Smart orchard design improves crop pollination

1. More sustainable and environmentally-friendly agricultural practices, including ecological intensification, are needed to reduce biodiversity loss and environmental degradation.

2. We evaluated the potential of ecological intensification through the enhancement of pollination services in an intensively managed and insect-pollinated crop, Macadamia integrifolia. We compared the effects and importance of agronomic practices that include agronomic input (i.e. irrigation and managed honeybees), orchard design requiring no external inputs (i.e. spatial orchard structure) and landscape factors in ten South African macadamia orchards.

3. In comparison to experimental pollinator exclusion, insect pollination increased the initial and final nut set by 304% and 23%, respectively. However, nut set was pollination limited as hand pollination further improved nut set.

4. Flower visitation rates increased with the cover of semi-natural habitats in the surrounding landscape (1km radius). This effect was outperforming the effect of the number of managed honeybee colonies, as agronomic practice.

5. Initial nut set increased with orchard design and flower visitation rates. Perpendicular orientation of the planted macadamia rows towards the semi-natural habitats increased initial nut set more than threefold compared to parallel row orientation. The initial nut set was 80% higher at the edge to semi-natural habitats than in the orchard centre. In contrast, agronomic practices, such as irrigation, did not increase initial nut set.

6. Final nut set depended on the preconditions of the initial nut set, additionally, high altitudes and the position in the centre of the orchard had positive effects.

7. Synthesis and applications. Pollination services were prerequisites for high yields in macadamia and could be improved without further agronomic input. Especially, the orchard design, i.e. spatial arrangement of tree rows and semi-natural habitats at local and landscape scales, was more important to boost insect pollination and the initial development of macadamia nuts than agronomic practices, such as high levels of irrigation. Considering the urgency to reduce the environmental impacts of agricultural production, we highlight the high potential of ecological intensification by a smart orchard design and the restoration and conservation of semi-natural habitats in the orchards and their surrounding landscape.

Methods
Please see the README document ("README_Data-set_SmartOrchardDesignImprovesCropPollination.txt") and the accompanying published article: Anders, M., Grass, I., Linden, V. M. G., Taylor, P. J., & Westphal, C. (2023). Smart orchard design improves crop pollination. Journal of Applied Ecology, 60, 624–637. https://doi.org/10.1111/1365-2664.14363

1. 为减少生物多样性丧失与环境退化，亟需推广更具可持续性且环境友好的农业实践，其中包括生态集约化（ecological intensification）。
2. 本研究以集约化管理的虫媒作物澳洲坚果（Macadamia integrifolia）为对象，通过强化传粉服务来评估生态集约化的应用潜力。我们在南非的10个澳洲坚果果园中，对比了三类措施的效果与重要性：一是农艺投入类实践（即灌溉与人工饲养的蜜蜂），二是无需外部投入的果园设计（即果园空间结构），三是景观因子。
3. 与实验性排除传粉者的对照组相比，虫媒传粉分别使初始坐果率与最终坐果率提升了304%和23%。然而，坐果仍受传粉限制：人工辅助授粉可进一步提高坐果率。
4. 访花率随周边1公里半径范围内半自然生境的覆盖占比升高而提升，且该效应优于作为农艺实践的人工饲养蜜蜂群数量的影响。
5. 初始坐果率随果园设计与访花率的提升而升高。与树行平行于半自然生境的果园相比，澳洲坚果树行垂直于半自然生境的处理可使初始坐果率提升三倍以上。果园边缘与半自然生境接壤处的初始坐果率比果园中心高出80%。与之相反，灌溉这类农艺实践并未提升初始坐果率。
6. 最终坐果率以初始坐果率为前提条件，此外，高海拔与果园中心位置对其具有正向影响。
7. 综合与应用。传粉服务是澳洲坚果实现高产的前提条件，且无需额外增加农艺投入即可得到强化。尤为关键的是，相较于高灌溉量这类农艺实践，果园设计——即局地与景观尺度上的树行与半自然生境空间布局——对提升虫媒传粉效率与澳洲坚果初始坐果发育更为重要。鉴于降低农业生产环境影响的紧迫性，本研究强调：通过智能化果园设计，以及恢复与保护果园及其周边景观中的半自然生境，可有效推动生态集约化，具备极高的应用潜力。

研究方法
详见README文档（"README_Data-set_SmartOrchardDesignImprovesCropPollination.txt"）及已发表的配套论文：Anders, M., Grass, I., Linden, V. M. G., Taylor, P. J., & Westphal, C. (2023). 智能化果园设计提升作物传粉效率. Journal of Applied Ecology, 60, 624–637. https://doi.org/10.1111/1365-2664.14363