More efficient resource use, especially nitrogen (N) in agricultural fields could considerably reduce the losses and spillover effects on the environment. Cereal-legume mixtures can lead to more efficient uptake of growth-limiting resources, and increase and stabilize yields, due to the variation in functional traits that facilitate partitioning of niche space. Here we identify crop mixtures with functional traits that facilitate optimal N resource use in two selected cereal-legume mixtures by using the multi-dimensional trait space concept. Combinations of pea-barley and faba bean-wheat crops were grown in the field as pure cultures and mixtures in Central Sweden, during two years with contrasting weather. The ecological niche space was defined via the n-dimensional hypervolumes represented by N pool, tiller/branch number, shoot biomass, and grain yield functional traits. Regressions and correlations allowed quantifying the relations between functional traits and plant N pools. Differences in trait space were not a result of crop mixing per se, as similar hypervolumes were found in the pure culture and mixture-grown crops. Instead, the trait space differences depended on the cultivar identities admixed. Furthermore, cereals increased their efficiency for N uptake and therefore benefitted more than the legumes in the mixtures, in terms of accumulated N and grain yields. Tiller and shoot biomass production in cereals was positively correlated to N pool accumulation during the season. Resource acquisition through increased N uptake in the mixture was associated with a reduced overlap in niche-space in the mixtures, and initial seed N pools significantly contributed to within-season N accumulation, shoot and tiller production.

更有效地利用资源，尤其是农田中的氮，可以大大减少对环境的损失和溢出效应。谷物和豆类的混合物由于功能性状的变化而有利于利基空间的分配，因此可导致更有效地利用限制生长的资源，并增加和稳定产量。在这里，我们通过多维性状空间概念，识别出具有功能性状的作物混合物，这些性状有助于在两种选定的谷物-豆类混合物中最佳利用氮资源。在瑞典中部，两年间在天气相对的情况下，豌豆-大麦和蚕豆-小麦的作物以纯种和混合物的形式在田间种植。生态位空间是通过n定义的N库，分till /分支数，枝条生物量和谷物产量功能性状表示的三维超体积。回归和相关性可以量化功能性状与植物氮库之间的关系。性状空间的差异并不是作物本身混合的结果，因为在纯培养和混合种植的农作物中也发现了类似的超量。相反，性状空间差异取决于混合的品种身份。此外，谷物的氮吸收效率得到了提高，因此就累积的氮和谷物产量而言，谷物中的豆类受益于混合物中的豆类。谷物分iller和枝条生物量的产生与本季氮库的积累呈正相关。通过增加混合物中氮的吸收获得资源与减少混合物中利基空间的重叠有关，初始种子氮库显着促进了季节内氮的积累，芽和分till的产生。