Functional traits in cover crop mixtures: Biological nitrogen fixation and multifunctionality
Functional traits in cover crop mixtures: Biological nitrogen fixation and multifunctionality
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DOI：
10.1111/1365-2664.13011
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发表时间：
2018-01-01
影响因子：
5.7
通讯作者：
Blesh, Jennifer
中科院分区：
文献类型：
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作者：
Blesh, Jennifer
1. 具有互补植物功能性状（包括生物固氮（BNF））的覆盖作物混合物可以向农田提供氮(N)，同时提供其他生态系统功能，如N保留和杂草抑制（即多功能）。了解不同农场之间这些关系的变化有助于推进农业生态学中基于性状的研究和营养管理的生态方法。这项农场试验探讨了两种和三种覆盖作物混合（豆科植物、芸苔属植物和冷季草）对由农场管理历史驱动的不同土壤肥力水平梯度生态系统功能的贡献。我评估了覆盖作物的功能性状多样性可以解释多功能性变化的预测，以及混合作物中豆科植物的生物量和BNF与整个农场梯度中有机质土壤氮有效性指标呈负相关。不同农场的生态系统功能差异很大。正如预期的那样，功能多样性是多功能性的重要预测因子，尽管这种关系很弱。混合覆盖作物的多种功能明显高于单一种植的谷物和黑麦，但每种功能的最高水平并未达到观测到的最高水平，这表明了功能之间的权衡。线性回归模型表明，豆科植物生物量和土壤生物量与反映土壤有机质氮有效性的土壤性状呈负相关，而非豆科植物和杂草生物量与土壤肥力的其他指标呈正相关。合成与应用。覆盖作物混作可以增加轮作内的功能多样性。设计具有互补植物性状的混合物可能对增加多功能和农业生态系统的可持续性特别有效。生物固氮既是一种植物特性，也是一项关键的生态系统功能，在不同的土壤条件下，通过农场研究了解生物固氮的变化，可以为基于生态学原理的土壤肥力管理提供信息。
1. Cover crop mixtures with complementary plant functional traits including biological nitrogen fixation (BNF) may supply nitrogen (N) to farm fields while simultaneously providing other ecosystem functions such as N retention and weed suppression (i.e., multifunctionality). Understanding variation in these relationships across farms can help advance trait-based research in agroecology and ecological approaches to nutrient management.2. This on-farm experiment explored the contributions of two-and three-species cover crop mixtures, which combined legumes, brassicas and cool season grasses, to ecosystem functions across a gradient of soil fertility levels driven by farm management history.3. I evaluated the predictions that functional trait diversity of the cover crops would explain variation in multifunctionality, and that legume biomass and BNF within mixtures would be inversely correlated with indicators of soil N availability from organic matter across the farm gradient.4. Ecosystem functions varied widely across farms. As expected, functional diversity was a significant predictor of multifunctionality, although the relationship was weak. Cover crop mixtures had significantly greater multifunctionality than a cereal rye monoculture, though not at the highest observed levels of each function, indicating trade-offs among functions. Linear regression models showed that legume biomass and BNF were negatively correlated with soil properties indicative of N availability from soil organic matter, whereas non-legume and weed biomass were positively correlated with other measures of soil fertility.5. Synthesis and applications. Cover crop mixtures can increase functional diversity within crop rotations. Designing mixtures with complementary plant traits may be particularly effective for increasing multifunctionality and agroecosystem sustainability. On-farm research to understand variation in biological nitrogen fixation, which is both a plant trait and a key ecosystem function, across heterogeneous soil conditions, can inform management of soil fertility based on ecological principles.