Temporal niche differentiation increases the land equivalent ratio of annual intercrops: A meta-analysis
Temporal niche differentiation increases the land equivalent ratio of annual intercrops: A meta-analysis
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DOI：
10.1016/j.fcr.2015.09.010
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发表时间：
2015-12
影响因子：
5.8
通讯作者：
Yang Yu;T. Stomph;D. Makowski;W. Werf
中科院分区：
文献类型：
--
作者：
Yang Yu;T. Stomph;D. Makowski;W. Werf
需要可持续的农业集约化，以满足未来更高的粮食需求，同时减少农业的生态足迹。间作是一种提高单位土地农业生产力的战略，其基础是改善资源捕获的生态机制。间作系统特性和品种性状组合对间作生产力的影响尚未作定量综合。在这里，我们使用的间作文献的荟萃分析，研究间作系统的设计和物种性状如何影响混合系统的生产力。重点研究了种间时间生态位分化、间作模式、相对密度、C3和C4树种的使用以及氮肥用量等因素的影响。土地当量比（LER）被用来作为评价混合系统与单一作物相比的相对生产力的指标。平均LER为1.22 ± 0.02，在50项最高被引研究和文献随机样本之间没有发现LER差异，表明高被引论文中的高LER代表了整个文献。时间生态位分化的贡献很大，高LER的C3和C4物种相结合的系统，但不是在系统的基础上C3物种的混合物。施氮量与时间生态位分化对LER的影响呈正交互作用。间作文献以谷物/豆类混合物的研究为主。然而，对C3/C4混合谷物的研究表明，这些混合谷物具有较高的土地利用效率，通过使用混合谷物，特别是C3/C4混合谷物，可以显著提高农业土地利用效率。因此，提高田间作物多样性可对粮食生产的可持续增长作出重要贡献。
Sustainable intensification of agriculture is needed to meet higher future food demands while mitigating agriculture’s ecological footprint. Intercropping is a strategy for increasing agricultural productivity per unit land that is based on ecological mechanisms for improved resource capture. No quantitative synthesis has been made on the effect of intercrop system properties and species trait combinations on intercrop productivity. Here we use meta-analysis of the intercropping literature to study how the productivity of mixed systems is affected by intercrop system design and species traits. We focus on the effects of temporal niche differentiation between species, intercropping pattern, relative densities, the use of C3 and C4 species and the rate of nitrogen fertilizer. Land equivalent ratio (LER) is used as index for assessing the relative productivity of a mixed system as compared to sole crops. Average LER was 1.22 ± 0.02, and no differences in LER were found between the 50 most highly cited studies and a random sample from the literature, indicating that high LERs in highly cited papers are representative of the entire literature. Temporal niche differentiation contributed substantially to high LER in systems combining a C3 and C4 species, but not in systems based on C3 species mixtures. The amount of N fertilizer interacted positively with the effect of temporal niche differentiation on LER. The intercropping literature is dominated by studies on cereal/legume mixtures. However, the few studies on C3 cereal/C4 cereal mixtures indicate these mixtures have high LER.Substantial improvements in land use efficiency in agriculture may be obtained by using mixtures, particularly C3/C4 mixtures. Thus, enhanced within-field crop diversity can make an important contribution to sustainable increases in food production.