赵溪竹 林兴军 白亭玉 王丽萍 赖剑雄 赵青云

摘 要 可可是世界最重要的多年生經济作物之一，为了揭示不同园龄可可园土壤演变规律，为其可持续生产提供依据。以休耕地为对照（CK），研究低龄（4 a）、中龄（12 a）和老龄（32 a）3种不同园龄土壤培育可可苗期生长及其与根际土壤有机碳（SOC）含量、土壤酶活性和微生物区系等关系。结果表明，32 a园龄土壤培育可可苗生物量显著高于4 a、12 a和CK，分别增加了89.15%、29.24%和28.03%；32 a和12 a园龄处理根际SOC含量显著高于4 a园龄，老龄园有利于SOC的积累；随着园龄增加，脲酶活性增加，且与SOC含量极显著正相关，12 a和32 a园龄土壤脲酶活性分别比CK显著增加了44.36%和43.11%；12 a园龄处理根际土壤中可培养细菌数量减少，真菌数量则显著增加，12 a土壤可培养真菌数量分别是4 a、32 a和CK的3.04、1.46和3.23倍，园龄可能导致土壤微生物区系变化。综上所述，随着土壤园龄增加，可可苗生物量、根际SOC含量和脲酶活性均增加，根际土壤微生物区系发生变化，根际土壤真菌数量与SOC含量、脲酶活性极显著正相关，可可根际SOC含量是光合作用、植株生长、土壤酶活性和土壤微生物共同作用的结果。

关键词 园龄；根际；土壤微生物；土壤酶活性；可可

中图分类号 S571.3；S-3 文献标识码 A

Effect of Planting Age on Theobroma cacao Seedling Biomass

and Rhizosphere Soil Environment

ZHAO Xizhu， LIN Xingjun， BAI Tingyu， WANG Liping， LAI Jianxiong， ZHAO Qingyun*

Spice and Beverage Research Institute， Chinese Academy of Tropical Agricultural Sciences / Key Laboratory of Genetic

Resources Utilization of Spice and Beverage Crops， Ministry of Agriculture， Wanning， Hainan 571533， China

Abstract Cocoa is one of the most important perennial cash crops worldwide. Our aim was to analyze the development laws of soil quality， provide the basis for promoting sustainable production. Comparing seedling biomass， soil organic carbon（SOC）content， enzyme activities， rhizosphere microorganism population quantifies and their relationships of 4 years， 12 years and 32 years soil of cocoa plantations. Short fallow was used as treeless references（CK）. The main results obtained were as follows： The seedling biomass were significantly increased by 89.15%， 29.24% and 28.03% in soil of 32 years compared with that of 4 years， 12 years and CK， respectively. The SOC content was significantly increased in soil of 32 years and 12 years compared with that of 4 years， and aging was conductive to the accumulation of SOC. As the planting age increased， soil urease activities increased， which was extremely significantly positive correlation with the SOC content. Soil urease activities of 12 and 32 years obviously increased by 44.36% and 43.11%， respectively compared with that of CK. The culturable bacteria in rhizosphere soil decreased， and the culturable fungi significant increased. The culturable fungi number in 12 years soil were 3.04， 1.46 and 3.23 times higher compared with that in 4 years， 32 years and CK， respectively. Planting age may lead to changes of soil microflora. In conclusion， with the increase of planting age， the seedling biomass， rhizosphere SOC content and soil urease activities were increased， and the soil microflora changed. The culturable fungi in rhizosphere soil was significantly positively related to SOC content and urease activities. The SOC content in rhizosphere soil was the result of photosynthesis， seedlings growth， enzyme activities and microorganism.

Key words planting age； rhizosphere； soil microbes； soil enzyme activity； Theobroma cacao

doi 10.3969/j.issn.1000-2561.2017.08.009

可可（Theobroma cacao L.）是世界三大饮料作物之一，梧桐科多年生常绿小乔木，具有极高的经济价值，是制作巧克力的主要原料，也是饮料、糖果的重要配料[1]。可可是典型的热带经济作物，广泛种植于世界70多个国家和地区，据国际可可组织（ICCO）统计，2014/2015年度世界可可总产量约420万t[2-3]，预计到2020～2025年，可可产量再增加100万t才能满足消费者的需求[4]。……