Designing Management Strategies for Sheep Production and Bees in Dryland Pastures

Abstract

Novel grazing management practices for livestock and bee health are becoming increasingly crucial in pasture-based farming systems. The effect of pasture type and spring closing dates on lamb liveweight gain, pasture production, botanical composition, bloom density and bee visitation was monitored over 2 years. Total annual dry matter yield (DMY) of diverse pastures in 2020/2021 was 8.8 t DM ha−1. This yield was greater than the DMY obtained from both simple (7.6 t DM ha−1) and legume pastures (6.6 t DM ha−1). In 2021/2022, the total annual DMY of simple (8.6 t DM ha−1) and diverse pastures (9.0 t DM ha−1) was similar. However, the legume pastures produced 27–30% less than simple and diverse pastures. In successive years, lambs grew faster in legume pastures (287, 215 g per head d−1) than diverse (207, 151 g per head d−1) and simple pastures (204, 132 g per head d−1). However, spring liveweight production (kg ha−1 day−1) from pastures did not differ due to the lower stocking density of legume pastures as compared to the other two pasture mixtures. Bloom density (flower/m2) and bee visitation (bees/min−1 m2) were 16 and 40 times greater with legume rather than simple pastures. Bloom density for diverse pastures was also relatively lower than for the legume pastures. Our findings indicated that the diversification of pastures greatly increased pasture productivity, while legume pastures provided the highest bee benefit without penalizing lamb liveweight production in spring.

Keywords

• lamb growth
• closing dates
• pasture diversity
• ecosystem benefits
• pollinator health