Root system-based limits to agricultural productivity and efficiency: the farming systems context.
Root system-based limits to agricultural productivity and efficiency: the farming systems context.
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DOI：
10.1093/aob/mcw122
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发表时间：
2016-10
期刊：
影响因子：
4.2
通讯作者：
K. Thorup-Kristensen;J. Kirkegaard
中科院分区：
文献类型：
--
作者：
K. Thorup-Kristensen;J. Kirkegaard
背景技术全球对改善根系功能的遗传和管理策略重新产生了兴趣，以提高农业生产力并最小化环境破坏。改善根系对水和养分的捕获是一个显而易见的策略，但很少有研究考虑所提出的遗传改良与系统规模的作物管理之间的重要相互作用，这将影响可能的成功。范围 为了举例说明这些相互作用，使用了丹麦和澳大利亚的对比谷物农业系统，其中提出改善从更深的土壤层吸收水和氮，以提高这两个系统的生产力和环境成果。分析表明，水和氮的可用性，特别是在更深的层（> 1 m），受到先前作物和管理的显着影响，并且可能与更深的生根作为特定的感兴趣性状产生强烈的相互作用。结论 在澳大利亚半干旱环境中，与当前根深遗传差异（0·36 t ha-1）相比，前期作物选择（0·42 t ha-1）、作物前休耕管理（0·65 t ha-1）和播种日期（0·63 t ha-1）对储存和吸收深度（>1 m）水分对粮食产量的影响更大。根深蒂固的基因型与管理的匹配提供了与深水捕获相关的最大改进。在丹麦较为湿润的环境中，减少氮素淋失是重点。这里，根区以下移动的氮量还受到先前作物选择或覆盖作物管理（影响高达 85 kg N ha-1）和小麦作物播种日期（高达 45 kg ha-1）的影响，这些影响超越了基因型之间根深差异的影响。这些例子强调了在提出对根系进行遗传改良以提高生产力或环境结果的研究中需要了解农业系统背景和重要的 G × E × M 相互作用。
BACKGROUND There has been renewed global interest in both genetic and management strategies to improve root system function in order to improve agricultural productivity and minimize environmental damage. Improving root system capture of water and nutrients is an obvious strategy, yet few studies consider the important interactions between the genetic improvements proposed, and crop management at a system scale that will influence likely success. SCOPE To exemplify these interactions, the contrasting cereal-based farming systems of Denmark and Australia were used, where the improved uptake of water and nitrogen from deeper soil layers has been proposed to improve productivity and environmental outcomes in both systems. The analysis showed that water and nitrogen availability, especially in deeper layers (>1 m), was significantly affected by the preceding crops and management, and likely to interact strongly with deeper rooting as a specific trait of interest. CONCLUSIONS In the semi-arid Australian environment, grain yield impacts from storage and uptake of water from depth (>1 m) could be influenced to a stronger degree by preceding crop choice (0·42 t ha-1), pre-crop fallow management (0·65 t ha-1) and sowing date (0·63 t ha-1) than by current genetic differences in rooting depth (0·36 t ha-1). Matching of deep-rooted genotypes to management provided the greatest improvements related to deep water capture. In the wetter environment of Denmark, reduced leaching of N was the focus. Here the amount of N moving below the root zone was also influenced by previous crop choice or cover crop management (effects up to 85 kg N ha-1) and wheat crop sowing date (up to 45 kg ha-1), effects which over-ride the effects of differences in rooting depth among genotypes. These examples highlight the need to understand the farming system context and important G × E × M interactions in studies on proposed genetic improvements to root systems for improved productivity or environmental outcomes.