Overyielding is accounted for partly by plasticity and dissimilarity of crop root traits in maize/legume intercropping systems

Positive biodiversity-productivity relationships have been found in biodiversity field experiments of grassland, forestry, and other natural terrestrial ecosystems, where diversity effects were separated by complementarity (CE) and selection effects (SE). However, we know little about how CE and SE are related to root traits and root dissimilarity.
A four-year field experiment was carried out with a split-plot design, where main plot was four nitrogen (N) applications (N0, N1, N2, N3) and five cropping systems (maize (Zea mays L.)/soybean (Glycine max L. Merrill.), maize/peanut (Arachis hypogaea L.) intercropped and the corresponding monocultures) with three replicates. Roots were sampled in the N0 and N2 treatments in two years. Intercropping effects were analyzed based on grain yield for four years and roots were sampled down to 60 cm depth, and analyzed with morphological parameters at different crop growth stages in two years.
Intercropping significantly increased grain yield and ab...

生物多样性与生产力间的正向关联已在草原、森林及其他自然陆地生态系统的生物多样性野外试验中被证实，此类试验中将多样性效应拆解为互补效应（complementarity, CE）与选择效应（selection, SE）。然而目前学界对互补效应、选择效应与根系性状及根系相异性之间的关联机制仍知之甚少。
本研究采用裂区试验设计，开展了为期4年的野外定位试验：主区设置4个施氮（Nitrogen, N）水平（N0、N1、N2、N3）与5种种植模式，包括玉米（Zea mays L.）/大豆（Glycine max L. Merrill.）间作、玉米/花生（Arachis hypogaea L.）间作，以及上述两种间作对应的单作体系，各处理均设置3次重复。
研究分别于两年内的N0与N2施氮处理小区采集根系样品。本研究基于4年的籽粒产量数据分析间作效应，根系采样深度达60 cm，并于两年内的不同作物生育期采集根系样品以分析其形态学参数。
间作可显著提升籽粒产量，且ab……