Data from: Pollination benefits are maximized at intermediate nutrient levels

Yield production in flowering crops depends on both nutrient resource availability and pollination but their relative roles and potential interactions are poorly understood. We measured pollination benefits to yield in sunflower, combining a gradient in insect pollination (0, 25, 50, 100%) with a continuous gradient in nitrogen (N) fertilization (from 0 to 150 kg N ha-1) in an experiment under realistic soil field conditions. We found that pollination benefits to yield were maximized at intermediate levels of N availability, bolstering yield by a c. 25% compared to complete pollinator exclusion. Interestingly, we found little decrease in yield when insect visits were reduced by 50% indicating that the incremental contribution of pollination by insects to yield is greater when the baseline pollination service provision is very low. Our findings shed light on the processes that drive crop production, providing evidence for non-linear relationships between pollination and resource availability. Our results support ecological intensification as a promising strategy for sustainable management of agroecosystems. In particular, we found optimal level of pollination to potentially compensate for lower N applications.显花作物（Flowering crops）的产量形成同时受养分资源有效性与传粉（Pollination）过程的共同调控，但二者的相对贡献及潜在互作机制目前仍未得到充分阐明。本研究以向日葵为研究对象，在真实农田土壤条件下开展田间试验，设置昆虫传粉（Insect Pollination）梯度（0、25%、50%、100%）与氮肥（Nitrogen, N）施用连续梯度（0至150 kg N·ha⁻¹）的双因子交叉处理，以此量化传粉对作物产量的增益效应。研究结果表明，传粉对产量的增益效应在养分有效性处于中等水平时达到峰值，相较于完全排除传粉者（Pollinator）的处理，产量可提升约25%。值得注意的是，当昆虫访花频次降低50%时，产量并未出现显著下降，这表明当基础传粉服务供给水平极低时，昆虫传粉对产量的增量贡献反而更高。本研究结果阐明了调控作物产量形成的关键过程，为传粉与资源有效性之间存在的非线性关联提供了实证依据。研究结果支持生态集约化（Ecological Intensification）作为农业生态系统（Agroecosystems）可持续管理的可行策略。尤为重要的是，本研究发现可通过优化传粉水平，潜在弥补较低氮肥施用量带来的产量损失。