Data from: Temporal dynamics of nutrient uptake by neighboring plant species: evidence from intercropping

1. The productivity of species-diverse plant assemblages strongly depends on the temporal dynamics of nutrient uptake by competing neighboring plants. Our understanding, however, of how rates of Nitrogen (N), Phosphorous (P) and Potassium (K) uptake might change through time between neighboring plant species under field conditions is still very limited. 2. Here we specifically measure temporal trajectories of N, P and K uptake by staple food plants such as wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and maize (Zea mays L.) when growing either in monocultures or in intercropping systems. We ask how (1) plant species combinations, (2) N fertilization, and (3) film mulching might affect key indexes of N, P and K uptake over time. We fit logistic models to characterize nutrient uptake trajectories. 3. Maximum cumulative N, P and K uptake (kg ha−1) by wheat and barley were significantly greater in wheat/maize or barley/maize intercropping systems than in wheat or barley monocultures. Cumulative nutrient uptake by intercropped maize (either with wheat or barley) was reduced by interspecific competition at early growth stages but it increased rapidly after wheat and barley were harvested. Maximum cumulative N and P (but not K) uptake by intercropped maize was significantly higher than uptake by monoculture maize, particularly when N fertilizer or film mulching was applied. 4. Intercropping induced significant temporal niche differentiation in maximum daily nutrient uptake rates (kg ha−1 d−1) between intercropped species. Fertilization had much stronger effects on maximum cumulative nutrient uptake of maize than wheat and barley. Mulching significantly increased maximum cumulative nutrient uptake of maize and advanced the time to reach its maximum daily P and K uptake rates. 5. Our study provides evidence of an important temporal niche differentiation mechanism (‘temporal complementarity’) in nutrient uptake rates between neighboring plant species. A better understanding of temporal trajectories of interspecific nutrient uptake rates remains crucial if we want to maximize nutrient-use efficiency and sustain over-yielding (i.e. high food production) in plant species-diverse systems such as intercropping.1. 物种丰富的植物群落的生产力在很大程度上依赖于竞争性邻株养分吸收的时间动态。然而，我们对于田间条件下邻株物种间氮（Nitrogen, N）、磷（Phosphorous, P）和钾（Potassium, K）的吸收速率随时间的变化规律的认知仍然十分有限。 2. 本研究专门测定了小麦（Triticum aestivum L.）、大麦（Hordeum vulgare L.）、玉米（Zea mays L.）等主食作物在单作或间作系统中的养分吸收时间轨迹。我们旨在探究三个核心问题：（1）植物物种组合方式，（2）氮肥施用水平，以及（3）地膜覆盖措施，如何随时间影响氮、磷、钾吸收的关键指标。本研究通过拟合逻辑斯蒂（logistic）模型来表征养分吸收的动态轨迹。 3. 小麦与大麦在小麦/玉米或大麦/玉米间作系统中的最大累积氮、磷、钾吸收量（kg ha⁻¹）显著高于其单作栽培模式。间作玉米（与小麦或大麦伴生）的累积养分吸收量在生长早期会因种间竞争而降低，但在小麦和大麦收获后会迅速提升。间作玉米的最大累积氮、磷（而非钾）吸收量显著高于单作玉米，尤其是在施用氮肥或实施地膜覆盖的情况下。 4. 间作会在间作物种间诱导产生显著的养分最大日吸收速率（kg ha⁻¹ d⁻¹）时间生态位分化。施肥对玉米最大累积养分吸收量的调控效应远强于对小麦和大麦的影响。地膜覆盖显著提升了玉米的最大累积养分吸收量，并提前了其达到最大日磷、钾吸收速率的时间节点。 5. 本研究证实了邻株物种间养分吸收速率存在一种重要的时间生态位分化机制——“时间互补性（temporal complementarity）”。若要最大化植物多样群落（如间作系统）的养分利用效率并维持过产现象（即实现高产粮食生产），深入理解种间养分吸收速率的时间动态轨迹仍然至关重要。