One of the challenges facing projects that promote onfarmtree planting or forest plantations is how to provideseeds and seedlings at reasonable cost to planting sites.This can be overcome if planting is done on forest blocksites through the forestry department’s central nursery.Earlier attempts to promote community tree plantingbased on central nurseries operated by extension agentsor non-governmental organizations (NGOs) proved bothcostly and ineffective. To reduce costs, there are continuedefforts to decentralise seedling production anddistribution to community levels through groups or centralnurseries organized in schools, camps belonging tocommunity chiefs and privately managed nurseries.In the past, group nurseries often did not survive pastthe group formation or project support stage. Centralnurseries, also, were sometimes abandoned when fundingpriorities changed. Yet, there are success stories andmany farmers continue to be effectively reached throughsuch nurseries. Certain group nurseries, for instance,were left under the management of a single individualyet continue to supply seedlings to the community.Privately owned nurseries, in contrast, have been ableto survive for longer periods, albeit with little supportfrom developmental organizations. Depending on theoperating scenario, all three types (group, central andprivate) are feasible seedling supply alternatives and canevolve along with the awareness and tree planting cultureof the community.
Tag: eucalyptus
Occurrence and abundance of arbuscular mycorrhizal fungi (AMF) in agroforestry systems of Rubavu and Bugesera Districts in Rwanda
Arbuscular mycorrhizal fungi (AMF) help to facilitate mobilization of nutrients from soil to plant. The study was carried out in humid Rubavu and semi-arid Bugesera districts in Rwanda. We hypothesized that the presence of tree species in farming systems enhances mycorrhizal fungal density. The occurrence and abundance of AMF in the soil around main agroforestry tree species in these regions was studied. Tree species in Rubavu included Alnus acuminata, Markhamia lutea, Grevillea robusta and Eucalyptus sp. and in Bugesera Acacia polyacantha, Senna spectabilis, Grevillea robusta and Eucalyptus sp. AMF spores were isolated from soil samples collected under and outside the trees canopies. Results show significant differences in spore density between species. The density of AMF spores was highest under A. acuminata and A. polyacantha and lowest in Eucalyptus sp. and G. robusta in Rubavu and Bugesera, respectively. Generally, the mean spore abundance (spores/g of soil) was significantly higher in Bugesera (3.1-6.6) than Rubavu (1.6-4.4). Spores abundance was also affected by distance from the tree trunk and tree size. The present work is the first attempt to study the AMF communities associated with tree species in agroforestry systems in Rwanda. We propose further studies relating mycorrhizal diversity in the agroforestry systems to performance and yields of crops