-d harvest schedules with 35-d harvest schedules and an alternating 21-d and 35-d schedule. Four conventional cultivars and four cultivars developed for higher digestibility were grown under each schedule.

Results

Delayed cutting (35-d) yields were 16% greater and the staggered treatments were 6% higher than the 28-d strategy. The nutritive value decreased significantly with the 35-d schedule, but a “staggered” system provided nutritive value similar to the 28-d schedule while achieving higher yields. The nutritive value of cultivars was in the order of HarvXtra>Hi-Gest> conventional cultivars. The HarvXtra but not Hi-Gest cultivars achieved similar digestibility under the 35-d cutting schedule compared with conventional cultivars on a 28-d schedule.

Conclusions

This study clearly demonstrates that higher nutritive value cultivars of fall dormancy 6–9 grown with staggered or late cutting schedules can increase yields while maintaining higher nutritive value. The combination of staggered or late schedules with improved cultivars can maximize yields while maintaining the nutritive value of alfalfa, potentially breaking the alfalfa yield-quality tradeoff.