北方农牧交错带间套作资源利用的研究进展

Progress and perspectives of resource use in intercropping system in agro-pastoral ecotone

中国北方农牧交错带土壤风蚀沙化面积大、农田自然资源利用效率低,气候变化对农业生产的影响较大,粮食安全面临威胁。本文以该地区农业生产中出现的生产和科学问题入手,探讨了间套作种植模式应用于北方农牧交错带地区的旱作农作系统,对于有效增加地表覆盖度和粗糙度以减少风蚀,减少水肥淋溶且加快有机物质分解以改善土壤可持续性,形成独特的冠层和根系结构的时空分布及不同作物组合的相互作用以提高资源利用效率及农田生产力的作用;分析了间套作系统生产力的限制因子和种间相互作用提高生产力的机理。在今后研究中应重点探明气候变化对当地间套作系统潜在产量、产量差及土壤可持续性的影响,并将田间试验、基本过程的作物模型和结构与功能模型有机结合,利用大田试验结果和结构与功能模型在器官尺度上阐明资源高效利用的机理,并在区域尺度定量评估间套作在减缓农业气候风险中的作用。

Soil erosion and low use efficiency of natural resources in the agro-pastoral ecotone in northern China have become severe problems especially under climate change, which threatens local food security. Concerning the problems existing in rainfed agriculture in the agro-pastoral ecotone in northern China, we discussed how intercropping improves vegetation cover and roughness to reduce soil wind erosion and nutrient leaching; to accelerate the decomposition of organic matter to improve soil fertility; and to increase resource use efficiencies and yields by temporal and spatial distribution of canopy and root structure and the interaction of different crop combinations. The limiting factors of the intercropping on crop productivity and the mechanisms of interspecific interactions were analyzed. Future researches should focus on the effect of climate change on potential yield and soil fertility of intercropping systems. The combination of field experiments and crop models, i.e. processbased crop simulation models and functionalstructural plant models, would be helpful to explore the mechanism of efficient resource use at organ level and to illuminate how intercropping could mitigate climate risk at regional level.