Session 4: Application of Agroforestry in Hong Kong – Case of Lai Chi Wo

Agroforestry is a relatively new concept in Hong Kong. The experimental farm in Lai Chi Wo was set up to test various eco-production models and agroforestry is one of the key trials.

Lai Chi Wo is a Hakka village in Hong Kong with about 400 years of history. Due to city development and population dynamics, the village has become deserted and the associated farmlands were abandoned for decades as the villagers have moved out of the village. The Policy for Sustainability Lab of the Centre for Civil Society and Governance at The University of Hong Kong started an agricultural-led revitalization initiative in 2013 and restored six hectares of farmland as part of the socio-economic initiatives aiming to inject vitality into the rural community. 

After decades of abandonment, the once active paddy rice field in Lai Chi Wo were outgrown with marsh and shrubs, some areas even turned into secondary forests. During the revitalization process, the marsh and shrublands were resumed into paddy fields and open farmlands. For the secondary forest-covered farmland, large trees or rare tree species were however retained to conserve the ecological values of the site.  

 

 

Agroforestry is one of the models that is tested in the experimental farm and two ways of agroforestry application are tested.

 

1. Growing crops under existing trees

Shade-tolerant crops are planted under the canopy of the retained trees to increase the productivity of the forest. This could provide incentives for the local communities to conserve the forest instead of turning it into conventional open farmlands. 

Ginger is one of the trial-crops growing under the tree shades. Apart from fresh ginger, different processed ginger products, for example, sun-dried ginger slices, ginger powder, ginger tea, ginger in brown sugar and ginger soap are produced for sale at a higher value. 

 

 

On the other hand, some high-priced crops, such as coffee, was planted under the scattered big trees. Coffee was introduced as a key perennial crop under the canopy. Part of the trial was enriched by papayas as the mid-story crop and chilli as the crop underneath to increase the overall complexity of the system. They also serve the purpose of controlling light intensity and growth of weed. Soil moisture retention and soil erosion have also improved. 

 

The result of the trial is quite promising as the quality and quantity of the ginger and coffee harvested are satisfactory. The initial result demonstrates that secondary forests could be used a productive landscape meeting the combined objectives of yield and biodiversity enhancement. This is a hopeful model that is well received by various stakeholders including the land owners, farm owners, local community, professionals from the coffee industry and the general public.  

 

2. Growing both trees and crops at the same time

An agroforestry system can also be built from scratch with careful design and detailed planning. Complementary tree and crop species are selected and planted according to spatial and temporal plan. The result will be a desired production system that fits the needs of the land operators.  

 

 

Some parts of the revitalized farmlands were not covered by tall trees but shrubs. After the vegetation was removed, an agroforest system was built from ground level. Coffee was chosen as the main crop in the system. Pigeon Pea was planted as a companion with the coffee in the early stages to provide shade and improve the soil at the same time. Native tree species, for example, Endospermum chinense, Lithocarpus glaber and Ormosia emarginata are introduced to enrich the system and eventually form the canopy layer. Mulching and cover crop will be used to control weed and retain soil moisture while the complexity of the whole system is also increased. 

The selection of Pigeon Pea as the companion with the coffee demonstrates initial success. The high growth speed of the Pigeon Pea makes it favourable to provide enough shade for the coffee and control weed growth at the same time. It also provides leaf litter to improve soil structure and water retention. 

 

Challenges

Despite the initial success demonstrated in the agroforestry trials, the application of agroforestry, which is a relatively new idea in Hong Kong, is facing a few challenges:

 

Land tenure

The typical land lease term for farmland in Hong Kong is 3 to 5 years. In general, agroforestry systems require a longer period to reach the peak return period. For example, coffee tree, the main crop in the agroforestry system in Lai Chi Wo, takes 3 to 5 years to start producing coffee cherries. 

Fortunately, the landowners in Lai Chi Wo are willing to have longer land lease terms which allows perennial crops to be planted. However, short term land tenure could be a deterring factor for local farmers to adopt agroforestry practices.

 

Acceptance by landowners and farm workers

For instance, the landowners often expect to see conventional open farmland set up on their land and question on the retention of trees on the farmland. This has led to skepticism on the farm operator’s hidden intention for nature conservation instead of using the land for agricultural purpose. Land owners worried that land with high conservation value will eventually result in their land development right being compromised.   

Experienced farm workers who have worked in conventional farms in Hong Kong also question about the presence of trees in farm and complaint about the “problems” and inconvenience brought by the trees. For example, the tree roots create obstacles for the movement of farming machine and competition for nutrients between the tree and the crops. 

It takes time for the stakeholders to really understand and embrace the concepts of agroforestry and eventually show support for the operation.

 

Lack of local experience and knowledge

Globally agroforestry has been practised for decades and practitioners in the field have gathered ample knowledge for its application. Nevertheless, very little of these knowledge could be directly applied in local context as most experience is not from the East Asia region. From the setup of the farm to the selection of crop and tree species to be planted, there is little information available from local and regional sources. 

The project team have sought advice from the Kadoorie Farm and Botanic Garden, the only local farming institution which has experience in systematic application of agroforestry, for the basic principles of the agroforestry system setup. In addition, the project team has also done a lot of trial and error to arrive at today’s agroforestry system. The system is indeed still evolving based on the performance observed. 

 

Continue to “Session 5: Conclusions and Implications”