集约经营雷竹林退化的土壤学机制及对策研究

Phyllostachys praecox is one kind of bamboos for edible shoot with a high economic profit up to 450k yuan/ha. Accordingly, it has been extensively cultivated in South China which is more than 60,000 ha only in Zhejiang province. However, the bamboo showed a significant degeneration after several years with a continuous intensive management. The degenerated bamboo area accounted for more than 25% of the total cultivated area. Up to now, there is no sufficient reason to explain such a phenomenon. Based on the former investigation and study, we assume that the bamboo rhizome up-floating is the main reason resulting in the bamboo degeneration while soil hypoxia induced by the mulching technique is the driven factor. Therefore, the objective of this study is to investigate the bamboo rhizome dynamic during the intensive management, use in-situ monitoring and simulation experimentation methods, incorporating with adopt GFS and HPLC-MS/MS analysis techniques, to elucidate the mechanism of the bamboo response to soil hypoxia. The result will verify the proposed hypothesis of bamboo degeneration and corresponding countermeasures will be tested in the field. Through this project, some effective evidences will be achieved for the bamboo sustainable production and a better understanding of soil science in practice will be deepened and extended as well in the future.

雷竹栽培经济价值高，每亩可达3万元；引种面积大，仅浙江省就超过100万亩。然而，覆盖栽培雷竹林退化现象严重，约占总面积25%以上，目前已有研究结果并没有很好给出雷竹林退化的关键因素。基于前期的调查研究，我们认为雷竹根鞭上浮是导致雷竹林退化的直接原因，而覆盖经营过程中根层土壤的缺氧是引起雷竹根鞭上浮的诱因。因此，本项目旨在通过覆盖经营中雷竹林根鞭生长的动态调查，采用原位监测及模拟培养技术，利用GFS及HPLC-MS/MS等先进测试手段，揭示雷竹根鞭对土壤缺氧的响应过程，验证雷竹林退化机制的设想，从而针对性地提出土壤改善措施，为雷竹林的高效可持续经营提供理论依据及应对策略，同时也可拓展土壤学在生产实践中的应用。

雷竹栽培经济价值高，每亩可达3万元；引种面积大，仅浙江省就超过100万亩。然而，覆盖栽培雷竹林退化现象严重，约占总面积25%以上，目前已有研究结果并没有很好给出雷竹林退化的关键因素。基于前期的调查研究，我们认为雷竹根鞭上浮是导致雷竹林退化的直接原因，而覆盖经营过程中根层土壤的缺氧是引起雷竹根鞭上浮的诱因。因此，本项目旨在通过覆盖经营中雷竹林根鞭生长的动态调查，采用原位监测及模拟培养技术，利用GFS及HPLC-MS/MS等先进测试手段，揭示雷竹根鞭对土壤缺氧的响应过程，验证雷竹林退化机制的设想，从而针对性地提出土壤改善措施，为雷竹林的高效可持续经营提供理论依据及应对策略，同时也可拓展土壤学在生产实践中的应用。通过项目实施，我们明确了雷竹林覆盖经营中土壤缺氧（可低于10%）可导致根鞭上浮（由20-30cm上浮至0-10cm），这是雷竹退化的关键；因此提出了覆盖雷竹林的插管通气技术，试验结果表明该措施可以显著改善雷竹的生理生化指标，提高雷竹生长性状，为雷竹林高效可持续经营提供了技术支撑。 同时，雷竹覆盖引起的土壤非淹水型缺氧有别于以前的淹水缺氧，为土壤学研究提出了新的方向。