Nutrient cycling in cocoa agroforestry systems (cAFS) is complex and poorly understood. To better understand the mass flow of carbon and nutrients into the soil sub-system under various contexts we quantified the mass flow of litterfall, its composition and seasonal variations in different agroforestry systems in Bokito (Central Cameroon). We studied litterfall dynamics and in situ leaf-litter cycling of cAFS established on past forest lands (F-cAFS) and savannah (S-cAFS). We also studied the decomposition of cocoa and associated tree leaf-litter in litterbags. Local secondary semi-deciduous forests were included as control. Annual litterfall in full-grown cAFS (> 15 years old) was high (9.4 Mg ha⁻¹ y⁻¹) and represented ca. 67% of litterfall in control forests. In full-grown cAFS, associated tree leaf-litter contributed to litterfall the most and ranged between 60 and 70% of the total amount recorded (6.3 Mg ha⁻¹ y⁻¹). The quantities and dynamics of the litter components monitored were similar in full-grown S- and F-cAFS. The microclimate was best buffered in forests and least buffered in young S-cAFS but could not be linked to leaf-litter decomposition. Forest leaf litterfall was higher and tended to cycle faster than total leaf-litter of cAFS, whose decomposition appeared limited by cocoa leaf-litter quality. Our study underlines (i) the critical contribution of associated trees to the nutrient cycle of agroecosystems established on poor soils and, (ii) the ability of farmers to channel associated tree communities towards similar functioning despite different past land-uses.

可可农林业系统（cAFS）中的养分循环非常复杂，人们对此知之甚少。为了更好地了解在各种情况下进入土壤子系统的碳和养分的质量流量，我们量化了Bokito（喀麦隆中部）不同农林业系统凋落物的质量流量，其组成和季节变化。我们研究了在过去的林地（F-cAFS）和大草原（S-cAFS）上建立的cAFS的凋落动力学和原地凋落物循环。我们还研究了垃圾袋中可可和相关树木凋落物的分解。包括当地次生半落叶林作为对照。成年cAFS（> 15岁）的年凋落物很高（9.4 Mg ha ^-1 y ^-1）并代表ca。控制林中凋落物的67％。在成熟的cAFS中，相关的树木凋落物对凋落物的贡献最大，范围为记录的总量的60％至70％（6.3 Mg ha ^-1 y ^-1）。在成熟的S-和F-cAFS中，所监测的垫料组件的数量和动态相似。小气候在森林中的缓冲效果最佳，而在S-cAFS幼木中的缓冲效果最低，但与凋落物分解没有关系。森林叶片凋落物含量高于cAFS的总凋落物，其循环速度更快，其分解似乎受到可可叶凋落物质量的限制。我们的研究强调（i）相关树木对在贫瘠土壤上建立的农业生态系统养分循环的重要贡献，以及（ii）尽管过去土地用途不同，农民引导相关树木群落实现类似功能的能力。