IN YOUR ORCHARD
THE BEE BOX
Cover Cropping for Pollinators When farmers want to improve and protect soil, their most precious natural resource, cover cropping and composting are the two practices most often used. Composting is a great way to increase organic matter while amending the soil with non-synthetic sources of fertilizer. In this Pollinator Partnership article, we will focus on the in-orchard benefits of cover cropping. Cover cropping involves planting combinations of grains, legumes, brassicas and wildflowers to cover the soil. Farmers then terminate the cover crop and incorporate the biological matter into the soil to improve soil health. Cover crops contribute a variety of agronomic benefits, including increasing water infiltration, decreasing compaction, suppressing weeds, reducing erosion, increasing nitrogen, supporting microbe activity, controlling pests and reducing dust. Cover crops can also significantly improve pollinator health if farmers select plant species that provide pollen and nectar during bloom. A popular cover crop practice among farmers is using modified cover crop seed mixes to include bee forage, whether the farmers grow insect-pollinated crops or not. Both managed pollinators (e.g., honey bees) and unmanaged pollinators (e.g., native solitary bees) benefit from having access to abundant and diverse sources of nutrition in blooming cover crops. Farmers who amend their land with bee forage are doing more than simply helping sustain local pollinator populations. They are increasing the potential for those bees to pollinate crops and increase yield. • Recent research conducted by the Almond Board of California and UC Davis showed almond orchards with cover crops had yields 100-225 pounds per acre higher than orchards with bare soil. ¹ • Cover crop species like brassicas stimulate bee colonies to increase their populations throughout the growing
season. More foraging bees collecting pollen and nectar results in more pollination of cash crops. ² • The vigor of individual bees is also improved when they are raised in resource-abundant versus resource-limited environments. Malnourished worker bees communicate less effectively, which reduces their potential. ³ • The positive effect that cover cropping has on pollinators lasts beyond the lifespan of the cover crop. For example, colonies with access to diverse sources of nutrition during the growing season will have lower pathogen loads and higher rates of winter survivability. 4
Photo credit: Billy Synk, Pollinator Partnership
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ALMOND FACTS
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