PDF(Pubmed)
Abstract：
Climate change models predict increasing precipitation variability in the mid-latitude regions of Earth, generating a need to reduce the negative impacts of these changes on crop production. Despite considerable research on how cover crops support agriculture in a changing climate, understanding is limited of how climate change influences the growth of cover crops. We investigated the early development of two common cover crop species-crimson clover (Trifolium incarnatum) and rye (Secale cereale)-and hypothesized that growing them in the mixture would ameliorate stress from drought or waterlogging. This hypothesis was tested in a 25-day greenhouse experiment, where the two factors (species number and water stress) were fully crossed in randomized blocks, and plant responses were quantified through survival, growth rate, biomass production and root morphology. Water stress negatively influenced the early growth of these two species in contrasting ways: crimson clover was susceptible to drought while rye performed poorly under waterlogging. Per-plant biomass in rye was always greater in mixture than in monoculture, while per-plant biomass of crimson clover was greater in mixture under drought. Both species grew longer roots in mixture than in monoculture under drought, and total biomass of mixtures did not differ significantly from the more-productive monoculture (rye) in any water condition. In the face of increasingly variable precipitation, growing crimson clover and rye together has potential to ameliorate water stress, a possibility that should be further investigated in field experiments.
摘要：
气候变化模型预测地球中纬度地区的降水变化会增加，需要减少这些变化对作物生产的负面影响。尽管对覆盖作物如何在气候变化中支持农业进行了大量研究，对气候变化如何影响覆盖作物生长的理解是有限的。我们调查了两种常见的覆盖作物物种-深红色三叶草（Trifoliumincarnatum）和黑麦（Secalegrain）的早期发育，并假设在混合物中种植它们可以缓解干旱或涝灾带来的胁迫。这个假设在25天的温室实验中得到了检验,其中两个因素（物种数量和水分胁迫）在随机分组中完全交叉，植物的反应是通过存活来量化的，增长率，生物量生产和根系形态。水分胁迫以相反的方式对这两个物种的早期生长产生了负面影响：深红色三叶草易受干旱影响，而黑麦在淹水下表现不佳。黑麦中的每株植物生物量在混合物中总是大于单一栽培中的生物量，而在干旱条件下，深红色三叶草的单株生物量更大。在干旱下，这两个物种在混合物中比在单一栽培中生长更长的根，在任何水条件下，混合物的总生物量与高产的单一栽培（黑麦）没有显着差异。面对日益多变的降水，一起种植深红色三叶草和黑麦有可能改善水分胁迫，应该在现场实验中进一步研究的可能性。
