Legumes increase grassland productivity with no effect on nitrous oxide emissions
Legumes increase grassland productivity with no effect on nitrous oxide emissions
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DOI：
10.1007/s11104-019-04338-w
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发表时间：
2020-01-01
期刊：
影响因子：
4.9
通讯作者：
Ostle, Nicholas J.
中科院分区：
文献类型：
--
作者：
Barneze, Arlete S.;Whitaker, Jeanette;Ostle, Nicholas J.
草地是重要的农业生产系统，其生态系统功能受到土地管理措施的影响。通常种植草-豆类混合物以提高草地生产力，同时减少对氮（N）肥料的需求。然而，鲜为人知的是，这种生产力的增加对温室气体（GHG）排放的影响，在草，豆类混合物。本研究的目的是调查豆科牧草混合物和氮肥添加量对生产力和温室气体排放的影响。我们测试的假设，豆类的相对比例的增加，将增加植物生产力和减少温室气体排放量，这些影响的幅度将减少氮肥添加。方法在受控环境中进行围隔实验，其中一种草和一种豆科植物以不同比例混合生长，有或没有氮肥。氮循环过程的影响进行了评估，通过测量地上和地下生物量，地上部氮吸收，土壤理化性质和温室气体排放。结果在施肥和未施肥土壤中，豆科牧草混合物的地上生产力和地上部氮吸收量均高于禾本科或豆科单一栽培。然而，我们没有发现豆类比例对N2 O排放量，土壤总氮或矿物氮在施肥或未施肥的土壤中的影响。结论本研究表明，包括豆科植物的草-豆科植物混合物的生产力的积极影响，但在短期内不受影响的N循环，主要受氮肥。豆科植物可用于草原管理策略，通过减少作物对氮肥的需求来缓解气候变化。
Aims Grasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition. Methods This was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions. Results Above-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils. Conclusions This study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.